Appendix
I.
Diagram/
Structure
of
Atrazine
and
Major
Degradates
and
Metabolites
Cl
|
C
/
\\
N
N
||
|
CH­
HN
 
C
C
 
NH­
CH2
|
\
//
|
(
CH3)
2
N
CH3
Atrazine
Atrazine
Soil
Degradates:

Cl
Cl
|
|
C
C
/
\\
/
\\
N
N
N
N
||
|
||
|
H2N
 
C
C
 
NH­
CH2
CH­
NH
 
C
C
 
NH2
\
//
|
|
\
//
N
CH3
(
CH3)
2
N
Deisopropylatrazine
Deethylatrazine
(
G­
28279)
(
G­
30033)

OH
|
C
/
\\
N
N
||
|
CH­
HN
 
C
C
 
NH­
CH2
|
\
//
|
(
CH3)
2
N
CH3
Hydroxyatrazine
(
G­
34048)
OH
OH
|
|
C
C
/
\\
/
\\
N
N
N
N
||
|
||
|
H2N
 
C
C
 
NHCH2
CHNH
 
C
C
 
NH2
\
//
|
|
\
//
N
CH3
(
CH3)
2
N
Deisopropylhydroxyatrazine
Deethylhydroxyatrazine
(
GS­
17792)
(
GS­
17794)

Cl
OH
|
|
C
C
/
\\
/
\\
N
N
N
N
||
|
||
|
H2N
 
C
C
 
NH2
H2N
 
C
C
 
NH2
\
//
\
//
N
N
Diaminochlorotriazine
Diaminohydroxyatrazine
(
G­
28273)
(
G­
17791)

OH
OH
|
|
C
C
/
\\
/
\\
N
N
N
N
||
|
||
|
CH­
HN
 
C
C
 
OH
HO
 
C
C
 
OH
|
\
//
\
//
(
CH3)
2
N
N
2,
4­
Hydroxy­
6­
isopropylamino­
s­
triazine
Cyanuric
Acid
(
G­
11957)
Atrazine
Photodegradates
(
Burkhard
and
Guth,
1976):

Cl
Cl
|
|
C
C
/
\\
/
\\
N
N
N
N
||
|
||
|
H2N
 
C
C
 
NHCH2
CH­
HN
 
C
C
 
NH2
\
//
|
|
\
//
N
CH3
(
CH3)
2
N
Deisopropylatrazine
Deethylatrazine
(
G­
28279)
(
G­
30033)

Cl
OH
|
|
C
C
/
\\
/
\\
N
N
N
N
||
|
||
|
H2N
 
C
C
 
NH2
CH­
HN
 
C
C
 
NHCH2
\
//
|
\
//
|
N
(
CH3)
2
N
CH3
Diaminochlorotriazine
Hydroxyatrazine
(
G­
28273)
(
G­
34048)
Major
Mammalian
Metabolites:

OH
OH
|
|
C
C
/
\\
/
\\
N
N
N
N
||
|
||
|
CH­
NH
 
C
C
 
NH­
CH2
CH­
NH
 
C
C
 
NH­
CH2
|
\
//
|
|
\
//
|
(
CH3)
2
N
CH3
(
CH3)
2
N
C
=
O
|
OH
Hydroxyatrazine
Ethanoichydroxyatrazine
(
G­
34048)

OH
OH
|
|
C
C
/
\\
/
\\
CH3
N
N
N
N
|
||
|
||
|
CH­
NH
 
C
C
 
NH­
CH2
CH­
NH
 
C
C
 
NH2
|
\
//
|
|
\
//
O
=
C
N
CH3
(
CH3)
2
N
|
OH
Isopropanoichydroxytriazine
Deethylhydroxyatrazine
(
GS­
17794)

OH
OH
|
|
C
C
/
\\
/
\\
N
N
N
N
||
|
||
|
H2N
 
C
C
 
NH­
CH2
H
2N
 
C
C
 
NH2
\
//
|
\
//
N
CH3
N
Deisopropylhydroxyatrazine
Diaminohydroxyatrazine
(
GS­
17792)
(
GS­
17791)
Major
Plant
Metabolites:

O
HO
 
C=
O
O
O
||
|
||
||
NH­
C­
CH2­
CH2­
CH­
NH2
HO
 
C
HO
 
C
|
|
|
S­
CH2­
CH­
C­
NH­
CH2­
C
 
OH
S­
CH2­
CH­
NH­
C­
CH2­
CH2­
CH­
NH2
|
||
||
|
C
O
O
C
/
\\
/
\\
N
N
N
N
||
|
||
|
CH­
NH­
C
C
­
NH­
CH2
CH­
NH­
C
C
­
NH­
CH2
|
\
//
|
|
\
//
|
(
CH3)
N
CH3
(
CH3)
N
CH3
S­(
4­
Ethylamino­
6­
isopropylamino­
­
L­
Glutamyl­
S­(
4­
ethylamino­
2s­
triazino)
Glutathione
6­
isopropylamino­
2­
s­
triazino)­
L­
Cysteine
O
 
CH3
O
 
CH2CH3
|
|
C
C
/
\\
/
\\
N
N
N
N
||
|
||
|
CH­
HN
 
C
C
 
NHCH2
CH­
NH
 
C
C
­
NH­
CH2
|
\
//
|
|
\
//
|
(
CH3)
2
N
CH3
(
CH3)
2
N
CH3
2­
Methoxy­
4­
ethylamino­
6­
isopropylamino­
2­
Ethoxy­
4­
ethylamino­
6­
isopropylamino­
s­
triazine
s­
triazine
Appendix
II.
Environmental
Fate
and
Transport
Characterization
Each
individual
guideline
study
is
discussed
separately.
The
chemical
names
and
structures
of
atrazine
and
its
degradation
products
are
listed
in
Appendix
1.

Hydrolysis
(
161­
1)

Based
on
the
results
of
the
hydrolysis
study
(
MRID
40431319),
atrazine
did
not
hydrolyze
at
pH
5,
7,
and
9.
It
was
concluded
that
hydrolysis
is
not
an
important
degradation
mechanism
for
atrazine.

Aquatic
Photodegradation
(
161­
2)

The
study
(
MRID
00024328)
showed
that
[
14C]
atrazine
degraded
with
a
registrant­
calculated
half­
life
of
25
±
2
hours
in
unbuffered
aqueous
solutions
(
initial
pH
6.8)
that
were
irradiated
with
a
125­
W
mercury
vapor
lamp
at
15oC;
in
unbuffered
aqueous
solutions
sensitized
with
1%
acetone,
the
half­
life
decreased
to
4.9
±
0.5
hours.

The
study
(
MRID
42089904)
showed
that
in
buffered
solution
at
pH
7,
atrazine
did
not
appreciably
degrade
under
natural
sunlight
conditions
with
a
calculated
half­
life
of
approximately
335
days
from
a
rate
constant
of
1.72
x
10­
4
hours­
1.
However,
under
artificial
light
irradiation
with
mercury
arc
lamp,
atrazine
degraded
at
a
faster
rate
with
a
half­
life
of
approximately
17
hours.
Due
to
the
lack
of
a
comparison
of
the
mercury
arc
lamp
with
natural
sunlight,
and
no
UV­
VIS
spectrum
of
atrazine
in
pH
7,
the
study
is
considered
to
be
supplemental.
For
the
purpose
of
risk
assessment,
the
half­
life
result
of
335
days
with
natural
sunlight
should
be
considered.
Information
is
requested
on
the
intensity
of
the
mercury
arc
lamp
and
the
US­
VIS
spectrum
of
atrazine
in
pH
7
for
more
accurate
review.

Soil
Photodegradation
(
161­
3)

The
study
(
MRID
40431320)
was
investigated
with
both
natural
and
artificial
sunlight
exposures.
The
results
with
artificial
sunlight
showed
a
half­
life
of
5.3
days,
when
corrected
with
dark
control,
the
half­
life
was
7.4
days.
With
natural
sunlight,
the
half­
life
was
determined
to
be
12
days.

The
study
(
MRID
42089905)
was
investigated
with
artificial
sunlight
exposure.
The
half­
life
under
non­
irradiated
conditions
was
267
days,
and
the
half­
life
under
irradiated
conditions
was
38
days.
The
net
half­
life
attributable
to
photodegradation
is
45
days.

Aerobic
Soil
Metabolism
(
162­
1)

The
study
(
MRID
40431321)
was
considered
supplemental.
Based
on
the
data
of
94
days,
the
half­
life
of
atrazine
in
loam
soil
was
calculated
as
140
days.
The
main
metabolites
detected
at
all
sampling
times
were
G­
30033
and
G­
28279,
but
the
metabolite
G­
34048
was
not
detected
until
days
62
and
94.
The
second
study
(
MRID
40629303)
was
also
considered
supplemental.
The
calculated
half­
life
was
146
days
under
non­
sterile
aerobic
conditions
and
to
be
very
slow
under
sterile
conditions.
The
degradates
identified
were
G­
30033,
G­
28279,
G­
28273,
G­
34048,
GS­
17794,
and
GS­
17792.

The
third
study
(
MRID
00040663)
with
four
Hawaiian
soils
was
rejected
due
to
several
deficiencies:
(
1)
no
material
balances,
(
2)
soils
were
not
completely
characterized,
(
3)
pattern
formation
and
decline
of
degradates
was
not
addressed,
and
(
4)
purity
of
the
test
substance
was
not
reported.

For
the
similar
deficiencies
as
the
third
study,
the
fourth
study
(
MRID
40431322)
with
a
wet
Tennessee
soil
was
also
rejected.

The
study
(
MRID
42089906)
with
atrazine
applied
on
California
loam
soil
showed
an
aerobic
half­
life
of
approximately
146
days.
The
degradates
identified
were
G­
30033,
G­
28279,
G­
28273,
and
G­
34048.

Anaerobic
Soil
Metabolism
(
162­
2)

The
study
(
MRID
40431321)
was
considered
supplemental.
The
calculated
half­
life
for
atrazine
under
anaerobic
conditions
was
about
159
days.
The
metabolites
G­
30033
and
G­
28279
were
present
at
all
sampling
times
in
both
soil
extracts
and
supernatant
water;
G­
28273
and
G­
34048
were
also
present,
but
not
at
all
sampling
times.

The
half­
life
value
was
not
established
in
the
second
study
(
MRID
40629303).
The
degradates
identified
were
G­
30033,
G­
28279,
G­
28273,
and
G­
34048.

The
study
(
MRID
42089906)
with
atrazine
applied
on
California
loam
soil
showed
that
when
flooded
with
water,
atrazine
degraded
with
a
calculated
half­
life
of
approximately
159
days.
The
degradates
identified
were
G­
30033,
G­
28279,
G­
28273,
and
G­
34048.

Anaerobic
Aquatic
Metabolism
(
162­
3)

The
study
(
MRID
40431323)
is
acceptable.
The
combined
water/
sediment
(
sandy
clay)
half­
life
was
calculated
as
608
days
(
330
days
in
sediment;
578
days
in
water).
Production
of
volatile
materials
was
minimal.
Bound
residues
increased
with
time,
but
leveled
to
about
10%
of
applied
dose
by
month
12.
About
70%
of
radioactivity
in
water
and
4%
in
sediment
was
still
associated
with
parent
atrazine
after
12
months.
Metabolites
were
present
at
low
levels
(
G­
30033,
4.7%;
G­
34048,
5%;
and
G­
28279,
1.4%).

Mobility/
Adsorption/
Desorption
(
163­
1)

Several
studies
(
MRID
00027134,
00116620,
00044017,
00098254,
and
00105942)
were
unacceptable
due
to
various
deficiencies.
The
study
(
MRID
40431324)
was
acceptable
and
partially
contributed
to
fulfill
data
requirements
for
the
mobility
of
atrazine.
A
batchequilibrium
adsorption/
desorption
was
conducted
with
four
different
soils
and
four
different
concentrations
of
14C­
label
atrazine.
The
Kads
constants
ranged
from
0.427
(
sand)
to
2.030
(
loam
soil).
The
Kdes
constants
ranged
from
2.261
(
silty
loam
soil)
to
14.90
(
sandy
loam
soil).
Koc
ranged
from
55.0
(
sandy
loam
soil)
to
135
(
loam
soil)
for
the
adsorption
phase.
These
results
indicated
that
atrazine
was
not
strongly
adsorbed
onto
soil
particles
and
that
desorption
occurred
readily.

A
batch­
equilibrium
adsorption/
desorption
was
conducted
with
four
different
soils
and
four
different
concentrations
of
14C­
label
G­
28273
(
MRID
40431327).
The
Kads
constants
ranged
from
0.108
(
sand)
to
0.800
(
silty
clay
loam).
The
Kdes
constants
ranged
from
1.172
(
silty
clay
loam)
to
6.620
(
sandy
loam).
Koc
ranged
from
11.6
(
sandy
loam)
to
59.5
(
silt
loam)
for
the
adsorption
phase.
These
results
indicated
that
G­
28273
was
not
strongly
adsorbed
onto
soil
particles
and
that
desorption
occurred
readily.

A
batch­
equilibrium
adsorption/
desorption
was
conducted
with
four
different
soils
and
four
different
concentrations
of
14C­
label
G­
28279
(
MRID
40431325).
The
Kads
constants
ranged
from
0.225
(
sand)
to
1.144
(
loam
soil).
The
Kdes
constants
ranged
from
1.784
(
silty
loam)
to
12.479
(
sand).
Koc
ranged
from
35.1
(
sandy
loam)
to
82.3
(
silty
loam)
for
the
adsorption
phase.
These
results
indicated
that
G­
28279
was
not
strongly
adsorbed
onto
soil
particles
and
that
desorption
occurred
readily.

A
batch­
equilibrium
adsorption/
desorption
was
conducted
with
four
different
soils
and
four
different
concentrations
of
14C­
label
G­
30033
(
MRID
40431328).
The
Kads
constants
ranged
from
0.116
(
sand)
to
0.963
(
silty
clay
loam).
The
Kdes
constants
ranged
from
8.104
(
silty
clay
loam)
to
12.87
(
silt
loam).
Koc
ranged
from12.8
(
sandy
loam)
to
66.5
(
silty
loam)
for
the
adsorption
phase.
These
results
indicated
that
G­
30033
was
not
strongly
adsorbed
onto
soil
particles
and
that
desorption
occurred
readily.

A
batch­
equilibrium
adsorption/
desorption
was
conducted
with
four
different
soils
and
four
different
concentrations
of
14C­
label
G­
34048
(
MRID
40431326).
The
Kads
constants
ranged
from
5.518
(
sand)
to
22.26
(
silty
clay
loam).
The
Kdes
constants
ranged
from
8.104
(
silty
clay
loam)
to
12.87
(
silt
loam).
Koc
ranged
from
350
(
sand)
to
680
(
silty
loam)
for
the
adsorption
phase.
These
results
indicated
that
G­
34048
was
the
strongest
adsorbed
among
the
atrazine
degradates.

In
a
series
of
studies
(
MRID
40431329
to
40431334)
with
soil
thin­
layer
chromatography,
only
the
degradate,
hydroxyatrazine
(
G­
34048),
showed
low
mobility,
others
(
atrazine,
diaminochlorotriazine
(
G­
28273),
deisopropylatrazine
(
G­
28279),
and
deethylatrazine
(
G­
30033)
showed
high
mobility
in
the
soil
environment.

In
a
series
reports
(
MRID
41257901,
41257902,
41257904,
41257905,
and
41257906),
the
adsorption/
desorption
characteristics
of
atrazine,
hydroxyatrazine
(
G­
34048),
diaminochlorotriazine
(
G­
28273),
deisopropylatrazine
(
G­
282279),
and
deethylatrazine
(
G­
30033)
were
addressed.
The
results
are
summarized
in
the
tables
below.

Sorption
Coefficients
of
Atrazine
and
Its
Main
Degradates
Soil
Atrazine
Diaminochloros
triazine
(
G­
28273)
Deisopropylatrazine
(
G­
28279)
Deethylatrazine
(
G­
30033)
Hydroxyatrazine
(
G­
34048)

Clay
2.46
(
86.9)
1.56
(
55.2)
2.73
(
96.8)
1.10
(
36.1)
389.6
(
13797)

Sand
0.20
(
38.5)
0.16
(
30.7)
0.16
(
30.4)
0.06
(
12.2)
1.98
(
374.2)

Sandy
Loam
0.79
(
70.4)
0.65
(
57.9)
0.51
(
45.2)
0.36
(
31.8)
6.52
(
583.3)

Loam
0.73
(
155.3)
0.36
(
76.0)
0.27
(
58.1)
0.21
(
44.9)
12.11
(
2572.9)
Number
in
parentheses
refer
to
Koc
values;
Koc
=
Kads
÷
%
O.
C.;
where
%
O.
C.
=
%
O.
M.
÷
1.7
Desorption
Coefficients
of
Atrazine
and
Its
Main
Degradates
Soil
Atrazine
(
G­
30027)
Diaminochloros
triazine
(
G­
28273)
Deisopropylatrazine
(
G­
28279)
Deethylatrazine
(
G­
30033)
Hydroxyatrazine
(
G­
34048)

Clay
9.12
(
322.9)
7..
80
(
276.2)
12.36
(
467.9)
8.14
(
288.3)
515.89
(
18271)

Sand
1.51
(
285.5)
Value
indeterminable
due
to
limited
adsorption
9.02
(
1704.2)

Sandy
Loam
7.27
(
650.5)
8.06
(
721.0)
15.28
(
1366.9)
11.19
(
1001.1)
14.87
(
1330.4)

Loam
4.76
(
1011.5)
6.87
(
1459.9)
6.98
(
1484.2)
3.92
(
833.3)
11.28
(
22397.6)
Number
in
parentheses
refer
to
Koc
values;
Koc
=
Kdes
÷
%
O.
C.;
where
%
O.
C.
=
%
O.
M.
÷
1.7
Adsorption/
Desorption
Study:
Soil
Characteristics
Soil
Type
Texture
Bulk
Density
(
g/
cm
3)
Organic
Matter
(%)
pH
Sand
%
Silt
%
Clay
%
CEC
meq/
100g
Clay
1.22
4.8
5.9
25
33
42
24.3
Sand
1.65
0.9
6.5
96
2
2
1.8
Sandy
Loam
1.28
1.9
7.5
63
20
17
6.1
Loam
1.57
0.8
6.7
44
47
9
4.3
The
dealkylated
degradates
(
G­
28273,
G­
28279,
and
G­
30033)
are
more
mobile
than
parent
atrazine,
but
hydroxyatrazine
(
G­
34048)
is
the
least
mobile
of
the
degradates.
Atrazine,
its
dealkylated
degradates,
and
hydroxyatrazine
are
very
mobile
in
the
sand
soil,
as
shown
by
their
low
(<
2)
adsorption
coefficients
(
Kads)
and
the
low
adsorption
Koc
values
(<
500).
In
clay
soil
the
adsorption
coefficients
and
Koc
values
were
higher
for
parent
atrazine
and
the
dealkylated
degradates,
but
still
fall
below
5
and
500.
However,
adsorption
of
hydroxyatrazine
was
the
strongest.

The
results
of
the
batch­
equilibrium
adsorption/
desorption
studies
indicate
that
the
dealkylated
degradates
are
as
likely
(
or
even
more
likely)
to
leach
to
ground
water
as
parent
atrazine.
However,
soil
characteristics
must
be
taken
into
account
when
assessing
the
leaching
potential
in
an
specific
region.
Terrestrial
Field
Dissipation
(
164­
1)

The
results
of
a
field
dissipation
study
with
corn
soil
at
Donaldsonville,
Georgia
(
MRID:
42165504)
predicted
a
half­
life
of
12.75
days
with
residues
decreasing
to
less
than
0.4
ppm
on
the
27­
day
sampling.
AAtrex
®
Nine­
O
®
was
applied
at
a
rate
of
4.4
lb
a.
i./
ac
to
a
test
corn
plot
of
sandy
loam
soil
on
June
14,
1986.
The
residues
of
degradates
G­
34048.
G­
30033,
and
G­
28279
found
in
the
top
0­
6"
depth
were
significant
lower
(<
0.05
to
0.31
ppm)
compared
to
the
parent
residues
which
ranged
<
0.05
to
0.73
ppm.
The
leaching
data
for
parent
atrazine
and
metabolites
at
depths
below
6­
12"
soil
depth
were
generally
below
the
screening
level
of
0.05
ppm.

The
results
of
a
field
dissipation
study
with
bare
ground
at
Donaldsonville,
Georgia
(
MRID
42165505)
predicted
a
half­
life
of
38.52
days
with
residues
decreasing
to
less
than
0.5
ppm
on
the
451­
day
sampling.
AAtrex
®
Nine­
O
®
was
applied
at
a
rate
of
18.0
lb
a.
i./
ac
to
a
field
plot
of
unvegetated
sandy
loam
soil
on
June
27,
1986.
The
residues
of
degradates
G­
34048.
G­
30033,
and
G­
28279
found
in
the
top
0­
6"
depth
were
significant
lower
(<
0.05
to
2.16
ppm)
compared
to
the
parent
residues
which
ranged
<
0.05
to
6.98
ppm.
The
leaching
data
for
parent
atrazine
and
metabolites
at
depths
below
6­
12"
soil
depth
were
generally
below
the
screening
level
of
0.05
ppm.

The
results
of
a
field
dissipation
study
with
bare
ground
at
Ripon,
California
(
MRID
40431336,
42165506)
predicted
a
half­
life
of
102.5
days.
Atrazine
(
90%
dry
flowable)
was
applied
at
a
nominal
concentration
of
18
lb
ai/
ac
to
a
field
plot
of
unvegetated
sandy
loam
soil
in
July
1986.
In
the
0­
to
6­
inch
depth,
atrazine
was
4.75
ppm
(
4.75
ppm
total
residues)
immediately
after
treatment,
decreased
to
1.05
ppm
(
1.20
ppm
total)
at
90
days,
and
0.67
ppm
(
0.94
ppm
total)
at
120
days,
increased
to
5.31
ppm
(
6.24
ppm
total)
at
180
days,
then
decreased
to
0.50
ppm
(
0.63
ppm
total)
at
267
days
and
0.20
ppm
(
0.26
ppm
total)
at
358
days
post­
treatment.
The
major
degradates
were
G­
34048.
G­
30033,
and
G­
28279.

The
results
of
a
field
dissipation
study
with
bare
ground
at
Hollandale,
Minnesota
(
MRID
40431337,
42165507)
indicated
a
half­
life
of
261
days.
Atrazine
(
90%
dry
flowable)
was
applied
at
a
nominal
concentration
of
20
lb
ai/
ac
to
a
field
plot
of
unvegetated
loam
soil
in
July
1986.
In
the
0­
to
6­
inch
depth,
atrazine
was
4.23
ppm
(
5.06
ppm
total
residues)
immediately
after
treatment,
increased
to
10.15
ppm
(
11.66
ppm
total)
at
14
days,
decreased
to
5.34
ppm
(
6.75
ppm
total)
at
28
days,
and
was
2.90
ppm
(
4.88
ppm
total)
at
360
days
post­
treatment.
The
major
degradates
were
G­
34048.
G­
30033,
and
G­
28279.

The
results
of
a
field
dissipation
study
with
a
corn
soil
at
Hollandale,
Minnesota
(
MRID
40431339,
42165508)
yielded
a
half­
life
of
261
days.
Atrazine
(
90%
dry
flowable)
was
applied
at
a
nominal
concentration
of
4.4
lb
ai/
ac
to
a
field
plot
of
loam
soil
planted
to
corn
in
July
1986.
In
the
0­
to
6­
inch
depth,
atrazine
was
1.20
ppm
(
1.37
ppm
total
residues)
immediately
after
treatment,
increased
to
1.40
ppm
(
1.59
ppm
total)
at
2
days,
ranged
from
0.48
to
1.00
ppm
(
0.90
­
1.17
ppm
total)
with
no
discernable
pattern
between
7
and
290
days,
and
was
0.37
ppm
(
0.91
ppm
total)
at
360
days
post­
treatment.
The
major
degradates
were
G­
34048.
G­
30033,
and
G­
28279.
The
results
of
a
field
dissipation
study
with
corn
soil
in
Ripon,
California
(
MRID
40431338,
42165509)
indicated
a
half­
life
of
58
days.
Atrazine
(
90%
dry
flowable),
applied
at
a
nominal
concentration
of
3.96
lb
ai/
ac
to
a
field
plot
of
sandy
loam
soil
planted
to
corn
in
July
1986.
In
the
0­
to
6­
inch
depth,
atrazine
was
1.15
ppm
(
1.15
ppm
total
residues)
immediately
after
treatment,
increased
to
2.82
ppm
(
2.82
ppm
total)
at
7
days,
decreased
to
1.18
ppm
(
1.18
ppm
total)
at
14
days,
decreased
to
0.50
ppm
(
0.74
ppm
total)
at
60
days,
and
was
0.02
ppm
(
0.53
ppm
total)
at
358
days
post­
treatment.
The
major
degradates
were
G­
34048.
G­
30033,
and
G­
28279.

Forestry
Field
Dissipation
(
164­
3)

A
field
dissipation
half­
life
of
87
days
was
estimated
for
exposed
soil
in
a
forestry
study
at
Oregon
City,
Oregon
(
MRID
Nos:
40431340,
42041405).
Atrazine
(
90%
G)
was
applied
aerially
at
4
lb
ai/
ac
to
10
acres
of
an
immature
Douglas
fir
forest
on
April
4,
1985.
In
tree
foliage
samples,
atrazine
was
168.2
­
294.2
ppm
immediately
post­
treatment,
76.7
­
88.0
ppm
at
7
days,
6.6
­
10.5
ppm
at
29
days,
and
1.6
­
3.2
ppm
at
88
days
post­
treatment.
The
registrantcalculated
half­
life
for
atrazine
in
foliage
was
13
days.

In
leaf
litter
samples,
atrazine
was
73.1
­
114.2
ppm
immediately
post­
treatment,
21.8
­
27.9
ppm
at
29
days,
7.2
­
8.1
ppm
at
88
days,
and
0.60
­
3.4
ppm
at
364
days
post­
treatment;
the
registrant
calculated
half­
life
was
66
days.
In
soil
(
0­
to
6­
inch
depth)
that
was
not
covered
with
leaf
litter,
atrazine
concentration
were
variable
with
no
discernible
pattern,
ranging
from
0.075
to
4.3
ppm.
G­
30033
was
isolated
at
up
to
0.118
ppm.
In
the
6­
to
12­
and
12­
to
18­
inch
soil
depths,
atrazine
was
<
0.05
to
0.432
ppm
and
<
0.05
to
0.110
ppm,
respectively.
In
soil
under
leaf
litter,
atrazine
concentration
were
variable
in
the
0­
to
6­
inch
depth,
ranging
from
0.077
to
4.7
ppm,
and
were
#
0.088
ppm
in
the
6­
to
12­
and
12­
to
18­
inch
depths.

Long­
Term
Terrestrial
Field
Dissipation
(
164­
5)

The
results
of
a
long­
term
field
dissipation
study
with
corn
soil
at
Hollandale,
Minnesota,
(
MRID
40431339,
42089911)
predicted
a
half­
life
of
402
days
with
an
r2
of
0.81.
In
the
0­
6"
soil
samples,
detectable
residues
of
atrazine,
G­
30033,
and
G­
34048
were
found
at
451,
510,
668,
847,
1032,
1211,
and
1389
DAT
(
days
after
treatment),
and
detectable
residues
of
G­
28279
were
found
at
451,
510,
668,
847,
and
1032
DAT.
In
the
6­
12"
soil
samples,
detectable
residues
of
atrazine
were
found
at
510,
668,
847,
1032,
and
1211
DAT,
detectable
residues
of
G­
30033
were
found
at
668,
847,
and
1032
DAT,
and
detectable
residues
of
G­
34048
were
found
at
451,
510,
668,
847,
1032,
1211,
and
1389
DAT.
The
12­
18"
soil
samples
produced
no
detectable
residues
of
atrazine,
G­
28279,
G­
30033,
or
G­
34048.
No
detectable
residues
of
atrazine,
G­
28279,
or
G­
30033
were
found
in
the
18­
24"
soil
samples;
however,
detectable
residues
of
G­
34048
were
found
at
1211
and
1389
DAT.
In
the
24­
36"
soil
samples,
no
detectable
residues
of
atrazine,
G­
28279,
G­
30033,
or
G­
34048
were
found.

The
results
of
a
long­
term
field
dissipation
study
with
bare
ground
at
Hollandale,
Minnesota,
(
MRID
40431337,
42089912)
predicted
a
half­
life
of
261
days
with
an
r2
of
0.94.
In
the
0­
6"
soil
samples,
detectable
residues
of
atrazine,
G­
30033,
and
G­
34048
were
found
at
449,
498,
659,
839,
1020,
1200,
and
1378
DAT,
and
detectable
residues
of
G­
28279
were
found
at
449,
498,
659,
839,
and
1020
DAT.
Detectable
residues
of
atrazine
and
G­
34048
were
found
in
the
6­
12"
soil
samples
at
449,
498,
659,
839,
1020,
and
1200
DAT,
detectable
residues
of
G­
30033
were
found
at
449,
498,
659,
839,
and
1200
DAT.
In
the
12­
18"
soil
samples,
detectable
residues
of
atrazine
were
found
at
449,
498,
659,
839,
1020,
1200,
and
1378
DAT,
no
detectable
residues
of
G­
28279
or
G­
30033
were
found,
detectable
residues
of
G­
34048
were
found
at
449,
659,
and
1200
DAT.
In
the18­
24"
soil
samples,
detectable
residues
of
atrazine
were
found
at
449,
498,
659,
839,
and
1020
DAT,
no
detectable
residues
of
G­
28279
were
found,
detectable
residues
of
atrazine
were
found
only
at
1020
DAT,
detectable
residues
of
G­
28279
were
found
449
and
498
DAT,
detectable
residues
of
G­
30033
were
only
found
at
498
DAT,
and
no
detectable
residues
of
G­
34048
were
found.

The
results
of
a
long­
term
field
dissipation
study
with
corn
soil
at
Ripon,
California,
(
MRID
40431338,
42089909)
predicted
a
half­
life
of
102
days
with
an
r2
of
0.84.
In
the
0­
6"
soil
samples,
detectable
residues
of
atrazine
were
found
at
552
DAT,
no
detectable
residues
of
G­
30033
were
found,
and
G­
34048
were
found
at
460,
552,
726,
873,
1045
DAT
samples.
In
the
6­
12"
soil
samples,
detectable
residues
of
atrazine
were
found
at
460
and
552
DAT,
detectable
residues
of
G­
28279
and
G­
30033
were
found
only
in
the
460
DAT
samples,
and
detectable
residues
of
G­
34048
were
found
at460,
552,
873,
and
1045
DAT
soils
samples.
At
the
12­
18"
soil
depth,
detectable
residues
of
atrazine
were
found
at
460
DAT
only,
no
detectable
residues
of
G­
28279
or
G­
30033
were
found,
and
detectable
residues
of
G­
34048
were
found
in
the
460,
552,
and
873
DAT
soil
samples.
In
the
18­
24"
soil
samples,
detectable
residues
of
atrazine
and
G­
28279
were
found
in
460
and
552
DAT
soil
samples,
no
detectable
residues
of
G­
30033
were
found,
and
detectable
residues
of
G­
34048
were
found
in
the
460
and
873
DAT
soil
samples.
No
detectable
residues
of
G­
28279
were
found
in
the
24­
36"
soil
samples,
while
detectable
residues
of
atrazine
and
G­
30033
were
found
at
460
DAT,
and
residues
of
G­
34048
were
found
at
460,
552,
and
873
DAT.

The
results
of
a
long­
term
field
dissipation
study
with
bare
ground
at
Ripen,
California,
(
MRID
40431336,
42089910)
predicted
a
half­
life
of
110
days
with
an
r2
of
0.92.
In
the
0­
6"
soil
samples,
detectable
residues
of
atrazine
and
G­
30033
were
found
only
at
460
DAT,
and
detectable
residues
of
G­
34048
were
found
in
460,
552,
and
837
DAT
samples.
No
detectable
residues
of
atrazine
or
G­
28279
were
found
in
the
6­
12"
soil
samples,
detectable
residues
of
G­
30033
were
found
only
at
552
DAT,
and
detectable
residues
of
G­
34048
were
found
in
the
460,
552,
and
873
DAT
soil
samples.
No
detectable
residues
of
atrazine,
G­
28279,
or
G­
33033
were
found
in
the
12­
18"
soil
samples,
while
detectable
residues
of
G­
34048
were
found
in
the
460,
552,
and
873
DAT
soil
samples.
In
the18­
24"
soil
samples,
no
detectable
residues
of
atrazine,
G­
28279,
or
G­
30033
were
found,
while
detectable
residues
of
G­
34048
were
found
in
the
460,
552,
and
873
DAT
soil
samples.
Detectable
residues
of
atrazine,
G­
28279,
G­
30033,
and
G­
34048
were
found
in
the
24­
36"
soil
samples
for
460
DAT
and
residues
of
atrazine
and
G­
34048
were
also
found
at
873
DAT.

Bioaccumulation
in
Fish
(
165­
4)

Based
on
an
accepted
study
(
MRID:
40431344),
total
[
14C]
atrazine
residues
accumulated
in
bluegill
sunfish
with
maximum
bioconcentration
factors
of
7.7x,
12x,
and
15x
in
edible
tissues
(
body,
muscle,
skin,
skeleton),
nonedible
tissues
(
fins,
head,
internal
organs),
and
whole
fish,
respectively,
during
28
days
of
exposure
to
uniformly
ring­
labeled
[
14C]
atrazineat
0.01
ppm
in
a
flow­
through
system.
After
21
days
of
depuration,
[
14C]
atrazine
were
0.21
ppm
in
edible
tissues,
0.38
ppm
in
nonedible
tissues,
and
0.28
ppm
in
whole
fish;
depuration
rates
were
74,
76,
and
78%,
respectively.

Spray
Drift
Data
Requirements
(
201­
1,
202­
1)

The
guidelines
require
data
of
droplet
size
spectrum
and
drift
field
evaluation.
No
atrazinespecific
spray
drift
studies
were
reviewed.
The
registrant,
Novartis,
is
a
member
of
the
Spray
Drift
Task
Force
(
SDTF).
The
SDTF
has
completed
and
submitted
to
the
Agency
a
series
of
studies
intended
to
characterize
spray
droplet
drift
potential
due
to
various
factors,
including
application
methods,
application
equipment,
meteorological
conditions,
crop
geometry
and
droplet
characteristics.
EFED
is
currently
evaluating
these
studies.
After
its
review,
the
Agency
will
determine
whether
a
reassessment
is
warranted
of
the
potential
risks
from
the
application
of
atrazine
to
nontarget
organisms.

Degradates
Detected
in
Laboratory
Studies
There
are
two
major
types
of
degradates
for
atrazine.
The
first
type
of
degradates
are
formed
via
dealkylation
of
the
amino
groups,
for
which
mono­
and
fully
dealkylated
degradates
are
known.
The
second
type
of
degradates
are
formed
by
substitution
of
a
chloro
group
by
a
hydroxy
group
in
either
parent
or
dealkylated
degradates.

The
following
table
provides
a
summary
of
atrazine
degradates
detected
in
the
laboratory
studies
discussed
above.

Major
Degradates
Photolysis
in
Water
Photolysis
on
Soil
Aerobic
Soil
Anaerobic
Soil
Anaerobic
Aquatic
Deethylatrazine
G­
30033
X
X
X
X
X
Deisopropylatrazine
G­
28279
X
X
X
X
X
Diaminochlorotriazine
G­
28273
X
X
X
X
Hydroxyatrazine
G­
34048
X
X
X
X
Deethylhydroxyatrazine
GS­
17794
X
X
Deisopropylhydroxyatrazine
GS­
17792
X
X
Appendix
III.
Submitted
Environmental
Fate
and
Transport
Studies
Balu,
K.
1989.
Atrazine:
Summary
of
surface
water
monitoring
data
for
atrazine.
Laboratory
Study
No.
EIR­
89001.
484
p.
Unpublished
study
prepared
and
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
41065205).

Balu,
K.
1991.
Responses
to
the
EPA
review
of
the
field
dissipation
study
on
Aatrex
Nine­
0
for
terrestrial
uses
on
bareground,
Hollandale,
Minnesota:
Supplement
to
EPA
MRID
Number
40431337.
Lab.
Project
Number:
ABR­
91064.
50
p.
Unpublished
study
prepared
and
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
42165507).

Balu,
K.
1991.
Responses
to
the
EPA
review
of
the
field
dissipation
study
on
Aatrex
Nine­
0
for
terrestrial
uses
on
bareground,
Ripon,
California:
Supplement
to
EPA
MRID
Number
40431336.
Lab.
Project
Number:
ABR­
91063.
110
p.
Unpublished
study
prepared
and
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
42165506).

Balu,
K.
1991.
Responses
to
the
EPA
review
of
the
field
dissipation
study
on
Aatrex
Nine­
0
for
terrestrial
uses
on
corn,
Hollandale,
Minnesota:
Supplement
to
EPA
MRID
Number
40431339.
Lab.
Project
Number:
ABR­
91066.
49
p.
Unpublished
study
prepared
and
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
42165308).

Balu,
K.
1991.
Responses
to
the
EPA
review
of
the
field
dissipation
study
on
Aatrex
Nine­
0
for
terrestrial
uses
on
corn,
Ripon,
California:
Lab.
Project
Number:
ABR­
91065.
111
p.
Unpublished
study
prepared
and
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
42165509).

Balu,
K.
and
P.
W.
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State
ground­
water
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atrazine
and
its
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degradation
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the
United
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Ciba
Study
No.
174­
91.
24
p.
Unpublished
study
prepared
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VA.;
submitted
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Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
43934414).

Burkhard,
N.
and
J.
A.
Guth.
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atraton
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ametryne
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aqueous
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Pesticide
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7(
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71.
(
Also
In:
Unpublished
submission
received
July
19,
1978
under
201­
403;
submitted
by
Shell
Chemical
Co.,
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D.
C.;
CDL:
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C).
(
MRID
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00024328).

Das,
Y.
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of
triazine(
U)­
carbon
14­
atrazine
on
soil
under
artificial
sunlight.
Lab.
Project
Number:
89070.
109
p.
Unpublished
study
prepared
by
Innovative
Science
Services,
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Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
42089905).

Forbis,
A.
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depuration,
and
bioconcentration
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metabolite
characterization
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carbon
14­
atrazine
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sunfish
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macrochirus):
Laboratory
Study
No.
34737.
107
p.
Unpublished
study
prepared
by
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Bio­
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Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
40431344).
Froelich,
L.,
T.
Bixler,
C.
Peake
et
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1982.
Soil
adsorption/
desorption
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FMC
57020:
M­
4861.
Unpublished
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received
Oct
1,
1982
under
279­
EX­
93;
submitted
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PA;
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248476­
D.
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MRID
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S.
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Nine­
0
for
terrestrial
uses
on
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in
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GA:
Lab.
Project
Number:
1641­
86­
71­
01­
21E­
27.
317
p.
Unpublished
study
prepared
by
Landis
International
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Others;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
42165505).

Guy,
S.
1987.
Field
dissipation
on
Aatrex
Nine­
0
for
terrestrial
uses
on
corn
in
Donalsonville,
GA:
Lab.
Project
Number:
1641­
86­
71­
01­
06B­
26.
325
p.
Unpublished
study
prepared
by
Landis
International
and
Others;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
42165504).

Hardies,
D.
E.
and
D.
Y.
Studer.
1982.
Soil
thin­
layer
chromatography
of
PPG­
1292:
BRC
22593.
Unpublished
study
received
April
5,
1982
under
2F2666;
submitted
by
PPG
Industries,
Inc.,
Barberton,
Ohio;
CDL:
070755­
J.
(
MRID
#
00098254).

Harris,
C.
I.
1967.
Fate
of
2­
chloro­
s­
triazine
herbicides
in
soil.
J.
Agric.
Food
Chem.
15(
1):
157­
162.
Also
In:
Unpublished
submission
received
July
17,
1978
under
100­
541;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
00027870).

Helling,
C.
S.
1971.
Pesticide
mobility
in
soils.
II.
Applications
of
soil
thin­
layer
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Soil
Science
Society
of
America
Proceedings
35:
737­
748.
Also
In:
Unpublished
submission
received
May
5,
1975
under
464­
323;
submitted
by
Dow
Chemical
U.
S.
A.,
Midland,
Mich.;
CDL:
221997­
S.
(
MRID
#
00044017).

Klaine,
S.
1987.
Biotic
and
abiotic
degradation
of
atrazine
and
three
of
its
metabolites
in
a
west
Tennessee
soil:
Laboratory
Study
No.
TX­
431.
63
p.
Unpublished
study
prepared
by
Memphis
State
University,
Memphis,
TN;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
40431322).

Leake,
C.,
D.
Lines
and
K.
Tiffen.
1981.
The
leaching
of
NC
21
314
in
four
soil
types
using
soil
TLC:
METAB/
81/
40.
Unpublished
study
received
July1,
1982
under
45639­
EX­
7;
prepared
by
FBC
Ltd.,
England;
submitted
by
FBC
Chemicals,
Inc.,
Wilmington,
DE;
CDL:
070966­
E.
(
MRID
#
00105942).

Nelson,
D.
and
D.
Schabacker.
1991.
Summary
report:
Soil
metabolism
of
carbon
14­
atrazine
and
metabolite
characterization/
identification:
Lab.
Project
Number:
6015­
185:
ABR­
91073.
321
p.
Unpublished
study
prepared
by
Hazleton
Labs
America,
Inc.
(
MRID
#
42089906).

Obien,
S.
R.
and
Green,
R.
E.
1969.
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of
atrazine
in
four
Hawaiian
soils.
Weed
Science
17(
4):
509­
514.
(
Also~
In:
Unpublished
submission
received
July
19,
1978
under
201­
403;
submitted
by
Shell
Chemical
Co.,
Washington,
D.
C.;
CDL:
234476­
C)
(
MRID
#
00040663).
Parshley,
Thomas
J.
1990.
Letter:
Atrazine
technical,
EPA
Reg.
No.
100­
529:
Additional
information
on
adsorption/
desorption
data:
Soil
series
names.
3
p.
Submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.

Rustum,
A.
1987.
Aerobic,
aerobic/
anaerobic,
and
sterile
soil
metabolism
of
carbon
14­
atrazine:
Laboratory
Study
No.
6015­
185.
133
p.
Unpublished
study
prepared
by
Hazleton
Laboratories
America,
Inc.,
Madison,
WI;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
40431321).

Rustum,
A.
1988.
Aerobic,
aerobic/
anaerobic,
and
sterile
soil
metabolism
of
14C­
atrazine:
Study
No.
HLA
6015­
185.
165
p.
Unpublished
study
prepared
by
Hazleton
Laboratories
America,
Inc.,
Madison,
WI;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
40629303).

Saxena,
A.
M.
1987.
Determination
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the
mobility
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soil­
aged
14C­
atrazine
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by
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Laboratory
Study
No.
HLA
6015­
186.
Unpublished
study
prepared
by
Hazleton,
Laboratories
America,
Inc.,
Madison,
WI;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
40431330).

Schabacker,
D.
1991.
Summary
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Aqueous
photolysis
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carbon
14­
atrazine
under
natural
and
artificial
light.
Lab.
Project
Number:
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A:
12112
B.
185
p.
Unpublished
study
prepared
by
Agrisearch
Inc.,
Frederick,
MD;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
42089904).

Schofield,
M.
1986.
Combined
field
dissipation
and
aquatic
non­
target
organism
accumulation
Studies
on
Aatrex
Nine­
O
for
forestry
use
at
Oregon
City,
Oregon:
Laboratory
Study
No.
32989.
135
p.
Unpublished
study
prepared
by
Analytical
Bio­
Chemistry
Laboratories,
Inc.,
Columbia,
MO;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
40431340).

Spare,
W.
1986.
Determination
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Laboratory
Study.
No.
1236.
33
p.
Unpublished
study
prepared
by
Agrisearch
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Frederick,
MD;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
40431319)

Spare,
W.
1987.
Anaerobic
aquatic
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of
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Laboratory
Study
No.
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69
p.
Unpublished
study
prepared
by
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submitted
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Geigy
Corp.,
Greensboro,
NC.
(
MRID
40431323).

Spare,
W.
1987.
Photodegradation
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soil
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artificial
and
natural
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1237.
68
p.
Unpublished
study
prepared
by
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Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
40431320).

Spare,
W.
1989.
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desorption
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14C­
atrazine:
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Project
No.
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59
p.
Unpublished
study
prepared
by
Agrisearch,
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MD;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
41257901).
Spare,
W.
1989.
Adsorption/
desorption
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14C­
G­
28273:
Agrisearch
Project
No.
12173.
55
p.
Unpublished
study
prepared
by
Agrisearch
Inc.,
Frederick,
MD;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
41257904).

Spare,
W.
1989.
Adsorption/
desorption
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14C­
G­
28279:
Agrisearch
Project
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12170.
57
p.
Unpublished
study
prepared
by
Agrisearch,
Inc.,
Frederick,
MD;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
41257905).

Spare,
W.
1989.
Adsorption/
desorption
of
14C­
G­
30033:
Agrisearch
Project
No.
12169.
57
p.
Unpublished
study
prepared
by
Agrisearch
Inc.,
Frederick,
MD;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
41257906).

Spare,
W.
1989.
Adsorption/
desorption
of
14C­
G­
34048:
Agrisearch
Project
No.
12171.
57
p.
Unpublished
study
prepared
by
Agrisearch,
Inc.,
Frederick,
MD;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
41257902).

Speth,
Robert
M.
1991.
Responses
to
the
EPA
review
of
the
atrazine
forestry
field
dissipation
study
at
Oregon
City,
Oregon.
Supplement
to
MRID
40431340).
Laboratory
Project
ID:
ABR­
91067.
45
p.
Unpublished
study
prepared
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
420414050).

Talbert,
R.
E.
and
O.
H.
Fletchall.
1965.
The
adsorption
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some
s­
triazines
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soils.
Weeds
13:
46­
52.
(
Also
In:
Unpublished
submission
received
July
19,
1978
under
201­
403;
submitted
by
Shell
Chemical
Co.,
Washington,
D.
C.;
CDL:
234472­
J).
(
MRID
#
00027134).

White,
S.
1987.
Field
dissipation
study
on
Aatrex
Nine­
O
for
terrestrial
uses
on
bareground,
Hollandale,
Minnesota:
Laboratory
Study
No.
1641­
86­
71­
01­
21E­
25.
356
p.
Unpublished
study
prepared
by
Minnesota
Valley
Testing
Labs,
Inc.,
New
Elm,
MN;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
40431337).

White,
S.
1987.
Field
dissipation
study
on
Aatrex
Nine­
O
for
terrestrial
uses
on
bareground,
Ripon,
California:
Laboratory
Study
No.
1641­
86­
71­
01­
21E­
23.
300
p.
Unpublished
study
prepared
by
Minnesota
Valley
Testing
Labs,
Inc.,
New
Elm,
MN;
Submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
40431336).

White,
S.
1987.
Field
dissipation
study
on
Aatrex
Nine­
O
for
terrestrial
uses
on
corn,
Hollandale,
Minnesota:
Laboratory
Study
No.
1641­
86­
71­
01­
06B­
24.
372
p.
Unpublished
study
prepared
by
Minnesota
Valley
Testing
Labs,
Inc.,
New
Elm,
MN;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
40431339).

White,
S.
1987.
Field
dissipation
study
on
Aatrex
Nine­
O
for
terrestrial
uses
on
corn,
Ripon,
California:
Laboratory
Study
No.
1641­
86­
71­
01­
06B­
22.
311
p.
Unpublished
study
prepared
by
Minnesota
Valley
Testing
Labs,
Inc.,
New
Elm,
MN;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
40431338).
Yu,
W.
C.
1986.
Determination
of
adsorption/
desorption
constants
of
atrazine:
Laboratory
Study
No.
59­
1A.
33
p.
Unpublished
study
prepared
by
Cambridge
Analytical
Associates,
Inc.,
Boston,
MA;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
40431324).

Yu,
W.
C.
1986.
Determination
of
adsorption/
desorption
constants
of
G­
28273:
Laboratory
Study
No.
59­
5A.
Unpublished
study
prepared
by
Cambridge
Analytical
Associates,
Inc.,
Boston,
MA;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
40431327).

Yu,
W.
C.
1986.
Determination
of
adsorption/
desorption
constants
of
G­
28279:
Laboratory
Study
No.
59­
6A.
Unpublished
study
prepared
by
Cambridge
Analytical
Associates,
Inc.,
Boston,
MA;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
40431325).

Yu,
W.
C.
1986.
Determination
of
adsorption/
desorption
constants
of
G­
30033:
Laboratory
Study
No.
59­
6A.
Unpublished
study
prepared
by
Cambridge
Analytical
Associates,
Inc.,
Boston,
MA;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
40431328).

Yu,
W.
C.
1986.
Determination
of
adsorption/
desorption
constants
of
G­
34048:
Laboratory
Study
No.
59­
7A.
Unpublished
study
prepared
by
Cambridge
Analytical
Associates,
Inc.,
Boston,
MA;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
#
40431326).
Appendix
IV.
Drinking
Water
Characterization
The
drinking
water
characterization
is
being
reported
in
a
separate
report,
entitled
"
Drinking
Water
Exposure
Assessment
for
Atrazine
and
Various
Chloro­
triazine
and
Hydroxy­
triazine
Degradates."
The
conclusions
and
summary
of
results
(
Chapter
10)
are
excerpted
below.

10.
Conclusions
and
Summary
of
Results
10.1)
Atrazine
concentrations
in
the
PLEX
and
comparison
to
Office
of
Drinking
Water
MCL
and
short
term
HALs
for
atrazine
Of
the
21,241
ground,
surface,
and
blend
water
source
CWSs
in
21
states
with
atrazine
data
in
the
PLEX
database
through
1998,
2,386
CWSs
(
11.2%)
had
one
or
more
atrazine
detections
above
limits
of
quantification
(
LOQs)
(
Table
4­
2
which
is
Table
4.2­
3
of
MRID
450587­
04).
Of
a
total
of
88,766
samples
in
the
database,
8,685
(
9.8%)
had
detections
above
the
LOQs
(
Table
4­
2).
The
LOQs
varied
from
0.01
to
0.5
ug/
L,
but
were
typically
at
0.1
ug/
L
(
Table
4­
3
which
is
Table
3.2­
6
of
MRID
450587­
04).

