UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
MEMORANDUM
DATE:
25
July
2005
SUBJECT:
Amended
Response
to
a
submitted
Dietary
Exposure
Assessment
and
a
comment
on
fish
consumption
in
the
US.
DP
Barcode
D319607.

FROM:
David
Soderberg,
Chemist,
RRB3
(
7509C)

THROUGH:
Catherine
Eiden,
Chief,
RRB3
(
7509C)

TO:
Mika
Hunter,
Chemical
Review
Manager,
SRB,
SRRD
(
7508C)

Regarding:

46421402
Freshwater
and
Estuarine
Finfish
and
Shellfish
Consumption
in
the
United
States,
D.
Petty,
18
June
2004,
Unpublished
study
by
Cerexagri,
Inc.
,
Report
#
NDR200403,
17
pages
46421401
Endothall:
Acute
and
Chronic
Dietary
Exposure
and
Risk
Assessment,
J.
Eickhoff,
24
November,
2004,
Unpublished
study
by
Cerexagri,
Report
#
Endothall
2004­
1;
41
pages
Note
that
this
amendment
simply
corrects
the
name
of
the
addressee.

Cerexagri
has
submitted
a
dietary
exposure
assessment
entitled,
"
Endothall:
Acute
and
Chronic
Dietary
Exposure
Assessment
for
Endothall"
(
MRID
46421401)
and
has
also
submitted
a
document
entitled
"
Freshwater
and
Estuarine
Finfish
and
Shellfish
Consumption
in
the
United
States"
(
MRID
464214­
02).
The
latter
document
merely
agrees
that
it
is
reasonable
to
use
the
fish
consumption
reported
in
USDA's
Continuing
Survey
of
Food
Intakes
by
Individuals
(
CSFII)
in
dietary
assessment.
Since
EPA
already
uses
CSFII
data
in
its
dietary
exposure
assessments
nothing
more
need
be
said
about
this
latter
document.

In
their
dietary
exposure
assessment
Cerexagri
submitted
both
an
acute
dietary
exposure
assessment
and
a
chronic
assessment.
HED,
however,
has
already
concluded
that
an
acute
RfD
could
not
be
established
for
endothall,
therefore
HED
has
not
performed
an
acute
dietary
exposure
assessment.
Because
of
this,
only
the
submitted
chronic
assessment
will
be
reviewed
2
here.
For
chronic
exposure
the
submitted
assessment
used
the
same
toxicological
endpoint
of
0.007
mg/
kg/
day
that
HED
used.

In
their
chronic
assessment
Cereagri
estimated
a
maximum
chronic
exposure
through
food
plus
drinking
water
to
"
children"
as
0.00451
mg/
kg/
day,
or
6.4
of
the
cPAD.
For
"
Adults"
Cerexagri
estimated
an
exposure
through
food
plus
drinking
water
of
0.000165
mg/
kg/
day,
or
2.4%
of
the
cPAD.
[
Note
that
"
children"
is
not
a
standard
subpopulation
used
by
HED,
and
"
adult"
without
some
further
clarification
as
to
age
range
is
also
not
normally
used
by
EPA.]
.

HED's
chronic
exposure
for
the
US
Population
through
food
plus
drinking
water
was
estimated
at
0.000137
ppm,
or
2.0%
of
the
PAD.
For
Adults,
20
­
49
years
of
age,
the
exposure
was
0.000112
mg/
kg/
day,
or
1.6%
of
the
cPAD.
The
most
highly
exposed
population
subgroup
was
children
3­
5
years
old
at
0.000285,
or
4.1%
of
the
PAD.
Other
subpopulation
groups
for
infants
through
children
6­
12
ranged
from
0.000208
mg/
kg/
day
(
3.0%
cPAD)
to
0.000280
mg/
kg/
day
(
4.0%
cPAD).

Thus,
despite
all
the
differences
in
approach
to
the
assessment
described
below,
the
two
assessments
came
out
remarkably
close.

Detailed
comparison
of
the
Cerexagri
approach
and
HED
approach
to
dietary
assessments.

Cerexagri's
assessment
addresses
residues
on
directly
treated
crops
only,
and
does
not
include
potential
exposure
through
irrigated
crops.
Therefore
the
submitted
assessment
can
only
be
compared
to
the
HED
assessment
that
does
not
include
irrigated
crops.
Cerexagri's
assessment
is
not
germane
to
HED's
upper
bound
assessment
of
exposure
through
all
crops,
including
those
that
are
irrigated,
that
may
contribute
to
endothall
residues
in
the
diet.
Because
of
the
difficulty
of
estimating
exposure
through
irrigated
crops,
HED
calculated
the
exposure
through
directly
treated
crops
only
as
a
low
bound,
and
exposure
through
both
directly
treated
crops
and
irrigated
crops
to
be
a
high
bound
on
exposure.

Of
directly
treated
crops,
Cerexagri
only
evaluated
use
of
endothall
on
cotton
and
potatoes.
These
are
the
registered
uses
of
endothall
that
Cerexagri
specifically
supports.
The
HED
assessment
also
included
the
currently
registered
use
of
endothall
on
hops
and,
although
there
are
no
currently
registered
uses
on
rice
and
sugar
beets,
there
are
current
tolerances
on
rice
and
sugar
beets,
so
it
was
necessary
for
HED
to
include
these
crops
in
this
Agency's
assessment.

The
submitted
Cerexagri
assessment
was
performed
using
LifelineTM.
This
is
one
of
several
exposure
modeling
programs
accepted
by
EPA.
Although
the
original
assessment
performed
by
EPA
used
another
program,
called
DEEMTM,
the
two
programs
have
been
thoroughly
compared
by
HED
and
usually
provide
fairly
equivalent
results.
In
the
case
of
endothall,
however,
HED
did
do
a
close
comparison
of
the
results
of
the
two
methods
and
found
some
discrepancies.
HED
believes
that
these
differences
may
be
due