The
population
and
%
of
the
assessed
population
exposed
to
1998,
1997,
1996,
1995,
1994,
and
1993
annual
mean
atrazine
concentrations
>
3
ug/
L
were
16,000
people
(
0.02%),
129,000
people
(
0.18%),
156,000
people
(
0.19%),
506,000
people
(
0.79%),
331,000
people
(
0.58%),
and
(
76,500
people
(
0.17%),
respectively.
The
assessed
populations
for
1998,
1997,
1996,
1995,
1994,
and
1993
were
approximately
79.9,
71.6,
82.3,
64.0,
57.1,
and
45.0
million,
respectively.

The
#
of
CWSs
and
%
of
the
assessed
CWSs
with
1998,
1997,
1996,
1995,
1994,
and
1993
annual
mean
atrazine
concentrations
>
3
ug/
L
were
4
CWSs
(
0.05%),
26
CWSs
(
0.31%),
73
CWSs
(
0.92%),
11
CWSs
(
0.14%),
95
CWSs
1.49%),
and
19
CWSs
(
0.49%),
respectively.
The
#
of
assessed
CWSs
in
those
years
were
8548,
8300,
7944,
7909,
6395,
and
3913
CWSs,
respectively.

Of
the
21,241
CWSs
with
atrazine
data
in
the
PLEX
database,
182
CWSs
had
one
or
more
annual
mean
atrazine
concentrations
>
the
MCL
of
3
ug/
L
during
the
1993­
1998
period
(
Tables
4­
1
and
4­
2).
Of
those
182
CWSs,
81
are
suppliers
and
101
are
purchasers.
Of
the
81
suppliers,
74,
5,
and
2
have
surface
water,
blend,
and
ground
water
sources,
respectively.
Of
the
81
suppliers,
33
are
in
Illinois,
16
are
in
Missouri,
12
are
in
Kansas,
12
are
in
Ohio,
4
are
in
Kentucky,
2
are
in
Indiana,
and
one
each
are
in
North
Carolina
and
Texas
(
Table
4­
2).

The
highest
atrazine
concentration
(
42
ug/
L)
reported
in
the
PLEX
database
from
1993
through
1998
is
well
below
the
Office
of
Drinking
Water
short
term
HALs
for
atrazine
of
100
ug/
L.
However,
because
only
one
sample
was
collected
per
quarter/
CWS
in
the
PLEX
database,
reported
maximum
atrazine
concentrations
in
the
PLEX
database
may
often
be
substantially
less
than
actual
peak
concentrations.
Because
the
VMS
(
on
100
surface
water
source
CWSs)
and
the
ARP
surface
water
monitoring
study
(
on
175
surface
water
source
CWSs)
have
substantially
more
time
series
data
than
the
PLEX
database,
observed
maximum
atrazine
concentrations
in
those
studies
for
a
given
CWS
should
generally
be
closer
to
actual
peak
atrazine
concentrations
in
the
CWS
than
observed
maximum
atrazine
concentrations
for
the
same
CWS
in
the
PLEX
database.
However,
the
maximum
reported
atrazine
concentrations
in
those
studies
(
63.5
and
49.5
ug/
L)
were
still
well
below
the
Office
of
Drinking
Water
short
term
HALs
for
atrazine
of
100
ug/
L.

10.2)
Atrazine
concentrations
in
the
Rural
Well
Survey
and
comparison
to
Office
of
Drinking
Water
MCL
and
short
term
HALs
for
atrazine
In
the
Rural
Well
Survey
from
September
1992
to
March
1995,
one
sample
was
collected
from
each
of
1505
wells
and
analyzed
for
atrazine,
and
various
chloro­
triazine
and
hydroxytriazine
degradates.
The
maximum,
99th
percentile,
and
95th
percentile
atrazine
concentrations
were
12.0,
2.4,
and
0.87
ug/
L.

Eight
wells
(
out
of
the
1,505
wells
sampled
in
the
Rural
Well
Survey)
had
atrazine
concentrations
exceeding
the
MCL
of
3
ug/
L.
Because
only
one
sample
was
collected
from
each
well,
it
is
not
known
how
many
if
any
of
those
8
wells
had
annual
mean
atrazine
concentrations
exceeding
3
ug/
L.
In
the
ARP
ground
water
monitoring
of
177
wells
from
May
1995
to
March
1998,
2
of
the
177
wells
had
a
maximum
annual
mean
atrazine
concentration
(
14.3
and
4.97
ug/
L
based
on
running
annual
means)
>
3
ug/
L.

The
highest
atrazine
concentration
detected
in
the
Rural
Well
Survey
(
12
ug/
L)
was
much
less
than
the
short
term
HAL
of
100
ug/
L.
However,
because
only
one
sample
was
collected
per
well
in
the
Rural
well
Survey,
the
reported
maximum
atrazine
concentration
in
the
Rural
Well
Survey
may
be
substantially
less
than
the
actual
peak
concentration.
In
the
ARP
ground
water
monitoring
study
of
only
177
wells,
but
which
included
12
samples/
well/
year
over
a
3
year
period,
one
well
had
a
maximum
atrazine
concentration
(
132
ug/
L)
greater
than
the
short
term
HAL
of
100
ug/
L.
However,
the
next
highest
atrazine
concentration
(
11.0
ug/
L)
was
well
below
the
HAL.

10.3)
Regression
estimated,
annual
mean
and
annual
maximum
total
chloro­
triazine
concentrations
in
the
surface
water
portion
of
the
PLEX
database
and
comparison
to
HED
subchronic
chronic
and
acute
DWLOCs.

The
regression
estimated,
highest
annual
mean
total
chloro­
triazine
concentration
(
17
ug/
L)
for
surface
water
source
CWSs
in
the
PLEX
database
from
1993
through
1998
is
slightly
below
the
sub­
chronic/
chronic
HED
DWLOC
of
18
ug/
L
for
children
and
infants
and
well
below
the
subchronic
chronic
HED
DWLOC
of
63
ug/
L
for
adults.

The
assessed
populations
in
the
surface
water
portion
of
the
Novartis
PLEX
database
for
1998,
1997,
1996,
1995,
1994,
and
1993
were
approximately
44.0,
38.2,
41.5,
31.4,
24.0,
and
23.9
million,
respectively.
The
#
of
assessed
surface
water
source
CWSs
in
those
years
were
2494,
2132,
2547,
1699,
1700,
and
1212,
respectively.

The
regression
estimated,
highest
total
chloro­
triazine
concentration
(
59.8
ug/
L)
for
surface
water
source
CWSsin
the
PLEX
database
from
1993
through
1998
is
well
below
the
single
HED
acute
DWLOC
of
298
ug/
L
(
for
pregnant
women).
In
the
PLEX
database
of
atrazine
data
(
collected
to
comply
with
the
monitoring
requirements
of
the
SDWA),
the
annual
maximum
reported
atrazine
concentration
for
a
CWS
also
represents
its
annual
maximum
reported
3­
month
quarterly
mean
because
only
one
sample
is
generally
collected
per
quarter
(
3
months).
Therefore,
the
EFED
compared
regression
estimated
annual
maximum
total
chloro­
triazine
concentrations
to
HED
chronic
as
well
as
acute
DWLOCs.
The
actual
annual
maximum
quarterly
mean
for
a
CWS
may
be
lower
or
higher
than
the
annual
maximum
reported
atrazine
concentration
for
the
CWS.

The
population
and
the
%
of
the
assessed
population
exposed
to
estimated
1998,
1997,
1996,
1995,
1994,
and
1993
annual
maximum
total
chloro­
triazine
concentrations
>
the
lowest
HED
sub­
chronic/
chronic
DWLOC
of
18
ug/
L
for
children
and
infants
were
1450
people
(
0.003%),
105,721
people
(
0.28%),
40,586
people
(
0.10%),
0
people
(
0.0%),
210,544
people
(
0.84%),
and
184,092
people
(
0.77%),
respectively.
The
assessed
populations
in
the
surface
water
portion
of
the
Novartis
PLEX
database
for
1998,
1997,
1996,
1995,
1994,
and
1993
were
approximately
44.0,
38.2,
41.5,
31.4,
24.0,
and
23.9
million,
respectively.

The
#
of
CWSs
and
%
of
the
assessed
CWSs
with
1998,
1997,
1996,
1995,
1994,
and
1993
annual
maximum
total
chloro­
triazine
concentrations
>
the
lowest
HED
sub­
chronic/
chronic
DWLOC
of
18
ug/
L
for
children
and
infants
were
2
CWSs
(
0.08%),
9
CWSs
(
0.42%),
19
CWSs
(
0.75%),
0
CWSs
(
0.0%),
30
CWSs
(
1.77%),
and
3
CWSs
(
0.25%),
respectively.
The
#
of
assessed
surface
water
source
CWSs
in
those
years
were
2494,
2132,
2547,
1699,
1700,
and
1212
CWSs,
respectively.

The
identities
of,
and
populations
served
by
CWSs
with
annual
maximum
total
chloro­
triazine
concentrations
>
the
HED
sub­
chronic/
chronic
DWLOC
of
18
ug/
L
for
children
and
infants
can
be
obtained
from
the
cumulative
exceedence
tables
in
Sub­
Appendix
A­
5.

The
regression
estimated,
highest
annual
maximum
total
chloro­
triazine
concentration
(
59.8
ug/
L)
for
surface
water
source
CWSs
in
the
PLEX
database
from
1993
through
1998
was
slightly
below
the
HED
sub­
chronic/
chronic
DWLOC
of
63
ug/
L
for
adults.

10.4)
Comparison
of
total
chloro­
triazine
and
total
hydroxy­
triazine
concentrations
in
the
Rural
Well
Survey
to
HED
DWLOCs
One
well
(
out
of
1505
sampled
in
the
Rural
Well
Survey)
had
a
total
chloro­
triazine
concentration
equaling
the
HED
sub­
chronic/
chronic
DWLOC
of
18
ug/
L
for
the
chronic
exposure
of
children
and
infants,
respectively.
No
wells
had
total
chloro­
triazine
concentrations
exceeding
the
HED
sub­
chronic/
chronic
DWLOC
of
18
ug/
L
for
children
and
infants,
the
HED
sub­
chronic/
chronic
DWLOC
of
63
ug/
L
for
adults
or
the
single
HED
acute
DWLOC
of
298
ug/
L
for
adult
women.

The
highest
total
hydroxy­
triazine
concentration
detected
(
7.66
ug/
L)
was
much
less
than
the
lowest
HED
chronic
DWLOC
of
99
ug/
L
for
children
and
infants.
V
­
1
Appendix
V.
Documentation
of
Water
Resource
Modeling
(
PRZM3­
EXAMS
&
GENEEC)

Aquatic
Exposure
Assessment
Modeling
Approach
For
aquatic
exposure
assessment,
the
tier
II
refinement
approach
with
PRZM
(
Pesticide
Root
Zone
Model)
and
EXAMS
(
EXposure
Analysis
Modeling
System)
was
simulated
to
generate
the
Estimated
Environmental
Concentrations
(
EEC's).

The
environmental
fate
data
for
atrazine
used
in
the
tier
2
refined
modeling
are
summarized
in
the
following
Table
.
Input
Parameters
for
PRZM
(
version
3.12)

Variable
(
units)
Variable
Description
Input
Value
Source
of
Info/
Reference
DWRATE(
1)
1
(
day­
1)
Dissolved
phase
pesticide
decay
rate
in
surface
horizon
DWRATE(
1)
=
DSRATE(
1)

4.748
x
10
­
3
Aerobic
soil
metabolism
study
(
GLN
162­
1)

140
and
146
days
DSRATE(
1)
1
(
day­
1)
Adsorbed
phase
pesticide
decay
rate
in
surface
horizon
DWRATE(
2)
(
day­
1)
DWRATE(
3)
(
day­
1)
Dissolved
phase
pesticide
decay
rate
in
1st,
and
2nd
subsurface
horizon
DWRATE(
2)
=
DSRATE(
2)

4.359
x
10
­
3
DWRATE(
3)
=
DSRATE(
3)

4.359
x
10
­
3
Anaerobic
soil/
anaerobic
aquatic
metabolism
study
(
GLN
162­
2/
3)

159
days
DSRATE(
2)
(
day­
1)
DSRATE(
3)
(
day­
1)
Adsorbed
phase
pesticide
decay
rate
in
1st
and
2nd
subsurface
horizon
KD(
1)
KD(
2)
KD(
3)
(
cm3
gm­
1
or
mL
g­
1
or
L
kg­
1)
Pesticide
partition
or
distribution
coefficients
for
each
horizon
use
KOC
value
of
87.78
to
estimate
KD
at
each
horizon
Mobility
­
Adsorption/
Desorption
study
(
GLN
163­
1)

average
of
86.9,
38.5,
70.4,
and
155.3
DEPI
(
cm)
Incorporation
depth
Actual
or
pesticide
label
Product
label
V
­
2
TAPP
(
kg
ha­
1)
Application
rate
Maximum
label
rate
Product
label
APPEFF
(
decimal)
Application
efficiency
0.75
for
aerial
spray;
0.90
for
ground
spray.
Product
label;
AGDRIFT2
DRFT
Spray
drift
fraction
0.05
for
aerial
spray;
0.01
for
ground
spray.
AGDRIFT2
Input
Parameters
for
EXAMS
(
Version
2.97.5)

Variable
(
units)
Variable
Description
Input
Value
Source
of
Info/
Reference
HENRY
(
atm­
m3mole­
1)
Henry's
law
constant
2.58
x
10
­
9
KBACW1
(
cfu/
mL)­
1
hour­
1
Bacterial
biolysis
in
water
column
9.89
x
10
­
5
twice
of
aerobic
soil
metabolism
half­
life
(
146
x2)

KBACS1
(
cfu/
mL)­
1
hour­
1
Bacterial
biolysis
in
benthic
sediment
4.75
x
10
­
5
608
days
KDP
(
hour­
1)
Direct
photolysis
1.72
x
10
­
4
335
days
KBH
(
mole­
1
hour­
1)
KNH
(
hour­
1)
KAH
(
mole­
1
hour­
1)
Base
hydrolysis
Neutral
hydrolysis
Acid
hydrolysis
0.0
0.0
0.0
Stable
KOC
(
mL
g­
1
O.
C.)
Partition
coefficient
for
organic
carbon
87.78
average
of
86.9,
38.5,
70.4,
and
155.3
MWT
(
g
mole­
1)
Molecular
weight
215.69
SOL
(
mg
L­
1)
Aqueous
solubility
33
QUANT
Reaction
quantum
yield
for
direct
hydrolysis
0
VAPR
(
torr)
Vapor
pressure
3
x
10­
7
V
­
3
PRZM
PRZM
(
Version
3.12)
relates
pesticide
movement
to
temporal
variations
of
hydrology,
agronomy,
pesticide
chemistry
and
meteorology.
In
order
to
run
PRZM,
four
types
of
input
data
are
needed:
meteorology,
soil,
hydrology
and
pesticide
chemistry.
Except
for
the
pesticide
chemistry,
the
other
three
types
of
input
data
were
adopted
based
on
the
standard
scenarios
established
by
the
Water
Quality
Tech
Team
(
WQTT)
of
EFED.

Based
on
the
rainfall
records
and
crop
productions,
the
modeling
scenarios
chosen
to
represent
the
high
runoff
potential
are
listed
below:

Use
Site/
Year
MLRA*
Soil
Hydrologic
Soil
Group
Corn
Ohio
(
48'
~
83')
111
Cardington
Silt
Loam
C
Sugarcane
Louisiana
(
64'~
83')
131
Sharkey
Clay
D
Sorghum
Kansas
(
48'
~
83')
112
Dennis
Silt
Loam
C
*
MLRA
represents
Major
Land
Resource
Area,
which
are
geographically
associated
land
resource
units
(
USDA,
1981).

The
meteorology
parameters
including
precipitation,
evaporation
and
air
temperature
were
obtained
from
ORD,
Athens
Laboraotry.
The
soil
properties
including
layer
depth,
soil
texture
class,
soil
composition
(
i.
e.,
percentage
sand,
silt,
clay,
and
organic
matter),
bulk
density,
field
capacity,
wilting
point,
and
available
water
for
each
selected
soil
were
extracted
from
PIRANHA
databases.

EXAMS
The
operation
of
EXAMS
involved
three
types
of
data
inputs:
Environment,
Load
and
Chemical.
The
standard
Georgia
farm
pond
data
file
was
used
to
describe
the
Environment
data
input.
The
P2E­
C1.
D(
X)
[
where
"
X"
representing
a
two­
digit
number
from
48
to
83,
or
64
to
83],
files
generated
by
PRZM
were
used
as
the
Load
data
input.
The
Chemical
data
input
was
created
based
on
the
E.
Fate
profile
of
atrazine.

EXAMS
was
run
using
data
from
36
years
using
Mode
3
which
used
monthly
environmental
data
and
the
daily
pulse
loads
of
runoff
and
spray
drift.
For
each
year
simulated,
the
maximum
annual
peak,
96­
hour
average,
21­
day
average,
60­
day
average,
90­
day
average
values,
and
the
annual
mean
were
extracted
from
the
EXAMS
output
file
REPORT.
XMS
with
the
TABLE20.
EXE
post­
processor.
The
10
year
return
EECs
(
or
10%
yearly
exceedance
EECs)
of
corn,
sugarcane,
and
sorghum
listed
in
the
Table
below
were
calculated
by
linear
interpolation
between
the
third
and
fourth
largest
values
by
the
program
TABLE20.
EXE.

Results
­
Aquatic
EECs
V
­
4
The
refined
tier
II
approach
with
PRZM/
EXAMS
was
implemented.
The
upper
tenth
percentile
concentration
values,
expressed
in
ppb
(
ug/
L),
are
summarized
below.
The
results
of
three
uses,
corn,
sugarcane,
and
sorghum,
were
based
on
the
standard
scenarios
provided
by
the
Water
Quality
Tech
Team
(
WQTT)
to
predict
reasonable
high
exposure
values,
i.
e.,
soils
with
high
runoff
potential
and
heavy
rainfall
amounts.

Use
Peak
96­
hr
average
21­
d
average
60­
d
average
90­
d
average
Corn
38.24
38.02
37.18
35.50
34.16
Sugarcane
205.10
204.10
202.20
198.10
194.20
Sorghum
72.70
72.31
70.64
67.74
65.86
The
modeling
results
indicate
that
atrazine
does
have
the
potential
to
move
into
surface
waters,
especially
for
sugarcane
use.

The
post­
processor,
LOAD.
EXE,
was
used
to
estimate
the
chemical
contributions
of
runoff,
erosion
and
spray
drift
to
the
standard
farm
pond.
The
results
expressed
as
percentages
are
tabulated
below:

Percent
of
Pesticide
Loadings
from
Different
Sources
to
the
Standard
Pond
Use
Runoff
Erosion
Spray
Drift
Corn
55.03%
3.47%
41.50%

Sugarcane
99.15%
0.85%
0.01%

Sorghum
71.80%
5.29%
22.91%

The
erosion
losses
were
the
smallest
among
the
three
components,
except
for
sugarcane
use
scanario.
Most
of
the
atrazine
losses
to
aquatic
environments
are
from
runoff.
Therefore,
any
mitigation
approaches
should
focus
on
reducing
chemical
runoff.
V
­
5
V
­
6
ATRAZINE
USE
ON
CORN
WATER
COLUMN
DISSOLVED
CONCENTRATION
(
PPB)
YEAR
PEAK
96
HOUR
21
DAY
60
DAY
90
DAY
YEARLY
1948
13.680
13.580
13.260
12.610
12.080
6.926
1949
14.140
14.060
13.880
13.320
13.190
10.440
1950
15.760
15.680
15.400
14.960
14.560
11.290
1951
23.380
23.250
22.760
21.830
21.200
15.030
1952
20.560
20.490
20.140
19.440
18.970
15.590
1953
29.880
29.730
29.300
28.060
27.050
19.430
1954
22.840
22.720
22.230
21.710
21.140
18.160
1955
19.090
19.010
18.790
18.220
18.000
15.290
1956
20.920
20.820
20.500
19.740
19.020
15.070
1957
32.860
32.720
32.200
30.610
29.410
20.940
1958
38.210
37.980
37.120
35.310
33.860
25.720
1959
37.370
37.200
36.610
35.180
33.910
27.120
1960
27.500
27.360
27.060
26.420
25.730
22.390
1961
27.630
27.470
26.840
25.580
24.640
20.060
1962
28.280
28.150
27.530
26.390
25.530
20.650
1963
25.710
25.580
25.240
24.330
23.520
19.600
1964
21.240
21.170
20.820
20.250
19.650
16.620
1965
20.510
20.420
19.980
19.010
18.450
14.920
1966
18.040
17.960
17.740
17.040
16.480
13.550
1967
30.050
29.900
29.490
28.380
27.460
18.950
1968
47.490
47.380
46.480
44.190
42.650
30.330
1969
43.270
43.080
42.260
40.680
39.310
32.090
1970
31.790
31.660
31.230
30.330
29.360
25.740
1971
28.230
28.100
27.580
26.680
26.080
21.600
1972
31.520
31.370
30.980
30.390
29.460
22.600
1973
25.110
25.010
24.570
23.860
23.370
20.090
1974
38.300
38.100
37.330
35.930
34.730
24.720
1975
27.160
27.040
26.580
26.280
25.750
22.750
1976
23.580
23.450
22.950
22.300
21.890
18.560
1977
19.460
19.380
19.020
18.390
18.120
15.750
1978
21.450
21.350
21.020
20.770
20.220
15.880
1979
20.200
20.090
19.640
18.900
18.530
15.320
1980
30.210
30.110
29.910
28.800
27.760
19.970
1981
30.530
30.360
29.820
28.610
27.920
22.190
1982
29.040
28.910
28.290
27.060
26.140
21.380
1983
24.270
24.140
23.910
23.410
23.120
19.420
Upper
10th
38.237
38.016
37.183
35.496
34.156
26.154
Percentile
MEAN
OF
ANNUAL
VALUES
=
19.337
STANDARD
DEVIATION
OF
ANNUAL
VALUES
=
5.287
UPPER
90%
CONFIDENCE
LIMIT
ON
MEAN
=
20.642
V
­
7
V
­
8
ATRAZINE
USE
ON
SUGARCANE
WATER
COLUMN
DISSOLVED
CONCENTRATION
(
PPB)
YEAR
PEAK
96
HOUR
21
DAY
60
DAY
90
DAY
YEARLY
1964
57.960
57.690
56.610
54.640
53.220
40.190
1965
87.580
87.270
86.000
83.530
81.670
63.870
1966
133.000
132.000
131.000
128.000
126.000
98.030
1967
103.000
103.000
102.000
99.860
98.170
79.370
1968
83.860
83.640
83.320
81.640
80.150
64.630
1969
119.000
119.000
118.000
116.000
114.000
88.150
1970
76.900
76.760
76.190
75.860
75.000
61.140
1971
85.600
85.320
84.500
83.870
82.530
64.820
1972
88.110
87.850
87.220
85.570
84.230
67.330
1973
97.760
97.450
96.430
94.080
92.280
72.340
1974
102.000
102.000
101.000
98.940
96.890
76.860
1975
143.000
143.000
141.000
137.000
134.000
105.000
1976
163.000
162.000
161.000
159.000
156.000
123.000
1977
175.000
174.000
172.000
169.000
166.000
131.000
1978
126.000
126.000
125.000
124.000
122.000
98.470
1979
155.000
155.000
154.000
150.000
146.000
115.000
1980
229.000
229.000
227.000
220.000
216.000
168.000
1981
208.000
207.000
205.000
201.000
197.000
157.000
1982
172.000
171.000
170.000
168.000
165.000
132.000
1983
179.000
178.000
177.000
172.000
169.000
134.000
Upper
10th
205.100
204.100
202.200
198.100
194.200
154.700
Percentile
MEAN
OF
ANNUAL
VALUES
=
97.010
STANDARD
DEVIATION
OF
ANNUAL
VALUES
=
35.121
UPPER
90%
CONFIDENCE
LIMIT
ON
MEAN
=
108.774
V
­
9
V
­
10
ATRAZINE
USE
ON
SORGHUM
WATER
COLUMN
DISSOLVED
CONCENTRATION
(
PPB)
YEAR
PEAK
96
HOUR
21
DAY
60
DAY
90
DAY
YEARLY
1948
50.720
50.410
49.010
46.270
44.190
21.970
1949
38.890
38.690
38.080
36.510
35.360
31.360
1950
32.120
31.940
31.560
30.860
30.210
26.320
1951
39.050
38.820
38.120
37.420
36.160
27.780
1952
66.370
65.950
64.290
60.950
58.370
39.860
1953
48.530
48.280
47.310
46.190
44.890
40.210
1954
34.520
34.350
34.090
33.460
33.020
29.870
1955
26.390
26.240
25.620
25.270
24.940
22.820
1956
23.430
23.310
22.760
22.200
21.590
19.080
1957
27.430
27.270
27.000
25.740
24.820
19.470
1958
23.490
23.370
22.830
21.960
21.510
18.600
1959
21.910
21.780
21.530
21.120
20.830
17.390
1960
26.250
26.140
25.560
24.690
23.900
18.820
1961
41.740
41.490
40.480
39.400
38.310
27.360
1962
64.500
64.110
63.410
60.600
58.330
41.460
1963
62.780
62.390
60.740
57.330
55.260
45.510
1964
48.410
48.170
47.260
45.690
44.840
41.030
1965
38.640
38.440
37.980
36.700
35.710
31.830
1966
40.540
40.310
39.390
37.540
36.360
29.680
1967
43.540
43.290
42.440
41.200
40.160
31.790
1968
37.350
37.160
36.290
34.420
33.420
29.770
1969
41.670
41.430
40.520
38.860
37.650
29.820
1970
60.560
60.200
59.150
56.200
53.950
38.740
1971
46.830
46.590
45.990
44.210
42.660
37.700
1972
34.560
34.360
33.620
32.650
32.020
29.550
1973
58.390
58.050
56.980
54.830
52.810
37.050
1974
100.000
99.840
97.310
91.840
88.580
60.470
1975
82.780
82.440
81.330
77.590
74.640
64.500
1976
55.640
55.560
55.250
54.460
53.760
47.640
1977
52.650
52.410
51.200
48.460
46.600
39.210
1978
47.580
47.330
46.240
43.870
42.320
36.220
1979
56.810
56.490
55.300
53.680
51.700
39.190
1980
75.400
75.050
73.280
69.150
66.500
48.800
1981
71.540
71.140
69.510
67.140
65.590
54.300
1982
69.750
69.380
68.410
65.320
62.780
52.210
1983
46.710
46.650
46.380
45.720
45.120
39.610
Upper
10th
72.698
72.313
70.641
67.743
65.863
52.837
Percentile
MEAN
OF
ANNUAL
VALUES
=
35.194
STANDARD
DEVIATION
OF
ANNUAL
VALUES
=
11.797
UPPER
90%
CONFIDENCE
LIMIT
ON
MEAN
=
38.105
VI
­
1
Fig.
USGS
1992
Lake/
Reservoir
Misc.
maxima
cumul.
exceed.
curves
0
2
4
6
8
10
12
14
0
20
40
60
80
100
120
%
of
lakes/
res
w.
maximum
>=
Y
Max.
concentration
(
ug/
L)

Atrazine
DEA
DIA
APPENDIX
VI.
Lake
and
Reservoir
Monitoring
Studies
and
Data
Plots
USGS
1992­
1993
Study
of
76
Mid­
Western
Reservoirs
(
USGS
Open­
File
Report
96­
393):

The
USGS
sampled
the
outflows
from
76
mid­
western
reservoirs
8
times
(
approximately
once
every
two
months)
from
April
1992
through
September
1993
(
USGS
Open­
File
Report
96­
393).
The
samples
were
analyzed
for
a
number
of
pesticides
and
pesticide
degradates
including
atrazine,
de­
ethyl
atrazine
(
DEA),
and
de­
isopropyl
atrazine
(
DIA).
The
reservoirs
were
selected
from
a
list
of
approximately
440
reservoirs
in
11
mid­
western
states.
The
locations
of
the
reservoirs
are
shown
below.
Information
about
the
sampled
reservoirs
is
supplied
in
table.

The
sampling
frequency
was
inadequate
for
EFED
to
provide
an
atrazine,
time
series
for
the
reservoirs.
However,
EFED
generated
1992
and
1993
cumulative
exceedence
curves
of
maximum
annual
atrazine,
DEA,
and
DIA
concentrations
versus
the
%
of
reservoirs
with
equal
or
greater
annual
maximum
concentrations.
VI
­
2
Fig.
USGS
1993
Lake/
Reservoir
Misc.
maxima
cumul.
exceed.
curves
0
2
4
6
8
10
12
0
20
40
60
80
100
120
%
of
lakes/
res
w.
maximum
>=
Y
Max.
concentration
(
ug/
L)

Atrazine
DEA
DIA
VII
­
1
APPENDIX
VII.
Stream
and
River
Monitoring
Studies
and
Data
Plots
USGS
1989­
1990
Reconnaissance
Study
of
Mid­
Western
Streams
(
USGS
Open­
File
Report
93­
457):

In
1989,
the
USGS
collected
one
"
pre­
application"
sample,
one
"
post­
application"
sample
and
one
"
Fall"
sample
from
52,
129,
and
143
mid­
western
streams,
respectively,
across
10
states.
In
1990,
the
USGS
collected
one
"
pre­
application"
sample,
and
one
"
post­
application"
sample
from
52
and
50
mid­
western
streams,
respectively,
across
10
states.
"
Pre­
application"
samples
were
generally
collected
in
March
or
April
before
the
applications
of
various
herbicides.
"
Postapplication
samples
were
collected
during
May
or
June
during
the
first
runoff
event
following
the
bulk
of
herbicide
applications.
"
Fall"
samples
were
generally
collected
in
October
or
November.

The
samples
were
analyzed
for
a
number
of
pesticides
including
atrazine,
DEA,
and
DIA.
The
number
of
samples
collected
at
each
site
(
1­
3
depending
upon
the
site)
was
not
adequate
for
EFED
to
generate
atrazine,
DEA,
and
DIA
time
series
curves.
However,
EFED
generated
1989
pre­
application,
post­
application,
and
Fall
cumulative
exceedence
curves
of
atrazine,
DEA,
and
DIA
concentrations
versus
the
%
of
sites
with
equal
or
greater
concentrations.
EFED
also
generated
1990
pre­
application
and
post­
application
cumulative
exceedence
curves
for
those
chemicals.

USGS
1990­
1992
Study
of
9
Mid­
western
Rivers/
Streams
(
USGS
Open­
File
Report
94­
396):

The
USGS
sampled
each
of
9
mid­
western
rivers/
streams
several
hundred
times
from
April
1990
through
July
1990.
Samples
were
manually
collected
1­
2
times
per
week
and
automatically
collected
during
runoff
events
either
at
several
hour
intervals
or
in
response
to
changes
in
flows.
During
runoff
events,
2­
4
samples
were
typically
collected
at
different
times
on
the
same
day.
The
samples
were
analyzed
for
a
number
of
pesticides
including
atrazine.
Using
the
same
sampling
methodology
in
the
Spring/
Summer
of
1991,
the
USGS
collected
additional
samples
from
2
of
the
9
rivers/
streams
(
the
Iroquois
River
in
IL
and
the
Sangamon
River
in
IL)
from
April
1991
through
March
1992
The
number
of
sites
sampled
(
9)
and
the
number
of
years
sampled
(
1­
2)
were
too
low
for
EFED
to
generate
cumulative
exceedence
curves
from
the
data.
However,
EFED
did
generate
two
sets
of
atrazine
time
series
curves
from
the
data.
In
one
set
of
atrazine
time
series
curves,
EFED
plotted
the
average
of
the
atrazine
concentrations
in
all
of
the
samples
collected
on
the
same
day
during
a
runoff
event.
In
the
other
set
of
atrazine
time
series
curves,
EFED
plotted
the
maximum
atrazine
concentration
in
all
of
the
samples
collected
on
the
same
day
during
a
runoff
event.

USGS
April
1991
to
September
1992
Study
of
the
Mississippi
River
Basin
(
USGS
Open­
File
Report
93­
657):
VII
­
2
The
USGS
sampled
8
sites
within
the
Mississippi
Basin
from
April
1991
through
September
1992.
Three
of
the
sampling
sites
were
on
the
Mississippi
River.
The
other
5
sampling
sites
were
on
other
rivers
within
the
Mississippi
Basin.
Two
samples
were
collected
per
week
from
May
6
to
July
15,
1991.
One
sample
was
collected
every
two
weeks
from
November
1991
through
February
1992.
One
sample
was
collected
per
week
during
all
other
periods
of
the
study
(
April
1991,
July
15,
1991­
October
30,
1991
and
March
1992­
July
1992).
The
samples
were
analyzed
for
a
number
of
pesticides
including
atrazine.

The
number
of
sites
sampled
(
8)
and
the
number
of
years
sampled
(
1)
were
too
low
for
EFED
to
generate
cumulative
exceedence
curves
from
the
data.
However,
EFED
did
generate
atrazine
time
series
curves
from
the
data.

USGS
1994­
1995
Reconnaissance
Study
of
Mid­
Western
Streams
(
USGS
Open­
File
Report
98­
181):

In
1994,
the
USGS
collected
one
"
pre­
application"
sample,
and
one
"
post­
application"
sample
from
52
and
50
mid­
western
streams,
respectively,
across
8
states.
In
1995,
the
USGS
collected
one
"
post­
application"
sample
from
50
mid­
western
streams
across
7
states.
"
Pre­
application"
samples
were
generally
collected
in
March
or
April
before
the
applications
of
various
herbicides.
"
Post­
application"
samples
were
collected
during
May
or
June
during
the
first
runoff
event
following
the
bulk
of
herbicide
applications.

The
samples
were
analyzed
for
a
number
of
pesticides
including
atrazine,
DEA,
and
DIA.
The
number
of
samples
collected
at
each
site
(
1­
2
depending
upon
the
site)
was
not
adequate
for
EFED
to
generate
atrazine,
DEA,
and
DIA
time
series
curves.
However,
EFED
generated
1994
and
1990
pre­
application
and
post­
application
cumulative
exceedence
curves
of
atrazine,
DEA,
and
DIA
concentrations
versus
the
%
of
sites
with
equal
or
greater
concentrations.
EFED
also
generated
1995
post­
application
cumulative
exceedence
curves
for
those
chemicals.
VIII
­
1
Figure
13.
Surface
Water
Monitoring
Results
for
Atrazine
in
the
Chesapeake
Bay's
Tidal
Rivers
Maximxum
Concentrations
by
Site
and
Year
(
1977
­
1993)

0
5
10
15
20
25
30
35
0
10
20
30
40
50
60
70
80
90
100
Exceedence
%
%
Sites
w/
Atrazine
Concs
>=
Y
Atrazine
Concs
(
ug/
L)
*
Reductions
in
Fish
&
Invertebrate
Population
Estimated
to
Occur
at
23
µ
g/
L
*
Reduction
in
Primary
Productivity
&
Macrophytes
Estimated
to
Occur
at
9.1
µ
g/
L
*
Reduction
in
Macrophytes
Likely
to
Occur
at
4
µ
g/
L
APPENDIX
VIII.
Chesapeake
Bay
Monitoring
Data
on
Atrazine
Levels
IX
­
1
APPENDIX
IX.
Documentation
of
Terrestrial
Fate
Residue
Model
and
Data
The
model
of
Hoerger
and
Kenega
(
1972),
as
modified
by
Fletcher
et
al.
(
1994)
was
used
to
estimate
pesticide
concentrations
on
selected
avian
or
mammalian
food
items.
This
model
predicts
the
maximum
concentrations
that
may
occur
immediately
following
a
direct
application
at
1
lb
ai/
A.
For
1
lb
ai/
A
applications,
peak
concentrations
(
i.
e.,
Day
0)
on
short
grass,
tall
grass,
broadleaf
plants,
and
fruits
are
predicted
to
be
as
high
as
240,
110,
135,
and
15
ppm,
respectively.
The
residue
monitoring
on
which
this
model
was
based,
did
not
include
insects.
However,
based
on
similar
surface
area
to
volume
ratio
between
insects
and
some
plant
parts,
the
predicted
maximum
concentration
for
broadleaf
plants
and
fruits
are
used
to
represent
maximum
concentrations
that
may
occur
on
small
and
large
insects,
respectively.
Linear
extrapolation
is
then
used
to
estimate
maximum
terrestrial
EEC's
for
single
applications
at
application
rates
other
than
1
lb
ai/
A.
For
example,
a
single
application
at
4
lbs
ai/
A
would
result
in
peak
concentrations
of
960
for
short
grass,
440
ppm
for
tall
grass,
540
ppm
for
broadleaf
foliage
and
small
insects,
and
60
ppm
for
fruits
and
large
insects.
If
multiple
applications
are
permitted,
the
peak
terrestrial
EECs
resulting
from
subsequent
applications
are
estimated
by
summing
the
maximum
EEC
predicted
for
the
last
application
with
the
remaining
concentrations
predicted
for
the
previous
application(
s).
After
application,
residues
on
food
items
are
predicted
to
decline
according
to
a
first
order
exponential
model.
If
the
maximum
initial
concentration
is
C0
and
the
half­
life
for
the
exponential
dissipation
of
the
active
ingredient
is
t1/
2,
the
remaining
concentration
at
time
t
is
given
by
the
following
formula:

C
Ce
t
t
t
=
 
0
2
1/
2
ln
The
general
formula
for
the
peak
EEC
(
Cpeak)
following
multiple
applications
is:

C
Ce
peak
i
n
In
t
=
 
 
 

 
0
1
1
2
1/
2
(
)
ln
where
C0
is
the
maximum
initial
concentration
after
one
application,
I
is
the
interval
in
days
between
applications,
n
is
the
number
of
applications,
and
t1/
2
is
the
half­
life
of
the
active
ingredient.

The
initial
concentration,
half­
life,
number
of
applications,
interval
between
treatments,
and
length
of
simulation
are
variable.
The
current
Fate
Model
has
two
limitations:
1)
for
more
than
two
applications,
only
one
time
interval
can
be
designated
for
a
run;
and
2)
between
treatments
per
fate
run
(
i.
e.,
two
or
more
treatment
intervals
can
not
be
used
per
run).
Four
examples
of
Fate
Model
printouts
follow;
one
each
for
short
grass,
foliage
and
small
insects,
long
grass,
and
fruits,
seeds
and
large
insects.

The
data
tables
used
in
the
risk
assessment
for
sugarcane,
corn
and
sorghum
are
presented
below.
IX
­
2
DAILY
PESTICIDE
RESIDUE
LEVELS
­­­­­­
MAXIMUM.
SUGARCANE
USE
RATE
SINGLE
APPLICATION
AT
4
LB
AI./
A
ON
SHORT
GRASS
Chemical
name
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
Atrazine
Initial
concentration
(
ppm)
­­­­­­­­­­­­­­­­­­­­­­­­­­­
960
Half­
life
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
17
Length
of
simulated
(
day)
­­­­­­­­­­­­­­­­­­­­­­­­­­­
160
DAY
RESIDUE
(
PPM)
DAY
RESIDUE
(
PPM)
DAY
RESIDUE
(
PPM)
0
960
46
147.1362
92
22.5511
1
921.6448
47
141.2576
93
21.6501
2
884.822
48
135.6139
94
20.78511
3
849.4704
49
130.1957
95
19.95467
4
815.5313
50
124.9939
96
19.15742
5
782.9481
51
120
97
18.39.202
6
751.6668
52
115.2056
98
17.6572
7
721.6352
53
110.6027
99
16.95173
8
692.8035
54
106.1838
100
16.27446
9
665.1237
55
101.9414
101
15.62424
10
638.5498
56
97.8685
102
15
11
613.0376
57
93.95834
103
14.4007
12
588.5447
58
90.20439
104
13.82534
13
565.0304
59
86.60042
105
13.27297
14
542.4556
60
83.14045
106
12.74267
15
520.7826
61
79.81871
107
12.23356
16
499.9757
62
76.6297
108
11.74479
17
480
63
73.56808
109
11.27555
18
460.8224
64
70.62878
110
10.82505
19
442.411
65
67.80693
111
9.977337
20
424.7352
66
65.09783
112
9.578712
21
407.7656
67
62.49695
113
9.578712
22
391.4741
68
60
114
9.196009
23
375.8334
69
57.6028
115
8.828598
24
360.8176
70
55.30138
116
8.475866
25
346.4017
71
53.0919
117
8.137228
26
332.5618
72
50.9707
118
7.812118
27
319.2749
73
48.
93425
119
7.5
28
306.5188
74
46.97917
120
7.200348
29
294.2724
75
45.10219
121
6.91267
30
282.5152
76
43.3002
122
6.636485
31
271.2278
77
41.57022
123
6.371336
32
260.3913
78
39.90935
124
6.116781
33
249.9878
79
38.31484
125
5.872396
34
240
80
36.78403
126
5.637774
35
230.4112
81
35.31439
127
5.412525
36
221.2055
82
33.90347
128
5.196277
37
212.3676
83
32.54891
129
4.988669
38
203.8828
84
31.24847
130
4.789353
39
195.737
85
30
131
4.598002
40
187.9167
86
28.8014
132
4.414299
41
180.4088
87
27.65069
133
4.237933
IX
­
3
42
173.2009
88
26.54595
134
4.068614
43
166.2809
89
25.48535
135
3.906059
44
159.6374
90
24.46713
136
3.75
45
153.2594
91
23.48958
137
3.600173
Maximum
residue
­­­­­­­­­­­­­­­­­­­­­­
960
Average
residue
­­­­­­­­­­­­­­­­­­­­­­
149.0321
IX
­
4
DAILY
PESTICIDE
RESIDUE
LEVELS
­­­­­­
MAXIMUM.
SUGARCANE
USE
RATE
SINGLE
APPLICATION
AT
4
LB
AI./
A
ON
BROADLEAF
FOLIAGE
Chemical
name
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
Atrazine
Initial
concentration
(
ppm)
­­­­­­­­­­­­­­­­­­­­­­­­­­­
540
Half­
life
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
17
Length
of
simulated
(
day)
­­­­­­­­­­­­­­­­­­­­­­­­­­­
100
DAY
RESIDUE
(
PPM)
DAY
RESIDUE
(
PPM)
DAY
RESIDUE
(
PPM)
0
540
46
82.7641
92
12.68499
1
518.4252
47
79.45738
93
12.17818
2
497.7124
48
76.2828
94
11.69162
3
477.8271
49
73.23506
95
11.2245
4
458.7364
50
70.30907
96
10.77605
5
440.4084
51
67.5
97
10.34551
6
422.8126
52
64.80314
98
9.932172
7
405.9198
53
62.21404
99
9.53535
8
389.7019
54
59.72839
100
9.154381
9
374.1321
55
57.34204
10
359.1842
56
55.05104
11
344.8336
57
52.85157
12
331.0564
58
50.73997
13
317.8296
59
48.71274
14
305.1313
60
46.7665
15
292.9402
61
44.89802
16
281.2363
62
43.1042
17
270
63
41.38205
18
259.2126
64
39.72869
19
248.8562
65
38.1414
20
238.9136
66
36.61753
21
229.3682
67
35.15453
22
220.2042
68
33.75
23
211.4063
69
32.40157
24
202.9599
70
31.10702
25
194.851
71
29.86419
26
187.066
72
28.67102
27
179.5921
73
27.52552
28
172.4168
74
26.42578
29
165.5282
75
25.36998
30
158.9148
76
24.35636
31
152.5656
77
23.38325
32
146.4701
78
22.44901
33
140.6182
79
21.55209
34
135
80
20.69102
35
129.6063
81
19.86435
36
124.4281
82
19.0707
37
119.4568
83
18.30876
38
114.6841
84
17.57727
39
110.1021
85
16.875
40
105.7031
86
16.20079
41
101.4799
87
15.55351
42
97.42548
88
14.9321
43
93.53301
89
14.33551
44
89.79606
90
13.76276
45
86.20841
91
13.21289
Maximum
residue
­­­­­­­­­­­­­­­­­­­­­­
540
Average
residue
­­­­­­­­­­­­­­­­­­­­­­
131.6416
IX
­
5
DAILY
PESTICIDE
RESIDUE
LEVELS
­­­­­­
MAXIMUM.
CORN
&
SORGHUM
USE
RATES
SINGLE
APPLICATION
AT
2
LB
AI./
A
ON
SHORT
GRASS
Chemical
name
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
Atrazine
Initial
concentration
(
ppm)
­­­­­­­­­­­­­­­­­­­­­­­­­­­
480
Half­
life
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
17
Length
of
simulated
(
day)
­­­­­­­­­­­­­­­­­­­­­­­­­­­
100
DAY
RESIDUE
(
PPM)
DAY
RESIDUE
(
PPM)
DAY
RESIDUE
(
PPM)
0
480
46
73.56808
92
11.27555
1
460.8224
47
70.62878
93
10.82505
2
442.411
48
67.80693
94
10.39255
3
424.7353
49
65.09783
95
9.977337
4
407.7657
50
62.49695
96
9.578709
5
391.4741
51
60
97
9.196009
6
375.8334
52
57.60279
98
8.828598
7
360.8176
53
55.30137
99
8.475866
8
346.4017
54
53.0919
100
8.137228
9
332.5618
55
50.9707
10
319.2749
56
48.93425
11
306.5188
57
46.97917
12
294.2724
58
45.1022
13
282.5152
59
43.30022
14
271.2278
60
41.57023
15
260.3913
61
39.90936
16
249.9878
62
38.31485
17
240
63
36.78404
18
230.4112
64
35.31439
19
221.2055
65
33.90346
20
212.3676
66
32.54891
21
203.8828
67
31.24848
22
195.737
68
30
23
187.9167
69
28.8014
24
180.4088
70
27.65069
25
173.2009
71
26.54595
26
166.2809
72
25.48535
27
159.6374
73
24.46713
28
153.2594
74
23.48958
29
147.1362
75
22.5511
30
141.2576
76
21.6501
31
135.6139
77
20.78511
32
130.1957
78
19.95467
33
124.9939
79
19.15742
34
120
80
18.39201
35
115.2056
81
17.6572
36
110.6028
82
16.95173
37
106.1838
83
16.27446
38
101.9414
84
15.62424
39
97.8685
85
15
40
93.95833
86
14.4007
41
90.20439
87
13.82534
42
86.60042
88
13.27298
43
83.14046
89
12.74267
44
79.81872
90
12.23356
45
76.6297
91
11.74479
Maximum
residue
­­­­­­­­­­­­­­­­­­­­­­
480
Average
residue
­­­­­­­­­­­­­­­­­­­­­­
117.0147
IX
­
6
DAILY
PESTICIDE
RESIDUE
LEVELS
­­­­­­
MAXIMUM.
CORN
&
SORGHUM
USE
RATES
SINGLE
APPLICATION
AT
2
LB
AI./
A
ON
BROADLEAF
FOLIAGE
Chemical
name
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
Atrazine
Initial
concentration
(
ppm)
­­­­­­­­­­­­­­­­­­­­­­­­­­­
270
Half­
life
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
17
Length
of
simulated
(
day)
­­­­­­­­­­­­­­­­­­­­­­­­­­­
100
DAY
RESIDUE
(
PPM)
DAY
RESIDUE
(
PPM)
DAY
RESIDUE
(
PPM)
0
270
46
41.38205
92
6.342496
1
259.2126
47
39.72869
93
6.089091
2
248.8562
48
38.1414
94
5.845812
3
238.9136
49
36.61753
95
5.612252
4
229.3682
50
35.15453
96
5.388024
5
220.2042
51
33.75
97
5.172756
6
211.4063
52
32.40157
98
4.966087
7
202.9599
53
31.10702
99
4.767675
8
194.851
54
29.86419
100
4.577191
9
187.066
55
28.67102
10
179.5921
56
27.52552
11
172.4168
57
26.42578
12
165.5282
58
25.36999
13
158.9148
59
24.35637
14
152.5656
60
23.38325
15
146.4701
61
22.44901
16
140.6182
62
21.5521
17
135
63
19.86435
18
129.6063
64
19.0707
19
124.4281
65
18.30876
20
119.4568
66
17.57727
21
114.6841
67
16.875
22
110.1021
68
16.20079
23
105.7031
69
15.55351
24
101.4799
70
14.9321
25
97.42548
71
14.33551
26
93.53301
72
13.76276
27
89.79606
73
13.21289
28
86.20841
74
13.21289
29
82.7641
75
12.68499
30
79.45739
76
12.17818
31
76.28281
77
11.69162
32
73.23506
78
11.2245
33
70.30908
79
10.77605
34
67.5
80
10.34551
35
64.80315
81
9.932172
36
62.21405
82
9.53535
37
59.72839
83
9.154381
38
57.34204
84
8.788632
39
55.05104
85
8.4375
40
52.85156
86
8.100393
41
50.73997
87
7.776756
42
48.71274
88
7.466048
43
46.76651
89
7.167754
44
44.89803
90
6.881379
45
43.1042
91
6.606445
Maximum
residue
­­­­­­­­­­­­­­­­­­­­­­
270
Average
residue
­­­­­­­­­­­­­­­­­­­­­­
65.8208
X
­
1
APPENDIX
X.
Terrestrial
Plant
Exposure
Formulae
Calculating
EECs
for
terrestrial
plants
inhabiting
dry
areas
adjacent
to
treatment
sites
Unincorporated
ground
application:
Runoff
=
maximum
application
rate
(
lbs
ai/
A)
x
runoff
value
Drift
=
maximum
application
rate
x
0.01
Total
Loading
=
runoff
(
lbs
ai/
acre)
+
drift
(
lbs
ai/
A)

Incorporated
ground
application:
Runoff
=
[
maximum
application
rate
(
lbs
ai/
A)
÷
minimum
incorporation
depth
(
cm.)]
x
runoff
value
Drift
=
maximum
application
rate
x
0.01
(
Note:
drift
is
not
calculated
if
the
product
is
incorporated
at
the
time
of
application.)
Total
Loading
=
runoff
(
lbs
ai/
A)
+
drift
(
lbs
ai/
A)

Aerial,
airblast,
forced­
air,
and
chemigation
applications:
Runoff
=
maximum
application
rate
(
lbs
ai/
A)
x
0.6
(
60%
application
efficiency
assumed)
x
runoff
value
Drift
=
maximum
application
rate
(
lbs
ai/
A)
x
0.05
Total
Loading
=
runoff
(
lbs
ai/
A)
+
drift
(
lbs
ai/
A)

Calculating
EECs
for
terrestrial
plants
inhabiting
semi­
aquatic
low­
lying
areas
Unincorporated
ground
application:
Runoff
=
maximum
application
rate
(
lbs
ai/
A)
x
runoff
value
x
10
acres
Drift
=
maximum
application
rate
x
0.01
Total
Loading
=
runoff
(
lbs
ai/
A)
+
drift
(
lbs
ai/
A)

Incorporated
ground
application:
Runoff
=
[
maximum
application
rate
(
lbs
ai/
A)/
minimum
incorporation
depth
(
cm)]
x
runoff
value
x
10
acres
Drift
=
maximum
application
rate
x
0.01
(
Note:
drift
is
not
calculated
if
the
product
is
incorporated
at
the
time
of
application.)
Total
Loading
=
runoff
(
lbs
ai/
A)
+
drift
(
lbs
ai/
A)

Aerial,
airblast,
and
forced­
air
applications:
Runoff
=
maximum
application
rate
(
lbs
ai/
acre)
x
0.6
(
60%
application
efficiency
assumed)
x
runoff
value
x
10
acres
Drift
=
maximum
application
rate
(
lbs
ai/
A)
x
0.05
Total
Loading
=
runoff
(
lbs
ai/
A)
+
drift
(
lbs
ai/
A)
XI
­
1
Appendix
XI.
Ecological
Effects
Characterization
a.
Toxicity
to
Terrestrial
Animals
I.
Birds,
Acute
and
Subacute
An
acute
oral
toxicity
study
using
the
technical
grade
of
the
active
ingredient
(
TGAI)
is
required
to
establish
the
toxicity
of
atrazine
to
birds.
The
preferred
test
species
is
either
mallard
duck
(
a
waterfowl)
or
bobwhite
quail
(
an
upland
gamebird).
Results
of
this
test
are
tabulated
below.

Avian
Acute
Oral
Toxicity
Surrogate
Species
%
ai
LD50
(
mg/
kg)
Probit
Slope
Toxicity
Category
MRID
No.
Author/
Year
Study
Classification1
Northern
bobwhite
quail
(
Colinus
virginianus)
14­
day
old
chicks;
8­
day
test
Tech.
940
slope
3.836
Slightly
toxic
00024721
Fink
1976
Core
Mallard
Duck
(
Anas
platyrhynchos)
6­
months
old;
14­
day
test
76
%
80
WP
>
2,000
slope
none
Practically
non­
toxic
00160000
Hudson,
Tucker
&
Haegle
1984
Supplemental
(
only
3
birds)
(
formulation)

Ring­
necked
Pheasant
(
Phasianus
colchicus)
3­
months
old;
14­
day
test
76
%
80
WP
>
2,000
slope
none
Practically
non­
toxic
00160000
Hudson,
Tucker
&
Haegle
1984
Supplemental
(
formulation)

Japanese
Quail
(
Coturnix
c.
japonica)
50­
60
days
old;
14­
day
test
Tech.
4,237
slope
>
6
Practically
non­
toxic
00024722
Sachsse
and
Ullman
1974
Supplemental
(
species
not
native)

1
Core
(
study
satisfies
guideline).
Supplemental
(
study
is
scientifically
sound,
but
does
not
satisfy
guideline)

Since
the
lowest
LD50
is
in
the
range
of
501
to
2,000
mg/
kg,
atrazine
is
categorized
as
slightly
toxic
to
avian
species
on
an
acute
oral
basis.
According
to
Hudson
et
al.
(
1984),
signs
of
intoxication
in
mallards
first
appeared
1
hour
after
treatment
and
persisted
up
to
11
days.
In
pheasants,
remission
of
signs
of
intoxication
occurred
by
5
days
after
treatment.
Signs
of
intoxication
included
weakness,
hyper­
excitability,
ataxia,
tremors;
weight
loss
occurred
in
mallards.
The
guideline
requirement
(
71­
1)
is
fulfilled
(
MRID
00024721).

Degradates:
The
major
atrazine
degradate,
hydroxyatrazine,
forms
a
large
percentage
of
the
recoverable
pesticide
in
various
compartments
of
the
environment.
Minor
atrazine
degradates
include
deethylatrazine,
deisopropylatrazine
and
diaminochlorotriazine.
Acute
mammalian
LD50
values
available
for
deethylatrazine
and
deisopropylatrazine
are
both
more
toxic
than
the
parent
atrazine.
Therefore,
a
special
(
70­
1)
acute
oral
test
with
the
upland
gamebird
(
preferably
northern
bobwhite)
are
required
to
address
the
concern
for
these
three
degradates.
The
requirement
(
70­
1)
has
not
been
fulfilled.
XI
­
2
Two
subacute
dietary
studies
using
the
TGAI
are
required
to
establish
the
toxicity
of
atrazine
to
birds.
The
preferred
test
species
are
mallard
duck
and
bobwhite
quail.
Results
of
these
tests
are
tabulated
below.

Avian
Subacute
Dietary
Toxicity
Surrogate
Species
%
ai
5­
Day
LC50
(
ppm)
1
Toxicity
Category
MRID
No.
Author/
Year
Study
Classification
Northern
bobwhite
(
Colinus
virginianus)
9­
days
old
chicks
99.0
>
5,000
(
no
mortality)
Practically
non­
toxic
00022923
Hill
et
al.
1975
Core
Northern
bobwhite
(
Colinus
virginianus)
young
adults
Tech.
>
10,000
Practically
non­
toxic
unknown
­
Gulf
South
Gough
&
Shellenberger
1972
Supplemental
(
Adult
birds
&
no
raw
data)

Ring­
necked
pheasant
(
Phasianus
colchicus)
10­
days
old
chicks
99.0
>
5,000
(
no
mortality)
Practically
non­
toxic
00022923
Hill
et
al.
1975
Core
Japanese
Quail
(
Coturnix
c.
japonica)
7­
days
old
chicks
99.0
>
5,000
(
7
%
mortality
at
5,000
ppm)
Practically
non­
toxic
00022923
Hill
et
al.
1975
Supplemental
(
species
not
native)

Mallard
duck
(
Anas
platyrhynchos)
10­
days
old
ducklings
99.0
>
5,000
(
30
%
mortality
at
5,000
ppm)
Practically
non­
toxic
00022923
Hill
et
al.
1975
Core
1
Test
organisms
observed
an
additional
three
days
while
on
untreated
feed.

Since
the
LC50
values
are
greater
than
5,000
ppm,
atrazine
is
categorized
as
practically
nontoxic
to
avian
species
on
a
subacute
dietary
basis.
The
time
to
death
was
Day
3
for
the
one
Japanese
quail
and
Day
5
for
three
mallard
ducks
(
J.
Spann
at
Patuxent
Wildlife
Center,
1999,
personal
communication).
The
guideline
requirement
(
71­
2)
is
fulfilled
(
MRID
00022923).

Subacute
dietary
studies
using
a
typical
end­
use
product
(
TEP)
may
be
required
on
a
case­
bycase
basis
to
establish
the
toxicity
of
atrazine
formulations
to
birds.
The
preferred
test
species
are
mallard
duck
and
bobwhite
quail.
Results
of
these
tests
are
tabulated
below.

Formulation
Avian
Subacute
Dietary
Toxicity
Surrogate
Species
%
ai
Form
5­
Day
LC50
(
ppm
ai)
1
Probit
Slope
Toxicity
Category
MRID
No.
Author/
Year
Study
Classification
Northern
bobwhite
(
Colinus
virginianus)
(
6­
weeks
old)
76
80
WP
5,760
slope
3.252
Practically
non­
toxic
00059214
Beliles
&
Scott
1965
Supplemental
(
birds
too
old)

Mallard
duck
(
Anas
platyrhynchos)
76
80
WP
19,560
slope
1.807
Practically
non­
toxic
00059214
Beliles
&
Scott
1965
Core
for
80W
formulation
1
Test
organisms
observed
an
additional
three
days
while
on
untreated
feed.

Since
the
LC50
values
are
greater
than
5,000
ppm,
atrazine
is
categorized
as
practically
nontoxic
to
avian
species
on
a
subacute
dietary
basis
for
the
80W
formulation.
In
the
mallard
study,
a
highly
noticeable
weight
loss
and
emaciated
birds
were
found
at
all
test
levels
(
1,000
to
XI
­
3
32,000).
No
additional
data
is
required
under
guideline
requirement
71­
2
for
atrazine
formulations
at
this
time.

Degradates:
The
major
atrazine
degradate,
hydroxyatrazine,
forms
a
large
percentage
of
the
recoverable
pesticide
in
various
environmental
compartments.
Acute
mammalian
LD50
values
available
for
deethylatrazine
and
deisopropylatrazine,
minor
degradates,
are
both
more
toxic
than
the
parent
atrazine.
Special
(
70­
2)
oral
dietary
tests
for
these
degradates
with
waterfowl
(
preferably
mallard
duck)
and
upland
gamebird
(
preferably
northern
bobwhite)
are
reserved
pending
the
results
of
acute
oral
toxicity
tests
on
these
degradates.
The
requirement
(
70­
2)
is
reserved.

ii.
Birds,
Chronic
Avian
reproduction
studies
using
the
TGAI
are
required
for
atrazine,
because
the
following
conditions
are
met:
(
1)
birds
may
be
subject
to
repeated
or
continuous
exposure
to
the
pesticide,
especially
preceding
or
during
the
breeding
season,
(
2)
the
pesticide
is
stable
in
the
environment
to
the
extent
that
potentially
toxic
amounts
may
persist
in
animal
feed,
(
3)
the
pesticide
is
stored
or
accumulated
in
plant
or
animal
tissues,
and/
or,
(
4)
information
derived
from
mammalian
reproduction
studies
indicates
reproduction
in
terrestrial
vertebrates
may
be
adversely
affected
by
the
anticipated
use
of
the
product.
The
preferred
test
species
are
mallard
duck
and
bobwhite
quail.
Results
of
these
tests
are
tabulated
below.

Avian
Reproduction
Surrogate
Species/
Study
Duration
%
ai
NOEC/
LOEC
(
ppm
ai)
Statistically
sign.
(
p=
0.05)
LOEC
Endpoints
MRID
No.
Author/
Year
Study
Classification
Northern
bobwhite
(
Colinus
virginianus)
20
weeks
97.1
NOAEC
225
LOAEC
675
NOAEC
<
75
LOAEC
75
29
%
red.
in
egg
production
67
%
incr.
in
defective
eggs
27
%
red.
in
embryo
viability
6­
13
%
red.
in
hatchling
body
wt.
10­
16
%
red.
in
14­
day
old
body
wt.
8.2
%
red.
in
14­
day
old
body
wt.
(
after
recovery
period)

6.7­
18
%
red.
in
14­
day
old
body
wt.
42547102
Pedersen
&
DuCharme
1992
Core
Mallard
duck
(
Anas
platyrhynchos)
20
weeks
97.1
NOAEC
225
LOAEC
675
NOAEC
75
LOAEC
225
49
%
red.
in
egg
production
61
%
red.
in
egg
hatchability
12­
17
%
red.
in
food
consumption
9­
13
%
red.
in
food
consumption
(
During
3
of
11
biweekly
periods)
42547101
Pedersen
&
DuCharme
1992
Core
In
the
bobwhite
study,
the
reproductive
endpoints
were
measured
after
a
3­
week
recovery
period.
A
statistically
significant
effect
during
the
recovery
period
was
a
700
percent
increase
in
the
number
of
defective
eggs
at
675
ppm
compared
to
controls;
the
number
of
defective
eggs
was
consistent
with
the
number
of
defective
eggs
during
the
treatment
period
at
675
ppm.
Bobwhite
and
mallard
tests
show
similar
toxic
effects
on
reduced
egg
production
and
embryo
viability/
hatchability.
In
an
8­
day
LC50
test
with
adult
Japanese
quail,
the
quail
fed
atrazine
had
XI
­
4
reduced
food
consumption,
lost
body
weight
and
egg
production
stopped
after
3
days
of
exposure
(
Sachsse
and
Ullman,
1975;
MRID
00024723).
The
guideline
requirement
(
71­
4)
is
fulfilled
for
both
avian
species
(
MRID
42547101,
42547102).

Degradates:
The
major
atrazine
degradate,
hydroxyatrazine,
forms
a
large
percentage
of
the
recoverable
pesticide
in
various
environmental
compartments.
Minor
degradates
were
deethylatrazine,
deisopropylatrazine
and
diaminochloro­
s­
triazine.
Subchronic
mammalian
toxicity
values
available
for
deethylatrazine,
deisopropylatrazine,
hydroxyatrazine
and
diaminochlorotriazine
indicate
greater
or
equal
toxicity
compared
to
the
parent
atrazine
in
10­
day
pregnancy
tests,
13­
week
dog
dietary
tests,
1­
year
dog
dietary
tests
and
2­
year
carcinogenicity
tests.
The
requirement
for
avian
reproductive
tests
with
degradates
are
reserved
pending
the
acute
oral
and
dietary
test
results.
The
requirement
(
70­
4)
for
degradates
is
reserved.

iii.
Mammals,
Acute
Wild
mammal
testing
is
required
on
a
case­
by­
case
basis,
depending
on
the
results
of
lower
tier
laboratory
mammalian
studies,
intended
use
pattern
and
pertinent
environmental
fate
characteristics.
In
most
cases,
rat
or
mouse
toxicity
values
obtained
from
the
Agency's
Health
Effects
Division
(
HED)
substitute
for
wild
mammal
testing.
The
acute
toxicity
values
cited
in
HED's
one­
liners
are
reported
below.

Mammalian
Toxicity
Surrogate
Species
%
ai
Test
Type
Toxicity
Value
Affected
Endpoints
MRID
No./
Author
Laboratory
mouse
(
Mus
musculus)
??
Acute
oral
1,750
mg/
kg
LD50
(
mortality)
Weed
Sci.
Assoc.
1967
Laboratory
rat
(
Rattus
norvegicus)
Tech.
Acute
oral
1,869
mg/
kg
LD50
(
mortality)
00230303
Ciba­
Geigy
1975
Laboratory
rat
(
Rattus
norvegicus)
Tech.
Acute
oral
2,030
mg/
kg
LD50
(
mortality)
00231466
Instituto
di
Ricerche
Laboratory
rat
(
Rattus
norvegicus)
95
Acute
oral
2,850
mg/
kg
LD50
(
mortality)
00027097
Consultox
Lab.
Ltd.

Laboratory
rat
(
Rattus
norvegius)
??
Acute
oral
3,080
mg/
kg
LD50
(
mortality)
Weed
Sci.
Assoc.
1967
Laboratory
mouse
(
Mus
musculus)
Tech.
Acute
oral
3,992
mg/
kg
LD50
(
mortality)
00230303
Ciba­
Geigy
1977
FORMULATIONS:

Laboratory
rat
(
Rattus
norvegicus)
85.5
Acute
oral
­
female
male
1,180
mg/
kg
1,317
mg/
kg
LD50
(
mortality)
00249196
Stillmeadow
Inc.
1980
Laboratory
rat
(
Rattus
norvegicus)
85.5
90
W
Acute
oral
1,440
mg/
kg
LD50
(
mortality)
00000527
Industry
Bio­
Test
1971
Laboratory
rat
(
Rattus
norvegicus)
85.5
Acute
oral
1,992
mg/
kg
LD50
(
mortality)
00000847
Hill
Top
Research,
Inc.
Mammalian
Toxicity
Surrogate
Species
%
ai
Test
Type
Toxicity
Value
Affected
Endpoints
MRID
No./
Author
XI
­
5
Laboratory
rat
(
Rattus
norvegicus)
76
80
WP
Acute
oral
>
1,520
mg/
kg
<
1,900
mg/
kg
LD50
(
mortality)
00046159
WIL
Res.
Lab.
1978
Laboratory
rat
(
Rattus
norvegicus)
76
Acute
oral
­
male
2,147
mg/
kg
LD50
(
mortality)
00240852
Industrial
Bio­
Test
1974
Laboratory
rat
(
Rattus
norvegicus)
Atratol
8P
Acute
oral
3,100
mg/
kg
(
as
product)
LD50
(
mortality)
00234490
Food
&
Drug
Res.
1977
Laboratory
rat
(
Rattus
norvegicus)
76
80
W
Acute
oral
3,876
mg/
kg
LD50
(
mortality)
00230305
Industrial
Bio­
Test
1965
Laboratory
rat
(
Rattus
norvegicus)
51.0
Acute
oral
­
female
male
546
mg/
kg
729
mg/
kg
LD50
(
mortality)
00245364
Food
&
Drug
Res.
Lab.

Laboratory
rat
(
Rattus
norvegicus)
44.3
Aatrex
Acute
oral
­
female
male
2,437
mg/
kg
2,038
mg/
kg
LD50
(
mortality)
00000519
Not
listed
Laboratory
rat
(
Rattus
norvegicus)
43
Flowable
Acute
oral
830
mg/
kg
LD50
(
mortality)
00000522
Not
listed
Laboratory
rat
(
Rattus
norvegicus)
42.0
Acute
oral
811
mg/
kg
LD50
(
mortality)
00002041
Bio/
Dynamics
Inc.
1976
Laboratory
rat
(
Rattus
norvegicus)
40.8
Acute
oral
­
female
male
224
mg/
kg
738
mg/
kg
LD50
(
mortality)
00242662
Raltech
Sci.
Serv.
1980
Laboratory
rat
(
Rattus
norvegicus)
40.8
Acute
oral
­
female
male
432
mg/
kg
690
mg/
kg
LD50
(
mortality)
00000537
WIL
Res.
Lab.
1978
Laboratory
rat
(
Rattus
norvegicus)
40.8
Acute
oral
­
female
male
439
mg/
kg
769
mg/
kg
LD50
(
mortality)
00246393
Toxigenics,
Inc
1981
Laboratory
rat
(
Rattus
norvegicus)
40.8
Acute
oral
­
female
male
>
694
mg/
kg
775
mg/
kg
LD50
(
mortality)
00243485
Cosmopolitan
Safety
Evalutation,
Inc
1980
Laboratory
rat
(
Rattus
norvegicus)
40.8
Acute
oral
1,306
mg/
kg
LD50
(
mortality)
00253726
Bio/
Dynamics
Inc.
1984
Laboratory
rat
(
Rattus
norvegicus)
40.8
Atrazine
4L
Acute
oral
­
female
male
1,918
mg/
kg
1,705
mg/
kg
LD50
(
mortality)
00241725
Cosmopolitan
Safety
Evaluation,
Inc
An
analysis
of
the
results
indicate
that
atrazine
and
its
formulations
range
from
224
to
3,992
mg/
kg
which
categorized
atrazine
as
moderately
to
slightly
toxic
to
small
mammals
on
an
acute
oral
basis.
Initial
symptoms,
piloerection
and
decreased
activity,
were
reported
as
early
as
30
minutes
posttreatment.
Other
signs
of
toxicity
include
salivation,
lacrimation,
muscular
weakness,
tremor
ataxia,
diarrhea,
adrenal
degradation,
congested
lungs,
and
degeneration
of
kidneys
and
adrenal
glands.
Matching
toxicity
values
for
males
and
females
in
most
cases
(
i.
e.,
7
out
of
9
studies)
indicate
that
females
are
more
sensitive
to
atrazine
than
male
rats.
Atrazine
does
not
appear
to
be
dermally
toxic
to
adult
rats
and
rabbits;
dermal
LD50
values
are
greater
than
2,000
mg/
kg.
Atrazine
generally
causes
corneal
opacity
which
clears
by
day
7.
The
need
for
mammalian
acute
toxicity
is
fulfilled.
XI
­
6
Degradates:
The
major
atrazine
degradate,
hydroxyatrazine,
forms
a
large
percentage
of
the
recoverable
pesticide
in
various
compartments
of
the
environment.
Therefore,
a
special
(
70­
3)
acute
oral
test
with
small
mammals
is
required
to
address
degradate
concerns.

Degradate
Mammalian
Acute
Oral
Toxicity
Surrogate
Species/
Study
Duration
%
ai
Test
Type
Toxicity
Value
Affected
Endpoints
MRID
No.

Laboratory
rat
(
Rattus
norvegicus)
95.7
%
Deethylatrazine
(
G­
30033)
Acute
oral
­
female
male
668
mg/
kg
1,881
mg/
kg
LD50
(
mortality)
signs
within
30
minutes
died
within
24­
48
hours
43012302
Laboratory
rat
(
Rattus
norvegicus)
Tech.
Deisopropylatrazine
(
G­
28279)
Acute
oral
­
female
male
810
mg/
kg
2,290
mg/
kg
LD50
(
mortality)
signs
within
0.5­
48
hours
died
within
6­
48
hours
43012301
Acute
mammalian
oral
toxicity
data
are
available
for
two
degradates,
deethylatrazine
and
deisopropylatrazine.
The
female
LD50
values
are
more
toxic
to
laboratory
rats
than
technical
grade
values
for
the
parent
pesticide,
atrazine.
These
degradates
have
LD50
values
between
501
and
2,000
mg/
kg
which
indicates
that
these
degradates
are
slight
toxicity
orally.
As
with
atrazine,
the
female
toxicity
values
for
the
degradates
indicate
greater
toxicity
than
for
male
rats.
The
requirement
(
71­
3)
for
these
two
degradates
are
fulfilled,
but
the
requirement
(
70­
3)
has
not
been
fulfilled
for
the
major
degradate,
hydroxyatrazine.

iv.
Mammals,
Chronic
Wild
mammal
reproduction
testing
is
required
on
a
case­
by­
case
basis,
depending
on
the
results
of
lower
tier
laboratory
mammalian
studies,
intended
use
pattern
and
pertinent
environmental
fate
characteristics.
Atrazine
is
persistent
and
initial
residue
levels
exceed
acute
toxicity
values.
Usually
mammalian
chronic
data
are
rat
and/
or
mouse
toxicity
values
are
obtained
from
the
Agency's
Health
Effects
Division
(
HED)
and
substitute
for
wild
mammalian
testing.
HED
reproductive
and
systematic
toxicity
values
are
reported
below.

Mammalian
Subchronic
and
Reproduction
Toxicity
Surrogate
Species/
Study
Duration
%
ai
NOAEL/
LOAEL
(
ppm
ai)
Statistically
sign.
(
p=
0.05)
LOEC
Endpoints
MRID
No.
Author/
Year
Study
Classification
Laboratory
Rat
(
Rattus
norvegicus)
2­
Generation
Dietary
Tech.
NOAEL
50
LOAEL
500
NOAEL
50
LOAEL
500
red.
adult
body
weight
and
red.
adult
food
consumption
red.
pup
body
weight
in
second
generation
40431303
Ciba­
Geigy
1987
Minimum
Laboratory
Rat
(
Rattus
norvegicus)
2­
Yr
Carcinogenicity
98.9
NOAEL
10
LOAEL
70
NOAEL
70
LOAEL
500
incr.
carcinomas
for
females
(
adenomas
&
fibroadenomas)

red.
mean
adult
body
weight
00158930
American
Biogenics
Corp.
1986
Minimum
Laboratory
Rat
(
Rattus
norvegicus)
2­
Yr
Carcinogenicity
97
NOAEL
70
LOAEL
400
red.
adult
body
weight
gain
42204401
Hazleton
Lab.
1992
Minimum
Mammalian
Subchronic
and
Reproduction
Toxicity
Surrogate
Species/
Study
Duration
%
ai
NOAEL/
LOAEL
(
ppm
ai)
Statistically
sign.
(
p=
0.05)
LOEC
Endpoints
MRID
No.
Author/
Year
Study
Classification
XI
­
7
Laboratory
Rat
(
Rattus
norvegicus)
Fed
for
14
days
97.4
NOAEL
100
LOAEL
200
reduced
estrogen
levels
41570901
Hazelton
Lab.
1990
Supplementary
Laboratory
rat
(
Rattus
norvegicus)
Dosed
on
Days
6
­
15
97.4
NOAEL
100
LOAEL
500
increased
fused
sternebrae
1
&
2
43012308
Ciba­
Geigy
1992
Guideline
Laboratory
rat
(
Rattus
norvegicus)
Dosed
on
Days
6
­
15
95.7
NOAEL
100
LOAEL
500
NOAEL
500
LOAEL
2,000
17
%
red.
adult
body
weight
gain
incr.
in
fused
sternebrae
1
&
2
incr.
poor
ossification
of
fifth
toe
43013209
Ciba­
Geigy
1992
Guideline
Laboratory
rat
(
Rattus
norvegicus)
Dosed
on
Days
6­
15
?
96.7
NOAEL
200
LOAEL
1,400
red.
body
weight
gain
delayed
ossification
40566301
Ciba­
Geigy
1984
Minimum
Dog
 
Beagle
(
Canis
sp.)
13­
Week
Feeding
Tech.
NOAEL
<
200
LOAEL
200
red.
body
weight
in
males
00163339
WARF
Institute
1997
Supplementary
Dog
 
Beagle
(
Canis
sp.)
1­
Year
Feeding
97
NOAEL
150
LOAEL
1,000
increases
in
deaths,
cachexia,
ascite
decr.
body
weight
&
food
consumption
irregular
heart
beat,
incr.
heart
rate,
incr.
cardiac
lesions
40431301
41293800
Ciba­
Geigy
1987
Minimum
New
Zealand
Rabbit
(
Lepis
sp.)
96.3
NOAEL
33
LOAEL
165
NOAEL
165
LOAEL
2,475
red.
body
weight
gain
and
red.
food
consumption.

incr.
resorptions,
red.
fetal
body
weights
and
delayed
ossification
of
appendages
00143008
40566301
Ciba­
Geigy
1984
Supplemental
Minimum
Laboratory
mice
(
Mus
musculus)
22­
Month
Oncology
batch
84180
2
NOAEL
300
LOAEL
1,500
23.5
%
red.
male
body
weight
11
%
red.
female
body
weight
incr.
incidence
of
cardiac
thrombi
in
females
40431302
Ciba­
Geigy
1987
Guideline
The
above
mammalian
chronic
studies
provide
adequate
toxicity
data
on
chronic
and
reproductive
effects.
HED
has
concluded
there
is
evidence
that
atrazine
is
associated
with
endocrine
disruption.
Direct
measurements
of
norepinephrine,
dopamine,
and
GnRH,
and
of
serum
hormones
such
as
certain
steroid
hormones
and
luteinizing
hormone,
as
well
as
changes
in
estrous
cycling
and
histomorphic
changes
in
hormone
responsive
tissues,
indicate
neuroendocrine
disruption.
The
need
for
chronic
mammalian
toxicity
data
is
fulfilled.

Degradates:
The
major
atrazine
degradate,
2­
hydroxyatrazine,
forms
a
large
percentage
of
the
recoverable
pesticide
in
various
environmental
compartments.
Several
subchronic
and
chronic
toxicity
studies
for
atrazine
degradates
and/
or
metabolites
are
summarized
in
the
table
below
for
deethylatrazine,
deisopropylatrazine,
diaminochlorotriazine
and
hydroxyatrazine.
XI
­
8
Degradate
Mammalian
Subchronic
and
Reproduction
Toxicity
Surrogate
Species/
Study
Duration
%
ai
NOAEL/
LOAEL
(
ppm
ai)
Statistically
sign.
(
p=
0.05)
LOAEL
Endpoints
MRID
No.
Author/
Year
Study
Classification
Laboratory
rat
(
Rattus
norvegicus)
Fed
for
14
days
assumed
to
be
98.2
Diaminochlorotriazine
(
G­
28273)
NOAEL
<
100
LOAEL
100
200
red.
LH
and
prolactin
levels
red.
estrogen,
LH,
prolactin
and
progesterone
41570901
Hazleton
Lab.
1990
Supplemental
Laboratory
rat
(
Rattus
norvegicus)
Diet
for
13
weeks
95.7
Deethylatrazine
(
G­
30033)
NOAEL
50
LOAEL
500
red.
in
female
body
weight
red.
in
food
efficiency
for
male
and
female
rats
43012306
Ciba­
Geigy
1991
Acceptable­
Guideline
Laboratory
rat
(
Rattus
norvegicus)
Diet
for
13
weeks
96.7
Deisopropyltriazine
(
G­
28279)
NOAEL
50
LOAEL
500
red.
in
body
weights
and
red.
body
weight
gains
in
males
and
females
43012305
Ciba­
Geigy
1992
Core­
Guideline
Laboratory
rat
(
Rattus
norvegicus)
Diet
for
13
weeks
98.2
Diaminochlorotriazine
(
G­
28273)
NOAEL
10
LOAEL
100
NOAEL
100
LOAEL
250
Estrous
cycle
effects
in
female
rats
red.
body
weight
gain
in
males
and
females
Week
12
43012307
Ciba­
Geigy
1991
Core­
Guideline
Laboratory
rat
(
Rattus
norvegicus)
Diet
for
13
weeks
97.1
Hydroxyatrazine
(
G­
34048)
NOAEL
100
LOAEL
300
renal
effects
­
high
urine
output
with
low
S.
G.
red.
hematopoietic
parameters
in
both
sexes
41293501
Ciba­
Geigy
1989
Minimum
Dog
 
Beagle
(
Canis
sp.)
13­
Week
Feeding
95.7
Deethylatrazine
(
G­
30033)
NOAEL
100
LOAEL
1,000
red.
body
weight
&
weight
gain
in
males
and
females;
red.
heart
to
brain
weight;
normocytic/
normochromic
anemia,
paroxysmal
atrial
fibrillation
and
right
atrial
wall
hemorrhagic
inflammation
with
angiomatous
hyperplasia
43012304
Ciba­
Geigy
1992
Core­
Minimum
Dog
­­
Beagle
(
Canis
sp.)
14­
Week
Feeding
96.7
Deisopropylatrazine
(
G­
28279)
NOAEL
100
LOAEL
500
red.
body
weight,
weight
gain
and
food
consumption
in
females
red.
organ
to
brain
weight
for
heart,
testes,
prostrate
glands
in
males
43012303
Ciba­
Geigy
1992
Core­
Minimum
Dog
 
Beagle
(
Canis
sp.)
1­
Year
Feeding
98.7
Diaminochlorotriazine
(
G­
28273)
NOAEL
5
LOAEL
100
1
of
8
females
had
tremors
41392401
Ciba­
Geigy
1990
Minimum
Laboratory
rat
(
Rattus
norvegicus)
Dosed
on
Days
6­
15
95.7
Deethylatrazine
(
G­
30033)
NOAEC
5
LOAEC
25
Development:
NOAEL
25
LOAEC
100
red.
body
weight;
weight
gain
and
food
consump.

Fused
sternebrae
1
&
2
Poor
ossification
of
digit
5
43013209
Ciba­
Geigy
1992
Acceptable­
Guideline
Laboratory
rat
(
Rattus
norvegicus)
Dosed
on
Days
6­
15
97.4
Deisopropylatrazine
(
G­
28279)
NOAEL
5
LOAEL
25
Development:
NOAEL
5
LOAEL
25
red.
maternal
body
weight,
weight
gain
&
food
consumption
fused
sternebrae
1
and
2.
poor
ossification
at
100
ppm
43012308
Ciba­
Geigy
1992
Core
­
Guideline
Degradate
Mammalian
Subchronic
and
Reproduction
Toxicity
Surrogate
Species/
Study
Duration
%
ai
NOAEL/
LOAEL
(
ppm
ai)
Statistically
sign.
(
p=
0.05)
LOAEL
Endpoints
MRID
No.
Author/
Year
Study
Classification
XI
­
9
Laboratory
rat
(
Rattus
norvegicus)
Dosed
on
Days
6­
15
98.2
Diaminochlorotriazine
(
G­
28273)
NOAEL
500
LOAEL
3000
Development:
NOAEL
50
LOAEC
500
red.
body
weight
gain
and
food
consumption
incr.
resorption
of
embryos
incr.
unossified
bones
41392402
Ciba­
Geigy
1989
Minimum
Laboratory
rat
(
Rattus
norvegicus)
Dosed
on
Days
6­
15
97.1
Hydroxyatrazine
(
G­
34048)
NOAEL
500
LOAEL
2,500
Development:
NOAEL
500
LOAEL
2500
decr.
mother's
food
consumption
red.
young
body
weight
incr.
delay
in
ossification
of
skull
bones
41065202
42873702
Ciba­
Geigy
1989
Minimum
Laboratory
rat
(
Rattus
norvegicus)
2­
yr
Carcinogenicity
97.1
Hydroxyatrazine
(
G­
34048)
NOAEL
10
LOAEL
25
incr.
in
accumulation
of
interstitial
matrix
in
the
kidney
in
females
only
43532001
Ciba­
Geigy
1995
Reserved
Laboratory
rat
(
Rattus
norvegicus)
2­
yr
Carcinogenicity
97.1
Hydroxyatrazine
(
G­
34048)
NOAEL
25
LOAEL
200
incr.
in
urinary
tract
effects
in
both
sexes
42662901
Ciba­
Geigy
1993
Supplemental
Comparison
of
various
subchronic
and
chronic
toxicity
levels
for
the
following
degradates
(
deethylatrazine,
deisopropylatrazine,
diaminochlorotriazine
and
hydroxyatrazine)
with
atrazine
data
suggest
that
the
toxicity
of
these
degradates
are
equal
to
or
slightly
more
toxic
to
laboratory
rats
and
beagles
than
atrazine.
The
degradate
studies
typically
show
similar
types
of
toxic
effects
seen
in
atrazine
tests.
The
mammalian
chronic
studies
provide
adequate
data
on
chronic
and
reproductive
effects
of
degradates.

v.
Reptile
Eggs
Atrazine
was
tested
on
eggs
of
the
turtle,
red­
eared
slider
(
Pseudemys
elegans)
and
the
American
alligator
(
Alligator
mississippiensis)
to
determine
if
atrazine
produced
endocrine
effects
on
the
sex
of
the
young
(
Gross,
2001).
The
turtle
and
alligator
eggs
were
placed
in
nests
constructed
of
sphagnum
moss
treated
with
0,
10,
50
100
and
500
Fg/
L
for
10
days
shortly
after
being
laid.
The
test
temperatures,
27.3EC
for
the
turtle
and
32.8E
for
alligators,
were
temperatures
which
normally
yield
all
male
young.
No
adverse
effects
were
found.
Analysis
of
the
embryonic
fluids
indicated
that
no
atrazine
was
present
in
the
eggs
at
the
detection
limit
(
0.5
Fg/
L).
Under
these
conditions,
atrazine
does
not
appear
to
be
an
endocrine
disruptor.
The
nonguideline
study
is
classified
as
supplemental
and
provides
useful
information
on
the
potential
effects
of
atrazine
on
endocrine­
mediated
pathways
(
MRID
455453­
03
and
455453­
02).

vi.
Insects
A
honey
bee
acute
contact
study
using
the
TGAI
is
required
for
atrazine
because
its
widespread
use
on
corn
and
other
crops
that
need
insect
pollination
will
result
in
honey
bee
exposure.
Results
of
this
test
are
tabulated
below.
XI
­
10
Nontarget
Insect
Acute
Contact
Toxicity
Surrogate
Species
%
ai
LD50
(
Fg/
bee)
Toxicity
Category
MRID
No.
Author/
Year
Study
Classification
Honey
bee
(
Apis
mellifera)
Tech.
96.69
(
4.79%
dead)
relatively
non­
toxic
00036935
Atkins
et
al.
1975
Core
Test
results
indicate
that
atrazine
is
categorized
as
relatively
non­
toxic
to
bees
on
an
acute
contact
basis.
The
guideline
(
141­
1)
is
fulfilled
(
MRID
00036935).

A
honey
bee
toxicity
of
residues
on
foliage
study
using
the
typical
end­
use
product
is
not
required
for
atrazine
because
the
acute
contact
honey
bee
LD50
is
greater
than
0.11
Fg/
bee.
The
guideline
requirement
(
141­
2)
is
fulfilled
(
MRID
00036935).

vii.
Terrestrial
Field
Testing
No
field
tests
have
been
required,
because
atrazine
shows
low
toxicity
to
birds,
mammals
and
insects.

b.
Toxicity
to
Freshwater
Animals
I.
Freshwater
Fish
and
Amphibia,
Acute
Two
freshwater
fish
toxicity
studies
using
the
TGAI
are
required
to
establish
the
toxicity
of
atrazine
to
fish.
The
preferred
test
species
are
rainbow
trout
(
a
coldwater
fish)
and
bluegill
sunfish
(
a
warmwater
fish).
Results
of
these
tests
are
tabulated
below.

Freshwater
Fish
Acute
Toxicity
Surrogate
Species/
Static
or
Flow­
through
test
%
a.
i.
96­
hour
LC50
(
ppb)
(
measured/
nominal)
Probit
Slope
Toxicity
Category
MRID
No.
Author/
Year
Study
Classification
Rainbow
trout
(
Oncorhynchus
mykiss)
Static
test
98.8
5,300
(
nominal)
slope
­
2.723
moderately
toxic
00024716
Beliles
&
Scott
1965
Core
Brook
trout
(
Salvelinus
tontinalis)
Flow­
through
test
94
6,300
4,900
(
8­
day
test)
not
specified
moderately
toxic
00024377
Macek
et
al.
1976
Supplemental
(
52­
gram
fish
&
no
raw
data)

Fish
from
the
Nile
River
Chrysichthyes
auratus
Static­
renewal
­
daily
150
mg/
L
CaCO3;
22EC
96
6,370
(
not
specified)
moderately
toxic
45202911
Hussein,
El­
Nasser
&
Ahmed
1996
Supplemental
(
non­
native
sp.;
26­
gram
fish;
no
raw
data)

Bluegill
sunfish
(
Lepomis
macrochirus)
Flow­
through
test
94
>
8,000
6,700
(
7­
day
test)
(
not
specified)
moderately
toxic
00024377
Macek
et
al.
1976
Supplemental
(
6.5­
gram
fish
&
no
raw
data)

Tilapia
38
grams
(
Oreochromis
niloticus)
Static­
renewal
­
daily
150
mg/
L
CaCO3:
22EC
96
9,370
(
not
specified)
moderately
toxic
45202911
Hussein,
El­
Nasser
&
Ahmed
1996
Supplemental
(
non­
native
sp.;
38­
gram
fish;
no
raw
data)
Freshwater
Fish
Acute
Toxicity
Surrogate
Species/
Static
or
Flow­
through
test
%
a.
i.
96­
hour
LC50
(
ppb)
(
measured/
nominal)
Probit
Slope
Toxicity
Category
MRID
No.
Author/
Year
Study
Classification
XI
­
11
Fathead
minnow
(
Pimephales
promelas)
24­
Hour
renewal
test
94
15,000
(
nominal)
15,000
(
5­
day
test)
slightly
toxic
00024377
Macek
et
al.
1976
Supplemental
(
no
raw
data)

Carp
(
Cyprinus
carpio)
Semi­
static
test
93.7
18,800
(
nominal)
slope
not
reported
slightly
toxic
45202913
Neskovic
et
al.
1993
Supplemental
(
no
raw
data)

Fathead
minnow
juvenile
(
Pimephales
promelas)
Flow­
through
test;
52
mg/
L
CaCO3
97.1
20,000
(
measured)
Slope
­
6.889
slightly
toxic
42547103
Dionne
1992
Core
Bluegill
sunfish
(
Lepomis
macrochirus)
Static
test
98.8
24,000
(
nominal)
no
slope
slightly
toxic
00024717
Beliles
&
Scott
1965
Core
Brown
trout
(
Salmo
trutta)
1.9
gr.
Static­
Renewal
­
daily
pH
6;
10EC;
11
mg/
L
CaCO3
??
27,000
(
nominal)
slightly
toxic
45202909
Grande,
Anderson
&
Berge
1994
Supplemental
(
no
raw
data;
slight
aeration
&
purity
unknown)

Zebrafish
(
Brachydanio
rerio)
??
37,000
(???????)
slightly
toxic
?????????
Korte
&
Greim
1981
Supplemental
(
article
unavailable)

Bluegill
sunfish
(
Lepomis
macrochirus)
Static
test
100
57,000
(
nominal)
slightly
toxic
00147125
Buccafusco
1976
Core
Goldfish
(
Carassius
auratus)
Static
test
98.8
60,000
(
nominal)
Slope
­
2.695
slightly
toxic
00024718
Beliles
&
Scott
1965
Supplemental
(
not
an
acceptable
species)

The
lowest
fish
LC50
value
falls
in
the
range
of
>
1
­
10
ppm,
hence
atrazine
is
categorized
as
moderately
toxic
to
freshwater
fish
on
an
acute
basis.
The
guideline
requirement
(
72­
1)
is
fulfilled
(
MRID
00024716,
00024717,
000147125).

The
following
table
presents
fish
toxicity
data
for
formulated
products.

Freshwater
Fish
and
Amphibian
Acute
Toxicity
Surrogate
Species/
Flow­
through
or
Static
%
ai
formul.
96­
hour
LC50
(
ppb)
(
measured/
nominal)
Toxicity
Category
MRID
No.
Author/
Year
Study
Classification
Black
Bass
­
fry
(
Micropterus
salmoides)
Static
test;
20EC
78
mg/
L
hardness
80
80
W
12,600
(
nominal)
slope
­
5.86
slightly
toxic
45227717
R.
O.
Jones
1962
Supplemental
(
48­
hours;
limited
raw
data)

Channel
Catfish
yolk
sac
(
Ictalurus
punctatus)
Static
test;
23.3­
25.8EC
78
mg/
L
hardness
80
80
W
16,000
(
nominal)
slope
­
3.36
sightly
toxic
45227717
R.
O.
Jones
1962
Supplemental
(
limited
raw
data)
Freshwater
Fish
and
Amphibian
Acute
Toxicity
Surrogate
Species/
Flow­
through
or
Static
%
ai
formul.
96­
hour
LC50
(
ppb)
(
measured/
nominal)
Toxicity
Category
MRID
No.
Author/
Year
Study
Classification
XI
­
12
Bluegill
Sunfish
fry
(
Lepomis
macrochirus)
Static
test;
25­
27EC
78
mg/
L
hardness
80
80
W
20,000
(
nominal)
no
slope
slightly
toxic
45227717
R.
O.
Jones
1962
Supplemental
(
limited
raw
data)

American
Toad
­
larvae
(
Bufo
americanus)
Flow­
through
test
40.8
4L
10,700
late
stage
26,500
early
stage
(
nominal)
slightly
toxic
45202910
Howe
et
al.
1998
Supplemental
(
no
raw
data)

Northern
Leopard
Frog
larvae
(
Rana
pipiens)
Flow­
through
test
40.8
4L
14,500
late
stage
47,600
early
stage
(
nominal)
slightly
toxic
45202910
Howe
et
al.
1998
Supplemental
(
no
raw
data)

Coho
Salmon
(
Oncorhynchus
kisutch)
Renewal
daily;
144
hr
40.8*
AAtrex
Liquid
>
18,000
25
%
mortality
(
measured)
slightly
toxic
45205107
Lorz
et
al.
1979
Supplemental
(
no
LC50
value
&
12­
17
months
old)

Rainbow
trout
(
Onchorhynchus
mykiss)
Flow­
through
test
40.8
4L
20,500
(
nominal)
slightly
toxic
45202910
Howe
et
al.
1998
Supplemental
(
no
raw
data)

Channel
Catfish
(
Ictalurus
punctatus)
Flow­
through
test
40.8
4L
23,800
(
nominal)
slightly
toxic
45202910
Howe
et
al.
1998
Supplemental
(
no
raw
data)

Rainbow
trout
(
Oncorhynchus
mykiss)
Static
test
43
Liquid
24,000
(
unknown)
slightly
toxic
40098001
Mayer
&
Ellersieck
1986
Supplemental
(
no
raw
data)

Bluegill
sunfish
(
Lepomis
macrochirus)
Static
test
43
Liquid
42,000
(
unknown)
slightly
toxic
40098001
Mayer
&
Ellersieck
1986
Supplemental
(
no
raw
data)

*
Percent
a.
i.
assumed
based
on
description
as
a
liquid
formulation,
AAtrex.

All
toxicity
values
for
the
atrazine
formulation
are
>
10
and
100
ppm,
therefore
this
atrazine
product
is
classified
as
slightly
toxic.

Degradates:
The
major
atrazine
degradate,
hydroxyatrazine,
forms
a
large
percentage
of
the
recoverable
pesticide
in
aquatic
environmental
compartments.
Therefore,
acute
fish
testing
with
bluegill
and
rainbow
trout
are
required
to
address
degradate
concerns.
The
requirement
for
special
degradate
tests
(
72­
1)
has
not
been
fulfilled.

ii.
Freshwater
Fish,
Chronic
A
freshwater
fish
early
life­
stage
test
using
the
TGAI
is
required
for
atrazine
because
the
enduse
product
is
expected
to
be
transported
to
water
from
the
intended
use
site,
and
the
following
conditions
are
met:
the
pesticide
is
intended
for
use
such
that
its
presence
in
water
is
likely
to
be
continuous
and
recurrent;
an
aquatic
acute
EC50
is
less
than
1
mg/
L
(
i.
e.,
Chironomus
tentans
LC50
0.72
ppm);
and
the
pesticide
is
persistent
in
water
(
i.
e.,
half­
life
greater
than
4
days).
The
preferred
test
species
is
rainbow
trout.
XI
­
13
Freshwater
Fish
Early
Life
Stage
Toxicity
Surrogate
Species/
Study
Duration/
Flow­
through
or
Static
Renewal
%
ai
NOAEC/
LOAEC
Fg/
L
(
ppb)
(
measured
or
nominal)
Statistically
sign.
(
p=
0.05)
Endpoints
Affected
MRID
No.
Author/
Year
Study
Classification
Rainbow
trout
(
Oncorhynchus
mykiss)
86
days,
flow­
through
50
mg/
L
CaCO3
Tech.
NOAEC
410
LOAEC
1,100
(
measured)
sign.
delays
in
hatching
@
1,100
and
3,800
Fg/
L
sign.
red.
wet
wt.
at
30
&
58
days
@
1,100
&
3,800
Fg/
L
sign.
red.
dry
wt.
@
3,800
Fg/
L
58.8
%
mortality
@
3,800
Fg/
L
at
swim­
up
45208304
Whale
et
al.
1994
Invalid
(
DMSO
used
as
solvent,
which
aids
in
transport
of
chemicals
across
cell
membranes)

Rainbow
trout
embryo­
larvae
(
Oncorhynchus
mykiss)
27
days;
flow­
through
80
WP
Hardness
50
mg/
L:
LC50
660
LC01
29
Slope
1.2
Hardness
200
mg/
L:
LC50
810
LC01
77
Slope
1.38
%
normal
survival
50/
200
mg/
L
19
Fg/
L
­
94
98
54
­
88
90
54
**
­
68
74
5,020
**
­
10
9
50,900
**
­
0
0
45202902
Birge,
Black
&
Bruser
1979
Supplemental
(
short
test;
no
raw
data
for
statistical
analyses)

Channel
catfish
embryo­
larvae
(
Ictalurus
punctatus)
8
days;
flow­
through
80
WP
Hardness
50
mg/
L:
LC50
220
Slope
0.977
Hardness
200
mg/
L:
LC50
230
Slope
0.84
highly
teratogenic
in
all
tests;
no
results
for
soft
water
420
Fg/
L
­
16%
terata
830
Fg/
L
­
47
%
terata
46,700
Fg/
L
­
86
%
terata
45202902
Birge,
Black
&
Bruser
1979
Supplemental
(
short
test;
no
raw
data
for
statistical
analyses)

Zebrafish
(
Brachydanio
rerio)
35
Days;
pH
8;
27+
1EC
Flow­
through
test
Hardness
24
mg/
L
98
NOAEC
300
LOAEC
1,300
(
measured)
35­
Day
LC50
890
Slope
1.25
2
­
3
%
sign.
incr.
in
edema
45­
62
%
mortality
45202908
Gorge
&
Nagel
1990
Supplemental
(
no
raw
data)

In
addition
to
survival
of
rainbow
trout
and
catfish
embryo­
larvae,
Birge
et
al.
(
1979)
also
reported
that
"
Atrazine
was
highly
teratogenic
in
all
tests."
The
frequency
of
teratogenicity
was
reported
for
channel
catfish
in
hard
water
and
included
in
the
table
above;
no
data
on
frequency
was
reported
for
soft
water
or
for
rainbow
trout.
(
MRID
#
45202902).
The
guideline
requirement
(
72­
4)
for
a
fish
early
life
stage
test
is
fulfilled
by
four
fish
life­
cycle
tests
with
rainbow
trout,
bluegill
and
fathead
minnows
(
listed
below).

Degradates:
The
major
atrazine
degradate,
hydroxyatrazine,
forms
a
large
percentage
of
the
recoverable
pesticide
in
aquatic
environmental
compartments.
Therefore,
a
special
fish
early
life­
stage
test
(
72­
4)
is
reserved
to
address
degradate
concerns,
pending
the
results
of
acute
fish
tests.

A
freshwater
fish
life­
cycle
test
using
the
TGAI
is
required
for
atrazine
because
the
end­
use
product
is
expected
to
be
transported
to
water
from
the
intended
use
site
and
studies
of
other
organisms
indicate
that
the
reproductive
physiology
of
fish
may
be
affected.
The
preferred
test
species
is
fathead
minnow.
Results
of
four
fish
life­
cycle
tests
are
tabulated
below;
the
fish
full
life
cycle
guideline
requirement
(
72­
5)
is
fulfilled
by
the
brook
trout
study
(
MRID
00024377).
XI
­
14
Freshwater
Fish
Life­
Cycle
Toxicity
Surrogate
Species/
Study
Duration/
Flow­
through
or
Static
Renewal
%
ai
NOAEC/
LOAEC
Fg/
L
(
ppb)
(
measured
or
nominal)
Statistically
sign.
(
p=
0.05)
Endpoints
Affected
MRID
No.
Author/
Year
Study
Classification
Brook
trout
(
Salvelinus
frontinalis)
44
weeks,
flow­
through
94
NOAEC
65
LOAEC
120
(
measured)
7.2
%
red.
mean
length
16
%
red.
mean
body
weight
00024377
Macek
et
al.
1976
Core
Bluegill
sunfish
(
Lepomis
macrochirus)
6­
18
months,
flow­
through
94
NOAEC
95
LOAEC
500
(
measured)
LOAEC
based
on
loss
of
equilibrium
in
a
28­
day
test
conducted
at
the
same
lab.
00024377
Macek
et
al.
1976
Supplemental
(
Low
survival
in
the
controls)

Fathead
minnow
(
Pimephales
promelas)
39
weeks;
flow­
through
97.1
NOAEC
<
150
LOAEC
150
(
measured)
6.7
%
red.
in
F1
length
22
%
red.
in
F1
body
wt.
(
sign.
diff.
from
neg.
control)
42547103
Dionne
1992
Supplemental
(
Failed
to
identify
a
NOAEC)

Fathead
minnow
(
Pimephales
promelas)
43
weeks,
static­
renewal
94
NOAEC
210
LOAEC
870
(
measured)
LOAEC
based
on
25%
mortality
in
a
96­
hour
test
conducted
at
the
same
lab.
00024377
Macek
et
al.
1976
Supplemental
(
High
mortality
in
control
adults)

iii,
Sublethal
Effects,
Fish
and
Amphibians
Fish:

Adult
largemouth
bass
(
Micropterus
salmoides)
were
exposed
to
nominal
concentrations
of
technical
grade
atrazine
(
purity
97.1%)
at
0,
25,
35,
50,
75,
and
100
Fg/
L
for
20
days
to
determine
the
potential
effects
on
endocrine­
mediated
functions
(
Wieser
and
Gross,
2002)
.
Additionally,
bass
were
exposed
to
commercial
grade
(
purity
42.1%)
atrazine
at
100
Fg/
L.
After
20
days,
plasma
concentrations
of
estradiol,
11­
ketotestosterone,
testosterone,
and
vitellogenin
(
a
protein
that
serves
in
yolk
formation)
were
measured.
Female
bass
treated
with
100
Fg/
L
formulated
atrazine
contained
significantly
higher
plasma
estradiol
and
exhibited
plasma
vitellogenin
roughly
37
times
greater
(
260
Fg/
ml)
than
controls
(
7
Fg/
ml).
Male
bass
treated
with
100
Fg/
L
formulated
atrazine
contained
significantly
lower
plasma
11­
ketotestosterone.
While
not
statistically
significant,
plasma
testosterone
(
286
pg/
ml)
was
lower
than
controls
(
433
pg/
ml)
and
plasma
vitellogenin
(
42
Fg/
ml)
was
7
times
greater
than
control
(
6
Fg/
ml).
Although
there
was
considerable
variability
in
plasma
vitellogenin
levels,
atrazinetreated
fish
appeared
to
have
elevated
plasma
vitellogenin
relative
to
controls.
at
50
and
100
Fg/
L
of
atrazine.
Plasma
11­
ketotestosterone
was
significantly
lower
in
fish
exposed
to
atrazine
concentrations
greater
than
35
Fg/
L.
Treatment
of
fish
with
commercial
grade
atrazine
resulted
in
a
significant
increase
in
plasma
estradiol
in
female
fish
and
a
significant
decrease
in
11­
ketotestosterone
in
male
fish.
Although
not
statistically
significant,
plasma
vitellogenin
in
both
female
and
male
fish
appeared
to
be
increased
in
fish
treated
with
technical
and
commercial
grade
atrazine.

Although
high
variability
confounds
this
study's
ability
to
resolve
the
effects
of
atrazine
on
plasma
steroids
and
vitellogenesis,
the
study
has
demonstrated
that
technical
grade
atrazine
affects
plasma
11­
ketotestosterone
in
males
and
that
the
formulated
product
affects
plasma
XI
­
15
estradiol
in
females.
The
non­
guideline
study
is
classified
as
supplemental
and
provides
useful
information
on
the
potential
effects
of
atrazine
on
endocrine­
mediated
pathways.
(
MRID
45622304).
Furthermore,
previous
studies
with
commercial
atrazine
showed
increased
plasma
vitellogenin
levels
and
decreased
plasma
testosterone
levels
at
concentrations
greater
than
50
Fg/
ml
(
Gross
et
al.
1997;
Grady
et
al.
1998).

Effects
on
behavior
were
found
to
be
significant
(
p
<
0.0001)
in
zebrafish
(
Brachydanio
rerio)
following
1­
week
exposures
at
5
to
3125
Fg/
L
atrazine
(
Steinberg
et
al.,
1995).
Fish
exposed
to
atrazine
for
1­
week
showed
a
pronounced
preference
(
p
<
0.0001)
for
the
dark
part
of
the
aquarium
compared
to
the
control.
Since
no
significant
difference
were
found
between
the
effects
at
the
various
test
concentrations
(
5Fg/
L:
79%;
25Fg/
L:
85%;
125
Fg/
L:
83%;
625
Fg/
L:
81%;
3125
Fg/
L:
81%),
these
changes
in
swimming
behavior
appears
to
be
threshold
effects.
After
4
weeks
at
the
above
exposures,
15
to
24
percent
more
of
the
treated
fish
preferred
dark
habitats
than
did
the
controls.
The
authors
concluded
that
atrazine
probably
has
an
effect
on
the
sensory
organs
and
the
nervous
system
at
atrazine
concentrations
commonly
found
in
surface
waters.
(
MRID
#
45204910).

Saglio
and
Trijase
(
1998)
measured
5
behavioral
activities
in
goldfish
following
24­
hour
exposures
to
0.5,
5
and
50
Fg/
L
atrazine.
A
number
of
behavioral
measurements
were
statistically
significant
(
p
<
0.05)
from
controls,
but
in
most
instances
the
significance
was
inconsistent
and
failed
to
show
a
dose­
related
effect.
The
only
behavioral
effect
showing
a
consistent,
dose­
related
effect
was
reduction
in
grouping
(
i.
e.,
significant
at
5
Fg/
L
(
31%
reduction)
and
50
Fg/
L
(
39%
reduction).
Other
behaviors
with
statistically
significant
effects
were
surfacing
at
5
Fg/
L
(
341%
increase),
burst
swimming
at
0.5
and
50
Fg/
L
(
1.00
and
2.25
units,
respectively,
the
controls
showed
no
effect).
Following
the
introduction
of
skin
extract,
5
Fg/
L
of
atrazine
significantly
(
p
<
0.05)
reduced
sheltering
(
81%)
and
grouping
(
60%),
but
these
effects
showed
no
consistency
with
effects
at
0.5
and
50
Fg/
L.
This
study
shows
that
a
24­
hour
exposure
at
5
Fg/
L
atrazine
significantly
affected
aspects
of
swimming,
positioning
in
water
column,
increased
number
of
mouth
openings
at
the
surface,
and
social
behaviors.
(
MRID
#
45202914).

Fischer­
Scherl
et
al.
(
1991)
reported
acute
and
chronic
atrazine­
induced
alterations
in
the
rainbow
trout
kidneys
affecting
renal
corpuscles,
renal
tubules,
and
renal
interstitium.
Additionally,
the
accumulation
of
cellular
debris
in
Bowman's
space
affects
glomerular
filtration.
Compared
to
control
fish,
chronic
28­
day
exposures
at
5,
10
and
20
Fg/
L
almost
obliterated
Bowman's
space
due
to
a
proliferation
of
podocytes
with
their
epithelial
foot
processes
forming
tight
and
intensive
connections.
The
most
conspicuous
feature
was
the
thickening
of
the
glomerular
basement
membrane,
with
formation
of
so­
called
spikes.
In
some
glomerula
sub­
endothelial
humps,
electron­
dense
deposits
attached
to
glomerular
basement
membrane,
have
been
detected.
In
some
instances,
moderate
electron­
dense
material
and
membranous
structures
were
deposited
in
Bowman's
space.
At
higher
chronic
concentrations
(
40
and
80
Fg/
L)
renal
corpuscles
appeared
hypercellular
and
enlarged
due
to
a
proliferation
of
podocytes
and
mesangial
cells.
Also,
the
amount
of
membrane­
bound
vesicles
with
varying
electron­
dense
contents
had
increased
in
the
urinary
space
of
renal
corpuscles.
Fibrillar
XI
­
16
structures
and
fibrocytes
were
found
around
Bowman's
capsule
indicating
beginning
periglomerular
fibrosis.
Acute
96­
hour
exposures
at
1.4
and
2.8
mg/
L
caused
a
more
pronounced
obliteration
of
Bowman's
space
due
to
the
proliferation
of
mesangial
cells
and
more
renal
corpuscles
were
affected.
Increasing
amounts
of
cellular
debris
accumulated
in
Bowman's
space.
Simultaneously,
epithelial
cells
of
the
parietal
layer
of
Bowman's
capsule
displayed
an
increased
number
of
lysosomes
and
swollen
mitochondria.
Also,
the
number
of
glomerular
endothelial
cells
exhibiting
vacuolar
degeneration
increased.
Furthermore,
light
microscopy
shows
minor
alterations
to
renal
tubules,
but
electron
micrographs
revel
considerable
changes.
First,
obvious
alterations
of
tubules
appeared
at
10
Fg/
L.
Basilar
labyrinth
was
dilated
and
irregularly
arranged.
The
mitochondria
were
electron­
dense
and
showed
club­
shaped
ends
of
circular
structure.
At
40
Fg/
L,
part
of
the
endoplasmic
reticulum
appeared
foamy
and
fragments
of
endoplasmic
reticulum
were
heavily
distended.
At
80
Fg/
L
in
proximal
and
distal
tubular
epithelia
lysis
of
the
cytoplasm
with
formation
of
vacuoles
and
vesicles
and
condension
of
mitochondria
was
prominent.
In
many
tubular
epithelia,
only
remnants
of
the
former
parallelarranged
tubular
system
were
present,
mitochondria
were
swollen,
lysosomal
structures
as
well
as
a
vacuolization
of
the
cytoplasm
were
detectable.
In
proximal
tubules,
lysomes
had
increased
in
number
and
size.
At
acute
exposures
(
1,400
and
2,800
Fg/
L),
tubular
structural
lesions
similar
to
those
described
at
80
Fg/
L
were
present,
but
a
distinctly
higher
number
of
renal
tubules
was
affected.
Extensive
cytoplasmic
vacuolization
was
evident
and
the
parallel
arrangement
of
the
basilar
labyrinth
was
completely
lost,
some
mitochondria
were
dark
and
condensed.
Tubules
of
the
basilar
labyrinth
appeared
foggy,
partly
involving
mitochondria.
Except
for
an
increase
in
cells
with
mitotic
figures
at
concentrations
of
5,
10,
20
Fg/
L,
no
conspicuous
alterations
in
basic
interstitial
architecture
could
be
detected.
Beginning
at
40
Fg/
L,
a
loosening
of
the
hemopoietic
tissue
was
evident.
Cells,
preumably
macrophages,
phagocytizing
material
had
increased
in
number.
In
addition
to
these
effects,
sinusendothelial
cells
were
severely
damaged
at
a
concentration
of
80
Fg/
L.
They
separated
from
the
basement
membrane
and
exhibited
numerous
vesicular
and
lysosomal
structures
as
well
as
swollen
degenerating
mitochondria.
Alterations
in
renal
interstitium
were
considerable
at
acute
exposures
with
1,400
and
2,800
Fg/
L.
Interstitial
tissue
was
loosened
and
a
state
of
spongiosus
was
indicated.
Numerous
macrophages
were
present.
Nuclei
of
interstitial
cells
were
pyknotic
or
karyorhectic,
mitochondria
were
swollen
and
the
cytoplasm
displayed
lytic
areas.
Cell
boundaries
in
some
parts
of
the
interstitium
were
lost.
Cell
organelles
were
scarce,
but
lysosomal
structures
abundant.
(
MRID
#
45202907)

Davies
et
al.
(
1994)
exposed
three
fish
species
to
0.9,
3.0,
10,
50
and
340
Fg/
L
atrazine
for
a
period
of
10
days
and
measured
effects
on
growth
and
properties
of
various
tissues,
such
as
blood,
muscle
and
liver.
Statistically
significant
(
p
<
0.05)
effects
occurred
at
levels
as
low
as
0.9
and
3.0
Fg/
L.
The
most
sensitive,
consistent
statistically
significant
effect
was
with
the
species
Galaxias
maculatus
at
10
Fg/
L
(
i.
e.,
144%
increase
in
muscle
RNA/
DNA
levels),
and
the
DNA
levels
were
significantly
reduced
25%.
In
Pseudaphritis
urvillii
consistent
significant
effects
were
found
on
glutathione
(
GSH)
in
the
liver
at
50
Fg/
L
(
24%
reduction)
and
340
Fg/
L
(
13%
reduction).
Consistent,
significant
effects
with
rainbow
trout
were
found
at
50
and
340
Fg/
L
(
i.
e.,
reductions
of
15%
and
14%,
respectively,
in
protein
levels
in
muscle);
and
at
350
Fg/
L
(
159%
reduction
in
growth
and
a
23%
increase
in
glucose
levels)
(
MRID
#
45202904).
XI
­
17
Alazemi
et
al.
(
1996)
reported
gill
damage
to
a
freshwater
fish;
the
damage
was
characterized
by
the
presence
of
breaks
in
the
gill
epithelium
at
500
Fg/
L
which
developed
into
deep
pits
at
5,000
Fg/
L.

Hussein
et
al.
(
1996)
exposed
two
important
Rile
River
fish
(
Oreochromis
niloticus
and
Chrysichthyes
auratus)
to
3,000
and
6,000
Fg/
L
atrazine
for
up
to
28
days.
Fish
exposed
to
these
concentrations
showed
some
clinical
signs
such
as
rapid
respiration
and
increased
rate
of
gill
cover
movements;
slower
reflexes
and
swimming
movements;
reduction
in
feeding
activities;
loss
of
equibrium
and
death.
These
signs
were
more
pronounced
in
C.
auratus
than
O.
niloticus.
About
25
percent
of
the
treated
fish
had
abdominal
swelling
(
ascites)
in
the
two
species.
Abnormal
behavior
could
be
attributed
to
the
effect
of
atrazine
on
CNS
and
cardiovascular
system.
Exposure
to
3,000
and
6,000
Fg/
L
resulted
in
significant
(
p
<
0.01)
decreases
in
the
number
of
red
blood
cells
(
RBC),
hemoglobin
and
haematocrit
levels
compared
to
controls
in
both
species.
While
the
data
appear
to
show
clear
differences
from
controls,
these
conclusions
could
not
be
verified
from
the
data
given
in
the
article
.
The
authors
also
reported
significant
(
p
<
0.01)
changes
in
mean
corpuscular
volume
(
MCV),
mean
corpuscular
hemoglobin
(
MCH),
and
mean
corpuscular
hemoglobin
(
MCHC),
serum
components,
and
brain
and
serum
AChE
levels.
While
some
of
these
measurements
also
appear
to
show
clear
differences
between
3,000
and
6,000
Fg/
L
and
the
controls,
such
as
brain
and
serum
AChE,
whether
the
effects
are
significantly
different
than
the
controls
could
not
be
confirmed
from
the
data
presented
in
the
article.
(
MRID
#
45202911).

Neskovic
et
al.
(
1993)
exposed
carp
to
atrazine
concentrations
of
1,500,
3,000
and
6,000
Fg/
L
and
found
biochemical
changes
in
the
activity
of
some
enzyme
activity
levels
in
serum
and
some
organs.
Alkaline
phosphatase
levels
were
significantly
(
p
<
0.05)
higher
in
serum
at
all
test
levels
than
in
controls.
Alkaline
phosphatase
levels
were
lower,
but
not
significantly
(
p<
0.05)
less
than
control
levels
in
the
heart,
liver
and
kidneys
at
all
test
levels.
The
greatest
drop
in
alkaline
phosphatase
activity
was
found
in
the
liver
and
ranged
from
26.1%
(
1,500
Fg/
L)
to
50.2%
(
6,000
Fg/
L).
Somewhat
weaker
effects
were
found
on
glutamic­
oxaloacetic
(
GOT)
in
the
liver
and
kidney
(
p
<
0.1).
No
statistically
significant
(
p
<
0.01)
effects
were
found
on
glutamic­
pyruvic
transaminase
(
GPT).
Histopathological
effects
include
damage
to
gills
(
>
1,500
Fg/
L),
liver
(
almost
normal
at
1,500
Fg/
L
and
vacuolization
of
hepatocytes
at
>
3,000
Fg/
L),
kidney
(
more
or
less
normal
at
3,000
Fg/
L
and
with
tubular
epithelium
and
intertubular
tissue
degradation
at
6,000
Fg/
L)
and
intestine
(
slightly
greater
lymphocyte
infiltration
and
stronger
mucous
secretion
at
6,000
Fg/
L)
(
MRID
#
45202913).

In
addition,
effects
on
reproductive
function
of
Atlantic
salmon
(
Salmo
salar)
were
reported
by
Moore
and
Waring
(
1998)
when
mature
male
Atlantic
salmon
(
Salmo
salar
L.)
parr
exposed
to
nominal
concentrations
of
0.5,
5,
10,
and
20
Fg/
L.
Measured
exposure
concentrations
in
the
study
were
0.04,
3.6,
6.0
and
14.0
Fg/
L
and
represented
8,
72,
60,
and
70
percent
of
nominal
concentrations,
respectively.
There
appears
to
be
uncertainty
about
actual
exposure
concentrations,
since
the
water
samples
were
collected
only
after
the
test
period
and
the
authors
concluded
that
atrazine
in
the
water
samples
suffered
rapid
degradation
as
the
result
of
an
unavoidable
delay
in
being
analyzed.
1Tavera­
Mendosa,
L.,
S.
Ruby,
P.
Brouseau,
M.
Fournier,
D.
Cyr,
and
D.
Marcogliese.
2002a.
Response
of
amphibian
tadpole
(
Xenopus
laevis)
to
atrazine
during
sexual
differentiation
of
the
testis.
Environmental
Toxicology
and
Chemistry
21(
3):
527­
531.

2Tavera­
Mendosa,
L.,
S.
Ruby,
P.
Brouseau,
M.
Fournier,
D.
Cyr,
and
D.
Marcogliese.
2002b.
Response
of
amphibian
tadpole
(
Xenopus
laevis)
to
atrazine
during
sexual
differentiation
of
the
ovary.
Environmental
Toxicology
and
Chemistry
21(
6):
1264­
1267.

3Hayes,
T.,
K.
Haston,
M.
Tsui,
A.
Hoang,
C.
Haeffele,
and
A.
Vonk.
2002.
Atrazine
Induced
Hermaphroditism
at
0.1
ppb
in
American
Leopard
Frogs
(
Rana
pipiens):
Laboratory
and
Field
Evidence.
Environmental
Health
Perspectives.

4Hayes,
T.,
A.
Collins,
M.
Lee,
M.
Mendoza,
N.
Noriega,
A.
Stuart,
A.
Vonk.
2002b.
Hermaphroditic,
Demasculinized
Frogs
Following
Exposure
to
the
Herbicide
Atrazine
at
Ecologically
Relevant
Low
Doses.
Proc.
Natl.
Acad.
Sci
U.
S.
A.,
99
(
8):
5476
­
5480.

5Carr,
J.
A.,
A.
Gentles,
E.
E.
Smith,
W.
L.
Goleman,
L.
J.
Urquidi,
K.
Thuett,
R.
J.
Kendall,
J.
P.
Giesy,
T.
S.
Gross,
K.
R.
Solomon,
and
G.
Van
Der
Kraak.
2003.
Response
of
Larval
Xenopus
laevis
to
atrazine:
assessment
of
growth,
metamorphosis,
and
gonadal
and
laryngeal
morphology.
Environmental
Toxicology
and
Chemistry
22(
2):
396
­
405.

XI
­
18
Amphibians:

Studies
(
Tavera­
Mendoza
et
al.
2002a1,
Tavera­
Mendoza
et
al.
2002b2,
Hayes
et
al.
2002a3,
Hayes
et
al.
2002b4,
Carr
et
al.
20035)
have
recently
been
conducted
on
the
affects
of
atrazine
on
gonadal
development
in
amphibians.
These
studies
are
in
review
and
will
be
presented
before
a
Scientific
Advisory
Panel
in
June
2003.
Since
the
studies
are
currently
in
review,
their
results
are
not
included
in
this
discussion.

iv.
Freshwater
Invertebrates,
Acute
A
freshwater
aquatic
invertebrate
toxicity
test
using
the
TGAI
is
required
to
establish
the
toxicity
of
atrazine
to
aquatic
invertebrates.
The
preferred
test
species
is
Daphnia
magna.
Results
of
this
test
and
others
are
tabulated
below.

Freshwater
Invertebrate
Acute
Toxicity
Surrogate
Species/
Static
or
Flow­
through
%
ai
96­
hour
LC50/
EC50
FG/
L
(
ppb)
(
measured/
nominal)
Probit
Slope
Toxicity
Category
MRID
No.
Author/
Year
Study
Classification
Midge
(
Chironomus
tentans)
Static
test
94
720
(
nominal)
highly
toxic
00024377
Macek
et
al.
1976
Supplemental
(
48­
hour
LC50
&
raw
data
are
missing)

Midge
(
Chironomus
riparius)
85.5
1,000
(
unknown)
highly
toxic
45087413
Johnson
1986
Supplemental
(
raw
data
are
missing)
Freshwater
Invertebrate
Acute
Toxicity
XI
­
19
Waterflea
(
Daphnia
magna)
85.5
3,500
(
unknown)
moderately
toxic
45087413
Johnson
1986
Supplemental
(
raw
data
are
missing)

Waterflea
<
24­
hours
old
(
Daphnia
magna)
26­
Hour
static
test
??
3,600
(
unknown)
at
least
moderately
toxic
00002875
Frear
&
Boyd
1967
Supplemental
(
unknown
ai,
26­
hour
test
&
no
raw
data)

Waterflea
(
Ceriodaphnia
dubia)
48­
Hour
static
test
97
>
4,900
(
measured)
Slope
­
no
mortality
unknown
45208309
Jop
1991
Supplemental
(
EC50
value
not
determined)

Scud
(
Gammarus
fasciatus)
Static
test
94
5,700
(
nominal)
moderately
toxic
00024377
Macek
et
al.
1976
Supplemental
(
48­
hour
LC50
&
raw
data
are
missing)

Stonefly
(
nymph)
(
Acroneuria
sp.)
Flow­
through
test
67.4
mg/
L
CaCO3
98.5
6,700
(
measured)
moderately
toxic
Brooke
1990
Supplemental
(
study
not
seen;
OW
in
draft
WQC)

Waterflea
(
Daphnia
magna)
Static
test
94
6,900
(
nominal)
moderately
toxic
00024377
Macek
et
al.
1976
Supplemental
(
raw
data
are
missing)

Scud
juvenile
(
Hyalella
azteca)
Flow­
through
test
67.4
mg/
L
Ca
CO3
98.5
14,700
(
measured)
slightly
toxic
Brooke
1990
Supplemental
(
no
study;
cited
by
OW
in
draft
WQC)

Scud
juvenile
(
Gammarus
pulex)
Static­
renewal
­
daily
??
14,900
(
measured)
4.4
@
10
days
slightly
toxic
45202917
Taylor,
Maund
&
Pascoe
1991
Supplemental
(
raw
data
are
missing)

Leech
(
Glossiphonia
complanata)
Static­
renewal
weekly
99.2
>
16,000
(
measured)
6,300
Fg/
L
@
28
days
slightly
toxic
45202916
Streit
&
Peter
1978
Supplemental
(
raw
data
are
missing)

Leech
(
Helobdella
stagnalis)
Static­
renewal
weekly
99.2
>
16,000
(
measured)
9,900
Fg/
L
@
27
days
slightly
toxic
45202916
Streit
&
Peter
1978
Supplemental
(
raw
data
are
missing)

Snail
(
Ancylus
fluviatilis)
Static­
renewal
weekly
99.2
>
16,000
(
measured)
>
16,
000
Fg/
L
@
40
days
(
35
%
mortality)
slightly
toxic
45208305
Oris,
Winner
&
Moore
1991
Supplemental
(
raw
data
are
missing)

Waterflea
<
12
hr
old
(
Ceriodaphnia
dubia)
Static
48­
hour
test
57
mg/
L
CaCO3
>
99
>
30,000
(
measured)
Slope
­
no
data
slightly
toxic
45202917
Taylor,
Maund
&
Pascoe
1991
Supplemental
(
raw
data
are
missing)

Midge
(
Chironomus
riparius)
Static­
renewal
­
daily
10­
Day
test
??
>
33,000
(
measured)
18,900
Fg/
L
@
10
days
slightly
toxic
00027204
Drake
1976
Supplemental
(
raw
data
are
missing)
(
EC50
115
ppm
exceeds
water
solubility
(
33
ppm)

Formulations
%
ai
Product
Waterflea
(
Daphnia
magna)
Flow­
through
test
79.6
80
WP
49,000
(
higher
concs.
than
31,000
Fg/
L
were
cloudy)
(
measured)
slope
2.433
slightly
toxic
42041401
Putt
1991
Supplemental
for
formulation
(
EC50
was
not
identified
due
to
insolubility)
Freshwater
Invertebrate
Acute
Toxicity
XI
­
20
Waterflea
(
Daphnia
pulex)
Static
test;
15EC
282
mg/
L
hardness
With
&
without
sediment
40.8
4
L
36,500
(
nominal)
46,500
(
with
sediment)
slightly
toxic
45227712
Hartman
&
Martin
1985
Supplemental
for
formulation
(
EC50
exceeds
water
solublity
and
low
temp.)

Since
the
lowest
LC50/
EC50
is
in
the
range
of
0.1
to
1
ppm,
atrazine
is
categorized
as
highly
toxic
to
aquatic
invertebrates
on
an
acute
basis.
The
guideline
requirement
(
72­
2)
is
not
fulfilled.

Degradates:
The
major
atrazine
degradate,
hydroxyatrazine,
forms
a
large
percentage
of
the
recoverable
pesticide
in
aquatic
compartments
of
the
environment.
Therefore,
acute
aquatic
invertebrate
testing
with
Daphnia
magna
is
required
to
address
degradate
concerns.
The
requirement
for
the
special
degradate
test
(
72­
2)
has
not
been
fulfilled.

v.
Freshwater
Invertebrate,
Chronic
A
freshwater
aquatic
invertebrate
life­
cycle
test
using
the
TGAI
is
required
for
atrazine
since
the
end­
use
product
is
expected
to
be
transported
to
water
from
the
intended
use
site
and
the
following
conditions
are
met:
the
pesticide
is
intended
for
use
such
that
its
presence
in
water
is
likely
to
be
continuous;
an
aquatic
acute
LC50
is
less
than
1
mg/
L;
and
the
pesticide
is
persistent
in
water
(
i.
e.,
half­
life
greater
than
4
days).
The
preferred
test
species
is
Daphnia
magna.
Results
of
these
tests
are
tabulated
below.

Freshwater
Aquatic
Invertebrate
Life­
Cycle
Toxicity
Surrogate
Species/
Study
Duration/
Flow­
through
or
Static
Renewal
%
ai
NOEC/
LOEC
Fg/
L
(
ppb)
(
measured
or
nominal)
Statistically
sign.
(
p=
0.05)
Endpoints
Affected
MRID
No.
Author/
Year
Study
Classification
Scud
(
Gammarus
fasciatus)
30
days
/
flow­
through
94
NOAEC
60
LOAEC
140
(
measured)
25
%
red.
in
development
of
F1
to
seventh
instar.
00024377
Macek
et
al.
1976
Core
Midge
(
Chironomus
tentans)
38
days
/
flow­
through
94
NOAEC
110
LOAEC
230
(
measured)
25
%
red.
in
F0
pupation
29
%
red.
in
F0
adult
emergence
18
%
red.
in
F1
pupation
28
%
red.
in
F1
adult
emergence
00024377
Macek
et
al.
1976
Core
Waterflea
(
Daphnia
magna)
21
days
/
flow­
through
94
NOAEC
140
LOAEC
250
(
measured)
54
%
red.
in
F0
young/
female
00024377
Macek
et
al.
1976
Core
Waterflea
(
Daphnia
pulex)
28­
Day
static­
renewal
70­
Day
static­
renewal
test
99.2
NOAEC
1,000
LOAEC
2,000
(
nominal)
16
%
sign.
red.
in
young/
adult
31
%
red.
in
young/
adult
45202915
Schober
&
Lampert
1977
Supplemental
(
no
raw
data
for
statistical
analyses)
Freshwater
Aquatic
Invertebrate
Life­
Cycle
Toxicity
XI
­
21
Waterflea
­
6
generations
(
Daphnia
magna)
Static­
renewal
test
??
Cups:
NOAEC
200
LOAEC
2,000
(
unknown)
4
L
aquarium:
NOAEC
??
LOAEC
??
(
water
from
treated
corrals)
66
%
reduction
in
#
of
young
in
generations
4,
5,
&
6.

72%
reduction
in
#
of
young
Kaushik,
Solomon,
Stephenson
and
Day
1985
Supplemental
(
methods
and
raw
data
are
not
reported)

Leech
(
Helobdella
stagnalis)
40
Days
Static­
Renewal
weekly
99.2
NOAEC
<
1,000
LOAEC
1,000
(
measured)
65%
red.
in
percent
hatch
45202916
Streit
&
Peter
1978
Supplemental
(
no
raw
data
for
statistical
analyses)

Waterflea
<
12
hr.
old
(
Ceriodaphnia
dubia)
Two
7­
Day
static­
renewal
tests;
Renewed
M,
W,
&
F
57
CaCO3;
Temp.
25EC
>
99
NOAEC
2,500
LOAEC
5,000
NOAEC
2,500
LOAEC
5,000
(
measured)
sign.
red.
in
mean
total
number
of
young
per
living
female
(
3
broods)
45208305
Oris,
Winner
and
Moore
1991
Supplemental
(
no
raw
data
for
analyses)

Green
hydra
(
normal)
(
Chlorohydra
viridissima)
21­
Day
Static
test
??
NOAEC
<
5,000
LOAEC
5,000
(
nominal)
sign.
red.
in
budding
rates
45202901
Benson
&
Boush
1983
Supplemental
(
no
raw
data
for
analyses)

Waterflea
3­
day
old
adult
(
Ceriodaphnia
dubia)
Two
4­
Day
static­
renewal
tests;
Renewed
M
&
W
57
CaCO3;
Temp.
25EC
>
99
NOAEC
5,000
LOAEC
10,000
NOAEC
10,000
LOAEC
20,000
(
measured)
sign.
red.
in
mean
total
number
of
young
per
living
female
(
3
broods)
45208305
Oris,
Winner
and
Moore
1991
Supplemental
(
no
raw
data
for
analyses)

Freshwater
Snail
(
Ancylus
fluviatilis)
40
Days
Static­
Renewal
weekly
99.2
1,000
4,000
16,000
(
measured)
38­
39%
red.
in
egg
capsules
&
eggs
in
April/
May
56­
57%
red.
in
eggs
in
April/
May
15­
16%
red.
in
eggs
in
July/
Aug.
68­
73%
red.
in
eggs
in
April/
May
65­
71%
red.
in
eggs
in
July/
Aug.
45202916
Streit
&
Peter
1978
Supplemental
(
no
raw
data
for
statistical
analyses)

Leech
(
Glossiphonia
complanata)
27­
Days
Static­
Renewal
weekly
99.2
1,000
4,000
16,000
(
measured)
no
reduction
in
egg
production
17
%
higher
mortality
33
%
higher
mortality
67
%
higher
mortality
45202916
Streit
&
Peter
1978
Supplemental
(
no
raw
data
for
statistical
analyses)

Growth
stages
and/
or
number
of
young
are
reduced
by
atrazine
exposures
for
insects
and
crustaceans.
The
guideline
requirement
(
72­
4)
is
fulfilled
(
MRID
00024377).

Daphnia
pulicaria
was
tested
in
a
12­
day
partial
life
cycle
study
to
determine
whether
atrazine
has
an
effect
on
the
sex
ratio
(
Madsen,
2000).
No
male
Daphnia
young
were
found
at
measured
test
concentrations
0,
0.93,
4.1,
8.7,
44,
and
87
Fg/
L
(
MRID
#
45299504).

Degradates:
The
major
atrazine
degradate
is
hydroxyatrazine
which
forms
a
large
percent
of
the
recoverable
pesticide
in
aquatic
compartments
of
the
environment.
Therefore,
a
special
aquatic
invertebrate
life­
cycle
test
(
72­
4)
is
reserved
to
address
degradate
concerns,
pending
the
results
of
acute
test.

vi.
Freshwater
Field
Studies
XI
­
22
Walker
(
1964)
treated
Missouri
ponds
and
plastic­
lined
limnocorrals
with
atrazine
for
aquatic
weed
control
at
levels
of
500
to
2,000
Fg/
L
and
quantitatively
examined
effects
on
bottom
organisms.
Among
the
most
sensitive
organisms
were
mayflies
(
Ephemeroptera),
caddis
flies
(
Tricoptera),
leeches
(
Hirudinea)
and
gastropods
(
Musculium).
The
most
significant
reduction
in
bottom
fauna
was
observed
during
the
period
immediately
following
the
application.
Six
to
eight
weeks
after
treatment,
nine
out
of
fourteen
taxonomic
groups
had
not
recovered.
The
total
number
of
bottom
organisms
per
square
foot
was
52
percent
lower
than
in
the
controls.
In
addition,
three
categories
(
water
bugs,
mosquitoes,
and
leeches)
were
no
longer
present.
(
MRID
#
45202919).

Streit
and
Peter
(
1978)
reviewed
Walker's
findings
and
investigated
long­
term
atrazine
effects
on
three
benthic
freshwater
invertebrates:
Ancylus
fluviatilis
(
Gastropoda
­
Basommatophora),
Glossiphonia
complanata
and
Helobdella
stagnalis
(
both:
Annelida
­
Hirudinea)
in
the
laboratory
(
see
Chronic
Invertebrate
toxicity
table).
Ingestion
rates
for
G.
complanata
were
determined
over
a
27­
day
period
at
atrazine
concentrations
of
1,
4
and
16
ppm.
The
total
ingestion
per
individual
was
measured
daily
(
except
between
Day
23
and
27).
Two
significant
results
were:
(
1)
Contaminated
leeches
ate
significantly
more
limpets
than
the
controls
(
300,
345
and
405%
of
control
ingestion
rates
for
1,000,
4,000
and
16,000
Fg/
L
atrazine
exposures,
respectively).
(
2)
There
was
a
constant
feeding
intensity
from
immediately
after
the
beginning
of
the
exposure
period.
The
same
phenomenon
was
seen
for
snails,
A.
fluviatilis,
but
the
intensity
of
feeding
was
much
less
(
i.
e.,
120,
130
and
140%
of
control
ingestion
rates
at
1,000,
4,000
and
16,000
Fg/
L,
respectively).
Other
observations
included:
(
1)
Leeches
found
sometimes
lying
on
their
backs
suggesting
that
they
have
difficulty
staying
firmly
attached
to
the
substrate.
(
2)
With
increasing
atrazine
concentrations,
an
increasing
percentage
of
snails
could
be
detected
that
were
just
sucked
out
but
not
wholly
eaten.
Similar
effects
were
observed
with
the
snails
which
suggest
that
leech
and
snail
behavior
might
be
affected
in
some
way.
Compared
to
controls,
Ancylus
egg
production
was
significantly
reduced
after
40
days
exposure
to
atrazine
at
16,000
Fg/
L
in
March/
April,
April/
May
(
68%
fewer
egg
capsules
and
73%
fewer
eggs)
and
July/
August
(
65%
fewer
egg
capsules
and
71%
fewer
eggs).
Lower
Ancylus
reproduction
was
also
found
at
4
Fg/
L
in
April/
May
(
56­
57
percent)
and
July/
August
(
15­
16
percent).
At
1,000
Fg/
L,
fewer
capsules
and
eggs
were
found
only
in
April/
May
(
38
and
39
percent,
respectively).
The
average
number
of
eggs
per
brood
in
leech,
Glossiphonia
complanata
was
not
affected
by
27­
days
of
atrazine
exposure.
The
no
significant
effect
was
found
on
the
number
of
live­
born
young
of
Helobdella
stagnalis.
At
1,000
and
4,000
Fg/
L
only
a
part
of
the
egg
masses
developed.
Only
about
10
percent
of
the
young
in
the
16,000
Fg/
L
treatment
hatched.
Atrazine
did
not
affect
the
time
for
normal
development
(
5­
6
days).
(
MRID
#
45202916).

Kettle
et
al.
(
1987)
monitored
effects
of
atrazine
(
40.8%)
on
diet
and
reproductive
success
of
bluegill
in
experimental,
Kansas
ponds.
The
0.045­
hectare,
2.1­
meter
deep
ponds
were
each
stocked
with
adult
fish
(
50
bluegills,
20
channel
catfish
and
7
gizzard
shad).
On
July
24,
atrazine
was
applied
to
two
ponds
at
20
Fg/
L,
another
two
ponds
at
500
Fg/
L
and
two
controls.
Atrazine
concentrations
were
measured
during
the
study
and
70%
of
the
original
concentration
was
detected
at
the
end
of
the
136­
day
study.
Bluegills
were
the
only
species
to
spawn
during
the
study.
Atrazine
had
no
significant
effect
on
mortality
of
the
original
stocked
fish,
but
the
XI
­
23
number
of
young
bluegills
retrieved
were
significantly
(
p
<
0.01)
reduced
compared
to
control
ponds
(
i.
e.,
95.7
%
fewer
in
20
Fg/
L­
treated
ponds
and
96.1
%
fewer
in
500
Fg/
L­
treated
ponds).
Stomach
analyses
of
adult
bluegills
indicate
that
the
bluegill
controls
had
significantly
(
p
<
0.001)
higher
numbers
of
food
items
per
fish
stomach
and
higher
numbers
of
prey
taxa
per
fish
stomach.
The
number
of
food
items
per
stomach
were
reduced
85
and
78
percent
in
20
and
500
Fg/
L
­
treated
ponds,
respectively.
Reductions
in
taxa
per
stomach
were
57
and
52
percent
in
20
and
500
Fg/
L­
treated
ponds,
respectively.
Stomachs
of
bluegills
from
treated
ponds
had
fewer
numbers
of
Ephemeroptera
(
p
<
0.001),
Odonata
(
p
<
0.001),
Coleoptera
(
p
<
0.01)
and
Diptera
(
not
significant,
p
>
0.05)
than
the
controls.
The
macrophyte
community
in
treated
ponds
was
noticeably
reduced,
relative
to
controls,
throughout
the
summer.
Visual
estimates
of
the
macrophyte
communities
in
the
ponds
showed
roughly
a
60
percent
decline
in
the
20
Fg/
L
ponds
and
a
90
percent
decline
in
the
500
Fg/
L
ponds
two
months
after
atrazine
addition.
These
estimates
were
verified
by
rake
hauls
which
produced
these
same
relative
differences.
The
following
May,
10
months
after
treatment,
when
macrophytes
are
normally
well
established
in
Kansas
ponds,
the
ponds
were
drained.
Relative
to
control
ponds,
20
Fg/
L
ponds
had
a
90
percent
reduction
in
macrophyte
coverage
and
the
500
Fg/
L
ponds
had
a
>
95
percent
reduction
in
macrophyte
coverage.
Differences
were
noted
in
the
macrophyte
species
present.
Control
ponds
contained
Potamogeton
pusillus
and
P.
nodosus,
Najas
quadalupensis,
and
small
amounts
of
Chara
globularis,
whereas
the
treated
ponds
contained
mostly
C.
globularis.
(
MRID
#
45202912).

c.
Toxicity
to
Estuarine
and
Marine
Animals
i.
Estuarine
and
Marine
Fish,
Acute
Acute
toxicity
testing
with
estuarine/
marine
fish
using
the
TGAI
is
required
for
atrazine
because
the
end­
use
product
is
expected
to
reach
this
environment
because
of
its
use
in
coastal
counties.
The
preferred
test
species
is
sheepshead
minnow.
Results
of
these
tests
are
tabulated
below.

Estuarine/
Marine
Fish
Acute
Toxicity
Surrogate
Species/
Static
or
Flow­
through/
Salinity
&
Temperature
%
ai
96­
hour
LC50
(
ppb)
(
measured/
nominal)
Probit
Slope
Toxicity
Category
MRID
No.
Author/
Year
Study
Classification
Sheepshead
Minnow
larvae
<
24­
hours
old
(
Cyprinodon
variegatus)
Static
test,
T
­
20EC
Salinity
25,
15,
5
g/
L;
97.1
Sal.
25
g/
L
2,000
Sal.
15
g/
L
2,300
Sal.
5
g/
L
16,200
(
measured)
Slope
­
no
data
moderately
toxic
45208303
&
45227711
Hall,
Jr.,
Ziegenfuss,
Anderson,
Spittler
&
Leichtweis
1994
Supplemental
(
no
raw
data
on
mortalities)

Spot
(
Leiostomus
xanthurus)
Static
test
Salinity
­
12
g/
L;
T
­
22+
1EC
97.4
8,500
(
nominal)
Slope
­
no
data
moderately
toxic
45202920
Ward
&
Ballantine
1985
Supplemental
(
no
raw
data)

Sheepshead
minnow
(
Cyprinodon
variegatus)
Flow­
through
test
Salinity
­
31
g/
L;
T
­
22­
23EC
97.1
13,400
(
measured)
Slope
4.377
slightly
toxic
43344901
Machado
1994
Core
Estuarine/
Marine
Fish
Acute
Toxicity
Surrogate
Species/
Static
or
Flow­
through/
Salinity
&
Temperature
%
ai
96­
hour
LC50
(
ppb)
(
measured/
nominal)
Probit
Slope
Toxicity
Category
MRID
No.
Author/
Year
Study
Classification
XI
­
24
Spot
(
juvenile)
(
Leiostomus
xanthurus)
Flow­
through
test
Salinity
­
29
g/
L;
T
­
28EC
99.7
>
1,000
(
nominal)
Slope
­
none
unknown
40228401
Mayer
1986
Supplement
(
48­
hour
test)

Sheepshead
minnow
(
Cyprinodon
variegatus)
Flow­
through
test
97.4
>
16,000
(
30
%
mortlity)
(
measured)
Slope
­
none
unknown
45202920
Ward
&
Ballantine
1985
Supplemental
(
no
raw
data)

Since
the
LC50
are
in
the
range
of
1
­
10
ppm,
Atrazine
is
categorized
as
moderately
toxic
to
estuarine/
marine
fish
on
an
acute
basis.
Toxicity
data
on
sheepshead
minnow,
Cyprinodon
variegatus,
indicates
that
atrazine
toxicity
increases
with
increasing
salinity
levels.
The
pattern
of
increasing
toxicity
is
opposite
to
atrazine
toxicity
data
on
the
copepod,
Eurytemora
affinis.
The
guideline
requirement
(
72­
3a)
is
fulfilled
(
MRID
43344901).

Degradates:
The
major
atrazine
degradate,
hydroxyatrazine,
forms
a
large
percentage
of
the
recoverable
pesticide
in
aquatic
environmental
compartments.
Therefore,
a
special
acute
estuarine
fish
test
(
72­
3)
is
required
to
address
concerns
for
the
toxicity
of
atrazine
degradates
to
estuarine
fish
(
preferably
sheepshead
minnow).
The
requirement
(
72­
3)
has
not
been
fulfilled.

ii.
Estuarine
and
Marine
Fish,
Chronic
An
estuarine/
marine
fish
early
life­
stage
toxicity
test
using
the
TGAI
is
required
for
atrazine
because
the
end­
use
product
may
be
applied
directly
to
the
estuarine/
marine
environment
or
is
expected
to
be
transported
to
this
environment
from
the
intended
use
site,
and
the
following
conditions
are
met:
the
pesticide
is
intended
for
use
such
that
its
presence
in
water
is
likely
to
be
continuous;
an
aquatic
acute
LC50
or
EC50
is
less
than
1
mg/
L;
and
the
pesticide
is
persistent
in
water
(
i.
e.,
half­
life
greater
than
4
days).
The
preferred
test
species
is
sheepshead
minnow.
Results
of
this
test
are
tabulated
below.

Estuarine/
Marine
Fish
Early
Life­
Stage
Toxicity
Under
Flow­
through
Conditions
Surrogate
Species/
Study
Duration/
Flow­
through
or
Static
Salinity
&
Temperature
%
ai
NOAEC/
LOAEC
Fg/
L
(
ppb)
(
measured
or
nominal)
Statistically
sign.
(
p=
0.05)
Endpoints
Affected
MRID
No.
Author/
Year
Study
Classification
Sheepshead
Minnow
(
Cyprinodon
variegatus)
Study
duration
­
unknown
Flow­
through
test
Salinity
­
13g/
L;
T
30+
1EC
97.4
NOAEC
1,900
LOAEC
3,400
(
measured)
89
%
red.
in
juvenile
survival
45202920
Ward
&
Ballantine
1985
Supplemental
(
no
raw
data
for
statistical
analyses)

Biagianti­
Risbourg
and
Bastide
(
1995)
exposed
juvenile
gray
mullets
(
Liza
ramada)
to
170
Fg/
L
atrazine
for
9,
20,
and
29
days
in
static
tests
and
for
11
days
followed
by
18
days
of
XI
­
25
decontamination;
and
then
measured
the
sublethal
effects
on
the
liver.
At
170
Fg/
L,
10,
25
and
60
percent
mortality
occurred
following
9­,
20­
and
29­
day
exposures,
respectively;
control
mortality
was
a
constant
10
percent
throughout
the
test.
Treated
mullets
showed
normal
behavior
until
Day
20
after
which
they
stopped
feeding
and
rapidly
died;
which
is
in
contrast
to
the
90
percent
survival
of
the
treated
fish
that
were
transferred
to
clean
water
after
11
days
of
exposure.
After
3­
days
exposure,
a
number
of
abnormalities
were
found
in
the
liver
(
i.
e.,
hepatic
parenchyma
with
a
few
cytologically
detectable
perturbations
and
hepatocytes
had
particularly
large
lipofuscin
granules
(
MRID
#
45204902).
The
guideline
requirement
(
72­
4)
is
not
fulfilled
since
the
study
was
lacking
raw
data
and
could
not
be
evaluated.

Degradates:
The
major
atrazine
degradate,
hydroxyatrazine,
forms
a
large
percentage
of
the
recoverable
pesticide
in
aquatic
environmental
compartments.
Therefore,
a
special
estuarine
fish
early
life­
stage
test
(
72­
4)
is
considered
to
address
concerns
for
the
toxicity
of
atrazine
degradates
to
estuarine
fish
(
preferably
sheepshead
minnow).
The
requirement
(
72­
4)
has
not
been
fulfilled
and
is
reserved
pending
the
results
of
the
acute
estuarine
fish
test.

An
estuarine/
marine
fish
life­
cycle
test
using
the
TGAI
is
reserved
pending
the
results
of
acute
and
early
life­
stage
tests
on
estuarine
fish
studies.
The
guideline
requirements
(
72­
5)
is
reserved.

iii.
Estuarine
and
Marine
Invertebrates,
Acute
Acute
toxicity
testing
with
estuarine/
marine
invertebrates
using
the
TGAI
is
required
for
atrazine
because
the
end­
use
product
is
expected
to
reach
this
environment
because
of
its
use
in
coastal
counties.
The
preferred
test
species
are
mysid
shrimp
and
eastern
oyster.
Results
of
these
tests
are
tabulated
below.

Estuarine/
Marine
Invertebrate
Acute
Toxicity
Surrogate
Species/
Static
or
Flow­
through/
Salinity
&
Temperature
%
ai.
96­
hour
LC50/
EC50
Fg/
L
(
ppb)
(
measured/
nominal)
Probit
Slope
Toxicity
Category
MRID
No.
Author/
Year
Study
Classification
Copepod
(
Acartia
tonsa)
Static­
renewal
­
daily
Salinity
­
31
g/
L;
T
22EC
70
Tech.
88
(
measured)
Slope
0.947
very
highly
toxic
45202918
Thursby
et
al.
1990
memo
Supplemental
(
12%
control
mortality)

Copepod
(
Acartia
tonsa)
Static
test
Salinity
­
20
g/
L;
T
20+
1EC
97.4
94
(
nominal)
Slope
­
none
very
highly
toxic
45202920
Ward
&
Ballantine
1985
Supplemental
(
no
raw
data)

Copepod
(
Acartia
tonsa)
Static­
renewal
­
daily
Salinity
­
31­
32
g/
L;
T
22EC
70
Tech.
139
(
measured)
Slope
0.543
highly
toxic
45202918
Thursby
et
al.
1990
memo
Supplemental
(
20%
control
mortality)

Copepod
nauplii
<
24
hours
old
(
Eurytemora
affinis)
Static
test;
T
­
20EC
Salinity
­
5,
15
&
25g/
L
97.1
Sal.
5
g/
L
500
Sal.
15
g/
L
2,600
Sal.
25
g/
L
13,300
(
measured)
Slope
­
no
data
highly
toxic
to
slightly
toxic
45208303
&
45227711
Hall,
Ziegenfuss,
Anderson,
Spittler
&
Leichtweis
1994
Supplemental
(
no
raw
data
on
mortality)
Estuarine/
Marine
Invertebrate
Acute
Toxicity
Surrogate
Species/
Static
or
Flow­
through/
Salinity
&
Temperature
%
ai.
96­
hour
LC50/
EC50
Fg/
L
(
ppb)
(
measured/
nominal)
Probit
Slope
Toxicity
Category
MRID
No.
Author/
Year
Study
Classification
XI
­
26
Mysid
Shrimp
(
Americamysis
bahia)
Flow­
through
test
Salinity
26
g/
L;
T
22+
1EC
97.4
1,000
(
Measured)
Slope
­
none
highly
toxic
45202920
Ward
&
Ballantine
1985
Supplemental
(
no
raw
data)

Brown
Shrimp
(
juvenile)
(
Penaeus
aztecus)
Flow­
through
test
Salinity
­
30
g/
L;
T
27EC
99.7
1,000
(
nominal)
Slope
­
none
at
least
highly
toxic
40228401
Mayer
1986
Supplemental
(
48­
hr
LC50
&
no
raw
data)

Copepod
­
17
days
old
(
Acartia
tonsa)
Flow­
through
test
Salinity
­
31­
33
/
L,
T
­
20EC
97.1
4,300
(
measured)
Slope
­
2.467
moderately
toxic
45208308
McNamara
1991
Supplemental
(
cloudy
with
no
0.45
Fm
filter
of
undissolved
test
material)

Mysid
Shrimp
(
Americamysis
bahia)
Flow­
through
test
Salinity
­
32
g/
L;
T
25­
26EC
97.1
5,400
(
measured)
Slope
4.513
moderately
toxic
43344902
Machado
1994
Core
Pink
Shrimp
(
Penaeus
duorarum)
Static
test
Salinity
26
g/
L;
T
22+
1EC
97.4
6,900
(
nominal)
Slope
­
none
moderately
toxic
45202920
Ward
&
Ballantine
1985
Supplemental
(
no
raw
data)

Copepod
(
Acartia
clausii)
Static­
renewal
­
daily
Salinity
­
31
g/
L;
T
6­
6.2EC
70
Tech.
7,900
(
nominal)
Slope
0.958
moderately
toxic
45202918
Thursby
et
al.
1990
memo
Core
Grass
Shrimp
(
Palaemonetes
pugio)
Static
test
Salinity
­
26
g/
L;
T
22+
1EC
97.4
9,000
(
nominal)
Slope
­
none
Moderately
toxic
45202920
Ward
&
Ballantine
1985
Supplemental
(
no
raw
data)

Eastern
oyster
(
juvenile)
(
Crassostrea
virginica)
(
Shell
deposition)
Flow­
through
test
Salinity
­
28
g/
L;
T
­
28EC
99.7
>
1,000
no
effect
(
nominal)
Slope
­
none
unknown
40228401
Mayer
1986
Supplemental
(
EC50
has
not
been
identified
&
no
raw
data)

Mud
Crab
(
Neopanope
texana)
Static
test
Salinity
&
T
­
unknown
Tech.
>
1,000
(
nominal)
Slope
­
none
slightly
toxic
00024719
Bentley
&
Macek
1973
Supplemental
(
LC50
exceeds
water
solubility)

Since
the
lowest
acute
LC50/
EC50
value
is
in
the
range
of
>
1
­
10
ppm,
atrazine
is
categorized
as
moderately
toxic
to
estuarine/
marine
invertebrates
on
an
acute
basis.
Toxicity
data
on
the
copepod,
Eurytemora
affinis,
indicates
that
atrazine
toxicity
decreases
with
increasing
salinity
levels.
The
pattern
of
decreasing
toxicity
is
opposite
to
atrazine
toxicity
data
on
sheepshead
minnows,
Cyprinodon
variegatus.
The
guideline
requirement
(
72­
3c)
for
shrimp
is
fulfilled
(
MRID
43344902),
but
the
guideline
requirement
(
72­
3b)
for
oysters
is
not
fulfilled.
XI
­
27
Estuarine/
Marine
Invertebrate
Acute
Toxicity
­
Formulations
Surrogate
Species/
Static
or
Flow­
through
%
ai.
Product
96­
hour
LC50/
EC50
Fg/
L
(
ppb)
(
measured/
nominal)
Probit
Slope
Toxicity
Category
MRID
No.
Author/
Year
Study
Classification
Eastern
Oyster
(
Crassostrea
virginica)
(
Shell
deposition)
Flow­
through
test
Salinity
­
11.8
mg/
L;
T
21EC
79.6
80
WP
>
800
no
effect
(
nominal)
Slope
­
none
unknown
00024720
Wright
&
Beliles
1966
Supplemental
(
EC50
has
not
been
identified)

Pacific
Oyster
(
Crassostrea
gigas)
24­
Hour
Static­
Renewal
??
>
100
(
nominal)
0.1
­
50%
dead
at
22
days
0.2
­
50%
dead
at
18
days
unknown
45227722
Moraga
&
Tanguy
2000
Supplemental
(
no
96­
hour
LC50
value)

European
Brown
Shrimp
(
Crangon
crangon)
Static
test;
15EC
??
WP
10,000
­
33,000
(
nominal)
no
slope
slightly
toxic
45227728
Portmann
1972
Supplemental
(
only
48
hours
&
no
raw
data)

European
Cockle
(
Cardium
edule)
Static
test;
15EC
??
WP
>
100,000
(
nominal)
no
slope
practically
non­
toxic
45227728
Portmann
1972
Supplemental
(
only
48
hours;
LC50
exceeds
water
solubility
&
no
raw
data)

Fiddler
Crab
(
Uca
pugilator)
Static
test
Salinity
­
30
g/
L;
T
19EC
79.6
80
WP
198,000
(
nominal)
Slope
­
none
unknown
00024395
Union
Carbide
Corp.
1975
Supplemental
(
LC50
exceeds
water
solubility)

Fiddler
Crab
(
Uca
pugilator)
Static
test
Salinity
­
30
g/
L;
T
19EC
Unknown
4­
1­
3­
1
WDL
239,000
(
nominal)
Slope
­
none
unknown
00024395
Union
Carbide
Corp.
1975
Supplemental
(
LC50
exceeds
water
solubility)

The
toxicity
of
formulated
atrazine
products
to
marine/
estuarine
invertebrates
are
uncertain,
because
the
EC/
LC50
values
are
not
definitive.

Degradates:
The
major
atrazine
degradate,
hydroxyatrazine,
forms
a
large
percentage
of
the
recoverable
pesticide
in
aquatic
environmental
compartments.
Therefore,
estuarine
invertebrate
acute
tests
(
72­
3b
and
c)
are
required
to
address
concerns
for
the
toxicity
of
atrazine
degradates
to
estuarine
invertebrates
(
preferably
Americamysis
bahia
and
Crassostrea
virginica).
The
requirement
(
72­
3b
and
c)
have
not
been
fulfilled
for
any
atrazine
degradate.

iv.
Estuarine
and
Marine
Invertebrate,
Chronic
An
estuarine/
marine
invertebrate
life­
cycle
toxicity
test
using
the
TGAI
is
required
for
atrazine
because
the
end­
use
product
may
be
applied
directly
to
the
estuarine/
marine
environment
or
is
expected
to
be
transported
to
this
environment
from
the
intended
use
site,
and
the
following
conditions
are
met:
the
pesticide
is
intended
for
use
such
that
its
presence
in
water
is
likely
to
be
continuous
and
recurrent;
an
aquatic
acute
EC50
is
less
than
1
mg/
L;
and
the
pesticide
is
persistent
in
water
(
e.
g.,
half­
life
greater
than
4
days).
The
preferred
test
species
is
mysid
shrimp.
Results
of
this
test
are
tabulated
below.
XI
­
28
Estuarine/
Marine
Invertebrate
Life­
Cycle
Toxicity
Species/
Duration/
Flow­
through/
Static­
renewal
%
ai
NOAEC/
LOAEC
Fg/
L
(
ppb)
(
measured/
nominal)
Statistically
sign.
(
P=
0.05)
Endpoints
Affected
MRID
No.
Author/
Year
Study
Classification
Mysid
(
Americamysis
bahia)
Duration
of
test
­
unknown
Flow­
though
test
Salinity
20
g/
L;
25+
1EC
97.4
NOAEC
80
LOAEC
190
(
measured)
37
%
red.
in
adult
survival
45202920
Ward
&
Ballantine
1985
Supplemental
(
no
raw
data
for
statistical
analyses)

The
guideline
requirement
(
72­
4b)
for
an
estuarine
invertebrate
life­
cycle
test
is
not
fulfilled.

Degradates:
The
major
atrazine
degradate,
hydroxyatrazine,
forms
a
large
percentage
of
the
recoverable
pesticide
in
aquatic
environmental
compartments.
Therefore,
a
special
estuarine
invertebrate
life­
cycle
test
(
72­
3)
is
required
to
address
concerns
for
the
toxicity
of
atrazine
degradates
to
estuarine
invertebrates
(
preferably
Americamysis
bahia).
The
requirement
(
72­
4b)
has
not
been
fulfilled
for
any
atrazine
degradate,
but
is
reserved
pending
the
results
of
the
acute
mysid
test.

v.
Estuarine
and
Marine
Field
Studies
Field
studies
are
not
available
with
atrazine
effects
on
estuarine
and/
or
marine
animals.
No
estuarine
field
studies
are
required.

d.
Toxicity
to
Plants
I.
Terrestrial
Terrestrial
plant
testing
(
seedling
emergence
and
vegetative
vigor)
is
required
for
herbicides
that
have
terrestrial
non­
residential
outdoor
use
patterns
and
that
may
move
off
the
application
site
through
volatilization
(
vapor
pressure
>
1.0
x
10­
5mm
Hg
at
25oC)
or
drift
(
aerial
or
irrigation)
and/
or
that
may
have
endangered
or
threatened
plant
species
associated
with
the
application
site.

For
seedling
emergence
and
vegetative
vigor
testing
the
following
plant
species
and
groups
should
be
tested:
(
1)
six
species
of
at
least
four
dicotyledonous
families,
one
species
of
which
is
soybean
(
Glycine
max)
and
the
second
is
a
root
crop,
and
(
2)
four
species
of
at
least
two
monocotyledonous
families,
one
of
which
is
corn
(
Zea
mays).

Terrestrial
Tier
II
studies
are
required
for
all
herbicides
and
any
pesticide
showing
a
negative
response
equal
to
or
greater
than
25%
in
Tier
I
tests.
Tier
II
tests
measure
the
response
of
plants,
relative
to
a
control,
and
five
or
more
test
concentrations
at
a
test
level
that
is
equal
to
the
highest
use
rate
(
expressed
as
lbs
ai/
A).
Results
of
Tier
II
toxicity
testing
on
the
technical
material
are
tabulated
below.
XI
­
29
Nontarget
Terrestrial
Plant
Seedling
Germination
Toxicity
(
Tier
II)

Surrogate
Species
%
ai
EC25/
EC05
(
lbs
ai/
A)
Probit
Slope
Endpoint
Affected
MRID
No.
Author/
Year
Study
Classification
Monocot
­
Corn
(
Zea
mays)
97.7
<
4.0
/
<
4.0
No
effect
41223001
Chetram
1989
Core
Monocot
­
Oat
(
Avena
sativa)
97.7
1.8
/
0.12
slope
0.834
%
red..
in
radicle
length
41223001
Chetram
1989
Core
Monocot
­
Onion
(
Allium
cepa)
97.7
<
4.0
/<
4.0
No
effect
41223001
Chetram
1989
Core
Monocot
­
Ryegrass
(
Lolium
perenne)
97.7
<
4.0
/
<
4.0
slope
0.834
No
effect
41223001
Chetram
1989
Core
Dicot
­
Root
Crop
­
Carrot
(
Daucus
carota)
97.7
<
4.0
/
<
4.0
No
effect
41223001
Chetram
1989
Core
Dicot
­
Soybean
(
Glycine
max)
97.7
<
4.0
/
<
4.0
No
effect
41223001
Chetram
1989
Core
Dicot
­
Lettuce
(
Lactuca
sativa)
97.7
<
4.0
/
<
4.0
No
effect
41223001
Chetram
1989
Core
Dicot
­
Cabbage
(
Brassica
oleracea
alba)
97.7
<
4.0
/
<
4.0
No
effect
41223001
Chetram
1989
Core
Dicot
­
Tomato
(
Lycopersicon
esculentum)
97.7
<
4.0
/
<
4.0
No
effect
41223001
Chetram
1989
Core
Dicot
­
Cucumber
(
Cucumis
sativus)
97.7
0.80
/
0.60
slope
0.864
%
red.
in
radicle
length
41223001
Chetram
1989
Core
Results
from
the
Tier
II
seedling
germination
tests
indicate
that
cucumber
is
the
most
sensitive
dicot
and
oats
is
the
most
sensitive
monocot.
These
studies
are
acceptable
(
MRID
41223001),
but
the
guideline
requirement
for
seed
germination
testing
has
now
been
included
in
the
seedling
emergence
toxicity
test.

Nontarget
Terrestrial
Plant
Seedling
Emergence
Toxicity
(
Tier
II)

Surrogate
Species
%
ai
EC25
/
NOAEC
(
lbs
ai/
A)
Probit
Slope
Endpoint
Affected
MRID
No.
Author/
Year
Study
Classification
Monocot
­
Corn
(
Zea
mays)
97.7
<
4.0
/
<
4.0
No
effect
42041403
Chetram
1989
Core
Monocot
­
Oat
(
Avena
sativa)
97.7
0.004
/
0.0025
red.
in
dry
weight
42041403
Chetram
1989
Core
Monocot
­
Onion
(
Allium
cepa)
97.7
0.009
/
0.005
red.
in
dry
weight
42041403
Chetram
1989
Core
Monocot
­
Ryegrass
(
Lolium
perenne)
97.7
0.004
/
0.005
red.
in
dry
weight
42041403
Chetram
1989
Core
Dicot
­
Root
Crop
­
Carrot
(
Daucus
carota)
97.7
0.003
/
0.0025
red.
in
dry
weight
42041403
Chetram
1989
Core
Dicot
­
Soybean
(
Glycine
max)
97.7
0.19
/
0.025
red.
in
dry
weight
42041403
Chetram
1989
Core
Dicot
­
Lettuce
(
Lactuca
sativa)
97.7
0.005
/
0.005
red.
in
dry
weight
42041403
Chetram
1989
Core
Nontarget
Terrestrial
Plant
Seedling
Emergence
Toxicity
(
Tier
II)

Surrogate
Species
%
ai
EC25
/
NOAEC
(
lbs
ai/
A)
Probit
Slope
Endpoint
Affected
MRID
No.
Author/
Year
Study
Classification
XI
­
30
Dicot
­
Cabbage
(
Brassica
oleracea
alba)
97.7
0.014
/
0.01
red.
in
dry
weight
42041403
Chetram
1989
Core
Dicot
­
Tomato
(
Lycopersicon
esculentum)
97.7
0.034
/
0.01
red.
in
dry
weight
42041403
Chetram
1989
Core
Dicot
­
Cucumber
(
Cucumis
sativus)
97.7
0.013
/
0.005
red.
in
dry
weight
42041403
Chetram
1989
Core
For
Tier
II
seedling
emergence,
the
most
sensitive
dicot
is
the
carrot
and
the
most
sensitive
monocots
are
oat
and
ryegrass.
The
guideline
requirement
(
123­
1a)
is
fulfilled
(
MRID
42041403).

Nontarget
Terrestrial
Plant
Vegetative
Vigor
Toxicity
(
Tier
II)

Surrogate
Species
%
ai
EC25
/
NOAEC
(
lbs
ai/
A)
Endpoint
Affected
MRID
No.
Author/
Year
Study
Classification
Monocot
­
Corn
(
Zea
mays)
97.7
<
4.0
/
<
4.0
No
effect
42041403
Chetram
1989
Core
Monocot
­
Oat
(
Avena
sativa)
97.7
2.4
/
2.0
red.
in
dry
weight
42041403
Chetram
1989
Core
Monocot
­
Onion
(
Allium
cepa)
97.7
0.61
/
0.5
red.
in
dry
weight
42041403
Chetram
1989
Core
Monocot
­
Ryegrass
(
Lolium
perenne)
97.7
<
4.0
/
<
4.0
No
effect
42041403
Chetram
1989
Core
Dicot
­
Root
Crop
­
Carrot
(
Daucus
carota)
97.7
1.7
/
2.0
red.
in
plant
height
42041403
Chetram
1989
Core
Dicot
­
Soybean
(
Glycine
max)
97.7
0.026
/
0.02
red.
in
dry
weight
42041403
Chetram
1989
Core
Dicot
­
Lettuce
(
Lactuca
sativa)
97.7
0.33
/
0.25
red.
in
dry
weight
42041403
Chetram
1989
Core
Dicot
­
Cabbage
(
Brassica
oleracea
alba)
97.7
0.014
/
0.005
red.
in
dry
weight
42041403
Chetram
1989
Core
Dicot
­
Tomato
(
Lycopersicon
esculentum)
97.7
0.72
/
0.5
red.
in
plant
height
42041403
Chetram
1989
Core
Dicot
­
Cucumber
(
Cucumis
sativus)
97.7
0.008
/
0.005
red.
in
dry
weight
42041403
Chetram
1989
Core
For
Tier
II
vegetative
vigor,
the
most
sensitive
dicot
is
cucumber
and
the
most
sensitive
monocot
is
onion.
The
guideline
requirement
(
123­
1b)
is
fulfilled
(
MRID
42041402).

ii.
Aquatic
Plants
Aquatic
plant
testing
is
required
for
any
herbicide
that
has
outdoor
non­
residential
terrestrial
uses
that
may
move
off­
site
by
runoff
(
solubility
>
10
ppm
in
water),
by
drift
(
aerial
or
irrigation),
or
XI
­
31
that
is
applied
directly
to
aquatic
use
sites
(
except
residential).
Aquatic
Tier
II
studies
are
required
for
all
herbicides
and
any
pesticide
showing
a
negative
response
equal
to
or
greater
than
50%
in
Tier
I
tests.
The
following
species
should
be
tested
at
Tier
II:
Kirchneria
subcapitata,
Lemna
gibba,
Skeletonema
costatum,
Anabaena
flos­
aquae,
and
a
freshwater
diatom.
Aquatic
plant
testing
is
required
for
atrazine
because
atrazine
is
applied
on
crops
outdoors
and
would
appear
to
be
mobile
with
a
water
solubility
value
of
33
ppm.

Results
of
Tier
II
toxicity
testing
on
technical
grade
and
typical
end­
use
products
(
TEP)
are
tabulated
below.
The
data
are
presented
in
four
toxicity
tables
separating
the
freshwater
data
from
the
marine
data
and
the
short,
7­
day
or
less
tests
from
the
longer
tests.

Nontarget
Freshwater
Plant
Toxicity
(
Tier
II)

Surrogate
Species/
Duration/
Measured/
nominal
%
ai
Conc.
(
ppb)
Probit
Slope
%
Response
MRID
No.
Author/
Year
Study
Classification
Vascular
Plants:

Duckweed
(
Lemna
gibba)
5­
Day
test;
Static­
Renewal
97
170
(
nominal)
Slope
3.93
50%
red.
in
growth
41065203d
Hughes
1986
Supplemental
(
5
days,
not
14
days)

Duckweed
(
Lemna
gibba)
7­
Day
test;
Static­
Renewal
97
170
(
measured)
Slope
2.2
50%
red.
in
growth
42041404
Hoberg
1991
Supplemental
(
7
days,
not
14
days)

Non­
Vascular
Plants:

Cyanophyceae
Oscillatoria
lutea
(
1week;
nominal)
76
80
W
<
1
1,000
93%
red.
chlorophyll
production
100%
red.
chlorophyll
prod.
Torres
and
O'Flaherty
1976
Supplemental
(
raw
data
unavailable)

Chlorophyceae
Stigeoclonium
tenue
(
1
week;
nominal)
76
80
W
<
1
1,000
67%
red.
chlorophyll
production
90%
red.
chlorophyll
production
Torres
and
O'Flaherty
1976
Supplemental
(
raw
data
unavailable)

Green
Algae
­
Chlorophyceae
Chlorella
vulgaris
(
1
week;
nominal)
76
80
W
1
1,000
50%
red.
chlorophyll
production
80­
87%
red.
chlorophyll
production
Torres
and
O'Flaherty
1976
Supplemental
(
raw
data
unavailable)

Xanthophyceae
Tribonema
sp.
(
1
week;
nominal)
76
80
W
1
1,000
42%
red.
chlorophyll
production
75%
red.
chlorophyll
production
Torres
and
O'Flaherty
1976
Supplemental
(
raw
data
unavailable)

Xanthophyceae
Vaucheria
geminata
(
1
week;
nominal)
76
80
W
1
1,000
41%
red.
chlorophyll
production
100%
red.
chlorophyll
production
Torres
and
O'Flaherty
1976
Supplemental
(
raw
data
unavailable)

Chlorophyceae
Chlamydomonas
reinhardi
(
24
hour;
nominal)
Unk.
19
44
48
50%
red.
carbon
uptake;
media:
Taub
&
Dollar
(
TD)
45020015
Larsen
et
al.
1986
Supplemental
(
raw
data
unavailable)
Nontarget
Freshwater
Plant
Toxicity
(
Tier
II)

Surrogate
Species/
Duration/
Measured/
nominal
%
ai
Conc.
(
ppb)
Probit
Slope
%
Response
MRID
No.
Author/
Year
Study
Classification
XI
­
32
Chlorophyceae
Kirchneria
subcapitata
=
Selenastrum
capricornutum
(
96
hours;
nominal)
Tech.
26
26
50%
red.
cell
growth
50%
red.
floresence
Caux,
Menard,
and
Kent
1996
Supplemental
(
NOAEC
and
raw
data
unavailable)

Chlorophyceae
Kirchneria
subcapitata
=
Selenastrum
capricornutum
(
24
hours;
nominal)
Unk.
34
42
53
50%
red.
14­
carbon
uptake;
media:
Taub
&
Dollar
(
TD);
algal
assay
&
TD,
respect.
45020015
Larsen
et
al.
1986
Supplemental
(
raw
data
unavailable)

Cyanophyceae
Anabaena
cylindrica
(??
hours;
nominal)
97
37
50%
red.
in
photosynthesis
Stratton
&
Corke
1981
Supplemental
(
no
raw
data)

Chlorophyceae
Scenedesmus
obliquus
(
24
hour;
nominal)
Unk.
38
49
57
50%
red.
14­
carbon
uptake;
media:
Taub
&
Dollar
(
TD)
45020015
Larsen
et
al.
1986
Supplemental
(
raw
data
unavailable)

Chlorophyceae
Kirchneria
subcapitata
=
Selenastrum
capricornutum
(
120
hours;
measured)
97.1
49
NOAEC
16
Slope
4.002
50%
red.
cell
growth
43074802
Hoberg
1993
Core
Cyanophyceae
Anabaena
inaequalis
(??
hours;
nominal)
97
50
50%
red.
in
photosynthesis
Stratton
&
Corke
1981
Supplemental
(
no
raw
data)

Chlorophyceae
Kirchneria
subcapitata
=
Selenastrum
capricornutum
(
120
hours;
nominal)
97.4
53
NOAEC
<
32
LOAEC
32
Slope
4.127
50%
red.
growth
17%
red.
growth
41065204
Parrish
1978
Supplemental
(
NOAEC,
method
&
raw
data
unavailable)

Bacillariophyceae
Navicula
pelliculosa
(
120
hours;
nominal)
97.1
60
NOAEC
<
10
LOAEC
10
Slope
2.31
50%
red.
growth
41065203a
Hughes
1986
Core
(
EC50
extrapolated;
and
NOAEC
was
not
determined)

Chlorophyceae
Ankistrodesmus
sp.
(
24
hours;
nominal)
Unk.
61
72
219
50%
red.
14­
carbon
uptake;
media:
Taub
&
Dollar
(
TD),
TD
&
algal
assay,
respect.
45020015
Larsen
et
al.
1986
Supplemental
(
raw
data
unavailable)

Ulothrix
subconstricta
Tentative
species
identification
(
24
hours;
nominal)
Unk.
88
50%
red.
14­
carbon
uptake;
medium:
Taub
&
Dollar
(
TD)
45020015
Larsen
et
al.
1986
Supplemental
(
raw
data
unavailable)

Cyanophyceae
Anabaena
variabilis
(??
hours;
Nominal)
97
100
50%
red.
in
photosnythesis
Stratton
&
Corke
1981
Supplemental
(
no
raw
data)

Stigeoclonium
tenue
Tentative
species
Identification
(
24
hours;
nominal)
Unk.
127
224
50%
red.
14­
carbon
uptake;
media:
Taub
&
Dollar
(
TD)
45020015
Larsen
et
al.
1986
Supplemental
(
raw
data
unavailable)
Nontarget
Freshwater
Plant
Toxicity
(
Tier
II)

Surrogate
Species/
Duration/
Measured/
nominal
%
ai
Conc.
(
ppb)
Probit
Slope
%
Response
MRID
No.
Author/
Year
Study
Classification
XI
­
33
Chlorophyceae
Kirchneria
subcapitata
=
Selenastrum
capricornutum
(
96
hours;
measured)
97
130
NOAEC
76
Slope
6.628
50%
red.
cell
growth
42060701
Hoberg
1991
Supplemental
(
higher
light
intensity
than
recommended)

Cyanophyceae
Anabaena
cylindrica
(
24
hour;
nominal)
Unk.
178
182
253
50%
red.
14­
carbon
uptake;
media:
Taub
&
Dollar
(
TD),
algal
assay,
&
TD,
respect.
45020015
Larsen
et
al.
1986
Supplemental
(
raw
data
unavailable)

Cyanophyceae
Anabaena
flos­
aquae
(
120
hours;
nominal)
97
230
NOAEC
<
100
LOAEC
100
Slope
1.95
50%
red.
growth
22%
red.
growth
41065203a
Hughes
1986
Core
(
NOAEC
was
not
determined)

Chlorophyceae
Chlorella
pyrenoidosa
(
120
hours;
nominal)
97.4
282
NOAEC
130
Slope
4.216
50%
red.
growth
7%
red.
growth
41065204
Parrish
1978
Supplemental
(
NOAEC,
method
&
raw
data
unavailable)

Chlorophyceae
Chlorella
vulgaris
(
24
hours;
nominal)
Unk.
293
305
325
50%
red.
14­
carbon
uptake;
media:
Algal
assay,
Taub
&
Dollar
(
TD),
&
TD,
respect.
45020015
Larsen
et
al.
1986
Supplemental
(
raw
data
unavailable)

Longer
Term,
Nontarget
Freshwater
Plant
Toxicity
Surrogate
Species/
Duration/
Measured/
nominal
%
ai
Conc.
(
ppb)
Probit
Slope
%
Response
MRID
No.
Author/
Year
Study
Classification
Vascular
Plants:

Broad
Waterweed
Elodea
canadensis
(
20
days;
measured)
????
NOAEC
2
LOAEC
10
200%
incr.
dark
respiration
33%
incr.
net
photosynthesis
45227714
Hofmann
and
Winkler
1990
Supplemental
(
raw
data
unavailable)

Pondweed
Potamogeton
perfoliatus
(
4
weeks;
initial
conc.
nominal,
terminal
conc.
measured)
???
30
Week
3:
LOAEC
5
NOAEC
<
5
4
Weeks:
LOAEC
50
NOAEC
5
50%
red.
O2
product.
sign.
red.
O2
product.

sign.
red.
O2
product.
Kemp
et
al.
1985
Supplemental
(
raw
data
unavailable)

Duckweed
Lemna
gibba
(
14
days;
measured)
97.1
37
LOAEC
3.4
NOAEC
<
3.4
Slope
1.716
50%
red.
growth
19%
red.
growth
(
frond
production)
43074804
Hoberg
1993
Supplemental
(
NOAEC
was
not
determined)

Duckweed
­
Lemna
gibba
(
14
days;
measured)
97.4
43
NOAEC
10
Slope
1.995
50%
red.
growth
(
frond
production)
43074803
Hoberg
1993
Core
Broad
Waterweed
Elodea
canadensis
(
3
weeks;
nominal)
???
80
50%
red.
shoot
length
45087410
Forney
and
Davis
1981
Supplemental
(
raw
data
unavailable)
Longer
Term,
Nontarget
Freshwater
Plant
Toxicity
Surrogate
Species/
Duration/
Measured/
nominal
%
ai
Conc.
(
ppb)
Probit
Slope
%
Response
MRID
No.
Author/
Year
Study
Classification
XI
­
34
Eurasian
Water­
Milfoil
Myriophyllum
spicatum
(
4
weeks;
initial
conc.
nominal,
terminal
conc.
measured)
????
91
NOAEC
5
LOAEC
50
50%
red,
O2
product.

Sign.
red.
O2
product.
Kemp
et
al.
1985
Supplemental
(
raw
data
unavailable)

Non­
Vascular
Plants:

36
freshwater
algal
strains
(
2
weeks;
nominal)
99.0
10
1,000
growth
<
than
control
strong
growth
red.
Butler
et
al.
1975
Supplemental
(
raw
data
unavailable)

Chlorophyceae
Chlorella
vulgaris
(
11
days;
nominal)
99.9
25
50%
red.
cell
growth
45227703
Burrell
et
al.
1985
Supplemental
(
raw
data
unavailable)

Cyanophyceae
Anabaena
inaequalis
(
12­
14
days1;
nominal)
>
95
30
100
300
50%
red.
cell
count
50%
red.
growth
rate
50%
red.
photosynthesis
45087401
Stratton
1984
Supplemental
(
NOAEC
and
raw
data
unavailable)

Chlorophyceae
Ankistrodesmus
braunii
(
11
days;
nominal)
99.9
60
50%
red.
cell
growth
45227703
Burrell
et
al.
1985
Supplemental
(
raw
data
unavailable)

Chlorophyceae
Scenedesmus
quadricauda
(
12­
14
days1;
nominal)
>
95
100
200
300
50%
red.
cell
count
50%
red.
growth
rate
50%
red.
photosynthesis
45087401
Stratton
1984
Supplemental
(
NOAEC
and
raw
data
unavailable)

Chlorophyceae
Chlorella
pyrenoidosa
(
12­
14
days1;
nominal)
>
95
300
1,000
500
50%
red.
cell
count
50%
red.
growth
rate
50%
red.
photosynthesis
Stratton
1984
Supplemental
(
NOAEC
and
raw
data
unavailable)

Cyanophyceae
Anabaena
cylindrica
(
12­
14
days;
nominal)
>
95
1,200
3,600
500
50%
red.
cell
count
50%
red.
growth
rate
50%
red.
photosynthesis
Stratton
1984
Supplemental
(
NOAEC
and
raw
data
unavailable)

Cyanophyceae
Anabaena
variabilis
(
12­
14
days;
nominal)
>
95
4,000
5,000
100
50%
red.
cell
count
50%
red.
growth
rate
50%
red.
photosynthesis
Stratton
1984
Supplemental
(
NOAEC
and
raw
data
unavailable)

Nontarget
Marine/
Estuarine
Plant
Toxicity
(
Tier
II)

Surrogate
Species/
Duration/
Measured/
nominal
%
ai
Conc.
(
ppb)
Probit
Slope
%
Response
MRID
No.
Author/
Year
Study
Classification
Vascular
Plants:

Fontinalis
sp.
(
24
hours;
measured)
????
NOAEC
2
LOAEC
10
red.
net
O2
production
Supplemental
(
raw
data
unavailable)
Nontarget
Marine/
Estuarine
Plant
Toxicity
(
Tier
II)

Surrogate
Species/
Duration/
Measured/
nominal
%
ai
Conc.
(
ppb)
Probit
Slope
%
Response
MRID
No.
Author/
Year
Study
Classification
XI
­
35
Pondweed
(
Estuarine)
Potamogeton
perfoliatus
(
2
hours;
nominal)
????
77
50%
red.
O2
evolution
45227718
Jones
and
Winchell
1984
Supplemental
(
Insufficient
duration;
raw
data
unavailable)

Pondweed
Potamogeton
perfoliatus
(
2
hours;
nominal)
???
80
650
50%
red.
O2
product.

87%
red.
O2
product..
45227718
Jones
et
al.
1986
Supplemental
(
Insufficient
duration;
raw
data
unavailable)

Zannichellia
palustris
(
2
hours;
nominal)
????
91
50%
red.
O2
evolution
45227719
Jones
and
Winchell
1984
Supplemental
(
Insufficient
duration;
raw
data
unavailable)

Pondweed
(
Estuarine)
Potamogeton
perfoliatus
(
2
hours;
nominal)
Unk.
100
52
to
69%
red.
in
photosynthesis
45087404
Jones
&
Estes
1984
Supplemental
(
raw
data
unavailable)

Widgeon­
Grass
(
Estuarine)
Ruppia
maritima
(
2
hours;
nominal
?????
102
50%
red.
O2
evolution
45227719
Jones
and
Winchell
1984
Supplemental
(
Insufficient
duration;
raw
data
unavailable)

Non­
Vascular
Plants:

Blue­
green
­
Cyanophyceae
Oscillatoria
lutea
(
1week;
nominal)
76
80
W
1
1,000
93%
red.
chlorophyll
production
100%
red.
chlorophyll
prod.
00023544
Torres
and
O'Flaherty
1976
Supplemental
(
raw
data
unavailable)

Green
Algae
­
Chlorophyceae
Stigeoclonium
tenue
(
1
week;
nominal)
76
80
W
1
1,000
67%
red.
chlorophyll
production
90%
red.
chlorophyll
production
00023544
Torres
and
O'Flaherty
1976
Supplemental
(
raw
data
unavailable)

Green
Algae
­
Chlorophyceae
Chlorella
vulgaris
(
1
week;
nominal)
76
80
W
1
1,000
50%
red.
chlorophyll
production
80­
87%
red.
chlorophyll
prod.
00023544
Torres
and
O'Flaherty
1976
Supplemental
(
raw
data
unavailable)

Xanthophyceae
Tribonema
sp.
(
1
week;
nominal)
76
80
W
1
1,000
42%
red.
chlorophyll
production
75%
red.
chlorophyll
production
00023544
Torres
and
O'Flaherty
1976
Supplemental
(
raw
data
unavailable)

Xanthophyceae
Vaucheria
geminata
(
1
week;
nominal)
76
80
W
1
1,000
41%
red.
chlorophyll
production
100%
red.
chlorophyll
prod.
00023544
Torres
and
O'Flaherty
1976
Supplemental
(
raw
data
unavailable)

Chrysophyceae
Isochrysis
galbana
(
120
hours;
nominal)
97.4
22
NOAEC
<
13
LOAEC
13
Slope
3.065
50%
red.
growth
30%
red.
growth
41065204
Parrish
1978
Supplemental
(
NOAEC,
method
&
raw
data
unavailable)

Marine
Diatom
Skeletonema
costatum
(
120
hours;
nominal)
97.4
24
NOAEC
<
13
LOAEC
13
Slope
3.343
50%
red.
growth
14%
red.
growth
41065204
Parrish
1978
Supplemental
(
NOAEC,
method
&
raw
data
unavailable)

Marine
Diatom
Skeletonema
costatum
(
120
hours;
measured)
97.1
53
NOAEC
14
Slope
2.798
50%
red.
cell
growth
43074801
Hoberg
1993
Core
Nontarget
Marine/
Estuarine
Plant
Toxicity
(
Tier
II)

Surrogate
Species/
Duration/
Measured/
nominal
%
ai
Conc.
(
ppb)
Probit
Slope
%
Response
MRID
No.
Author/
Year
Study
Classification
XI
­
36
Marine
Green
­
Chlorophyceae
Chlamydomonas
sp.
(
72
hours;
nominal);
Salinity
30
g/
L
99.7
60
50%
red.
O2
production
40228401
Mayer
1986
Supplemental
(
72
hrs
&
endpoint)

Marine
Yellow
­
Chrysophyceae
Monochrysis
lutheri
(
72
hours;
nominal);
Salinity
30
g/
L
99.7
77
50%
red.
O2
production
40228401
Mayer
1986
Supplemental
(
72
hrs
&
endpoint)

Marine
Red
­
Rhodophyceae
Porphyridium
cruentum
(
72
hours;
nominal);
Salinity
30
g/
L
99.7
79
50%
red.
in
O2
production
40228401
Mayer
1986
Supplemental
(
72
hrs
&
endpoint)

Marine
Green
­
Chlorophyceae
Neochloris
sp.
(
72
hours;
nominal);
Salinity
30
g/
L
99.7
82
50%
red.
in
O2
production
40228401
Mayer
1986
Supplemental
(
72
hrs
&
endpoint)

Marine
Bacillariophyceae
Cyclotella
nana
(
72
hours;
nominal);
Salinity
30
g/
L
99.7
84
50%
red.
in
O2
production
40228401
Mayer
1986
Supplemental
(
72
hrs
&
endpoint)

Marine
Bacillariophyceae
Achnanthes
brevipes
(
72
hours;
nominal);
Salinity
30
g/
L
99.7
93
50%
red.
in
O2
production
40228401
Mayer
1986
Supplemental
(
72
hrs
&
endpoint)

Marine
Yellow
­
Chrysophyceae
Isochrysis
galbana
(
240
hours;
nominal);
Salinity
30
g/
L
99.7
100
50%
red.
cell
growth
40228401
Mayer
1986
Supplemental
(
NOAEC
unavailable)

Marine
Green
­
Chlorophyceae
Chlorococcum
sp.
(
240
hours;
nominal);
Salinity
30
g/
L
99.7
100
50%
red.
cell
growth
40228401
Mayer
1986
Supplemental
(
NOAEC
unavailable)

Marine
Green
­
Chlorophyceae
Platymonas
sp.
(
72
hours;
nominal);
Salinity
30
g/
L
99.7
100
50%
red.
O2
production
40228401
Mayer
1986
Supplemental
(
72
hrs
&
endpoint)

Marine
Bacillariophyceae
Thalassiosira
fluviatilis
(
72
hours;
nominal);
Salinity
30
g/
L
99.7
110
50%
red.
O2
production
40228401
Mayer
1986
Supplemental
(
72
hrs
&
endpoint)

Marine
Bacillariophyceae
Stauroneis
amphoroides
(
72
hours;
nominal);
Salinity
30
g/
L
99.7
110
50%
red.
O2
production
40228401
Mayer
1986
Supplemental
(
72
hrs
&
endpoint)
Nontarget
Marine/
Estuarine
Plant
Toxicity
(
Tier
II)

Surrogate
Species/
Duration/
Measured/
nominal
%
ai
Conc.
(
ppb)
Probit
Slope
%
Response
MRID
No.
Author/
Year
Study
Classification
XI
­
37
Marine
Algae
Microcystis
aeruginosa
(
120
hours
­
nominal)
97.4
129
NOAEC
65
Slope
3.162
50%
red.
growth
7%
red.
growth
41065204
Parrish
1978
Supplemental
(
NOAEC,
method
&
raw
data
unavailable)

Marine
Green
­
Chlorophyceae
Chlorella
sp.
(
72
hours;
nominal);
Salinity
30
g/
L
99.7
140
50%
red.
O2
production
40228401
Mayer
1986
Supplemental
(
NOAEC
unavailable
Blue­
green
­
Cyanophyceae
Anabaena
cylindrica
(
24
hour;
nominal)
Unk.
178
182
253
50%
red.
14­
carbon
uptake;
media:
Taub
&
Dollar
(
TD),
algal
assay,
&
TD,
respect.
45020015
Larsen
et
al.
1986
Supplemental
(
raw
data
unavailable)

Marine
green
­
Chlorophyceae
Dunaliella
tertiolecta
(
120
hours;
nominal)
97
180
NOAEC
<
100
LOAEC
100
Slope
1.95
50%
red.
growth
34%
red.
growth
41065203
Hughes
1986
Supplemental
(
NOAEC
unavailable)

Marine
Yellow
­
Chrysophyceae
Phaeodactylum
tricornutum
(
240
hours;
nominal);
Salinity
30
g/
L
99.7
200
50%
red.
cell
growth
40228401
Mayer
1986
Supplemental
(
NOAEC
unavailable)

Marine
Bacillariophyceae
Nitzschia
closterium
(
72
hours;
nominal);
Salinity
30
g/
L
99.7
290
50%
red.
O2
production
40228401
Mayer
1986
Supplemental
(
72
hrs
&
endpoint)

Marine
Bacillariophyceae
Amphora
exigua
(
72
hours;
nominal);
Salinity
30
g/
L
99.7
300
50%
red.
O2
production
40228401
Mayer
1986
Supplemental
(
72
hrs
&
endpoint)

Marine
Green
­
Chlorophyceae
Dunaliella
tertiolecta
(
240
hours;
nominal);
Salinity
30
g/
L
99.7
300
50%
red.
cell
growth
40228401
Mayer
1986
Supplemental
(
NOAEC
unavailable)

Marine
Red
­
Rhodophyceae
Porphyridium
cruentum
(
120
hours)
97.4
308
NOAEC
<
130
LOAEC
130
Slope
2.449
50%
red.
growth
16%
red.
growth
41065204
Parrish
1978
Supplemental
(
NOAEC,
method
&
raw
data
unavailable)

Marine
Bacillariophyceae
Nitzschia
(
Ind.
684)
(
72
hours;
nominal);
Salinity
30
g/
L
99.7
430
50%
red.
O2
production
40228401
Mayer
1986
Supplemental
(
72
hrs
&
endpoint)

Marine
Green
­
Chlorophyceae
Kirchneria
subcapitata
(
120
hours;
nominal)
97.4
431
NOAEC
200
Slope
4.217
5%
red.
in
growth
4%
red.
in
growth
41065204
Parrish
1978
Supplemental
(
NOAEC,
method
&
raw
data
unavailable)
Nontarget
Marine/
Estuarine
Plant
Toxicity
(
Tier
II)

Surrogate
Species/
Duration/
Measured/
nominal
%
ai
Conc.
(
ppb)
Probit
Slope
%
Response
MRID
No.
Author/
Year
Study
Classification
XI
­
38
Marine
Bacillariophyceae
Navicula
inserta
(
72
hours;
nominal);
Salinity
30
g/
L
99.7
460
50%
red.
in
O2
production
40228401
Mayer
1986
Supplemental
(
72
hrs
&
endpoint)

Formulation
Nontarget
Marine/
Estuarine
Algal
Toxicity
(
Tier
II)

Species/
Duration/
Measured/
nominal
%
ai
Conc.
(
ppb)
Probit
slope
%
Response
MRID
No.
Author/
Year
Study
Classification
Mar.
Yellow
­
Chrysophyceae
Isochrysis
galbana
(
nominal);
Salinity
30
g/
L
76
80
WP
100
(
240
hrs)

200
(
2
hrs)
50%
red.
cell
growth
50%
red.
O2
production
40228401
Mayer
1986
Supplemental
(
NOAEC
unavailable)

Mar.
Yellow
Chlorophyceae
Chlorococcum
sp.
(
nominal);
Salinity
30
g/
L
76
80
WP
100
(
240
hrs)

400
(
2
hrs)
50%
red.
cell
growth
50%
red.
O2
production
40228401
Mayer
1986
Supplemental
(
NOAEC
unavailable)

Mar.
Yellow
­
Chrysophyceae
Phaeodactylum
tricornutum
(
nominal);
Salinity
30
g/
L
76
80
WP
200
(
240
hrs)

200
(
2
hrs)
50%
red.
cell
growth
50%
red.
O2
production
40228401
Mayer
1986
Supplemental
(
NOAEC
unavailable)

Mar.
Green
­
Chlorophyceae
Dunaliella
tertiolecta
(
nominal);
Salinity
30
g/
L
76
80
WP
400
(
240
hrs)

600
(
2
hrs)
50%
red.
cell
growth
50%
red.
O2
production
40228401
Mayer
1986
Supplemental
(
NOAEC
unavailable)

Longer­
term
Nontarget
Marine/
Estuarine
Plant
Toxicity
Surrogate
Species/
Duration/
Measured/
nominal
%
ai
Conc.
(
ppb)
Probit
Slope
%
Response
MRID
No.
Author/
Year
Study
Classification
Vascular
Plants:

Sago
Pondweed
(
Estuarine)
Potamogeton
pectinatus
(
28
days;
measured/
nominal)
???
Salinity
12
ppt:

NOAEC
7.5
LOAEC
14.3
Salinity
1
&
6
ppt:

NOAEC
14.3
LOAEC
30
sign.
red.
dry
weight
sign.
red.
dry
weight
45088231
Chesapeake
Bay
Program
1998
Supplemental
(
raw
data
unavailable)

Estuarine
rush
Juncus
roemerianus
(
5
weeks
­
1
year;
measured
97.1
LOAEC
30
NOAEC
30
NOAEC
<
30
250
ppb
3,
800
ppb
sign.
red.
chlorophyll
a
in
5
weeks
(
1
year)
partial
recovery
(
1
yr)
practically
no
survival
45087405
Lytle
&
Lytle
1998
Supplemental
(
raw
data
unavailable)
Longer­
term
Nontarget
Marine/
Estuarine
Plant
Toxicity
Surrogate
Species/
Duration/
Measured/
nominal
%
ai
Conc.
(
ppb)
Probit
Slope
%
Response
MRID
No.
Author/
Year
Study
Classification
XI
­
39
Pondweed
Potamogeton
perfoliatus
(
4
weeks;
initial
conc.
nominal,
terminal
conc.
measured)
???
30
Week
3:
LOAEC
5
NOAEC
<
5
4
weeks:
LOAEC
50
NOAEC
5
50%
red.
O2
product.
sign.
red.
O2
product.

sign.
red.
O2
product.
45227720
Kemp
et
al.
1985
Supplemental
(
raw
data
unavailable)

Pondweed
(
Estuarine)
Potamogeton
perfoliatus
(
3
weeks;
nominal)
???
53
50%
red.
????
45087410
Forney
and
Davis
1981
Supplemental
(
raw
data
unavailable)

Eelgrass
(
Estuarine)
Zostera
marina
(
10
days;
measured)
Unk.
est.
69
50
80
50%
red.
leaf
growth
25%
red.
leaf
growth
62%
red.
leaf
growth
45227729
Schwarzschild
et
al.
1994
Supplemental
(
raw
data
unavailable)

Estuarine
Eelgrass
Zostera
marina
(
21
days;
nominal)
???
100
NOAEC
10
21­
day
LC50
red.
production
45227705
Delistraty
and
Hershner
1984
Supplemental
(
raw
data
unavailable)

Wild
Celery
(
Estuarine)
Vallisneria
americana
(
6
weeks;
nominal)
???
163
50%
red.
shoot
length
no
difference
at
0,
3,
or
6
parts/
thousand
45087410
Forney
and
Davis
1981
Supplemental
(
raw
data
unavailable)

Seagrass
(
Estuarine)
Halodule
wrightii
(
22
­
23
days;
measured)
Atrazi
ne
4L
30,000
46­
58%
red.
total
aboveground
biomass
45205101
Mitchell
1987
Supplemental
(
raw
data
unavailable)

Non­
Vascular
Plants:

Marine
Brown
macroalgae
Laminaria
hyperborea
(
18
days;
nominal)
???
NOAEC
<
10
LOAEC
10
50
&
100
sign.
red.
growth
rate
delayed
sporophyte
formation
????
Hopkin
&
Kain
1978
Supplemental
(
raw
data
unavailable)

Marine
Yellow
­
Chrysophyceae
Isochrysis
galbana
(
240
hours;
nominal);
Salinity
30
g/
L
99.7
100
50%
red.
cell
growth
40228401
Mayer
1986
Supplemental
(
NOAEC
unavailable)

Marine
Green
­
Chlorophyceae
Chlorococcum
sp.
(
240
hours;
nominal);
Salinity
30
g/
L
99.7
100
50%
red.
cell
growth
40228401
Mayer
1986
Supplemental
(
NOAEC
unavailable)

Marine
Yellow
­
Chrysophyceae
Phaeodactylum
tricornutum
(
240
hours;
nominal);
Salinity
30
g/
L
99.7
200
50%
red.
cell
growth
40228401
Mayer
1986
Supplemental
(
NOAEC
unavailable)

Marine
Green
­
Chlorophyceae
Dunaliella
tertiolecta
(
240
hours;
nominal);
Salinity
30
g/
L
99.7
300
50%
red.
cell
growth
40228401
Mayer
1986
Supplemental
(
NOAEC
unavailable)
XI
­
40
The
Tier
II
results
indicate
that
the
marine
algae
Isochrysis
galbana
is
the
most
sensitive
nonvascular
aquatic
plant
(
EC50
22
ppb)
and
the
most
sensitive
vascular
aquatic
plant
is
wild
celery
(
4
ppb).
Comparison
of
atrazine
toxicity
levels
for
three
different
endpoints
suggest
that
the
endpoints
in
decreasing
order
of
sensitivity
are
cell
count,
growth
rate
and
oxygen
production
(
Stratton
1984).
Walsh
(
1983)
exposed
Skeletonema
costatum
to
atrazine
and
concluded
that
atrazine
is
only
slightly
algicidal
at
relatively
high
concentrations
(
i.
e.,
500
&
1,000
ppb).
Caux
et
al.
(
1996)
compared
the
cell
count
IC50
and
fluorescence
LC50
and
concluded
that
atrazine
is
algicidal
at
concentrations
which
effect
cell
counts.
Abou­
Waly
et
al.
(
1991)
measured
growth
rates
on
days
3,
5,
and
7
for
two
algal
species.
The
pattern
of
atrazine
effects
on
growth
rates
differ
sharply
between
the
two
species.
Atrazine
had
a
strong
early
effect
on
Anabaena
flosaquae
followed
by
rapid
recovery
in
clean
water
(
i.
e.,
EC50
values
for
days
3,
5,
and
7
are
58,
469,
and
766
ppb,
respectively).
The
EC50
values
for
Selenastrum
capricornutum
continued
to
decline
from
Day
3
through
7
(
i.
e.,
283,
218,
and
214
ppb,
respectively.
Based
on
theses
results,
it
appears
that
the
timing
of
peak
effects
for
atrazine
may
differ
depending
on
the
test
species.
The
guideline
requirement
(
123­
2)
is
fulfilled
for
only
three
out
of
five
species
(
MRID
43074801,
43074802,
43074803).
However,
sufficient
data
exists
on
numerous
other
algal
species
to
provide
a
broad
range
of
toxicity
effects.
No
additional
algal
studies
are
required.

Degradates:
The
major
atrazine
degradate
is
hydroxyatrazine
which
forms
a
large
percent
of
the
recoverable
pesticide
in
aquatic
compartments
of
the
environment.
Therefore,
special
tests
are
required
for
algal
and
vascular
plant
species
(
123­
2)
to
address
concerns
for
the
toxicity
of
atrazine
degradates
to
aquatic
plants.

Degradate
Deethylatrazine
Nontarget
Aquatic
Plant
Toxicity
(
Tier
II)

Species/
Duration/
Measured/
nominal
%
ai
Conc.
(
ppb)
Probit
slope
%
Response
MRID
No.
Author/
Year
Study
Classification
Fresh.
Blue­
Green
­
Cyanophyceae
Anabaena
inaequalis
(
12­
14
days1;
nominal)
>
95
1,000
4,000
2,500
50%
red.
cell
count
50%
red.
growth
rate
50%
red.
photosynthesis
Stratton
1984
Supplemental
(
NOAEC
and
raw
data
unavailable)

Freshwater
Green
­
Chlorophyceae
Scenedesmus
quadricauda
(
12­
14
days;
nominal)
>
95
1,200
2,000
1,800
50%
red.
cell
count
50%
red.
Growth
rate
50%
red.
photosynthesis
Stratton
1984
Supplemental
(
NOAEC
and
raw
data
unavailable)

Freshwater
Green
­
Chlorophyceae
Chlorella
pyrenoidosa
(
12­
14
days1;
nominal)
>
95
3,200
7,200
1,800
50%
red.
cell
count
50%
red.
growth
rate
50%
red.
photosynthesis
Stratton
1984
Supplemental
(
NOAEC
and
raw
data
unavailable)

Fresh.
Blue­
Green
­
Cyanophyceae
Anabaena
variabilis
(
12­
14
days;
nominal)
>
95
3,500
7,500
700
50%
red.
cell
count
50%
red.
growth
rate
50
%
red.
photosynthesis
Stratton
1984
Supplemental
(
NOAEC
and
raw
data
unavailable)

Fresh.
Blue­
Green
­
Cyanophyceae
Anabaena
cylindrica
(
12­
14
days;
nominal)
>
95
8,500
5.500
4,800
50%
red.
cell
count
50%
red.
growth
rate
50%
red.
photosynthesis
Stratton
1984
Supplemental
(
NOAEC
and
raw
data
unavailable)
XI
­
41
Degradate
Deisopropylatrazine
Nontarget
Aquatic
Plant
Toxicity
(
Tier
II)

Species/
Duration/
Measured/
nominal
%
ai
Conc.
(
ppb)
Probit
slope
%
Response
MRID
No.
Author/
Year
Study
Classification
Fresh.
Blue­
Green
­
Cyanophyceae
Anabaena
inaequalis
(
12­
14
days1;
nominal)
>
95
2,500
7,000
9,000
50%
red.
cell
count
50%
red.
growth
rate
50%
red.
photosynthesis
Stratton
1984
Supplemental
(
NOAEC
and
raw
data
unavailable)

Freshwater
Green
­
Chlorophyceae
Scenedesmus
quadricauda
(
12­
14
days;
nominal)
>
95
6,900
6.500
4,000
50%
red.
cell
count
50%
red.
Growth
rate
50%
red.
photosynthesis
Stratton
1984
Supplemental
(
NOAEC
and
raw
data
unavailable)

Freshwater
Green
­
Chlorophyceae
Chlorella
pyrenoidosa
(
12­
14
days1;
nominal)
>
95
>
10,000
>
10,000
3,600
50%
red.
cell
count
50%
red.
growth
rate
50%
red.
photosynthesis
Stratton
1984
Supplemental
(
NOAEC
and
raw
data
unavailable)

Fresh.
Blue­
Green
­
Cyanophyceae
Anabaena
variabilis
(
12­
14
days;
nominal)
>
95
5,500
9,200
4,700
50%
red.
cell
count
50%
red.
growth
rate
50
%
red.
photosynthesis
Stratton
1984
Supplemental
(
NOAEC
and
raw
data
unavailable)

Fresh.
Blue­
Green
­
Cyanophyceae
Anabaena
cylindrica
(
12­
14
days;
nominal)
>
95
>
10,000
>
10,000
9,300
50%
red.
cell
count
50%
red.
growth
rate
50%
red.
photosynthesis
Stratton
1984
Supplemental
(
NOAEC
and
raw
data
unavailable)

Degradate
Diamino­
Atrazine
Nontarget
Aquatic
Plant
Toxicity
(
Tier
II)

Species/
Duration/
Measured/
nominal
%
ai
Conc.
(
ppb)
Probit
slope
%
Response
MRID
No.
Author/
Year
Study
Classification
Fresh.
Blue­
Green
­
Cyanophyceae
Anabaena
inaequalis
(
12­
14
days1;
nominal)
>
95
7,000
>
10,000
>
100,000
50%
red.
cell
count
50%
red.
growth
rate
50%
red.
photosynthesis
Stratton
1984
Supplemental
(
NOAEC
and
raw
data
unavailable)

Freshwater
Green
­
Chlorophyceae
Scenedesmus
quadricauda
(
12­
14
days;
nominal)
>
95
4,600
10,000
>
100,000
50%
red.
cell
count
50%
red.
Growth
rate
50%
red.
photosynthesis
Stratton
1984
Supplemental
(
NOAEC
and
raw
data
unavailable)

Freshwater
Green
­
Chlorophyceae
Chlorella
pyrenoidosa
(
12­
14
days1;
nominal)
>
95
>
10,000
>
10,000
>
100,000
50%
red.
cell
count
50%
red.
growth
rate
50%
red.
photosynthesis
Stratton
1984
Supplemental
(
NOAEC
and
raw
data
unavailable)

Fresh.
Blue­
Green
­
Cyanophyceae
Anabaena
variabilis
(
12­
14
days;
nominal)
>
95
>
10,000
>
10,000
100,000
50%
red.
cell
count
50%
red.
growth
rate
50
%
red.
photosynthesis
Stratton
1984
Supplemental
(
NOAEC
and
raw
data
unavailable)

Fresh.
Blue­
Green
­
Cyanophyceae
Anabaena
cylindrica
(
12­
14
days;
nominal)
>
95
>
10,000
>
10,000
>
100,000
50%
red.
cell
count
50%
red.
growth
rate
50%
red.
photosynthesis
Stratton
1984
Supplemental
(
NOAEC
and
raw
data
unavailable)

Degradate
Hydroxyatrazine
Nontarget
Aquatic
Plant
Toxicity
(
Tier
II)

Species/
Duration/
Measured/
nominal
%
ai
Conc.
(
ppb)
Probit
slope
%
Response
MRID
No.
Author/
Year
Study
Classification
Fresh.
Blue­
Green
­
Cyanophyceae
Anabaena
inaequalis
(
12­
14
days1;
nominal)
>
95
>
10,000
>
10,000
>
100,000
50%
red.
cell
count
50%
red.
growth
rate
50%
red.
photosynthesis
Stratton
1984
Supplemental
(
NOAEC
and
raw
data
unavailable)

Freshwater
Green
­
Chlorophyceae
Scenedesmus
quadricauda
(
12­
14
days;
nominal)
>
95
>
10,000
>
10,000
>
100,000
50%
red.
cell
count
50%
red.
Growth
rate
50%
red.
photosynthesis
Stratton
1984
Supplemental
(
NOAEC
and
raw
data
unavailable)
Degradate
Hydroxyatrazine
Nontarget
Aquatic
Plant
Toxicity
(
Tier
II)

Species/
Duration/
Measured/
nominal
%
ai
Conc.
(
ppb)
Probit
slope
%
Response
MRID
No.
Author/
Year
Study
Classification
XI
­
42
Freshwater
Green
­
Chlorophyceae
Chlorella
pyrenoidosa
(
12­
14
days1;
nominal)
>
95
>
10,000
>
10,000
>
100,000
50%
red.
cell
count
50%
red.
growth
rate
50%
red.
photosynthesis
Stratton
1984
Supplemental
(
NOAEC
and
raw
data
unavailable)

Fresh.
Blue­
Green
­
Cyanophyceae
Anabaena
variabilis
(
12­
14
days;
nominal)
>
95
>
10,000
>
10,000
>
100,000
50%
red.
cell
count
50%
red.
growth
rate
50
%
red.
photosynthesis
Stratton
1984
Supplemental
(
NOAEC
and
raw
data
unavailable)

Fresh.
Blue­
Green
­
Cyanophyceae
Anabaena
cylindrica
(
12­
14
days;
nominal)
>
95
>
10,000
>
10,000
>
100,000
50%
red.
cell
count
50%
red.
growth
rate
50%
red.
photosynthesis
Stratton
1984
Supplemental
(
NOAEC
and
raw
data
unavailable)

The
Tier
II
results
for
atrazine
degradates
indicate
that
deethylatrazine
is
more
toxic
than
the
other
four
degradates
and
the
most
sensitive
algae
of
the
five
species
usually
is
the
blue­
green
alga
Anabaena
inaequalis
with
EC50
values
ranging
from
100
to
>
100,000
ppb.
Atrazine
is
more
toxic
to
these
algal
than
any
degradate.
The
order
of
descending
toxicity
for
these
algal
species
are
atrazine
>
deethylatrazine
>
deisopropylatrazine
>
diamino­
atrazine
>
hydroxyatrazine
The
data
are
useful,
but
the
test
species
are
not
the
species
specified
for
pesticide
registration.
The
requirement
(
123­
2)
has
not
been
fulfilled.
XI
­
43
e.
Multi­
species
Tests
(
Microcosms,
Field
Studies)

i.
Simulated
Aquatic
Field
Studies
(
Microcosms)

a.
Freshwater
Microcosm
Tests
Application
rate
(
lb
ai/
A)

Nominal/
Measured
Conc.
Concentration
affecting
endpoint
(
time
to
effect)

o
percent
difference
from
controls
Narrative
of
Study
Trends
MRID
No.

Author/
Year
Freshwater
microcosm:

Measured
close
to
nominal
throughout
the
testing
period:

concentrations
of
0.5,
5,
50,

100,
500,
and
5000
ppb
0.5
and
5
ppb
o
no
reduction
in
net
oxygen
loss
50
ppb
o
25­
30%
reduction
in
net
oxygen
loss
100
ppb
o
40­
50%
reduction
in
net
oxygen
loss
500
ppb
o
90%
reduction
in
net
oxygen
loss
5,000
ppb
o
100%
reduction
to
negative
net
oxygen
production
Spirogyra,
Oedogonium,
Microcystis,

Apthanothece,
and
Scenedesmus
sp.
in
mixed
culture.

Microcosms
inoculated
with
algae
demonstrated
effects
at
concentrations
>
50
ppb.
Physical
appearance
of
the
microcosms
was
altered
at
5,000
ppb.
Observations
and
reculture
demonstrated
that
the
effects
were
algistatic.
45087407
Brockway
et
al.,
1984
Freshwater
Microcosm:

(
Duration
7
weeks
exposure)

Mean
measured
concentrations
of
5.08
+
0.03
Fg/
L;

range:
4.2
­
6.0
Fg/
L
NOEC:
5
ppb
o
slight
non­
sign.
shifts
in
water
parameters:

o
DO
decreased
from
means
of
9.4
­
9.9
mg/
L
(
controls)
differing
weekly
by
0.2
­
0.6
mg/
L
o
pH
decreased
from
means
of
8.4
­
9.0
(
controls)

differing
weekly
by
0.0
­
0.4
units
o
conductivity
increased
from
159.3
­
189.3
FS/
cm
(
controls)
differing
by
0.2
­
10.0
FS/
cm
o
alkalinity
increased
from
means
of
1.4
­
2.2
mg/
L
(
controls)
differing
by
0.0
­
0.3
mg/
L
o
no
significant
adverse
effects
on
phyto­
&

zooplankton,
or
15
macro­
invertebrate
species
o
Cyclopoida
sign.
increased
in
week
3
Laboratory
microcosms
(
4
replicates)
were
tested
with
0
and
5
Fg/
L
atrazine
for
7
weeks.
The
plankton
and
macroinvertebrates
were
introduced
together
with
2­
cm
layer
of
natural
sediments
into
glass
aquaria
with
a
50
cm
water
column
with
a
14­
hour
photoperiod.
Water
was
circulated
through
the
microcosms
at
a
flow
rate
of
3.5
L/
min.
during
an
acclimation
period
for
biota
of
3
months.

This
test
was
part
of
a
study
of
pesticide
interaction
between
atrazine
and
chlorpyrifos
to
determine
the
adequacy
of
chronic
safety
factors.
45087417
van
den
Brink
et
al.
1995
Supplemntal
(
raw
data
unavailable)

Freshwater
Microcosm:

Mean
measured
concentrations
of
3.2,
10,
32,
110,
and
337
ppb
NOEC:
10
ppb;
LOEC:
32
ppb
o
dissolved
oxygen,
magnesium,
and
calcium;

NOEC:
110
ppb;
LOEC:
337
ppb
o
potassium,
chlorophyll­
a,
protein,
and
species
equilibrium
number
Laboratory
microcosms
were
inoculated
with
foam
blocks
taken
from
a
pond.
The
effect
to
protozoans
from
atrazine
exposure
was
examined
by
measuring
structure
(
species
number,
biomass),
and
function
(
colonization
rate,
oxygen
production,
chlorophyll
concentration)
of
the
community
as
well
as
ion
concentrations
of
the
biomass
after
21
days.
45087416
Pratt
et
al.
1988
Supplemental
(
raw
data
unavailable)

Freshwater
Microcosm:

(
6
weeks)

Meas.
peak
20
ppb
on
day
1,

mean
measured
concentration
of
approximately
10
ppb
10
ppb
(
6
weeks)

o
sign.
(
0.05)
reduced
dissolved
oxygen
(
DO),
but
was
recovering
by
test
termination
Laboratory
microcosms
were
treated
with
a
stock
solution
of
atrazine
and
soil
to
which
atrazine
was
bound.
At
the
end
of
the
study,
no
significant
effects
on
plant
biomass
or
daphnid/
midge
survival
were
noted,
but
DO
was
affected.
45205102
Huckins
et
al.
1986
Supplemental
(
raw
data
unavailable)
Application
rate
(
lb
ai/
A)

Nominal/
Measured
Conc.
Concentration
affecting
endpoint
(
time
to
effect)

o
percent
difference
from
controls
Narrative
of
Study
Trends
MRID
No.

Author/
Year
XI
­
44
Freshwater
microcosm:

(
30
days):
Macrophytes,
algae,

zooplankton
and
benthic
invertebrates;

Nominal
conc.
of
10,
100
and
1,000
ppb
as
a
soil
slurry
10
ppb
(
Day
2)

o
23%
red.
in
gross
primary
productivity
(
GPP);

recovery
by
Day
7
and
similar
to
controls
at
Day
30
100
ppb
(
Day
2)

o
32%
red.
in
GPP;
recovery
by
Day
7
and
similar
to
controls
at
Day
30
1,000
ppb
(
Day
2)

o
91%
red.
in
GPP;
no
recovery,
70%
red.

throughout
test
1,000
ppb
(
Day
30)

o
48%
red.
(
sign.
P<
0.05
level)
macrophyte
biomass
o
36%
red.
(
sign.,
P<
0.05)
Selenastrum
dry
weight
1,000
ppb
(
30­
day
aged
microcosm
water)

o
76%
red.
(
sign.
P<
0.05)
Selenastrum
dry
weight
1,000
ppb
(
Day
30)

o
reduced
O2,
community
respiration,
pH
o
20%
increase
in
conductivity
o
120%
increase
in
alkalinity
o
no
effect
on
soil
microbial
activity
4­
L
microcosms
were
established
in
the
laboratory
and
treated
with
a
soil
slurry
of
atrazine.
The
endpoints
examined
over
the
30­
day
experiment
included
effects
to
zoo­
and
phytoplankton
as
well
as
macrophytes
(
i.
e.,
Lemna
sp.,
Ceratophyllum
sp.,

and
Elodea
sp.).
Static
acute
and
chronic
assays
were
conducted
with
Daphnia
magna
and
Chironomus
riparius
using
treated
water
that
had
come
from
the
microcosm
after
30
days
or
from
a
vessel
that
contained
the
treated
water
for
30
days
(
i.
e.,
aged
treated
water).
The
author
concluded
that
microcosm
itself
ameliorated
the
phytotoxic
effect
at
1,000
ppb.
No
effect
on
invertebrates
up
to
1,000
ppb
and
effects
to
phytoplankton
at
10
and
100
ppb
were
not
observed
by
test
termination
(
30
days).
Conductivity,
pH,
and
alkalinity
were
also
affected
at
1,000
ppb.
45087413
Johnson,
1986
Supplemental
(
raw
data
unavailable)

Freshwater
Microcosm:

Emergent
vascular
plants;

Nominal
water
conc.
of
10,
50,

100,
500,
and
1,500
ppb;

measured
water
conc.
in
the
50
and
500
ppb
treatments
of
1.3
and
1.6
ppb,
respectively,
after
16
weeks
500
ppb
(
6
weeks)

o
sign.
(
0.05
level)
red.
shoot
length
of
Scirpus
acutus
1,500
ppb
(
6
weeks)

o
sign.
red.
shoot
length
of
Scirpus
acutus
and
Typha
latifolia
Greenhouse
microcosms
were
made
by
placing
rhizome
sections
in
tubs
which
were
filled
with
treated
water
to
1
cm
above
the
soil
surface.
The
plants
were
allowed
to
grow
for
16
weeks
and
shoot
height
of
hardstem
bulrush
and
broad­
leaved
cattail
was
monitored
bi­
weekly.
Also
non­
sign.
effects
of
chlorosis
and
reduced
growth
noted
at
50
and
100
ppb.
A
second
test
demonstrated
resiliency
of
both
plants
at
500
ppb.
45087415
Langan
and
Hoagland,

1996
Supplemental
(
raw
data
unavailable)

Freshwater
Microcosm:

(
14
days)
Measured
atrazine
concentrations
approximately
75%
of
nominal
(
15
and
153
ppb)
for
first
application
and
150%
of
nominal
(
385
and
2,167
ppb)
for
the
second
application
Sign.
(
0.1
level)
reduction
in
turbidity
and
chlorophyll
(
7
days),
and
increase
in
phosphorous
(
day
14)
and
nitrogen
(
days
7
and
14)
after
the
1st
application.
Copepod
and
rotifer
densities
were
also
sign.
reduced
on
days
7
and
14.

Sign.
reductions
in
productivity,
chlorophyll,
green
algal
colonies,
rotifers,
and
Bosmina
sp.
(
zooplankton)
after
2nd
application.
Phosphorous,
nitrogen,
and
pH
were
also
sig.

affected.
A
3x3
factorial
design
with
three
conc.
of
atrazine
(
0,
15,
and
153
ppb)
and
three
conc.
of
bifenthrin
(
0,
0.039,
and
0.287
ppb)
applied
as
soil
slurry
in
May,
then
again
one
month
later
but
with
atrazine
conc.
of
0,
385,
and
2,167
ppb
and
bifenthrin
conc.
of
0,
0.125,
and
3.15
ppb.
Atrazine
alone
caused
doseresponsive
reductions
in
chlorophyll,
turbidity,
primary
production,
increases
in
nitrogen
and
phosphorous,
and
reduced
levels
of
chlorophytes,
cladocerans,
copepod
nauplii,

and
rotifers.
General
recovery
after
14
days
for
atrazine
alone
in
the
first
phase,
but
recovery
not
complete
at
sampling
termination
after
second
phase
(
14
days).
No
synergistic
or
antagonistic
effects
were
noted.
45020014
Hoagland
et
al.,
1993
Supplemental
(
raw
data
unavailable)
Application
rate
(
lb
ai/
A)

Nominal/
Measured
Conc.
Concentration
affecting
endpoint
(
time
to
effect)

o
percent
difference
from
controls
Narrative
of
Study
Trends
MRID
No.

Author/
Year
XI
­
45
Freshwater
microcosm:

(
2
months;
measured)

Nominal
concentrations
of
0,

60,
100,
200,
500,
1,000
and
5,000
ppb.
Measurements
made
three
times
during
the
two
month
study.
60
ppb
(
nominal)

o
14­
carbon
uptake
decreased
immediately
after
treatment;
recovery
began
after
10
days;

o
stimulated
production
of
chlorophyll
a;

100
ppb
(
nominal)

o
14­
carbon
uptake
decreased
immediately
after
treatment;
recovery
began
after
10
days;

o
stimulated
production
of
chlorophyll
a;

200
ppb
(
nominal)

o
14­
carbon
uptake
decreased
immediately
after
treatment;
slight
recovery
2
months
after
treatment;

o
stimulated
production
of
chlorophyll
a;

o
inhibited
increases
in
dissolved
oxygen
during
light
phase
and
decreases
in
DO
during
dark
phase
500
ppb
(
nominal)

o
14­
carbon
uptake
decreased
immediately
after
treatment;
no
recovery;

o
minimal
inhibition
of
chlorophyll
a
production;

1,000
and
5,000
ppb
(
nominal)

o
14­
carbon
uptake
decreased
immediately
after
treatment;
recovery
began
after
10
days.

EC50s
for
Days
0­
10,
53­
60,
&
Mean
(
mean
measured
conc.)

Time
period;
14C
uptake;
DO
(
light);
DO
(
dark)

Days
0­
10
:
103
ppb
126
ppb
106
ppb
Days
53­
60:
159
ppb
154
ppb
164
ppb
Days
1­
60:
131
ppb
165
ppb
142
ppb
Results
of
single
species
assays,
microcosm,
and
pond
studies
were
compared.
14­
Carbon
fixation
was
used
as
the
end­
point
for
all
three
study
types.
Laboratory
results
with
eight
algal
species
ranged
from
37
to
308
ppb
for
carbon
uptake
inhibition
EC50
values.
Microcosm
EC50
values
ranged
from
103
to
159
ppb.
The
mean
pond
EC50
was
100
ppb
for
carbon
uptake
and
82
ppb
for
chlorophyll­
a
inhibition.
The
authors
stated
that
multiple
laboratory
studies
or
a
microcosm
study
represent(
s)

entire
ecosystem
functional
effects.
45020015
Larsen
et
al.,
1986
and
45087419
Stay
et
al.
1985
Supplemental
(
raw
data
unavailable)

Freshwater
microcosm:

(
60
days;
measured)

Nominal
concentrations
of
60,

100,
200,
500,
1,000,
and
5,000
ppb.
Concentrations
measured
on
Days
7,
28,
53,
60.
NOEC
<
60
ppb;

60
ppb
(
1
­
20
days)

o
sign.
(
0.05)
red.
14­
carbon
uptake
for
first
20
days
>
100
ppb
(
2
weeks)

o
sign.
(
0.05
level)
red.
primary
productivity;

o
sign.
red.
in
productivity/
dark
respiration
ratio;

o
pH
sign.
less
than
control
values
>
500
ppb
(
6
weeks)

o
all
endpoints
declined
immediately
after
treatment
and
never
recovered
during
the
experiment.
Taub
microcosms
were
3­
L
jars
inoculated
with
10
algal
species
on
Day
0,
Daphnia
magna
and
4
other
animal
species
on
Day
4.
On
Day
7,
27
microcosms
were
treated
with
atrazine;
no
other
atrazine
treatments
um
from
four
different
aquatic
systems.
Community
metabolism
was
measured
for
primary
productivity
and
light
and
dark
respiration.
At
the
high
treatment
levels
(
500,
1000
and
5000
ug/
L),
all
process
variables
declined
immediately
after
atrazine
treatment
and
did
not
recover
during
the
experiment.
At
the
low
treatment
levels
(
60,
100
and
200
ug/
L),
the
magnitude
of
the
responses
to
atrazine
was
not
constant,
but
with
3
phases;
an
autotrophic
phase,
daphnid
bloom
and
an
equilibrium
phase.
45087419
Stay
et
al.,
1989
Supplemental
(
raw
data
unavailable)
Application
rate
(
lb
ai/
A)

Nominal/
Measured
Conc.
Concentration
affecting
endpoint
(
time
to
effect)

o
percent
difference
from
controls
Narrative
of
Study
Trends
MRID
No.

Author/
Year
XI
­
46
Freshwater
microcosm:

(
6
weeks;
measured)

Single
dose;

Nominal
conc.
20,
100,
200,

500,
1,000
and
5,000
ppb.

Concentrations
were
measured
on
Days
0
and
42.
On
Day
42,

atrazine
levels
averaged
69
to
80%
of
the
initial
concentrations.
NOEC
=
20
ppb
LOEC
=
100
ppb
in
3
out
of
4
natural
plankton
communities
and
200
ppb
for
the
fourth
community.

>
100
ppb
(
2
weeks)

o
sign.
(
0.05
level)
red.
primary
productivity
o
sign.
red.
in
productivity/
dark
respiration
ratio
o
pH
sign.
less
than
control
values
Leffler
microcosms
were
constructed
with
inoculum
from
four
different
aquatic
systems
from
natural
communities
and
contains
organisms
representing
several
trophic
levels.
The
vessels
were
dosed
after
6
weeks
of
seeding
and
monitoring
for
6
more
weeks.
The
LOEC
for
3
of
the
systems
was
reported
to
be
100
ppb,
while
the
LOEC
for
the
fourth
was
200
ppb.
45087418
Stay
et
al.
1989
Supplemental
(
raw
data
unavailable)
XI
­
47
b.
Marine/
Estuarine
Microcosm
Tests
Application
rate
(
lb
ai/
A)

Nominal/
Measured
Conc.
Concentration
affecting
endpoint
(
time
to
effect)

o
percent
difference
from
controls
Narrative
of
Study
Trends
MRID
No.

Author/
Year
Estuarine
microcosm:

(
;
nominal)

Wild
Celery
Vallisneria
americana
1
treatment
Nominal
concentrations
of
4,
8,
16,
32,
and
64
ppb
NOEC
<
4
ppb
4
ppb
(
reproductive
season)

o
sign.
16%
reduction
in
tuber
formation
o
55%
reduction
in
biomass
8
ppb
(
reproductive
season)

o
21%
reduction
in
tuber
formation
16
ppb
(
mid
season
and
reproductive
season)

o
60%
reduction
in
tuber
formation
o
27%
reduction
in
tuber
weight
o
sign.
reduction
in
leaf
growth,
biomass,

and
female
flowers
64
ppb
(
reproductive
season)

o
75%
reduction
in
tubers
o
red.
female
flowers
Laboratory
microcosms
were
used
to
grow
Vallisneria
americana
through
entire
seasons
(
divided
into
three
periods
­

early­,
mid­,
and
reproductive).
The
aquaria
were
dosed
one
time
at
the
nominal
conc.
after
a
14­
day
acclimation
period.

With
respect
to
leaf
growth,
atrazine
caused
the
plants
to
be
shorter
and
more
fragile.
With
respect
to
flowering
and
rhizome
production,
effects
were
generally
first
noted
at
the
16
to
32
ppb
range.
Tuber
formation
appeared
to
be
the
most
sensitive
endpoint,
with
production
in
terms
of
numbers
significantly
reduced
at
the
4
ppb
level.
45020001
Cohn
1985
Supplemental
(
raw
data
unavailable)

Estuarine
lab.
microcosm:

(
7­
day
exposure;
nominal)

Nominal
concentrations
of
22,

220,
and
2,200
ppb
Estuarine
field
microcosm:

(
108­
days;
nominal)

Single
exposure;

Nominal
applications
of
0.4,

1.4,
4.5,
and
45
lb
ai/
A
"
NOEC"
=
10
ppb
(
based
on
author's
use
of
a
10­
fold
safety
factor
from
the
I1
level
=
100
ppb)

220
ppb
(
1
week)

o
sign.
(
0.05
level)
red.
in
cell
#
of
Thalassiosira
fluviatilis
o
sign.
red.
in
photosynthesis
of
T.
fluviatilis
and
Nitzschia
sigma
2,200
ppb
(
1
week)

o
sign.
red.
in
cell
#,
photosynthesis.,
and
chlorophyll
content
for
both
algae
1.4
lb
ai/
A
(
effect
up
to
5
days)

o
sign.
red.
in
surface
chlorophyll
and
primary
prod.

(
85­
89%)

1.4
lb
ai/
A
(
effect
up
to
8
&
17
days)

o
sign.
reduction
in
carbon
fixation
(
52­
73%)

0.4/
4.5
lb
ai/
A
(
effect
at
16
days,
but
not
26
days)

o
sign.
reduction
in
carbon
fixation
45
lb
ai/
A
(
42
days)

o
sign.
red.
in
carbon
fixation
Laboratory
studies
were
conducted
with
the
salt
marsh
edaphic
diatoms
Thalassiosira
fluviatilis
and
Nitzschia
sigma.
The
I50
for
both
species
combined
was
reported
to
be
939
ppb.
The
I1
was
reported
to
be
100
ppb,
and
by
applying
a
10­
fold
safety
factor,
the
acceptable
level
(
NOEC)
was
reported
to
be
10
ppb.

Subsequently,
studies
were
conducted
in
greenhouse
microcosms
(
1.4
lb
ai/
A)
and
in
two
field
studies
(
1.4
lb
ai/
A
or
0.4,
4.5,
and
45
lb
ai/
A)
on
the
beach
wherein
enclosures
were
sunk
into
the
sand
and
exposed
to
tidal
action.
Atrazine
treatment
also
appeared
to
cause
a
shift
to
a
Navicula
sp.

dominated
system.
Field
results
with
higher
rates
of
atrazine
were
as
expected,
with
carbon
fixation
reduced
for
up
to
16
days
at
the
2
lower
rates
and
up
to
42
days
at
the
highest
rate.
45087406
Plumley
and
Davis,
1980
Supplemental
(
raw
data
unavailable)
Application
rate
(
lb
ai/
A)

Nominal/
Measured
Conc.
Concentration
affecting
endpoint
(
time
to
effect)

o
percent
difference
from
controls
Narrative
of
Study
Trends
MRID
No.

Author/
Year
XI
­
48
Estuarine
microcosm:

(
5
Weeks;
measured)

3
weekly
applications
followed
by
2
weeks
observation.

Mean
measured
concen.
at
approximately
mid­
point
of
the
Spartina
test
were
30,
280,
and
3,100
ppb
and
in
the
Juncus
test
were
30,
250
and
3,800
ppb.
30,
280,
and
3,100
ppb
(
5
weeks)

o
sign.
(
0.05
level)
increase
in
peroxidase
activity
in
Spartina
alterniflora
30,
250,
and
3,800
ppb
(
5
weeks)

o
sign.
(
0.05
level)
red.
in
chlorophyll­
a
(
Chl­
a)
and
Chl­
a/
Chl­
b
ratio
in
Juncus
roemerianus
250
and
3,800
ppb
(
5
weeks)

o
sign.
red.
in
Chl­
b
in
J.
roemerianus
3,100
ppb
(
1
week)

o
sign.
red.
in
growth
in
S.
alterniflora
3,800
ppb
(
5
weeks)

o
sign.
red.
in
growth
in
J.
roemerianus
o
sign.
increase
in
oxidized
lipids
in
J.
roemerianus
250
ppb
(
1
year)

o
partial
recovery
in
J.
roemerianus
3,800
ppb
(
1
year)

o
practically
no
survival
of
J.
roemerianus.
Two
aquatic
estuarine
plants
were
exposed
to
atrazine
in
greenhouse
microcosms.
The
plants
were
exposed
to
atrazine
by
placing
treated
sand
on
the
surface
of
the
pots
three
times
(
once
a
week
for
the
first
3
weeks
of
the
study)
followed
by
2
more
weeks
for
a
total
of
5
weeks.
The
water
samples
were
taken
after
the
third
application.
The
pots
were
also
tidallyexposed
(
i.
e.,
low
tide
during
the
day
and
high
tide
at
night).

S.
alterniflora
plants
demonstrated
a
dose­
response
increase
in
peroxidase
activity.
In
contrast,
J.
roemerianus
plants
demonstrated
a
dose­
responsive
reduction
in
chlorophyll
and
an
increase
in
the
amount
of
oxidized
lipids.
The
authors
state
that
atrazine
"
should
pose
no
significant
adverse
effects
on
S.

alterniflora.
In
contrast,
if
chronic
levels
of
atrazine
persist
in
the
range
of
250
ug/
L
or
greater,
J.
roemerianus
most
likely
will
exhibit
die
off
or
decline
that
may
lead
to
loss
of
this
species
within
the
habitat."
45087405
Lytle
and
Lytle,
1998
Supplemental
(
raw
data
unavailable)

Estuarine
microcosm:

(????
days,
nominal)

Nominal
concentrations
of
0,

50,
and
100
ppb
Both
Nannochloris
oculata
and
Phaeodactylum
tricornutum
were
significantly
(
mostly
at
the
0.01
level)
affected
by
changes
in
light,
temperature,
and
atrazine
conc.
A
3x3x3
factorial
design
examined
the
effect
of
temperature,

light,
and
atrazine
conc.
on
two
species
of
estuarine
algae.
N.

oculata
was
sig.
affected
by
all
variables,
and
the
three
twoway
and
one
three­
way
interactions
were
also
significant.
P.

tricornutum
was
affected
by
the
main
variables
and
the
only
sig.
interaction
was
light
by
atrazine.
Mayasich
et
al.,
1986
Estuarine
microcosm:

(?????
day,
nominal)

Nominal
concentrations
of
0,

15,
30,
and
50
ppb
The
above
mentioned
algae
were
tested
together
and
this
variable
also
caused
a
sig.
(
0.01
level)
effect
on
N.
oculata
growth
rate
An
extension
of
the
above
described
study.
In
addition
to
separate
culture,
the
two
estuarine
algae
were
cultured
together.
The
end
result
was
that
P.
tricornutum
dominated
the
cultures
due
to
the
stress
of
atrazine
to
N.
oculata
under
optimum
growth
conditions
Mayasich
et
al.,
1987
Application
rate
(
lb
ai/
A)

Nominal/
Measured
Conc.
Concentration
affecting
endpoint
(
time
to
effect)

o
percent
difference
from
controls
Narrative
of
Study
Trends
MRID
No.

Author/
Year
XI
­
49
Estuarine
microcosm:

(
4
weeks;
measured)

Mean
measured
concentrations
in
water
were
130
ppb
for
the
"
low"
treatment
and
1,200
ppb
for
the
"
high"
treatment
over
a
four
week
period
(
4
weeks;
measured)
130
ppb
(
Week
1)

o
no
photosynthesis
130
ppb
(
Week
2­
4)

o
sign.
red.
in
plant
total
biomass;
no
change
in
biomass
for
3
weeks
130
ppb
(
Weeks
1­
4)

o
sign.;
averaged
50%
red.
photosynthesis
of
Potamogeton
perfoliatus
during
the
test;
steady
recovery
after
first
week,
but
not
fully
recovered
1,200
ppb
(
Weeks
1­
4)

o
sign.;
100%
red.
photosynthesis
throughout
the
test
1,200
ppb
(
Weeks
2­
4)

o
sign.;
plant
total
biomass
steadily
reduced
1,200
ppb
(
Weeks
3­
4)

o
sign.;
80%
red.
shoot
density
Aquatic
plants
were
planted
and
atrazine­
treated
sediments
were
added
to
700­
L
microcosms.
On
Day
1.5,
93.4%
of
the
total
atrazine
was
dissolved
in
water.
In
addition
to
photosynthesis,
it
was
demonstrated
that
shoot
growth
was
relatively
unaffected
at
130
ppb,
but
total
biomass
was
sign.

reduced
after
2­
4
weeks.
Plant
biomass
reductions
followed
a
1
week
lag
after
photosynthesis
reduction.
At
1,200
ppb,
plant
biomass
had
been
virtually
eliminated
by
the
end
of
the
test.

Mean
shoot
length
in
the
controls
declined
after
week
1
and
after
week
3
for
1,200
ppb.
45087403
Cunningham
et
al.,
1984
Supplemental
(
raw
data
unavailable)

Estuarine
microcosm:

(
22­
23
days;
measured)

Single
dose:

Day
0:
30,000
ppb
­
nominal;

Measured
only
Day
22
or
23:

16,400­
17,700
ppb
30,000
ppb
(
Day
5­
22)

o
sign.
(
p<
0.05)
red.
average
ratio
of
no.
of
ramets
(
branches):
initial
no.
of
ramets
30,000
ppb
(
Day
22
or23)

o
sign.
(
p<
0.05)
46­
58%
red.
in
total
above­
ground
biomass
o
sign.
(
p<
0.05)
18%
red.
in
average
dry
weight
per
ramet
Experiments
were
conducted
with
seagrass,
Halodule
wrightii,

examining
the
effect
of
atrazine
and
any
interactions
of
salinity
(
15,
25,
35
ppt),
light
intensity
(
115,
140,
173
uEm­
2s­

1),
and
cropping
(
either
cut
at
4­
cm
or
6­
cm).
None
of
these
environmental
factors
affected
the
response
of
the
grass
to
atrazine.
45205101
Mitchell,
1987
Supplemental
(
raw
data
unavailable)
XI
­
50
ii.
Aquatic
Field
Studies
(
including
Mesocosms
and
Limnocorrals)

a.
Freshwater
Ponds,
Lakes
and
Reservoirs
Application
rate
(
lb
ai/
A)

Nominal/
Measured
Conc.
Concentration
affecting
endpoint
(
time
to
effect)

o
Affected
Species
and
Life
Stage
Narrative
of
Study
Trends
MRID
No.

Author/
Year
Freshwater
Lake:
Plankton
(
Duration
18
days)

Measured
=
>
90%
of
nominal
over
the
test
period
(
18
days):

nominal
concentrations
of
0.1,

1,
10,
and
100
ppb
NOEC
=
<
0.1
ppb
o
transient
effects
on
water
chemistry
1
ppb
(
1
week)

o
decreased
primary
production;

o
increased
bacterial
numbers
o
decreased
in
zooplankton
numbers
(
cladocerans
affected
greater
than
copepods)

10
ppb
(
3
weeks)

o
65%
sign.
(
p
<
0.01)
red.
in
daphnid
population
growth
(
combined
effect
of
water
&
algae)

o
59%
sign.
(
p
<
0.05)
red.
in
daphnid
growth
(
algae)

100
ppb
(
3
weeks)

o
92%
sign.
(
p
<
0.01)
red.
in
daphnid
growth
(
combined)

o
69%
sign.
(
p
<
0.01)
red.
daphnid
growth
(
algae)
In
situ
enclosures
in
a
German
lake
were
treated
and
monitored
over
18
days.
Dose­
responsive
reductions
in
chlorophyll­
a
and
oxygen
and
increases
in
particulate
organic
carbon
were
observed
at
1,
10,
and
100
ppb.
Within
1
week
at
1
ppb,
primary
production
decreases
and
bacterial
number
increases
were
observed.
Zooplankton
numbers
then
decreased,
with
cladocerans
affected
more
than
copepods.
Additional
studies
at
0.1
ppb
also
demonstrated
transient
effects
on
water
chemistry
and
biological
parameters.
Most
of
the
parameters
were
recovered
or
were
recovering
within
42
days
of
application.
45087414
Lampert
et
al.,
1989
Supplemental
(
raw
data
unavailable)
Application
rate
(
lb
ai/
A)

Nominal/
Measured
Conc.
Concentration
affecting
endpoint
(
time
to
effect)

o
Affected
Species
and
Life
Stage
Narrative
of
Study
Trends
MRID
No.

Author/
Year
XI
­
51
Freshwater
Pond:
Plankton
Treated
3
times
on
7/
31,
8/
28
(
29
days
later),
and
9/
21/
1990
(
24
days
later)
at
5,
10,
25,
75,

200,
and
360
ppb.
Weekly
conc.
relatively
constant;
mean
measured
conc.
over
two
months
are
5,
10,
22,
68,
182,

and
318
ppb
(
63
days;
measured)
NOEC:
5
ppb
(
63
days)
compared
to
controls
10,
22
and
68
ppb
o
up
to
40%
red.
dissolved
oxygen
(
Days
7­
46)

o
up
to
10%
incr.
pH
(
Days
18­
63)

o
up
to
10%
red.
conductivity
(
Days
7­
53)

68
ppb
o
up
to
78%
red.
copepod
nauplii
and
no
increase
in
nauplii
at
182
&
318
ppb
o
diatoms
appear
to
become
the
dominant
phytoplankton
182
ppb
o
strong
red.
in
dissolved
oxygen
and
conductivity
and
strong
increase
in
pH
levels
(
same
for
318
ppb)

o
up
to
98%
red.
Cryptophyceae,
Cryptomonas
marsonii
and
S.
erosa/
ovatata
(
Days
21
to
tests
end)

o
up
to
10%
red.
conductivity
(
Days
7­
53)

o
up
to
98%
red.
seasonal
blooms
of
Cryptomonas
marsonii
&
S.
erosa/
ovatata
(
Days
21
to
tests
end)

o
prevented
Mallomonas
sp.
seasnal
bloom
(
318
ppb
too)

o
prevented
the
seasonal
bloom
of
Planktosphaeria
sp.

(
Chlorophyceae)
after
Day
30
(
same
at
318
ppb)

o
lower
numbers
&
early
seasonal
decline
of
rotifers,

Synchaeta
sp.
(
same
at
318
ppb)

318
ppb
o
up
to
80%
red.
phytoplankton
cell
density
(
throughout
test,
except
on
Day
35)

o
up
to
98%
red.
Cryptophyceae,
Cryptomonas
marsonii
and
S.
erosa/
ovatata
(
first
appeared
on
Day
10
­
Days
21
to
tests
end)

o
up
to
9%
incr.
pH
(
Days
18­
63)

o
up
to
10%
red.
conductivity
(
Days
7­
53)

o
strong
red.
in
cell
numbers
of
Planktosphaeria
sp.

(
Chlorophyceae)
after
Day
30
o
delays
in
reaching
and
lower
peak
daphnid
egg
ratio,

and
delayed
peaks
for
numbers
of
young
and
adults
Mesocosms
(
1,000
L
cylinders
)
in
southern
Bavaria
were
treated
with
atrazine
3
times
(
29
and
24
day
intervals)
over
63
summer
days.
Strongly
dose­
response
reductions
in
dissolved
O2,
pH,
and
conductivity
were
noted
at
concentrations
greater
than
5
ppb.
Changes
in
oxygen
concentrations
at
>
10
ppb
and
some
zooplankton
populations
at
68,
182,
and
318
ppb
reflect
indirect
functional
links
as
a
result
of
altered
primary
production.

At
68
ppb,
up
to
a
78%
reduction
in
copepod
nauplii
was
found
and
no
increase
in
the
number
of
nauplii
was
found
at
182
and
318
ppb.
At
182
ppb,
threshold
concentrations
for
direct
effects
by
atrazine
were
exceeded
in
several
phytoplankton
species.

Diatoms
appeared
to
become
the
dominant
phytoplankton
at
182
and
318
ppb.
One
rotifer
species
decreased
at
182
ppb
and
another
at
318
ppb
and
was
virtually
absent
from
Day
18
to
the
end
of
the
study.
Daphnid
reproduction
and
populations
decreased
at
318
ppb.
45020022
Juttner
et
al.
1995
Supplemental
(
raw
data
unavailable)
Application
rate
(
lb
ai/
A)

Nominal/
Measured
Conc.
Concentration
affecting
endpoint
(
time
to
effect)

o
Affected
Species
and
Life
Stage
Narrative
of
Study
Trends
MRID
No.

Author/
Year
XI
­
52
Artificial
freshwater
ponds
in
Kansas
treated
with
atrazine
to
achieve
concentrations
of
20
and
500
Fg/
L
Atrazine
levels
measured
in
the
water
column
four
times
during
the
first
two
months
of
the
study:
100%
of
nominal
at
time
zero
(
163
days;

measured).
Laboratory
data
shows
results
for
atrazine
sensitivity
tests
for
treated
field
samples:

1
ppb
o
sign.
(
0.05)
4%
increase
in
fluorescence
5
ppb
o
sign.
(
0.05)
9%
increase
in
fluorescence
o
sign.
(
0.05)
8%
decrease
in
C­
14
uptake
20
ppb
o
sign.
(
0.05)
30%
increase
in
fluorescence
o
sign.
(
0.05)
12%
decrease
in
C­
14
uptake
500
ppb
o
sign.
(
0.05)
136%
increase
in
fluorescence
o
sign.
(
0.05)
88%
decrease
in
C­
14
uptake
Field
pond
study
results:

20
ppb
o
sign.
(
0.05)
51%
red.
C­
14
uptake
(
4
hr.)
(
Days
2­
7)

o
sign.
42%
red.
phytoplankton
biomass
(
Days
2­
7)

o
3%
red.
growth
&
28%
red.
daphnid
reproduction
Simocephalus
serrulatus
correlated
with
food
levels
500
ppb
o
pH
red.
0.3
units
lower
than
controls
for
a
few
weeks
o
dissolved
O2
generally
red.
1­
3
mg/
L
(
a
few
weeks)

o
sign.
94%
red.
C­
14
uptake
(
4
hr.)
(
Days
2­
163)

o
usually
sign.
red.
phytoplankton
biomass
(
Days
2­

136)

o
rapid,
nearly
complete
red.
in
abundant
Peridinium
inconspicuum,
a
small
dinoflagellate
and
rapid
red.

in
7+
other
dominate
phytoplankton
sp.
after
7
days
o
incr.
in
several
flagellate
species;
mainly
Mallomonas
pseudocoronata,
Cryptomonas
marssonii
&
C.
erosa
o
zooplankton
dominance
shifted
to
rotifers,
mainly
Keratella
cochlearis
after
Day
31
o
>
50%
red.
in
the
copepod,
Tropocyclops
prasinus
mexicanus
by
Day
14
Single
treatment
of
two
0.045
hectare
ponds
each
with
either
20
or
500
ppb
atrazine
produced
dose
responsive
changes
in
pH,

DO
and
daily
carbon
uptake.
Phytoplankton
growth
was
reduced;
population
shifts
were
apparent
at
20
and
500
ppb.

Effects
on
phytoplankton
were
immediate,
within
2
days,
for
daily
carbon­
14
uptake
and
biomass
declines
at
both
treatment
levels,
which
is
consistent
with
other
researchers
in
laboratory
tests.
Atrazine
concentrations
down
to
1
ppb
affected
photosynthesis
in
lab
tests
with
phytoplankton
samples
from
the
pond.
While
atrazine
produced
direct
toxic
effects
on
just
certain
members
of
the
aquatic
community,
their
responses
also
affected
other
members
of
the
community.
At
500
ppb,
one
species
of
herbivorous
zooplankton
declined
by
more
than
75%

within
14
days
of
treatment.

Subsequent
laboratory
tests
demonstrated
some
atrazine
resistance
in
phytoplankton
and
showed
zooplankton
population
effects
were
due
to
loss
of
food
(
algae).
Further
evidence
of
resistance
was
indicated
by
a
dominant
phytoplankton
species
which
showed
less
toxic
responses
than
the
same
species
in
the
control
pond.
45020011
DeNoyelles
et
al.
1982
Supplemental
(
raw
data
unavailable)
Application
rate
(
lb
ai/
A)

Nominal/
Measured
Conc.
Concentration
affecting
endpoint
(
time
to
effect)

o
Affected
Species
and
Life
Stage
Narrative
of
Study
Trends
MRID
No.

Author/
Year
XI
­
53
Artificial
freshwater
ponds
in
Kansas
treated
with
atrazine
to
achieve
concentrations
of
20
and
500
Fg/
L
NOAEC
<
20
Fg/
L
20
Fg/
L
­
29%
increase
in
turbidity.

­
initial
depressed
phytoplankton,
followed
by
an
increase
in
standing
crop
and
numerical
dominance
of
resistant
species.

­
red.
production
of
Naajas
sp.
and
Potamogeton
spp.
in
areas
excluding
carp.

­
increase
in
Chara
­
82%
reduction
in
total
insect
emergence.

­
89%
red.
in
non­
predator
insect
emergence.

­
90%
red.
Labrundinia
pilosella
emergence.

­
50%
red.
in
total
insect
species
richness.

­
57%
red.
in
non­
predator
insect
species
richness.

100
Fg/
L
­
62%
increase
in
turbidity.

­
absence
of
periphyton
on
walkway
supports.

increase
in
Chara
sp.

­
83%
reduction
in
total
insect
emergence.

­
95%
red.
in
non­
predator
insect
emergence.

­
96%
red.
Labrundinia
pilosella
emergence.

­
71%
red.
in
total
insect
species
richness.

­
85%
red.
in
non­
predator
insect
species
richness.

­
5%
red.
in
insect
species
evenness.

500
Fg/
L
­
65%
increase
in
turbidity.

­
absence
of
periphyton
on
vascular
plants.

­
absence
of
Chara
sp.

­
70%
reduction
in
total
insect
emergence.

­
85%
red.
in
non­
predator
insect
emergence.

­
90%
red.
Labrundinia
pilosella
emergence.

­
59%
red.
in
total
insect
species
richness.

­
66%
red.
in
non­
predator
insect
species
richness.

­
15%
red.
in
insect
species
evenness.
Two
artificial
Kansas
ponds
each
(
0.045
ha.
and
2.1
m.
deep)

were
treated
with
technical
atrazine
at
20
Fg/
L
and
100
Fg/
L
and
with
a
41%
ai
CO­
OP
liquid
atrazine
at
20
Fg/
L
in
1981;
two
ponds
served
as
controls.
The
ponds
were
treated
again
on
30
May
1982,
but
the
41%
ai
ponds
were
converted
to
500
Fg/
L
with
technical
atrazine.
The
macrophyte
community
in
treated
ponds
was
noticeably
reduced,
relative
to
controls,
throughout
the
summer.
For
16
sampling
dates
between
8
May
and
28
September
1982
insect
emergence
was
monitored
in
each
pond
with
4
emergence
traps
for
48
hour
periods.
No
significant
differences
between
ponds
were
found
in
water
level,

temperature
or
oxygen
levels.
Mean
turbidity
varied
significantly
among
treatments
(
ANOVA),
increasing
with
increasing
atrazine
levels
up
to
100
Fg/
L.

The
phytoplankton
community
responses
to
atrazine
during
the
present
study
corroborate
results
from
the
1979
study
by
deNoyelles
et
al.
(
1979).
Macrophyte
response
also
paralleled
the
1979
study.
The
presence
of
live
plants
of
the
primary
emergent
vegetation,
Typha
spp.,
gradually
decreased,
as
in
previous
studies,
with
increasing
atrazine
concentration
both
within
and
outside
carp
exclusion
areas
(
Carney
1983,

deNoyelles
and
Kettle
1983).
45227706
Dewey
1986
Application
rate
(
lb
ai/
A)

Nominal/
Measured
Conc.
Concentration
affecting
endpoint
(
time
to
effect)

o
Affected
Species
and
Life
Stage
Narrative
of
Study
Trends
MRID
No.

Author/
Year
XI
­
54
Artificial
freshwater
ponds
in
Kansas
treated
with
atrazine
to
achieve
concentrations
of
20
and
500
Fg/
L
NOAEC
<
20
Fg/
L
20
Fg/
L
­
60%
sign.
(
p
<
0.05)
reduction
in
macrophtye
vegetation
at
summer's
end
including
elimination
of
Potamogeton
pusillus,

P.
nodosus,
&
Najas
quadalupensis;

­
95%
sign.
(
p
<
0.05)
red.
macrophyte
coverage
in
May,
10
months
after
treatment;

­
96%
sign.
(
p
<
0.01)
reduction
in
the
number
of
young
bluegill;

­
85%
sign.
(
p
<
0.001)
red.
in
the
number
of
food
items/
fish
stomach;

­
57%
sign.
(
p
<
0.001)
red.
in
the
number
of
prey
taxa/
fish
stomach.

500
Fg/
L
­
90%
sign.
(
p
<
0.05)
reduction
in
macrophtye
vegetation
at
summer's
end
including
elimination
of
Potamogeton
pusillus,

P.
nodosus,
&
Najas
quadalupensis;

­
>
95%
sign.
(
p
<
0.05)
red.
macrophyte
coverage
in
May,
10
months
after
treatment;

­
96%
sign.
(
p
<
0.01)
reduction
in
the
number
of
young
bluegill;

­
78%
sign.
(
p
<
0.001)
red.
in
the
number
of
food
items/
fish
stomach;

­
52%
sign.
(
p
<
0.001)
red.
in
the
number
of
prey
taxa/
fish
stomach.
Two
artificial
Kansas
ponds
each
(
0.045
ha.
and
2.1
m.
deep)

were
treated
with
20
Fg/
L
and
500
Fg/
L
on
24
July
and
two
ponds
served
as
controls.
The
macrophyte
community
in
treated
ponds
was
noticeably
reduced,
relative
to
controls,
throughout
the
summer.
Visual
estimates
of
the
macrophyte
communities
in
the
ponds
showed
roughly
a
60
percent
decline
in
the
20
Fg/
L
ponds
and
a
90
percent
decline
in
the
500
Fg/
L
ponds
two
months
after
atrazine
addition.
These
estimates
were
verified
by
rake
hauls
which
produced
these
same
relative
differences.
The
following
May,
10
months
after
treatment,
when
macrophytes
are
normally
well
established
in
Kansas
ponds,
the
ponds
were
drained.
Relative
to
control
ponds,
20
Fg/
L
ponds
had
a
90
percent
reduction
in
macrophyte
coverage
and
the
500
Fg/
L
ponds
had
a
>
95
percent
reduction
in
macrophyte
coverage.

Differences
were
noted
in
the
macrophyte
species
present.

Control
ponds
contained
Potamogeton
pusillus
and
P.
nodosus,

Najas
quadalupensis,
and
small
amounts
of
Chara
globularis,

whereas
the
treated
ponds
contained
mostly
C.
globularis.

Significant
indirect
effects
were
found
on
bluegill
diet
and
reproduction.
45202912
Kettle,
de
Noyelles,
Jr.,

Heacock
and
Kadoum
1987
Supplemental
(
raw
data
are
not
available
for
analyses)
Application
rate
(
lb
ai/
A)

Nominal/
Measured
Conc.
Concentration
affecting
endpoint
(
time
to
effect)

o
Affected
Species
and
Life
Stage
Narrative
of
Study
Trends
MRID
No.

Author/
Year
XI
­
55
Freshwater
limnocorrals:

(
3
controls
and
3
treated
at
nominal
concentrations
of
100
ppb
on
June
1
&
July
6,
1983)

Measured
conc.
range:
80­
140
ppb
after
the
first
application,

120­
165
ppb
after
the
second
application
(
329
days;
measured)
Effects
on
periphyton
and
environmental
parameters:

first
application:
80
­
140
ppb
o
no
sign.
effects
on
DO,
temperature,
Secchi
depth,

dissolved
inorganic
carbon
(
DIS),
NO3­
NO2­
N),

total
nitrogen,
and
total
phosphorus
o
periphyton
dry
wt.
lower
than
controls
after
Day
14
at
most
depths;
sign.
(
0.05)
red.
at
a
depth
of
0.5
m
on
Day
34
and
thereafter
o
sign.
94%
red.
C­
14
uptake
(
4
hr.)
(
Days
2­
163)

o
usually
sign.
red.
phytoplankton
biomass
(
Days
2­
136)

o
rapid,
nearly
complete
red.
in
the
abundant
Peridinium
inconspicuum,
a
small
dinoflagellate
and
rapid
red.

in
7+
other
dominate
phytoplankton
sp.
after
7
days
o
incr.
in
several
flagellate
species;
mainly
Mallomonas
pseudocoronata,
Cryptomonas
marssonii
&
C.
erosa
o
zooplankton
dominance
shifted
to
rotifers,
mainly
Keratella
cochlearis
after
Day
31
o
>
50%
red.
in
the
copepod,
Tropocyclops
prasinus
mexicanus
by
Day
14
second
application
120
­
165
ppb
o
sign.
(
0.05)
20%
red.
dissolved
oxygen
(
Days
37­
137)

o
sign.
(
0.05)
33%
increase
in
Secchi
depth
o
sign.
(
0.05)
62%
increase
dissolved
inorganic
carbon
o
sign.
(
0.05)
103%
increase
in
NO3­
NO2­
N
o
sign.
(
0.05)
red.
periphyton
dry
weight
at
depths
of
0.5
and
1.5
m
on
most
sampling
days
o
sign.
(
0.05)
red.
decr.
chlorophyll
(
19
days
after
second
appl.
(
Day
54
&
on
some
days
thereafter)

o
zooplankton
dominance
shifted
to
rotifers,
mainly
Keratella
cochlearis
after
Day
31
o
>
50%
red.
in
the
copepod,
Tropocyclops
prasinus
mexicanus
by
Day
14
Elaboration
of
the
80
ppb
treatment
from
Hamilton
et
al.,
1987.

After
the
first
application
(
pulse),
blue­
green
algae
were
eliminated
and
organic
matter
was
significantly
reduced.
After
the
second
pulse,
organic
matter,
chlorophyll,
biomass,
and
carbon
assimilation
were
reduced
by
between
36
and
67%,
along
with
certain
species
of
green
algae.
Diatom
numbers
were
greater
in
treatment
limnocorrals
than
in
the
control
limnocorrals
for
nine
weeks
after
the
second
pulse.
45020012
Herman
et
al.,
1986
Supplemental
(
raw
data
unavailable)
Application
rate
(
lb
ai/
A)

Nominal/
Measured
Conc.
Concentration
affecting
endpoint
(
time
to
effect)

o
Affected
Species
and
Life
Stage
Narrative
of
Study
Trends
MRID
No.

Author/
Year
XI
­
56
Texas
Lake
Mesocosm:

Measured
atrazine
concentrations
approximately
75%
of
nominal
(
15
and
153
ppb)
for
first
application
and
150%
of
nominal
(
385
and
2,167
ppb)
for
the
second
application
Phyto­
and
zooplankton
A
3x3
factorial
design
with
three
conc.
of
atrazine
(
0,
15,
and
153
ppb)
and
three
conc.
of
bifenthrin
(
0,
0.039,
and
0.287
ppb)

applied
as
soil
slurry
in
May,
then
again
one
month
later
but
with
atrazine
conc.
of
0,
385,
and
2,167
ppb
and
bifenthrin
conc.
of
0,

0.125,
and
3.15
ppb.
Atrazine
alone
caused
dose­
responsive
reductions
in
chlorophyll,
turbidity,
primary
production,

increases
in
nitrogen
and
phosphorous,
and
reduced
levels
of
chlorophytes,
cladocerans,
copepod
nauplii,
and
rotifers.

General
recovery
after
14
days
for
atrazine
alone
in
the
first
phase,
but
recovery
not
complete
at
sampling
termination
after
second
phase
(
14
days).
No
synergistic
or
antagonistic
effects
noted.
45020014
Hoagland
et
al.,
1993
Supplemental
(
raw
data
unavailable)

Duplicate
check
&

delete
this
Artificial
ponds:

(
measured)

Mean
measured
concentrations
of
18.4,
91.5
or
114
ppb
(
two
years
data),
and
314
ppb
Aquatic
plants,
phyto­
and
zooplankton
Nominal
applications
of
either
20,
100,
or
300
ppb
atrazine
were
monitored
for
effect
8
weeks
after
June
application
and
in
the
next
summer.
Conductivity
and
oxygen
concentration
were
affected
at
the
100
and
300
ppb
levels.
Reductions
in
aquatic
plant
numbers
were
observed
at
>
100
ppb
in
the
summer
after
application,
but
no
effects
on
microflora
or
fauna
were
observed.

The
year
after
treatment
(
with
10
to
30%
of
atrazine
still
in
the
water
column),
Chara
sp.
replaced
Myriophyllum
spicatum
and
Potamogeton
natans
at
levels
>
100
ppb.
Phytoplankton
became
dominated
with
cyanophytes
and
then
cryptophytes
as
the
concentration
of
atrazine
increased.
Zooplankton
numbers
at
100
and
300
ppb
were
also
reduced
the
following
year.
45020017
Neugebaur
et
al.,
1990
Supplemental
(
raw
data
unavailable)
XI
­
57
b.
Freshwater
Natural
and
Artificial
Streams
Application
rate
(
lb
ai/
A)

Nominal/
Measured
Conc.
Concentration
affecting
endpoint
(
time
to
effect)

o
Affected
species
and
life
stage
Narrative
of
Study
Trends
MRID
No.

Author/
Year
Small
Canadian
first­
order
stream
adjacent
to
a
tiled­
corn
field.
Atrazine
of
unspecified
purity
was
applied
at
4
liters
per
hectare
on
6
June
1989.

The
Canadian
Water
Quality
Guidelines
(
CCREM,
1987)

specify
a
guideline
of
2.0
Fg/
L
to
protect
freshwater
life.
Non­
statistical
pair­
wise
comparison
of
Total
Phytoplankton
counts
vs
sta
9,
the
control
indicates
reductions
at
all
downstream
stations
with
effects
generally
decreasing
with
time
and
distance.

Downstream
station
11
(
2.5
km
from
atrazine
source
­
sta.
5):

0.047
Fg/
L
(
range
0.004­
0.2Fg/
L)
atrazine
conc.

o
all
samples
with
reduced
total
phytoplankton
counts
o
mean
reduction
of
63
%
(
range
6
­
97
%)

o
highest
red.
(
97
%)
on
June
9,
first
sampling
day
o
reduced
70
%
in
final
sample
on
16
Nov.

Downstream
station
10
(
50
to
75
m
from
sta.
5)

0.366
Fg/
L
(
range
0.1
­
1.7
Fg/
L)
atrazine
conc.

o
2
out
of
11
samples
exceed
count
at
sta.
9
o
mean
reduction
of
45
%
(
range
+
55
­
92
%)

o
highest
red.
(
92
%)
on
June
9
o
reduced
47
%
in
final
sample
on
16
Nov.

Downstream
stations
6
&
7
(
a
few
meters
from
sta.
5)

0.81
(
0.17
­
1.89)
and
0.05
(
0.001­
0.224)
Fg/
L,
resp.

o
1
out
of
9
samples
at
sta.
6
exceeds
count
at
sta.
9
o
mean
reduction
sta.
6
of
53
%
(
range
+
68
­
99)

o
mean
reduction
sta.
7
of
66
%
(
range
3
­
95)

o
highest
red.
(
99
and
93
%,
resp.)
on
July
21
o
red.
45
&
27
%,
resp.
in
final
sample
on
16
Nov.

Ditch
(
station
5)
receiving
waters
from
the
4
tile
outlets:

2.62
Fg/
L
(
range
0.211
­
13.9
Fg/
L)
atrazine
conc.

o
mean
reduction
of
79
%
(
range
46
­
99
%)

o
highest
red.
(
92
%)
on
3
dates,
June
23
­
July
21
o
reduced
51
%
in
final
sample
on
16
Nov.
Atrazine
concentrations
up
to
20.39
Fg/
L
(
sta.
4)
in
field
tile
water,
13.9
Fg/
L
(
sta.
5)
in
receiving
ditch
and
1.89
Fg/
L
in
a
small
stream
(
sta.
6)
were
measured
in
New
Brunswick,

Canada
in
a
rural
headwater
basin
of
the
Petitcodiac
River.

The
fist­
order
stream
flowed
parallel
to
an
8­
hectare
subsurface
tile­
drained
field
of
silage
corn.
The
field
was
divided
into
4
plots
and
each
drained
separately
into
a
small
canal
and
into
the
stream.

Water,
phytoplankton
and
zooplankton
were
sampled
at
15­
day
intervals
at
11
sampling
sites
during
the
growing
season.

Total
phytoplankton
numbers
in
downstream
samples
were
consistently
much
less
than
those
from
upstream
(
control)

samples
during
the
period
of
low
flow
and
higher
atrazine
levels
(
during
the
summer).
Diatoms
dominated
the
phytoplankton
community.
Occurrence
of
other
algal
species
were
erratic
between
stations
and
over
time.
Zooplankton
numbers
were
too
low
to
discern
trends,
but
downstream
samples
were
consistently
lower
in
individuals
than
control
samples.
45020008
Lakshinarayana,
O'Neill,

Johnnavithula,
Leger
and
Milburn
1992
Supplemental
(
Replication
of
samples
and
statistical
analyses
were
not
made)
Application
rate
(
lb
ai/
A)

Nominal/
Measured
Conc.
Concentration
affecting
endpoint
(
time
to
effect)

o
Affected
species
and
life
stage
Narrative
of
Study
Trends
MRID
No.

Author/
Year
XI
­
58
Artificial
stream
test:

(
14
day;
measured)

Simulated
pulsed­
exposures;

5
Fg/
l
atrazine
on
Day
1
and
gradually
diluted
until
only
about
1
Fg/
L
on
Day
7
5
Fg/
L
to
about
1
Fg/
L
on
Day
7
o
atrazine
concentrations:

Day
Mean
conc.

1
4.74
5
3.56
10
1.20
14
1.19
Possible
atrazine
effect:

o
58
to
126
fold
increase
sign.
(
p<
0.05)
in
number
of
emergent
insects
on
Days
3,
5
and
7;

treatment
numbers
were
equal
to
or
greater
than
controls
in
all
samples
No
statistical
effects
found
in
atrazine
treatments
on:

o
periphyton
growth
measured
as
chlorophyll
a
levels;

chlorophyll
a
levels
decreased
gradually
in
all
samples
(
treatments
&
controls)
over
time,

"
may
have
masked
an
effect
of
atrazine"

o
indirect
effects
on
function
or
taxonomic
composition
of
benthic
community
structure
A
community
of
benthic,
stream
invertebrates
from
the
Patrick
Brook
in
Hinesburg,
Vermont,
located
in
the
LaPlatte
River
watershed.
Microbial
community
growth
was
incubated
for
2
weeks
this
substrate
was
placed
in
10
x
10
x
7
cm
polyethylene
boxes
and
placed
in
the
stream
for
invertebrate
colonization
for
3
weeks
in
July
1993.
During
the
same
3­
week
period
glass
slides
were
placed
in
the
stream
for
algal
settling
and
growth.

Four
benthic
invertebrate
boxes
and
9
periphyton
slides
were
randomly
placed
in
each
of
six
replicate
tanks.
The
flow
rate
was
calculated
as
20.8
L/
min.
throughout
the
test.
After
a
24­

hour
equilibration
period,
treatment
at
5
Fg/
L
atrazine
was
introduced
to
3
replicates
and
3
controls.
On
Day
3,
about
15
percent
of
the
water
was
replaced;
on
Days
6
and
7
water
replacements
were
50
percent
each
day;
about
15
%
was
replaced
on
Day
11
during
the
14­
day
test.

"
Dewey
(
1986)
also
observed
herbivorous
insects
emerging
earlier
from
artificial
ponds
treated
with
20
Fg/
L
atrazine
compared
to
controls.
Dewey
suggested
that
the
changes
she
saw
were
the
indirect
effect
of
atrazine
exposure,
which
had
reduced
the
amount
of
food
available
to
herbivorous
insects."
45087411
Gruessner
and
Watzin
1996
Supplemental
(
raw
data
unavailable
for
statistical
analyses)

Artificial
stream
tests:

(
14
day;
measured)

One
dose
and
recirculation;

two
atrazine
levels
(
40.8%
ai):

15.2
+
1.4
and
155.4
+
1.4
Fg/
l
atrazine
on
Day
1;

17.5
+
1.2
and
135.0
+
4.5
Fg/
L
on
Day
28
Interaction
test
with
alachlor
discussed
under
the
section
on
pesticide
interactions.
15.2
Fg/
L
(
initial
atrazine
concentration):

o
45%
red.
in
benthic
algal
biovolume
after
1
week
sign.
(
p
<
0.05);

o
35%
red.
in
benthic
algal
biovolume
after
2
weeks
non.
sign.
(
p
<
0.05);

o
45%
red.
in
benthic
algal
biovolume
after
4
weeks
sign.
(
p
<
0.05).

155.6
Fg/
L
(
initial
atrazine
concentration):

o
45%
red.
in
benthic
algal
biovolume
after
1
week
sign.
(
p
<
0.05)

o
50%
red.
in
benthic
algal
biovolume
after
2
weeks
sign.
(
p
<
0.05);

o
57%
red.
in
benthic
algal
biovolume
after
4
weeks
sign.
(
p
<
0.05).

Time­
dependent
analyses
showed
sign.
(
p
=
0.0083)

reduction
in
algal
biovolume
treated
with
both
15.2
and
155.6
Fg/
L
atrazine
throughout
the
test,
but
no
sign.
(
p
=

0.3629)
difference
between
15.2
and
155.6
Fg/
L
levels.
A
benthic
mud
community
of
epipelic
algae
were
collected
from
various
locations
of
Wahoo
Creek
and
acclimated
for
6
weeks
prior
to
atrazine
treatments.
Stream
water
came
from
Wahoo
Creek
on
March
25,
1993.
Wahoo
Creek
is
a
third­
order,
sediment­
dominated
Nebraska
stream
draining
primarily
agricultural
land
and
subject
to
major
runoff
events.

Each
model
stream
was
constructed
from
a
114­
L
oval­
shaped
plastic
tub
and
lined
with
two­
layers
of
4­
mil
clear
plastic.

Stream
velocities
ranged
from
0.05
to
0.1
m/
sec.
in
the
sending
segment
and
0.01
to
0.05
m/
sec.
in
the
returning
segment.

Lighting
was
12
hour/
12
hour
light/
dark
cycle.
To
replace
evaporated
water,
stream
water
from
the
transport
tank
was
mixed
for
24
hours
prior
addition
to
each
stream.
Epipelic
algae
were
sampled
immediately
before
herbicide
atrazine
addition,
24
hours
after
addition,
and
after
1,
2
and
4
weeks.

Algal
samples
were
analyzed
for
cell
density,
cell
biovolume
and
the
relative
abundance
of
6
dominant
taxa.
45020002
Carder
&
Hoagland
1998
Application
rate
(
lb
ai/
A)

Nominal/
Measured
Conc.
Concentration
affecting
endpoint
(
time
to
effect)

o
Affected
species
and
life
stage
Narrative
of
Study
Trends
MRID
No.

Author/
Year
XI
­
59
Natural
Tasmanian
stream:

(
2
weeks
to
7
months:

measured
concentrations)

Forests
aerially
sprayed
once
at
either
3
or
6
liters
ai
per
hectare
of
Gesaprim:
peak
of
22
ppb;
median
conc.
of
2.5
ppb
for
the
2
weeks
after
application
Atrazine
levels
in
24
Tasmanian
streams
averaged
2.85
Fg/
L
(
range<
0.01­
53
mg/
L).
In
forestry
areas,
the
mean
stream
conc.
was
2.00
(<
0.01­
8.9)
Fg/
L
with
35%
below
the
detection
limit
of
1.0
Fg/
L.

Spray
drift
into
the
stream
appeared
the
same
as
in
the
treated
forest
as
estimated
by
spray­
droplet
deposits
on
wood.

22
Fg/
L:

o
sign.
increase
(
p
<
0.01)
in
daytime
invertebrate
drift
at
site
2,
12
hours
after
treatment
o
site
3
also
showed
an
increase
in
daytime
invertebrate
drift
on
day
of
treatment,
but
not
statistically
sign.
(
p
>
0.05)

o
sign.
(
p<
0.001)
increase
in
night
drift
in
number
of
hydroptylid
larvae
on
days
1,
2,
4,
and
9
o
sign.
(
p<
0.001)
increase
in
night
drift
in
number
of
hydropsychid
larvae
on
days
2,
4,
and
9
The
effects
of
invertebrate
drift
at
site
2
were
associated
with
increased
spray
drift,
during
the
12
hours
immediately
following
application.
Poor
habitat
and
limited
taxa
at
site
2
precluded
drift
analyses
on
specific
taxa.

o
no
sign.
affect
on
mean
densities
of
benthic
invertebrates,
number
of
taxa
or
taxa
proportions
o
71%
sign.
(
p<
0.01)
increase
in
trout
population
at
site
2
sustained
over
four
months
o
no
sign.
effect
on
fish
mortality
or
physiology
Tasmanian
stream,
Big
Creek,
with
a
catchment
area
of
36
km2
was
studied
for
atrazine
aerially
sprayed
on
two
forest
areas
of
20
and
66
hectares,
at
rates
of
3
and
6
kg
ai/
ha
on
13
and
14
October
1987,
respectively.
Three
sampling
sites
were
picked:

Site
1
above
the
2
plantations,
sites
2
and
3
were
just
below
each
plantation.
Each
site
consisted
of
an
upstream
riffle
for
invertebrate
samples
and
an
area
100
m
downstream
for
sampling
brown
trout
(
Salmo
trutta).

Atrazine
levels
in
174
water
samples
from
44
sites
from
24
streams
averaged
2.85
Fg/
L
(
range<
0.01­
53
mg/
L).
Only
9.6%
of
samples
were
below
detection
limit
(
0.1Fg/
L)
and
only
24
%
were
below
1.0
Fg/
L.
In
forestry
areas,
the
mean
stream
conc.
was
2.00
Fg/
L
(
range
<
0.01­
8.9
Fg/
L)
with
35%

below
the
detection
limit
of
1.0
Fg/
L.

The
initial
measured
concentration
in
Big
creek
was
22
Fg/
L,

2
weeks
later
atrazine
averaged
2.5
(
range
1.2­
4.6)
Fg/
L,
and
over
the
following
2
months
ranged
from
0.01
to
0.09
Fg/
L.

Atrazine
levels
in
a
small
seepage
draining
the
2
plantations
range
0.8­
68
Fg/
L
over
the
next
2
months.

Site
2
sediments
ranged
from
1.6
to
22
Fg/
kg
wet
weight
two
weeks
after
spraying.

No
fish
mortality
or
behavioral
changes
were
recorded
during
applications.
However,
brown
trout
movement
within
the
application
area
was
significantly
different
(
increased)
than
the
upstream
control
movement.
No
changes
in
trout
physiology
were
observed.
45020003
Davies
et
al.,
1994
(
Species
are
not
native
to
North
America;

Raw
data
unavailable
for
statistical
analyses)
Application
rate
(
lb
ai/
A)

Nominal/
Measured
Conc.
Concentration
affecting
endpoint
(
time
to
effect)

o
Affected
species
and
life
stage
Narrative
of
Study
Trends
MRID
No.

Author/
Year
XI
­
60
Artificial
stream
in
laboratory
Technical
Atrazine:
98.2%

Experiment
1:

Constant
12­
day
exposures
at
0,
24
&
134
Fg/
L
atrazine
Experiment
2
involved
pulsed
exposures
of
4
herbicides
mixed
together
at
nominal
concentrations
of:

Atrazine
at
135
Fg/
L;

Alachlor
at
90
Fg/
L;

Metolachlor
at
200
Fg/
L;

Metribuzin
at
20
Fg/
L.

Full
concentrations
on
Days
8
&
9,
halved
on
Days
10
&
11,

and
discontinued
on
Day
12.
Constant
12­
day
exposure
tests
(
Days
8­
17)
10
and
25EC:

o
24
Fg/
L:

­
24%
red.
sign.
(
p<.
001)
in
ash­
free
dry
wt.
at
25EC
­
30%
red.
sign.
(
p<.
01)
in
chlorophyll
a
at
25EC
o
134
ug/
L:

­
47%
red.
sign.
(
p<.
001)
in
ash­
free
dry
wt.
at
10EC
­
31%
red.
sign.
(
p<.
001)
in
ash­
free
dry
wt.
at
25EC
­
44%
red.
s
ign.
(
P<.
001)
in
chlorophyll
a
at
25EC
­
30%
red.
s
ign.
(
P<.
01)
in
chlorophyll
a
at
10EC
Nutrient
uptake
was
affected
more
by
the
15EC
difference,

than
the
atrazine
concentrations.
Raw
data
were
absent
and
statistically
analyses
could
not
be
assessed.
As
cited:

­
35%
red.
N
uptake
at
134
Fg/
L
at
10EC;
not
sign.

­
25%
red.
N
uptake
at
134
Fg/
L
at
25EC;
not
sign.

­
31%
red.
silica
uptake
at
134
Fg/
L
at
10EC;
not
sign.

­
58%
red.
silica
uptake
at
134
Fg/
L
at
25EC;
not
sign.

­
14%
red.
P
uptake
at
134
Fg/
L
at
10EC;
not
sign.

­
8
%
red.
P
uptake
at
134
Fg/
L
at
25EC;
not
sign.
Six
artificial
streams
consisting
of
a
7.5
cm
OD
x
123
cm
long
Pyrex
glass
tube
were
tested
concurrently
for
pesticide
effects
on
aufwuchs
productivity
and
nutrient
uptake
(
NO2,
NO3,

phosphorus
PO4
and
silica
were
tested
after
an
7­
day
colonization
period
with
natural
waters
from
a
third
order
stream
in
the
Sandusky
Basin,
Ohio.
Two
experimental
designs
(
continuous
and
pulsed
exposures)
were
tested
under
constant
lighting,
flow
rates
of
7.8
mL/
min.
natural
creek
water
and
1.0
mL/
min.
nutrient
water
for
20­
day
periods.

Experiment
1.
Two
"
streams"
were
exposed
to
continuous
nominal
atrazine
concentrations
of
0,
50
and
200
Fg/
L
at
25EC
and
then
repeated
at
10EC
on
Days
8­
17.

Experiment
2.
Three
streams
were
treated
to
pulsed
exposures
of
a
mixture
of
four
herbicides.
These
results
are
not
relevant
to
the
risk
assessment
for
atrazine.
45020007
Krieger,
Baker
and
Kramer
1988
Supplemental
(
The
solvent
methanol
0.00057%
v/
v
was
not
added
to
controls;

raw
data
unavailable
for
statistical
analyses)

Two
artificial
model
streams
in
laboratory
continuously
exposed
for
30
days
with
60­

day
recovery
period
and
repeated
4
times
in
one
year.

Nominal
concentration
of
25
Fg/
L
technical
grade
atrazine
dissolved
in
DMSO;
atrazine
concentrations
in
streams
were
not
measured.
25
Fg/
L
Atrazine:

After
one
year
of
4
treatment
and
recovery
cycles,
it
was
reported
that
the
treatment
did
not
have
any
significant
or
lasting
effect
on
macroinvertebrate
population
structure,

periphyton
standing
biomass
or
rates
of
primary
production
and
community
respiration.

Two
out
of
200
statistical
tests
showed
significant
effects
for
atrazine
treatment:
equitability
(
p
<
0.029)
during
Winter
,

month
3,
and
taxa/
sample
(
P
<
0.001)
during
the
Spring,

month
3.
Macroinvertebrate
drift
in
streams
increased
abruptly
upon
injection
in
both
controls
and
treatments
which
was
attributed
to
the
solvent
rather
than
to
atrazine.

Initial
drift
samples
were
collected
only
in
the
autumn
and
summer.
Drift
in
the
summer
samples
were
"
substantially
higher"
in
the
atrazine­
treated
streams
than
in
the
DMSOtreated
control.
Pulses
in
the
number
of
drifting
organisms
following
toxicant/
solvent
injection
were
primarily
due
to
Baetis
mayflies.
Continuous­
flow
stream
treatment
for
30
days
at
25
ppb,

followed
by
60
days
of
no
treatment,
and
repeated
4
times
for
one
year
in
artificial,
3.96
m.­
long
concrete­
lined
streams
inside
a
laboratory.
Invertebrate
populations
were
introduced
by
colonization
from
incoming
drift
with
water
flowing
from
a
natural
creek
over
a
one
year
period
before
treatment.
Atrazine
was
injected
into
the
flowing
water
for
periods
as
described
above.
Benthic
invertebrate
populations
as
follows:
two
samples
(
10.2­
cm
diameter
cores)
during
pretreatment
were
collected
at
45­
day
intervals
for
1
year.
Three
post­
treatment
samples
were
made
every
30
days.

24­
Hour
invertebrate
drift
samples
were
collected
were
collected
on
days
1,
5,
10,
20,
and
29
during
treatment
and
on
days
14,
42
and
60
during
recovery
periods.

Dry
and
ash
weights
of
periphyton
standing
crop
on
four
25
x
75
mm
glass
slides
were
sampled
at
4­
day
intervals
for
28
days
before
and
after
each
treatment.

24­
Hour
gross
primary
production
and
community
respiration
rates
(
O2
levels)
were
measured
during
the
autumn
on
days
2,

4,
8,
15,
24
and
29
after
treatment
and
on
days
20,
42,
54
and
60
during
the
recovery
period.
45020009
Lynch
et
al.,
1985
Supplemental
DMSO
is
not
an
acceptable
solvent,

because
it
accelerates
the
movement
of
chemicals
across
cell
membranes.
As
such
it
represents
a
worst
case
exposure.

Raw
data
were
not
available
for
statistical
analyses.
Three
or
four
samples
are
considered
inadequate
for
field
samples
to
show
anything
short
of
severe
effects.
Application
rate
(
lb
ai/
A)

Nominal/
Measured
Conc.
Concentration
affecting
endpoint
(
time
to
effect)

o
Affected
species
and
life
stage
Narrative
of
Study
Trends
MRID
No.

Author/
Year
XI
­
61
Artificial
model
streams
in
laboratory:

(
7
days;
nominal)

Single
applications
to
spring
water;
Brazos,
Texas.

Nominal
test
concentrations:
0,

100,
1000
and
10,000
Fg/
L
o
statistically
significant
reductions
(*)
in
net
stream
community
productivity
compared
to
controls:

Day
1
Day
3
Day
7
100
Fg/
L
736
%*
117
%*
34
%

1000
Fg/
L
1367
%*
227
%*
119
%*

10,000
Fg/
L
1716
%*
264
%*
135
o
sign.
(
p<
0.02)
increase
in
Nitzschia
cell
numbers
o
no
significant
effect
on
other
dominant
algal
groups
o
no
significant
effect
on
community
respiration
rates
o
no
significant
effect
on
conductivity
or
alkalinity
Four
replicate
recirculating
artificial
streams
per
treatment.

Each
stream
(
2.43
m
long,
12.5
cm
wide
and
6
cm
deep)
was
lined
with
polyethylene
plastic
and
a
single
layer
of
gravel.

Water
from
Minter
Spring
is
a
nearly
anoxic
and
has
a
constant
temperature
(
21EC).
The
flow
rate
was
about
5
cm/
sec.
The
principal
algae
genera
were
Anabaena,
Nitzschia,
Rhopalodia
and
Navicula.
Five
weeks
for
colonization
of
benthic
algae
on
glass
slides.
Each
stream
received
a
single
treatment
which
was
recirculated.
Nominal
conc.
were
0,
0.1,
1.0
and
10
Fg/
L.

Endpoints
were
net
community
productivity,
respiration
rate,

cell
numbers
of
dominant
species,
conductivity
and
alkalinity.
45020010
Moorhead
and
Kosinski
1986
Supplemental
(
raw
data
unavailable)

Not
assayed,
nominal
conc.
of
5,
25,
and
125
ppb
Snail
(
Lymnaea
palustris)
Snails
exposed
to
one
time
dosing
in
mesocosm
of
either
5,
25,

or
125
ppb
and
monitored
for
12
weeks,
no
affect
on
growth,

fecundity,
or
saccharide
metabolism.
45020013
Baturo
et
al.,
1995
Mean
concentrations
over
two
months
of
5,
10,
22,
68,
182,

and
318
ppb
Phyto­
and
zooplankton
Mesocosms
in
Bavaria
were
treated
with
atrazine
3
times
over
3
summer
months.
Dose
responsive
reductions
in
dissolved
oxygen
and
pH
were
noted
at
concentrations
greater
than
5
ppb.
Substantial
biological
effects
were
generally
noted
at
concentrations
>
182
ppb.
Some
effects
on
copepod
nauplii
were
noted
at
68
ppb.
Diatoms
appeared
to
become
the
dominant
phytoplankton.
45020022
Jüttner
et
al.,
1995
Supplemental
(
raw
data
unavailable)

Nominal
concentrations
of
20,

100,
200,
and
500
ppb.

Measurements
bi­
weekly
or
monthly
but
results
based
on
nominal
concentration
Phytoplankton
Results
of
single
species
assays,
microcosm,
and
pond
studies
were
compared.
Carbon
fixation
was
used
as
the
end­
point
for
all
three
study
types.
Laboratory
results
with
eight
algal
species
ranged
from
37
to
308
ppb
for
carbon
uptake
inhibition
EC50
values.
Microcosm
EC50
values
ranged
from
103
to
159
ppb.
The
mean
pond
EC50
was
100
ppb
for
carbon
uptake
and
82
ppb
for
chlorophyll­
a
inhibition.
Authors
stated
that
multiple
laboratory
studies
or
a
microcosm
study
represent(
s)

entire
ecosystem
functional
effects.
45020015
Larsen
et
al.,
1986
Supplemental
(
raw
data
unavailable)

Table
1
­
cont.
Atrazine
Field
or
Mesocosm
Studies.
XI
­
62
Application
rate
(
lb
ai/
A)

and/
or
Nominal/
Measured
Concentration
Affected
Species
and
Life
Stage
Percentage
Affected
in
Comparison
to
the
Control
and
Type
of
Effect
Author/

Year
Measured
=
nominal
(
50
ppb)

at
time
zero,
declined
to
40%

of
nominal
after
8
weeks
Aquatic
plants
and
fish
Atrazine
and
esfenvalerate
were
applied
together
in
mesocosms
to
examine
possible
synergism
(
reduction
of
macrophytes
leading
to
extension
of
insecticide
residues
and
increased
fish
mortality).

Combinations
of
50
ppb
atrazine
and
esfenvalerate
at
0.25
to
1.71
ppb
did
not
result
in
synergism.

However,
Chara
sp.
totally
replaced
the
co­
dominant
Naja
sp.
six
weeks
after
application.
Fairchild
et
al.,
1994
Day
1
measured
concentrations
of
80,
140,
or
1,560
ppb
Periphyton
Applications
were
made
to
in
situ
limnocorrals
in
June
(
140
and
1,560
ppb)
or
June
&
July
(
80
ppb)

and
colonized
periphyton
slides
were
submersed
in
August
and
monitored
for
either
56
days
(
140
and
1,560
ppb)
or
210
days
(
80
ppb).
Trends
from
both
years
included
a
shift
from
a
chlorophyte
to
a
diatom
community,
and
a
development
of
some
atrazine
"
resistant"
colonies.
Community
production
was
reduced
by
21%
and
82%
at
the
140
and
1,560
ppb
levels,
respectively,
and
certain
algae
were
reduced
up
to
93%.
All
biotic
measures
indicated
reduced
growth,
with
cell
densities
lagging
productivity.
All
parameters
except
species
richness
returned
to
control
levels
prior
to
56
days
after
first
or
second
applications.
45020020
Hamilton
et
al.,
1987
Supplemental
(
raw
data
unavailable)

Day
1
measured
concentration
of
80
ppb
(
two
applications
of
100
ppb
made
35­
days
apart)
Phyto­
and
zooplankton
Elaboration
of
the
80
ppb
treatment
from
Hamilton
et
al.,
1987.
Two
weeks
after
first
application,

significant
declines
in
multiple
species
of
green
algae
were
observed,
whereas
crypto­
and
dinoflagellates
either
increased
or
stayed
the
same.
Low
population
densities
persisted
for
114
days
after
the
second
application.
Average
of
.25%
fewer
species
in
atrazine
limnocorrals.
Control
and
treated
values
equilibrated
within
one
year
of
treatment.
Only
two
zooplankters
were
affected
(
after
the
second
application).
A
MATC
was
suggested
to
be
between
100
and
200
ppb.
Hamilton
et
al.,
1988
Table
1
­
cont.
Atrazine
Field
or
Mesocosm
Studies.

Application
rate
(
lb
ai/
A)

and/
or
Nominal/
Measured
Concentration
Affected
Species
and
Life
Stage
Percentage
Affected
in
Comparison
to
the
Control
and
Type
of
Effect
Author/

Year
Measured
after
a
single
dose
at
1,100
ppb
­

Day
1:
200
ppb,
55
days
later:

60
ppb
Phytoplankton
Treatment
related
reductions
in
oxygen,
and
pH,
and
increases
in
conductivity
were
noted
after
atrazine
treatment,
with
oxygen
and
pH
returning
to
control
values
within
30­
40
days.
At
26
days
after
dosing,
78
algal
cells/
mL
were
present
in
the
control
and
no
cells
were
present
in
the
treated
enclosures.
Diversity
was
also
reduced
the
month
after
application.
45020016
Lay
et
al.,
1984
Supplemental
(
raw
data
unavailable)

Not
assayed,
nominal
concentrations
of
50,000,

100,000,
and
150,000
ppb
Autotrophs
Primary
production
and
respiration
was
monitored
in
a
freshwater
ecosystem
in
India.
Net
productivity
in
water
samples
was
reduced
by
23%
and
73%,
respectively,
at
50,000
and
100,000
ppb,

in
comparison
to
control
values,
and
was
negative
in
the
150,000
ppb
treatment
group.
Piska
and
Waghray,

1990
XI
­
63
c.
Marine
and
Estuarine
Waters
Application
rate
(
lb
ai/
A)

Nominal/
Measured
Conc.
Concentration
affecting
endpoint
(
time
to
effect)

o
Affected
Species
and
Life
Stage
Narrative
of
Study
Trends
MRID
No.

Author/
Year
Marine
Mesocosm:

Open
Ocean:
Phytoplankton:

(
15
days;
measured
conc.)

Measured
=
nominal
at
time
zero,
concentrations
of
0.12,

0.56,
and
5.8
ppb
0.12
ppb
(
differences
compared
to
controls)

o
sign.
lower
pH
levels
(
Days
5­
14);
indicative
of
reduced
photosynthesis
o
higher
dissolved
organic
nitrogen
(
DON)
(
Days
6­
11)

o
up
to
50%
red.
primary
production
(
Days
3­
11)

o
up
to
60%
red.
particulate
carbohydrates
(
Days
5­
15)

o
up
to
70%
red.
chlorophyll
(
Days
4­
15)

0.56
ppb
o
sign.
lower
pH
levels
(
Days
5­
13)

o
incr.
total
dis.
organic
phosphate
(
DOP)
(
Days
3­
14)

o
higher
DON
(
Days
5­
15)

o
up
to
50
%
red.
primary
production
(
Day
3­
13)

o
up
to
85%
red.
particulate
carbohydrate
(
Days
5­
15)

o
up
to
80%
red.
chlorophyll
(
Days
4­
15)

5.8
ppb
o
sign.
lower
pH
levels
(
Days
5­
11)

o
up
to
200%
increase
in
total
DOP
(
Days
3­
14)

o
up
to
200
%
increase
in
total
DON
(
Days
2­
15)

o
up
to
50%
red.
in
primary
productivity
(
Days
3­
7)

o
up
to
60%
red.
in
partic.
carbohydrates
(
Days
5­
15)

o
up
to
30%
red.
in
chlorophyll
conc.
(
Days
4­
15)
Mesocosms
(
2
m2)
inoculated
with
the
diatoms
Thalassiosira
punctigera,
T.
rotula,
Nitzschia
pungens
and
Skeletonema
costatum
and
a
prymnesiophtye,
Phaeocystis
globosa.

evidenced
a
dose­
responsive
elevation
in
dissolved
nitrogen
and
phosphorous
and
reduction
in
primary
production
at
0.12,
0.56,

and
5.8
ppb.
The
NOEL
was
reported
to
be
<
0.12
ppb.
Atrazine
at
concentrations
at
0.12,
0.56
and
5.8
ppb,
adversely
effects
primary
production
of
unicellar
algal
species
at
certain
growth
phases
and
causes
increases
in
"
excretions"
of
dissolved
organic
nitrogen
and
phosphorus.
"
Excretions"
may
be
caused
by
atrazine
stress
on
cells
or
lysis
of
cells.
45020021
Bester
et
al.,
1995
Supplemental
(
raw
data
unavailable)

Nominal
applications
of
0.4,

4.5,
or
45
lb
ai/
A
Salt
marsh
edaphic
alage
Elaboration
of
Plumley
et
al.,
concerning
the
carbon
uptake
for
algae
in
the
top
0.5
cm
of
enclosure
sediment.
Carbon
fixation
was
significantly
reduced
at
the
0.45
and
4.5
lb
ai/
A
treatment
levels
for
16
days
and
at
the
45
lb
ai/
A
treatment
level
for
42
days.
45087406
Plumley
and
Davis,

1980
XI
­
64
f.
Reported
Ecological
Incidents
The
Ecological
Incident
Information
System
(
EIIS)
maintained
by
EFED
has
a
total
of
61
reported
incidents
of
varying
certainty
for
atrazine.
Twelve
incidents
were
classified
as
"
Unlikely"
and
two
were
"
Unrelated."
In
only
one
case,
a
cotton
use,
was
fish
carcasses
analyzed
for
atrazine
residues.
The
shad
and
carp
tested
positive
for
atrazine
in
the
Richland,
Louisiana
incident
(
I004021­
004).
Most
incidents
involved
effects
on
fish
kills.
Other
nontarget
organisms
affected
include
grasses
and
on
occasions:
corn,
fruit
trees,
ornamentals,
garden,
raspberry,
oats,
cats,
chicken,
a
goat,
black
snake
and
a
cave
amphipod.

Four
incidents
are
listed
as
"
Highly
Probable"
including
a
home/
lawn
use
incident
(#
I001910)
and
a
corn
use
incident
affecting
100
bass
and
100
bream
(#
B000163­
001)
resulting
from
registered
use.
Two
home/
lawn
incidents
affecting
grass
were
concluded
to
be
misuse/
accidental
(#
I005579­
001,
I005132­
001).
Seventeen
incidents
are
listed
as
"
Probable"
including
7
corn
incidents
(
I007372­
002,
all
bluegill
and
largemouth
bass;
I000116­
002,
thousand
bluegill
and
thousand
largemouth
bass,
I001081­
001,
10
feet
of
grass
and
600
catfish;
I001081­
002,
bluegill
and
bass;
B000150­
003,
bass
and
bluegill;
I004697­
084,
fish;
I000636­
032,
bluegill
and
a
few
crappie),
4
agricultural
use
incidents
(
I001099­
001,
grass;
I001041­
001,
fescue
grass;
I003826­
006,
not
reported;
I005895­
074,
not
reported),
1
home/
lawn
incident
(
I000941­
078,
grass),
1
field
incident
(
I005595­
001,
unknown)
and
1
unreported
source
(
I000358­
004,
fruit
trees
and
garden).
Two
probable
incidents
were
classified
as
misuse
from
corn
use
(
I005879­
003,
pears,
raspberry
and
oats;
I007371­
013,
grass
and
ornamentals).

Twenty­
six
incidents
were
reported
as
"
Possible"
including
12
incidents
affecting
fish
(
i.
e.,
bluegill
(
3
incidents),
catfish
(
2),
bass
(
2),
carp
(
1),
quillback
carpsucker
(
1),
carp
(
1);
redhorse
(
1),
bream
(
1),
garfish
(
1),
minnow
(
1),
perch
(
1),
unspecified
fish
(
2);
cave
amphipod
(
1),
corn
(
4),
grass
(
4),
trees
(
2),
plants
(
1),
cat
(
1),
chicken
(
1),
goat
(
1),
and
unreported
(
3).

Given
the
low
toxicity
of
atrazine
to
fish,
aquatic
invertebrates
and
mammals,
the
reason
for
the
frequency
of
effects
on
these
organisms
is
uncertain.
About
60
percent
of
the
reported
fish
kills
listed
under
atrazine
in
the
incident
record
occur
during
the
Spring
when
atrazine
is
applied,
soils
are
saturated
and
heavy
rainfall
is
frequent.
Heavy
runoff
may
carry
atrazine,
other
pesticides
and
organic
loads
into
surface
waters.
The
high
volume
and
wide­
spread
use
of
atrazine
increases
the
probability
of
co­
occurrence
of
fish
kills
with
atrazine
applications.
There
are
some
scenarios
which
may
explain
atrazine
induced
fish
kills
as
well
as
causes
unrelated
to
atrazine
use.

Three
plausible
scenarios
could
exist
in
which
atrazine
applications
may
be
responsible
for
the
fish
kills.
First,
atrazine
concentrations
in
surface
waters
from
runoff
and/
or
spray
drift
may
be
much
higher
in
shallow
water
adjacent
to
treated
fields
than
estimated
by
EFED
or
found
in
monitoring
studies.
Second,
atrazine
in
surface
water
may
kill
aquatic
plants
and
the
decaying
process
of
dead
plants
may
lower
dissolved
oxygen
to
levels
too
low
for
fish
survival.
Third,
atrazine
is
reported
to
increase
the
toxicity
of
organophosphate
insecticides,
such
as
chlorpyrifos,
XI
­
65
and
a
number
of
other
pesticides
which
may
have
been
applied
earlier
to
atrazine­
treated
crops
or
applied
in
other
fields
upstream
in
the
watershed.

Possibilities
also
exist
that
other
causes,
not
atrazine,
may
be
responsible
for
some
or
all
of
the
reported
atrazine
incidents.
Heavy
organic
loads
consume
oxygen
from
the
water
as
the
organic
matter
oxidizes,
thereby
causing
low
dissolved
oxygen
levels
which
may
cause
fish
to
suffocate
and
die.
Other
pesticides
in
the
watershed
killed
the
fish
as
the
water
flowed
past
atrazinetreated
fields.
Since
limited
information
is
available
in
the
atrazine
incident
records,
such
as
water
and
tissue
analyses,
conclusions
of
responsibility
would
appear
to
be
uncertain
and
the
result
of
coincidence
with
little
evidence
for
cause
and
effect.

g.
Effects
of
Environmental
Factors
and
Life­
Stage
on
Aquatic
Atrazine
Toxicity
1.
Interaction
Effects
on
Atrazine
Toxicity
to
Plants
Some
intra­
laboratory
studies
suggest
that
atrazine
toxicity
is
affected
by
some
environmental
parameters,
such
as
temperature,
light
intensity
and
salinity
levels.
Mayer
et
al.
(
1998)
concluded
that
a
temperature
difference
of
1EC
will
cause
a
difference
in
algal
growth
rate
in
the
range
of
7
to
9
percent
at
the
typical
rate
increase
for
10EC
temperature
increase
(
Q10)
of
2
to
2.3.

In
general,
the
toxicity
of
pesticides
increase
with
increasing
temperature.
Mayasich,
Karlander
and
Terlizzi,
Jr.
(
1986)
tested
two
algal
species
in
27
combinations
of
temperature
(
15,
20
and
25EC),
light
intensity
(
0.208,
0.780
and
1.352
mW/
cm2)
and
atrazine
concentrations
of
0,
50
and
100
Fg/
L)
for
7­
day
periods.
Toxic
effects
of
atrazine
on
Nannochloris
oculata
growth
rates
were
significantly
(
p
<
0.01)
dependent
on
both
temperature
and
light
intensity
as
determined
by
the
3­
way
interactions.
Atrazine
toxicity
increased
to
N.
oculata
with
both
increasing
temperature
and
increasing
light
intensity,
except
at
15EC
and
1.352
mW/
cm2
where
growth
was
intermediate.
Previous
results
yielded
a
similar
anomaly
and
it
suggest
that
15EC
is
near
the
lower
limit
for
growth
of
this
algal
species.
With
Phaeodactylum
tricornutum,
growth
rates
were
significant
(
p
<
0.01)
for
light
intensity
and
atrazine
concentrations
and
was
significant
(
p
<
0.05)
for
temperature,
but
only
light
intensity
was
significantly
(
p
<
0.01)
related
to
an
increase
in
atrazine
toxicity.
Atrazine
toxicity
was
highest
at
the
lowest
light
intensity.
"
The
response
of
P.
tricornutum
to
atrazine
at
light
intensities
of
0.780
and
1.352
mW/
cm2
is
probably
a
reflection
of
primary
effectsonly
while
at
0.208
mW/
cm2
light
intensity
includes
secondary
effects"
(
Mayasich
et
al.,
1986).
With
respect
to
the
insignificant
effect
of
temperature
on
growth,
Ukeles
(
1961)
and
Fawley
(
1984)
found
that
the
growth
of
P.
tricornutum
was
unchanged
by
temperatures
in
the
range
of
14
to
24EC
and
14
to
25EC,
respectively.

Mayasich
et
al.
(
1987)
repeated
the
above
algal
study
with
lower
atrazine
concentrations
(
0,
15,
30
and
50
Fg/
L
and
fewer
temperatures
(
15
and
25EC)
and
light
intensities
(
0.208
and
1.352
mW/
cm2)
in
unialgal
and
bialgal
assemblages.
Generally
Phaeodactylum
tricornutum's
presence
significantly
(
p
<
0.01)
depressed
the
growth
of
Nannochloris
oculata,
but
it
did
not
alter
the
magnitude
of
the
responses
to
temperature,
light
intensity
or
atrazine
concentrations.
In
contrast,
the
presence
of
N.
oculata
generally
resulted
in
significant
(
p
<
0.01)
enhancement
of
P.
XI
­
66
tricornutum
growth.
The
bialgal
assemblage
produced
magnitudes
of
interactions
between
temperature
and
light
intensity
and
temperature
and
atrazine
were
both
significantly
(
p
<
0.01)
greater
for
N.
oculata.
P.
tricornutum
dominated
the
assemblage
over
all
concentrations
of
atrazine
under
simultaneously
low
levels
of
temperature
(
15EC)
and
light
intensity
(
0.208
mW/
cm2).
At
simultaneous
high
levels
of
temperature
and
light
intensity
and
the
absence
of
atrazine.
P.
tricornutum
and
N.
oculata
tended
to
be
co­
dominant.
At
increased
atrazine
concentrations,
P.
tricornutum
became
the
dominant
of
the
two
algal
species.
The
authors
concluded
that
the
enhanced
sensitivity
of
N.
oculata
to
atrazine
relative
to
that
exhibited
by
P.
tricornutum
posed
threat
to
the
diversity
and
structure
of
natural
phytoplankton
populations.
Thus,
a
nutritious
algal
species
for
larval
oysters
(
Dupry,
1973)
is
replaced
by
what
is
considered
to
be
a
poor
food
source
for
larval
bivalves
(
Walne,
1970).

Mayer
et
al.
(
1998)
tested
the
effect
of
four
main
environmental
factors
on
the
toxicity
of
atrazine
to
the
green
alga
Selenastrum
capricornutum
in
3
day
tests.
The
four
factors
tested
were
light
intensity
(
44
and
198
FE/
m2),
temperature
(
16
and
26EC),
nitrogen
source
(
NH4+
and
NO3­)
and
pH
(
7.6
and
8.6).
Temperature
influenced
growth
only
indirectly
by
interacting
with
light
intensity.
Algal
growth
measured
as
the
atrazine
EC50
values
was
marginally
reduced
under
low
light
intensity
at
high
and
low
temperatures
(
158
and
159
Fg/
L,
respectively
versus
the
atrazine
control,
164
Fg/
L).
High
light
intensity
at
the
low
temperature
reduced
the
toxicity
of
atrazine
to
the
alga
by
about
two
fold
(
LC50
300
Fg/
L)
while
high
light
intensity
and
high
temperature
reduced
the
toxicity
of
the
atrazine
by
about
118
fold
(
LC50
191
Fg/
L).
Nitrogen
source
and
pH
had
no
significant
effect
on
atrazine
toxicity
affecting
algal
growth
rates.

The
above
studies
indicate
that
the
toxicity
of
atrazine
to
plants
can
be
affected
by
environmental
parameters,
but
differences
in
those
effects
occur
depending
on
the
algal
species.
Hence,
increases
in
temperature
may
increase,
decrease
or
have
no
effect
on
atrazine
toxicity
to
algal
growth.
Light
intensity
generally
has
the
stronger
effect
on
atrazine
toxicity
to
algal
growth
and
may,
short
of
the
point
of
photo­
inhibition,
increase
the
toxicity
of
atrazine.
Nitrogen
source
and
pH
do
not
have
any
effect
on
the
toxicity
of
atrazine
to
algae.

2.
Interaction
Effects
on
Atrazine
Toxicity
to
Aquatic
Animals
Some
intra­
laboratory
studies
suggest
that
atrazine
toxicity
to
aquatic
animals
is
affected
by
environmental
parameters,
such
as
water
hardness,
salinity
and
differences
in
the
life­
stages
of
organisms.

High
levels
of
water
hardness
usually
reduce
the
toxicity
of
pesticides.
Intra­
laboratory
studies
on
two
fish
species
provide
comparative
LC50
values
for
two
levels
of
water
hardness
(
Birge,
Black
and
Bruser,
1979).
Embryo­
larval
rainbow
trout
were
exposed
to
atrazine
for
27
days
at
water
hardness
levels
of
50
and
200
mg/
L
and
produced
LC50
values
of
0.66
and
0.81
mg/
L,
respectively.
The
test
with
channel
catfish
at
the
same
water
hardness
levels
for
8
days
and
yielded
LC50
values
of
0.22
and
0.23
mg/
L.
With
rainbow
trout
embryo­
larvae,
the
soft
water
increased
toxicity
by
about
19
percent,
while
the
LC50
values
for
embryo­
larval
catfish
were
the
same.
It
is
uncertain,
if
the
shorter
exposure
period,
yolk
sac
or
differences
in
species
sensitivity,
XI
­
67
account
for
the
difference
in
water
hardness
effects
between
embryo­
larvae
of
channel
catfish
and
rainbow
trout.

Salinity
effects
at
5,
15
and
25
g/
L
on
the
toxicity
of
atrazine
are
opposite
for
the
estuarine
fish
larvae,
sheepshead
minnow
and
the
copepod
nauplii,
Eurytemora
affinis
(
Ziegenfuss,
Anderson,
Spittler
and
Leichtweis,
1994).
The
96­
hour
LC50
values
(
16.2,
2.3
and
2.0
mg/
L)
for
sheepshead
minnow
consistently
increased
with
increasing
salinity.
In
the
case
of
the
copepod
nauplii,
the
96­
hour
LC50
values
(
i.
e.,
0.5,
2.6
and
13.3
mg/
L)
consistently
decreased
with
increasing
salinity.
The
consistency
of
the
two
data
sets
suggest
that
salinity
effects
the
toxicity
of
atrazine.
Statistical
tests
for
both
species
indicate
significant
differences
between
the
LC50
valves
at
5
and
25
g/
L,
but
not
at
15
g/
L.
The
authors
concluded
that
the
two
species
may
be
more
physiologically
effective
in
metabolizing
and
mitigating
toxic
effects
of
atrazine
at
various
salinities.
The
increase
in
LC50
values
for
rainbow
trout
and
sheepshead
minnow
are
consistent
for
increasing
water
hardness
and
increasing
salinity.

For
many
pesticides,
the
earlier
life­
stages
are
normally
more
toxic
to
organisms
than
later
lifestages
Contrary
to
most
pesticides,
the
aquatic
toxicity
data
for
toad
and
frog
tadpoles
suggest
that
the
late
stages
are
more
sensitive
to
atrazine
than
early
tadpole
stages
(
Howe
et
al.,
1998).
The
late
stage
of
the
American
toad
tadpole
is
about
2.5
times
more
sensitive
to
atrazine
than
the
early
stage
(
10.7
versus
26.5
mg/
L).
For
the
northern
leopard
frog
tadpoles,
the
later
stage
is
about
3.3
times
more
toxic
than
the
early
tadpole
stage
(
14.5
versus
47.6
mg/
L).

The
above
studies
suggest
that
decreases
in
water
hardness
and
salinity
can
increase
the
toxicity
of
atrazine
to
fish,
but
increasing
salinity
may
mitigate
atrazine
toxicity
to
copepods.
Life
stages
show
differences
in
sensitivity
to
atrazine.
The
later
stages
in
frog
and
toad
tadpole
development
show
an
increased
sensitivity
to
atrazine
over
early
tadpole
stages.

h.
Pesticide
Toxicity
Interactions
1.
Plants
A
number
of
authors
have
reported
toxic
interactions
between
atrazine,
its
dealkylated
degradates
and
other
pesticides.
Synergism
between
atrazine
and
a
number
of
other
pesticides
has
also
been
reported
in
aquatic
organisms,
particularly
with
organophosphate
insecticides,
a
carbamate
insecticide
and
other
herbicides.

In
1974,
Putnam
and
Penner
reported
on
the
effects
of
interactions
of
herbicides
on
higher
plants.
Atrazine
was
cited
in
test
combinations
with
5
herbicides,
2
insecticides
and
a
fungicide.
Synergistic
effects
(
i.
e.,
increased
toxicity
higher
than
additivity)
was
identified
in
6
out
of
the
8
test
combinations.
Atrazine
was
synergistic
with
4
herbicides
(
i.
e.,
2,
4­
D
(
oil),
paraquat,
EPTC,
and
alachlor)
and
2
insecticides
(
i.
e.,
diazinon
and
fensulfothion).
Atrazine
test
combinations
with
dalapon,
a
herbicide,
and
dexon,
a
fungicide,
showed
antagonistic
interactions.
XI
­
68
Torres
and
O'Flaherty
(
1976)
report
additive
toxicity
of
atrazine
with
simazine
at
concentrations
of
1.0
ug/
L
and
1
mg/
L
for
Chlorella
vulgaris,
Stigeoclonium
tenue,
Tribonema
sp.,
Vaucheria
geminata,
and
Oscillatoria
lutea.
Additive
toxicity
of
malathion
with
atrazine
was
found
in
Chlorella
vulgaris,
but
could
not
be
assessed
with
other
species,
because
malathion
produced
total
inhibition
of
chlorophyll
production
at
1
ug/
L
or
greater
concentrations.
At
1
and
1,000
ug/
L,
pesticides
mixtures
increased
toxicity
from
2.4
to
100
percent
over
the
toxic
levels
of
atrazine
alone.
Mixtures
of
these
pesticides
at
concentrations
of
0.1
and
0.5
ug/
L
usually
enhanced
the
production
of
chlorophyll.

Stratton
(
1984)
also
tested
the
most
sensitive
algal
species,
Anabaena
inaequalis,
with
mixtures
of
atrazine
and
its
two
most
toxic
degradates,
deethylatrazine
and
deisopropylatrazine.
Cell
count
results
indicate
that
combinations
of
atrazine/
deethylatrazine
(
1.8)
and
atrazine/
deisopropylatrazine
(
1.3)
are
synergistic
and
deethylatrazine/
deisopropyl­
atrazine
mixtures
are
additive
(
1.03).
For
photosynthesis,
results
after
3
hour
exposures
indicate
that
all
mixture
combinations
for
these
three
chemicals
are
antagonistic
(
0.8,
0.86,
and
0.89).

Burrell
et
al.
(
1985)
reported
11­
day
interactions
between
algal
populations
and
between
algal
populations
and
pesticides.
Population
interactions
showed
that
Chlorella
vulgaris
inhibited
population
growth
of
Ankistrodesmus
braunii
by
32
percent.
The
addition
of
the
bacterium,
Chromobacterium
violaceum,
added
to
the
algal
mixture
further
inhibited
population
growth
of
A.
braunii
by
an
additional
17%
and
bacterial
growth
was
stimulated,
but
the
bacterium
had
no
effect
on
Chlorella
populations.
The
combined
effect
of
the
mixtures
of
atrazine
(
60
Fg/
L)
and
sodium
pentachlorophenate
(
Na­
PCP)
(
0,
300,
800,
1,000
and
1,200
Fg/
L)
and
atrazine
(
40
and
100
Fg/
L)
with
Na­
PCP
(
700
and
1,200
Fg/
L)
on
A.
braunii
populations
were
additive
over
a
wide
range
of
concentrations.
Similar
results
of
atrazine
(
10
and
100
Fg/
L)
and
Na­
PCP
(
300
and
1,200
Fg/
L)
were
obtained
with
C.
vulgaris.
In
mixed
algal
cultures
tested
with
atrazine
(
40
and
100
Fg/
L),
cell
numbers
of
A.
braunii
were
reduced
50
and
80
percent,
respectively,
which
was
not
significantly
different
than
effects
when
tested
alone.
In
the
same
mixed
culture
test,
atrazine
inhibited
growth
of
C.
vulgaris
by
79
and
85
percent,
respectively,
which
showed
a
significant
growth
inhibition
only
at
the
lower
test
concentration
(
40
Fg/
L).
The
authors
concluded
that
the
high
atrazine
concentration
(
100
Fg/
L)
did
not
alter
the
established
population
relationship
between
the
two
algal
species,
but
at
the
lower
concentration
(
40
Fg/
L),
A.
braunii
increased
the
susceptibility
of
C.
vulgaris
to
atrazine.
When
mixed
cultures
of
algae
were
treated
with
both
atrazine
(
60
Fg/
L)
and
Na­
PCP
(
300,
800,
1,000
and
1,200
Fg/
L),
chemical
antagonism
was
observed.
The
addition
of
the
bacterium,
C.
violaceum,
to
the
microcosm,
had
no
effect
on
the
level
of
antagonism
for
A.
braunii.
C.
violaceum
modified
the
antagonism
of
atrazine
toxicity
to
C.
vulgaris
by
about
40
percent,
but
the
antagonistic
effect
was
not
eliminated.
The
net
atrazine
toxicity
decreased
as
the
Na­
PCP
concentration
increased.
The
authors
found
no
reason
for
the
modification
of
atrazine
effects
by
C.
violaceum.

Carder
and
Hoagland
(
1998)
reported
that
pesticide
interactions
of
atrazine
(
0,
12
and
150
Fg/
L)
and
alachlor
(
0,
5,
90
Fg/
L)
on
benthic
algal
communities
in
artificial
recirculating
streams
showed
significant
interaction
(
i.
e.,
antagonism)
only
in
the
first
week
in
the
combination
of
high
alachlor
and
low
atrazine
test
concentrations.
The
authors
concluded
that
the
interaction
is
most
XI
­
69
likely
anomalous
and
the
lack
of
significant
synergistic
effects
may
be
attributed
to
different
modes
of
action.

2.
Aquatic
Animals
A
number
of
authors
have
reported
synergistic
effects
of
atrazine
with
the
aquatic
animals
with
one
or
more
of
the
following
pesticides:
(
i.
e.,
alachlor,
chlorpyrifos,
DDT,
malathion,
methyl
parathion,
parathion
and
trichlorfon).

Liang
and
Lichtenstein
(
1975)
also
found
atrazine
synergism
between
soil
residues
of
both
DDT
and
parathion
using
fruit
flies,
Drosophila
melanogaster
and
measured
lethal
effects
versus
the
age
of
the
pesticide
residues
in
soil.
Ten
grams
of
Plainfield
sand
(
1.2
%
organic
matter)
or
Plano
silt
loam
(
4.7%
organic
matter)
was
mixed
with
parathion
(
2.3
Fg/
10
g
of
soil
=
0.23
ppm)
or
DDT
(
30
Fg/
10
g
of
soil
=
3
ppm),
then
was
mixed
with
10
g
of
the
same
soil
type,
which
contained
increasing
atrazine
levels
(
40
to
1000
Fg/
10
g
of
soil
=
4
to
100
ppm)
or
controls.
Fifty
fruit
flies
were
placed
in
120
ml
test
jars
for
24
hours
with
the
10­
g
portions
of
air­
dried
soil
untreated
or
treated
with
atrazine,
parathion,
DDT
or
combinations
thereof.
The
resulting
24­
hour
fruit
fly
LD50
values
for
constant
soil
levels
of
parathion
(
2.3
ppm)
and
DDT
(
3.0
ppm)
were
as
follows:
parathion
(
6.2
ppm
atrazine
in
sand
and
92
ppm
in
loam)
and
DDT
(
8.5
ppm
atrazine
in
sand
and
68
ppm
in
loam).
Synergistic
effects
were
apparent
in
all
test
combinations
of
soil
and
pesticides
yielding
a
dose­
response
effect
on
fly
mortality
with
increasing
atrazine
soil
concentrations.
Fruit
fly
mortality
levels
with
both
parathion
and
DDT
in
soils
also
clearly
indicate
a
strong
reduction
in
toxicity
with
the
silt
loam
soil
with
a
higher
percentage
of
organic
matter
(
4.7%)
compared
to
sandy
soil
(
1.2%).

Additional
loam
soil
toxicity
tests
were
conducted
daily
for
4
days,
with
aged­
atrazine
soil
with
an
initial
50
ppm
aged
in
the
dark
at
22EC
and
both
fresh
and
aging­
parathion
soil
levels
(
0.35
ppm).
In
the
test
with
fresh
parathion
soils
and
aged­
atrazine
soils,
toxicity
to
fruit
flies
decreased
linearly
from
95%
mortality
on
Day
0
to
43.3%
over
four
days.
By
the
fourth
day,
atrazine
levels
had
declined
to
19
ppm,
which
was
barely
enough
to
synergize
parathion
in
loam
soils.
In
another
toxicity
test,
parathion­
treated
soils
were
aged
under
the
same
conditions
as
above
and
added
it
daily
to
the
initial
10
g
of
atrazine­
treated
soil
(
50
ppm).
In
this
test,
the
toxicity
to
fruit
flies
decreased
logarithmically
from
about
68%
on
Day
0
to
10%
mortality
on
Day
4.
The
measured
concentrations
of
aging
parathion
in
the
silt
loam
soil
decreased
at
a
rate
paralleling
the
logarithmic
toxicity
curve.
The
final
parathion
level
on
Day
4
was
0.24
ppm.

Liang
and
Lichtenstein
(
1975)
found
atrazine
to
be
synergistic
with
parathion
in
24­
hour
aquatic
tests
with
third­
instar
mosquito
larvae,
Aeddes
aegypti
and
also
assessed
the
effects
of
sand
and
loam
soils
on
their
individual
and
combined
toxicity
in
20
ml
of
pesticide­
treated
water.
Atrazine
at
10,000
Fg/
L
showed
no
toxicity
to
the
mosquito
larvae;
alone,
parathion
(
15
Fg/
L)
killed
20
+
7
percent
of
the
larvae;
and
at
these
concentrations,
the
combination
of
the
two
pesticides
produced
significantly
(
p
=
0.01)
higher
mortality
(
73
+
18
%).
Addition
of
5
g
of
Plainfield
sand
(
1.2%
organic
matter)
with
15
Fg/
L
parathion
reduced
the
toxicity
of
parathion
from
20
+
7%
to
18
+
4%,
but
when
sand
was
mixed
into
the
water,
mortality
drop
to
5%.
Plano
XI
­
70
silt
loam
soil
(
4.7%
organic
matter)
without
mixing
reduced
parathion
toxicity
from
20
+
7%
to
5
+
4%
and
when
the
loam
soil
was
mixed
into
the
water,
no
mosquito
larvae
died.
When
these
two
soils
were
added
to
the
same
combination
of
atrazine
and
parathion,
sand
reduced
the
mortality
from
73
+
14%
to
71
+
14%
(
unmixed)
and
to
18
+
4
%
when
mixed
into
the
water;
loam
soil
reduced
the
mortality
from
73%
to
64
+
4%
(
unmixed)
and
to
no
mortality
with
mixing.
The
combination
of
atrazine
and
parathion
was
significantly
(
p
=
0.01)
more
toxic
than
the
toxicity
of
parathion
or
atrazine
alone.

The
above
toxicity
test
method
was
repeated
using
1
and
5
grams
of
sand
or
silt
loam
to
measure
the
effect
of
different
amounts
of
soil
on
toxicity
following
24­
hour
exposures.
Atrazine
(
10
ppm)
produced
no
mortality
in
24
hours
to
mosquito
larvae.
Parathion
(
0.015
ppm)
produced
24
+
7%
mortality
(
no
soil),
16
+
7%
(
1g
of
sand),
2
+
2%
(
5
g
of
sand),
7
+
0%
(
1
g
of
loam
soil)
and
0%
(
5
g
of
loam
soil).
The
combination
of
atrazine
(
10
ppm)
and
parathion
(
0.015
ppm)
showed
synergistic
effects
on
mosquito
larvae
mortality:
62
+
8%
(
no
soil),
42
+
10%
(
1
g
of
sand),
2
+
2%
(
5
g
of
sand),
22
+
4%
(
1
g
of
loam
soil)
and
0%
(
5
g
of
loam
soil).
These
test
format
was
repeated
using
higher
pesticide
concentrations
and
again
the
mortality
levels
were
increased
with
a
mixture
of
atrazine
(
20
ppm)
and
parathion
(
0.30),
but
the
synergistic
increase
was
much
lower
than
in
the
previous
test.
The
24­
hour
results
indicated
that
atrazine
alone
was
not
toxic
to
mosquito
larvae;
0.30
ppm
parathion
(
93
+
6%
mortality
with
on
soil),
62
+
8%
with
5
g
of
sand
and
no
mortality
with
silt
loam
soil.
The
mixture
of
20
ppm
atrazine
and
0.30
ppm
parathion
produced
98
+
4%
mortality
with
no
soil,
76
+
4%
dead
when
shaken
with
5
g
of
sand,
and
38
+
10%
lethality
when
shaken
with
5
g
of
silt
loam
soil.
These
studies
demonstrate
that
atrazine
is
synergistic
with
parathion
and,
like
single
toxicants,
organic
matter
in
soils
and
sediments
will
modify
toxicity
of
pesticide
mixtures,
especially
if
the
organic
matter
is
suspended
in
the
water.
While
this
particular
study
has
limited
value
for
risk
assessment,
because
the
atrazine
levels
(
10
and
20
ppm)
exceed
the
normal
environmental
range
of
atrazine
exposures,
the
study
suggests
that
synergism
of
atrazine
and
parathion
may
occur
at
lower
concentrations,
possibly
in
the
range
of
environment
levels
of
atrazine.

Pape­
Lindstrom
and
Lydy
(
1997)
tested
atrazine
with
6
pesticides
for
chemical
interactions
using
4th
instar
midges
(
Chironomus
tentans).
The
96­
hour
test
results
for
the
pesticide
mixtures
indicated
that
atrazine
was
synergistic
with
the
phosphonate
insecticide,
trichlorfon,
(
0.26
toxic
units)
and
3
phosphorothioate
insecticides
(
i.
e.,
malathion
(
0.36
TU),
chlorpyrifos
(
0.58
TU)
and
methyl
parathion
(
0.59
TU).
The
atrazine­
mevinophos
(
a
phosphate)
mixture
was
less
than
additive
(
1.34
TU),
while
methoxychlor,
a
organochlorine
insecticide
mixture
was
also
less
than
additive
(
1.67
TU).
The
results
from
these
tests
are
questionable,
since
DMSO
was
used
as
a
solvent
with
atrazine.
These
tests
were
repeated
by
Belden
and
Lydy
(
2000)
without
DMSO
and
with
lower
atrazine
concentrations
(
0,
10,
40,
80,
and
200
Fg/
L).
Acute
96­
hour
tests
with
Chironomus
tentans
were
conducted
with
each
pesticide
and
EC1,
EC5,
EC15
and
EC50
values
were
determined
based
on
inability
of
the
midge
to
swim
when
prodded
with
forceps.
Chemical
interactions
were
tested
at
each
of
these
EC
levels
with
atrazine
levels
of
0,
10,
40,
80
and
200
Fg/
L
using
5
replicates
of
10
midges
each.
Atrazine
increased
the
toxicity
of
chlorpyrifos,
diazinon
and
parathion,
but
not
malathion.
The
authors
concluded
that
"
Interaction
terms
were
not
significant
for
atrazine
+
methyl
parathion
and
atrazine
+
diazinon;
however,
a
significant
XI
­
71
interaction
was
found
for
the
atrazine
+
chlorpyrifos
test
(
p
=
0.002,
df
­
12,
F
=
2.94)."
Synergistic
ratios
were
reported
as
follows:
chlorpyrifos,
1.83
at
40
Fg/
L
and
4.00
at
200
Fg/
L
atrazine;
at
200
Fg/
L
diazinon
the
SR
was
2.71
and
for
methyl
parathion,
the
SR
was
1.94.
The
variety
of
chemical
interactions
produced
by
atrazine
mixtures
indicates
that
the
effect
of
atrazine
on
an
organism
is
dependent
on
the
species,
cocontaminant,
and
the
concentration
of
atrazine.
Additional
tests
with
200
Fg/
L
atrazine
and
chlorpyrifos
showed
that
atrazine
increased
the
uptake
of
chlorpyrifos
by
42
percent,
and
that
the
atrazine
induction
of
cytochrome­
P450
increased
the
formation
of
the
O­
analog
which
increased
the
toxicity
of
chlorpyrifos
at
enviromentally
relevant
concentrations.

Howe
et
al.
1998
reported
synergism
between
atrazine
and
alachlor,
a
herbicide,
in
tests
with
young
rainbow
trout,
channel
catfish
and
early
and
late
tadpole
stages
of
the
northern
frog
and
the
American
toad.
The
results
are
presented
in
the
table
below.
(
MRID
#
45202910).

Species
(
stage)
Time
(
hour)
Atrazine
LC50
(
95%
CI)
mg/
L
Alachlor
LC50
(
95%
CI)
mg/
L
Atrazine­
Alachlor
LC50a
(
95%
CI)
mg/
L
Additive
Indexb
(
95%
CI)

Rainbow
trout
(
0.8­
1.0­
gram
juveniles)
24
96
31.6
(
28.2
­
35.4)
20.5
(
18.3
­
22.9)
10.6
(
9.5
­
11.7)
9.1
(
9.0
­
9.2)
9.5
(
8.3
­
10.9)
6.5
(
5.7
­
7.7)
­
0.20
(­
0.53­
0.059)
­
0.03
(­
0.28­
0.15)

Channel
catfish
(
0.9­
1.1­
gram
juveniles)
24
96
51.3
(
44.6
­
59.0)
23.8
(
22.3
­
25.5)
23.8
(
22.7
­
25.0)
16.7
(
15.1
­
18.4)
11.1
(
9.6
­
12.4)
7.5
(
5.3
­
8.4)
0.29
(
0.067­
0.55)
c
0.31
(
0.072­
0.57)
c
Northern
leopard
frog
(
0.7­
0.9­
gr
early
larvae)
24
96
69.7
(
63.1
­
77.2)
47.6
(
41.4
­
54.8)
14.9
(
13.3
­
16.6)
11.5
(
10.1
­
13.2)
12.1
(
11.0
­
12.9)
6.5
(
5.7
­
7.7)
0.015
(­
0.17­
0.24)
0.43
(
0.054­
0.87)
c
Northern
leopard
frog
(
1.4­
1.9­
gr
late
larvae)
24
96
45.3
(
42.3
­
48.5)
14.5
(
11.9
­
17.5)
7.3
(
6.6
­
8.0)
3.5
(
3.1
­
3.8)
5.9
(
5.5
­
6.4)
2.1
(
2.0
­
2.3)
0.07
(­
0.12­
0.25)
0.34
(
0.069­
0.56)
c
American
Toad
(
0.1­
0.2­
gr
early
larvae)
24
96
66.4
(
58.9
­
74.9)
26.5
(
23.0
­
30.5)
5.7
(
4.7
­
5.8)
3.9
(
3.7
­
4.2)
4.4
(
4.2
­
4.6)
1.8
(
1.7
­
1.9)
0.19
(­
0.057­
0.28)
0.89
(
0.68
­
1.2
)
c
American
Toad
(
0.4­
0.5­
gr
late
larvae)
24
96
15.8
(
13.5
­
18.4)
10.7
(
9.2
­
12.5)
4.3
(
3.8
­
4.8)
3.3
(
2.8
­
3.6)
2.9
(
2.6
­
3.3)
1.5
(
1.4
­
1.6)
0.17
(
0.11
­
0.46)
c
0.68
(
0.34
­
1.0
)
c
a
50:
50
mixture
of
atrazine
4L
(
40.8%
ai.)
and
alachlor
EC
(
43.0%
ai.).
b
An
additive
index
greater
than
zero
indicates
greater
than
additive
toxicity.
c
Significant
chemical
synergy
interaction
between
atrazine
and
alachlor.

h.
US
EPA,
Office
of
Water,
Water
Quality
Criteria
The
Office
of
Water
sets
ambient
aquatic
life
water
quality
criteria
to
be
used
under
two
sections
of
the
Clean
Water
Act,
section
304(
a)(
1)
and
section
303(
c)(
2).
In
section
304,
the
term
represents
a
non­
regulatory,
scientific
assessment
of
ecological
effects.
If
water
quality
criteria
associated
with
specific
stream
uses
are
adopted
by
a
state
as
water
quality
standards
under
section
303,
they
become
enforceable
maximum
acceptable
pollutant
concentrations
in
ambient
waters
within
that
state.
Water
quality
criteria
adopted
in
state
water
quality
standards
could
have
the
same
numerical
values
as
criteria
developed
under
section
304.
However,
in
many
situations
states
might
want
to
adjust
water
quality
criteria
developed
under
section
304
to
reflect
local
environmental
conditions
and
human
exposure
patterns.
Alternatively,
states
may
use
different
data
and
assumptions
than
EPA
in
deriving
numeric
criteria
that
are
scientifically
XI
­
72
defensible
and
protective
of
designated
uses.
It
is
not
until
their
adoption
as
a
part
state
water
quality
standards
that
criteria
become
regulatory.

The
ambient
aquatic
life
water
quality
criteria
for
atrazine
is
currently
under
review.
An
atrazine
draft
dated,
6/
12/
00,
has
been
published
for
public
comment.
The
proposed
water
quality
criteria
values
for
atrazine
are
presented
in
the
table
below.

OW,
Water
Quality
Criteria
for
Atrazine
(
Fg/
L)

Final
Acute
Value
Fish
Chronic
Value
Invertebrate
Chronic
Value
Freshwater
Criteria
657.3
11.56
85.11
Saltwater
Criteria
641.5
11.28
83.06
h.
US
EPA,
OPP,
Terrestrial
and
Aquatic
Most
Sensitive
Toxicity
Values
The
most
sensitive
terrestrial
and
aquatic
toxicity
values
used
to
assess
risks
from
pesticide
use
are
presented
in
the
table
below.

OPP,
Terrestrial
and
Aquatic
Toxicity
Values
for
Atrazine
Acute
Value
Dietary
Value
Chronic
Value
Terrestrial
Organisms:
Birds
Mammals
(
mg/
kg)
940
224
(
ppm)
>
5,000
(
30
%
dead)
 
(
ppm)
<
75
50
Freshwater
Organisms:
Fish
Invertebrates
(
Fg/
L)
4,500
720
 
 
(
Fg/
L)
65
60
Saltwater
Organisms:
Fish
Invertebrates
(
Fg/
L)
8,500
88
 
 
(
Fg/
L)
1,900
80
Terrestrial
Plants:
Seedling
Emergence:
Dicot
Monocot
Vegetative
Vigor;
Dicot
Monocot
(
lbs
ai/
A)

0.003
0.004
0.008
0.61
 
 
 
 
 
 
 
 
XI
­
73
Aquatic
Plants:
Freshwater
Plants:
Algae
Vascular
Plants
Saltwater
Plants:
Algae
Vascular
Plants
(
Fg/
L)

<
1
2
10
<
4
(
Fg/
L)

25
2
22
8
i.
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XII
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Appendix
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Atrazine:
Acute
toxicity
in
goldfish.
Prepared
by
Woodard
Res.
Corp.;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
No.
00024718).

Beliles,
R.
P.
and
W.
J.
Scott,
Jr.
1965.
Atrazine
safety
evaluation
on
fish
and
wildlife
Bobwhite
quail,
mallard
ducks,
rainbow
trout,
sunfish,
goldfish):
Atrazine:
Acute
toxicity
in
rainbow
trout.
Prepared
by
Woodard
Res.
Corp.;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
No.
00024716).

Beliles,
R.
P.
and
W.
J.
Scott,
Jr.
1965.
Atrazine
safety
evaluation
on
fish
and
wildlife
(
Bobwhite
quail,
mallard
ducks,
rainbow
trout,
sunfish,
goldfish):
Atrazine:
Acute
toxicity
in
sunfish.
Prepared
by
Woodard
Res.
Corp.;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
No.
00024717).

Bentley,
R.
E.
and
K.
J.
Macek.
1973.
Acute
toxicity
of
atrazine
to
mud
crab
(
Neopanope
texana).
Prepared
by
Bionomics,
Inc.;
Submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
No.
00024719).

Buccafusco,
R.
1976.
Acute
toxicity
of
Atrazina
technical
to
bluegill
(
Lepomis
macrochirus).
Prepared
by
EG
&
G
Bionomics,
Wareham,
MA;
submitted
by
unknown.
(
MRID
No.
00147125).

Chetram,
R.
S.
1989.
Atrazine:
Tier
2
seed
emergence
nontarget
phytotoxicity
test.
Lab,
Study
No.
LR
89­
07C.
Prepared
by
Pan­
Agricultural
Laboratories,
Inc.,
Madera,
CA.;
submitted
by
Ciba­
Geigy
Corporation,
Greensboro,
NC.
(
MRID
No.
42041403).

Chetram,
R.
S.
1989.
Atrazine:
Tier
2
seed
germination
nontarget
phytotoxicity
test.
Lab,
Study
No.
LR
89­
07B.
Prepared
by
Pan­
Agricultural
Laboratories,
Inc.,
Madera,
CA.;
submitted
by
Ciba­
Geigy
Corporation,
Greensboro,
NC.
(
MRID
No.
41223001).

Chetram,
R.
S.
1989.
Atrazine:
Tier
2
vegetative
vigor
nontarget
phytotoxicity
test,
Lab,
Study
No.
LR
89­
07A.
Prepared
by
Pan­
Agricultural
Laboratories,
Inc.,
Madera,
CA.;
submitted
by
Ciba­
Geigy
Corporation,
Greensboro,
NC.
(
MRID
No.
41223003).

Chetram,
R.
S.
1989.
Atrazine:
Tier
2
vegetative
vigor
nontarget
phytotoxicity
test,
Lab,
XII
­
2
Study
No.
LR
89­
07A.
Prepared
by
Pan­
Agricultural
Laboratories,
Inc.,
Madera,
CA.;
submitted
by
Ciba­
Geigy
Corporation,
Greensboro,
NC.
(
MRID
No.
42041402).

Dionne,
E.
1992.
Atrazine
technical
 
Chronic
toxicity
to
the
fathead
minnow
(
Pimephales
promelas)
during
a
full
life­
cycle
exposure.
SLI
Report
No.
92­
7­
4324.
Prepared
by
Springborn
Laboratories,
Inc.,
Wareham,
MA;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
No.
42547103).

Drake,
C.
H.
1976.
Acute
toxicity
of
technical
NC
1659
(
atrazine)
to
Daphnia
magna.
Lab.
Rep.
No.
BIOSC/
76/
E/
12.
Prepared
by
Fisons,
Ltd.,
submitted
by
Fisons
Corp.,
Agricultural
Chemicals
Div.,
Bedford,
MA.
(
MRID
No.
00027204).

Fink,
R.
1976.
Final
report:
Acute
oral
LD50
 
Bobwhite
quail.
Project
No.
108­
123.
Prepared
by
Wildlife
International,
Ltd.,
Easton,
MD;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
No.
00024721).

Gross,
T.
S.
2001.
Determination
of
potential
effects
of
10
day
neonatal
exposure
of
atrazine
on
histological
and
hormonal
sex
determination
in
incubated
American
alligator
(
Alligator
mississippiensis)
eggs.
Prepared
by
University
of
Florida,
Wildlife
Reproductive
Toxicology
Laboratory,
Gainesville,
FL,
NOVA98,02a;
submitted
by
Syngenta
Crop
Protection,
Inc.,
Greensboro,
NC.
(
MRID
No.
45545302).

Gross,
T.
S.
2001.
Determination
of
potential
effects
of
10
day
neonatal
exposure
of
atrazine
on
histological
and
hormonal
sex
determination
in
incubated
red­
eared
slider
(
Pseudemys
elegans)
eggs.
Prepared
by
University
of
Florida,
Wildlife
Reproductive
Toxicology
Laboratory,
Gainesville,
FL,
NOVA98,02b;
submitted
by
Syngenta
Crop
Protection,
Inc.,
Greensboro,
NC.
(
MRID
No.
45545303).

Heath,
R.
G.,
J.
W.
Spann,
E.
F.
Hill
and
J.
F.
Kreitzer.
1972.
Comparative
dietary
toxicities
of
pesticides
to
birds.
Prepared
by
U.
S.
Dept.
Interior,
Bureau
Sport
Fish.
Wildlife,
Spec.
Rep.
­
Wildlife.
No.,
152.
57
p.;
submitted
by
Fisons
Corp.
(
MRID
No.
00058746).

Hoberg,
J.
R.
1991.
Atrazine
technical:
Toxicity
to
the
freshwater
green
alga
Selenastrum
capricornutum.
SLI
Rep.
No.
91­
1­
3600.
Prepared
by
Springborn
Laboratories,
Inc.,
Wareham,
MA.;
submitted
by
Ciba­
Geigy
Corporation,
Greensboro,
NC.
(
MRID
No.
42060701).

Hoberg,
J.
R.
1991.
Atrazine
technical:
Toxicity
to
the
duckweed
Lemna
gibba
G3.
SLI
Rep.
No.
91­
1­
3613.
Prepared
by
Springborn
Laboratories,
Inc.,
Wareham,
MA.;
submitted
by
Ciba­
Geigy
Corporation,
Greensboro,
NC.
(
MRID
No.
42041404).

Hoberg,
J.
R.
1993.
Atrazine
technical:
Toxicity
to
duckweed,
(
Lemna
gibba).
SLI
Rep.
No.
93­
4­
4755.
Prepared
by
Springborn
Laboratories,
Inc.,
Wareham,
MA.;
submitted
by
Ciba­
Geigy
Corporation,
Greensboro,
NC.
(
MRID
No.
43074804).
XII
­
3
Hoberg,
J.
R.
1993.
Atrazine
technical:
Toxicity
to
duckweed,
(
Lemna
gibba).
SLI
Rep.
No.
93­
11­
5053.
Prepared
by
Springborn
Laboratories,
Inc.,
Wareham,
MA.;
submitted
by
Ciba­
Geigy
Corporation,
Greensboro,
NC.
(
MRID
No.
43074803).

Hoberg,
J.
R.
1993.
Atrazine
technical:
Toxicity
to
the
freshwater
green
alga,
(
Selenastrum
capricornutum).
SLI
Rep.
No.
93­
4­
4751.
Prepared
by
Springborn
Laboratories,
Inc.,
Wareham,
MA.;
submitted
by
Ciba­
Geigy
Corporation,
Greensboro,
NC.
(
MRID
No.
43074802).

Hoberg,
J.
R.
1993.
Atrazine
technical:
Toxicity
to
the
marine
diatom,
(
Skeletonema
costatum).
SLI
Rep.
No.
93­
4­
4753.
Prepared
by
Springborn
Laboratories,
Inc.,
Wareham,
MA.;
submitted
by
Ciba­
Geigy
Corporation,
Greensboro,
NC.
(
MRID
No.
43074801).

Hughes,
J.
R.
1986.
The
toxicity
of
atrazine,
Lot
No.
FL­
850612
to
four
species
of
aquatic
plants.
Lab.
Study
No.
267­
28­
1100.
Prepared
by
Malcolm
Pirnie,
Inc.,
White
Plains,
NY.;
submitted
by
Ciba­
Geigy
Corporation,
Greensboro,
NC.
(
MRID
No.
41065203).

Macek,
K.
J.,
K.
S.
Buxton,
S.
Sauter,
S.
Gnilka
and
J.
W.
Dean.
1976.
Chronic
toxicity
of
atrazine
to
selected
aquatic
invertebrates
and
fishes.
Prepared
by
EG
&
G
Bionomics,
Inc.,
Duluth,
MN;
submitted
by
Shell
Chemical
Co.,
Washington,
D.
C.
(
MRID
No.
00024377).

Machado,
M.
W.
1994.
Atrazine
technical
­­
Acute
toxicity
to
mysid
shrimp
(
Mysidopsis
bahia)
under
flow­
through
conditions.
Prepared
by
Springborn
Laboratories,
Inc.,
Wareham,
MA;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
No.
43344902).

Machado,
M.
W.
1994.
Atrazine
technical
­­
Acute
toxicity
to
sheepshead
minnow
(
Cyprinodon
variegatus)
under
flow­
through
conditions.
Prepared
by
Springborn
Laboratories,
Inc.,
Wareham,
MA;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
No.
43344901).

Madsen,
T.
J.
2000.
Effects
of
atrazine
on
the
sex
ratio
of
Daphnia
pulicaria.
Prepared
by
ABC
Laboratories,
Inc.,
Columbia,
MO,
ABC
Study
No.
45810;
submitted
by
Novartis
Crop
Protection,
Inc.,
Greensboro,
NC.
(
MRID
No.
45299504).

Mayer,
F.
L.,
Jr.
1986.
Acute
toxicity
handbook
of
chemicals
to
estuarine
organisms.
U.
S.
Environmental
Protection
Agency,
EPA/
600/
X­
86/
231.
274
pages.
(
MRID
No.
40228401).

Parrish,
R.
1978.
Effects
of
atrazine
on
two
freshwater
and
five
marine
algae.
Lab.
Study
No.
H82­
500.
Prepared
by
E
G
&
G
Bionomics,
Marine
Research
Laboratory,
Pensacola,
FL.;
submitted
by
Ciba­
Geigy
Corporation,
Greensboro,
NC.
(
MRID
No.
41065204).
XII
­
4
Pedersen,
C.
A.
and
D.
R.
DuCharme.
1992.
Atrazine
technical:
Toxicity
and
reproduction
study
in
bobwhite
quail.
Lab.
Proj.
ID.
No.
BLAL
No.
102­
012­
07.
Prepared
by
Bio­
Life
Associates,
Ltd.,
Neillsville,
WI;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
No.
42547102).

Pedersen,
C.
A.
and
D.
R.
DuCharme.
1992.
Atrazine
technical:
Toxicity
and
reproduction
study
in
mallard
ducks.
Lab.
Proj.
ID.
No.
BLAL
No.
102­
013­
08.
Prepared
by
Bio­
Life
Associates,
Ltd.,
Neillsville,
WI;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
No.
42547101).

Putt,
Arthur
E.
1991.
Atrazine
80%
WP:
Acute
toxicity
to
daphnids
(
Daphnia
magna)
underflow­
through
conditions.
Lab.
Study
No.
91­
5­
3761.
Prepared
by
Springborn
Laboratories,
Inc.,
Wareham,
MA.;
submitted
by
Ciba­
Geigy
Corporation.
(
MRID
#
42041401)

Sachsse,
K.
and
L.
Ullmann.
1974.
Acute
oral
LD50
of
technical
atrazin
(
G
30027)
in
the
Japanese
quail.
Project
No.
Siss
4407.
Prepared
by
Ciba­
Geigy,
Ltd.,
Basle,
Switzerland;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
No.
00024722).

Sachsse,
K.
and
L.
Ullmann.
1975.
8­
Day
feeding
toxicity
of
technical
G30027
(
Atrazine)
in
the
Japanese
quail.
Prepared
by
Ciba­
Geigy,
Ltd.,
Basle,
Switzerland;
submitted
by
Ciba­
Geigy
Corp.,
Greensboro,
NC.
(
MRID
No.
00024723).

Tucker,
R.
K.
and
D.
G.
Crabtree.
1970.
Handbook
of
toxicity
of
pesticides
to
wildlife.
U.
S.
Dept.
Interior,
Bureau
Sport
Fish.
Wildlife,
Denver
Wildlife
Res.
Center.
Submitted
by
Fison
Corp.
(
MRID
No.
???????).

Union
Carbide
Corp.
1975.
Acute
toxicity
of
SD
12011,
Code
4­
1­
2­
1
and
Code
4­
1­
3­
1
to
fiddler
crabs,
Uca
pugilator.
Prepared
by
Union
Carbide
Corp.;
submitted
by
Shell
Chemical
Co.,
Washington,
D.
C.
(
MRID
No.
00024395).

Wieser,
C.
M.
and
T.
Gross.
2002.
Determination
of
potential
effects
of
20
day
exposure
of
atrazine
on
endocrine
function
in
adult
largemouth
bass
(
Micropterus
salmoides).
Prepared
by
University
of
Florida,
Wildlife
Reproductive
Toxicology
Laboratory,
Gainesville,
FL,
Wildlife
No.
NOVA98.02e;
submitted
by
Syngenta
Crop
Protection,
Inc.,
Greensboro,
NC.
(
MRID
No.
45622304).
XIII
­
1
Appendix
XIII.
Data
Requirement
Tables
_________________________________________________________________________________________________________

ENVIRONMENTAL
FATE
Case
No:
0???
DATA
REQUIREMENTS
FOR
Chemical
No:
080803
ATRAZINE
Does
EPA
Have
Must
Additional
Use
Data
To
Satisfy
Bibliographic
Data
Be
Submitted
Data
Requirement
Pattern1
This
Requirement?
Citation
under
FIFRA
3(
c)(
2)(
B)?

(
Yes,
No,
or
Partially)

§
158.290
ENVIRONMENTAL
FATE
Degradation
Studies­
Lab:

161­
1
Hydrolysis
ABCJK
yes
40431319
no
161­
2
Photodegradation
In
Water
ABCJK
yes
42089904
no
161­
3
Photodegradation
On
Soil
ABCJK
yes
40431320,42089905
no
161­
4
Photodegradation
In
Air
no
Metabolism
Studies­
Lab:

162­
1
Aerobic
Soil
ABCJK
yes
42089906
no
162­
2
Anaerobic
Soil
ABCJK
yes
42089906
no
162­
3
Anaerobic
Aquatic
ABCJK
yes
40431323
no
162­
4
Aerobic
Aquatic
ABCJK
no
yes
Mobility
Studies:

163­
1
Leaching­
Adsorption/
Desorp.
ABCJK
yes
40331324,40431327,40431325
no
40431328,40431326
163­
2
Volatility
(
Lab)
ABCJK
no
yes
163­
3
Volatility
(
Field)
ABCJK
no
???

Dissipation
Studies­
Field:

164­
1
Soil
Dissipation
ABCJK
yes
42165504,42165505,40431336,
no
42165506,40431337,421655507
164­
2
Aquatic
(
Sediment)
ABCJK
no
yes
164­
3
Forestry
ABCJK
yes
40431340,42041405
no
164­
5
Soil,
Long­
term
ABCJK
yes
40431339,
42089911,40431337
no
XIII
­
2
42089912,40431338,42089909
40431336,42089910
Accumulation
Studies:

165­
3
Irrigated
Crops
165­
4
In
Fish
ABCJK
yes
40431344
no
165­
5
In
Aquatic
Non­
Target
Org.
ABCJK
no
yes
Ground
Water
Studies:

166­
1
Ground
Water
Small
Prosp.

166­
2
Ground
Water
Small
Retro.

Surface
Water
Studies:

167­
1
Field
Runoff
167­
2
Surface
Water
Monitoring
§
158.440
Spray
Drift:

201­
1
Droplet
Size
Spectrum
ABCJK
no
yes
202­
1
Drift
Field
Evaluation
ABCJK
no
yes
1
Use
Patterns:
A=
Terrestrial
Food
Crop;
B=
Terrestrial
Feed
Crop;
C=
Terrestrial
Non­
Food
Crop;
D=
Aquatic
Food
Crop;
E=
Aquatic
Non­

Food
Outdoor;
F=
Aquatic
Non­
Food
Industrial;
G=
Aquatic
Non­
food
Residential;
H=
Greenhouse
Food
Crop;
I=
Greenhouse
Non­

Food
Crop;
J=
Forestry;
K=
Outdoor
Recreation;
L=
Indoor
Food;
M=
Indoor
Non­
Food;
N=
Indoor
Medical;
O=
Indoor
Residential;
Z=
Use
Group
for
Site
00000
*
In
Bibliographic
Citation
column
indicates
study
may
be
upgradeable
XIII
­
3
Date:
November
2000
PHASE
IV
Case
No:
DATA
REQUIREMENTS
FOR
Chemical
No:
080803
ECOLOGICAL
EFFECTS
BRANCH
Data
Requirements
Composition1
Use
Pattern2
Does
EPA
Have
Data
To
Satisfy
This
Requirement?

(
Yes,
No)
Bibliographic
Citation
(
MRID)
Must
Additional
Data
Be
Submitted
under
FIFRA3(
c)(
2)(
B)?

6
Basic
Studies
in
Bold
71­
1(
a)
Acute
Avian
Oral,
Quail/
Duck
Northern
Quail
to
be
tested
TGAI
3
Major
Degradates
ABCJK
ABCJK
yes
no
00024721
no
yes
71­
1(
b)
Acute
Avian
Oral,
Quail/
Duck
(
TEP)
no
71­
2(
a)
Acute
Avian
Diet,
Quail
TGAI
Degradates
ABCJK
ABCJK
yes
no
00022923
no
reserved
71­
2(
b)
Acute
Avian
Diet,
Duck
TGAI
ABCJK
yes
00022923
no
71­
3
Wild
Mammal
Toxicity
no
71­
4(
a)
Avian
Reproduction
Quail
TGAI
Degradates
ABCJK
ABCJK
yes
no
42547102
no
reserved
71­
4(
b)
Avian
Reproduction
Duck
TGAI
Degradates
ABCJK
ABCJK
yes
no
42547101
no
reserved
71­
5(
a)
Simulated
Terrestrial
Field
Study
no
71­
5(
b)
Actual
Terrestrial
Field
Study
no
72­
1(
a)
Acute
Fish
Toxicity
Bluegill
TGAI
Major
Degradate
ABCJK
ABCJK
yes
no
00024717
no
yes
72­
1(
b)
Acute
Fish
Toxicity
Bluegill
(
TEP)

72­
1
©
Acute
Fish
Toxicity
Rainbow
Trout
TGAI
Major
Degradate
ABCJK
ABCJK
yes
no
00024716
no
yes
72­
1(
d)
Acute
Fish
Toxicity
Rainbow
Trout
(
TEP)
Date:
November
2000
PHASE
IV
Case
No:
DATA
REQUIREMENTS
FOR
Chemical
No:
080803
ECOLOGICAL
EFFECTS
BRANCH
Data
Requirements
Composition1
Use
Pattern2
Does
EPA
Have
Data
To
Satisfy
This
Requirement?

(
Yes,
No)
Bibliographic
Citation
(
MRID)
Must
Additional
Data
Be
Submitted
under
FIFRA3(
c)(
2)(
B)?

*
In
Bibliographic
Citation
column
indicates
study
may
be
upgradeable
XIII
­
4
72­
2(
a)
Acute
Aquatic
Invertebrate
Toxicity
TGAI
Major
Degradate
ABCJK
ABCJK
yes
no
00024377
no
yes
72­
2(
b)
Acute
Aquatic
Invertebrate
Toxicity
(
TEP)

72­
3(
a)
Acute
Estu/
Mari
Tox
Fish
TGAI
Major
Degradate
ABCJK
ABCJK
yes
no
43344901
no
yes
72­
3(
b)
Acute
Estu/
Mari
Tox
Mollusk
TGAI
Major
Degradate
ABCJK
ABCJK
no
no
yes
yes
72­
3
©
Acute
Estu.
Mari
Tox
Shrimp
TGAI
Major
Degradate
ABCJK
ABCJK
yes
no
43344902
no
yes
72­
3(
d)
Acute
Estu/
Mari
Tox
Fish
(
TEP)

72­
3(
e)
Acute
Estu/
Mari
Tox
Mollusk
(
TEP)

72­
3(
f)
Acute
Estu/
Mari
Tox
Shrimp
(
TEP)

72­
4(
a)
Early
Life­
Stage
Fish
(
Freshwater)
TGAI
Major
Degradate
ABCJK
ABCJK
no
no
45208304
no
reserved
72­
4(
a)
Early
Life­
Stage
Fish
(
Marine)
TGAI
ABCJK
no
45202920
*
yes
72­
4(
b)
Life­
Cycle
Aquatic
Invertebrate
TGAI
Major
Degradate
ABCJK
ABCJK
yes
no
00024377
no
reserved
72­
4(
b)
Life­
Cycle
Marine
Invertebrate
TGAI
Major
Degradate
ABCJK
ABCJK
no
no
45202920
*
yes
reserved
72­
5
Life­
Cycle
Fish
TGAI
Major
Degradate
ABCJK
ABCJK
yes
no
00024377
no
reserved
72­
6
Aquatic
Org.
Accumulation
72­
7(
a)
Simulated
Aquatic
Field
Study
72­
7(
b)
Actual
Aquatic
Field
Study
Date:
November
2000
PHASE
IV
Case
No:
DATA
REQUIREMENTS
FOR
Chemical
No:
080803
ECOLOGICAL
EFFECTS
BRANCH
Data
Requirements
Composition1
Use
Pattern2
Does
EPA
Have
Data
To
Satisfy
This
Requirement?

(
Yes,
No)
Bibliographic
Citation
(
MRID)
Must
Additional
Data
Be
Submitted
under
FIFRA3(
c)(
2)(
B)?

*
In
Bibliographic
Citation
column
indicates
study
may
be
upgradeable
XIII
­
5
122­
1(
a)
Seed
Germ./
Seedling
Emerg.
TEP
122­
1(
b)
Vegetative
Vigor
TEP
122­
2
Aquatic
Plant
Growth
123­
1(
a)
Seed
Germ./
Seedling
Emerg.
TEP
ABCJK
yes
42041403
no
123­
1(
b)
Vegetative
Vigor
TEP
ABCJK
yes
42041402
no
123­
2
Aquatic
Plant
Growth
TGAI
ABCJK
yes
41065203a
41065203b
43074801
43074802
43074803
no
124­
1
Terrestrial
Field
Study
124­
2
Aquatic
Field
Study
141­
1
Honey
Bee
Acute
Contact
TGAI
ABCJK
yes
00036935
no
141­
2
Honey
Bee
Residue
on
Foliage
TEP
no
no
141­
5
Field
Test
for
Pollinators
TEP
no
no
1
Composition:
TGAI=
Technical
grade
of
the
active
ingredient;
PAIRA=
Pure
active
ingredient,
radiolabeled;
TEP=
Typical
end­
use
product
2
Use
Patterns:
A=
Terrestrial
Food
Crop;
B=
Terrestrial
Feed
Crop;
C=
Terrestrial
Non­
Food
Crop;
D=
Aquatic
Food
Crop;
E=
Aquatic
Non­

Food
Outdoor;
F=
Aquatic
Non­
Food
Industrial;
G=
Aquatic
Non­
food
Residential;
H=
Greenhouse
Food
Crop;
I=
Greenhouse
Non­

Food
Crop;
J=
Forestry;
K=
Outdoor
Recreation;
L=
Indoor
Food;
M=
Indoor
Non­
Food;
N=
Indoor
Medical;
O=
Indoor
Residential;
Z=
Use
Group
for
Site
00000
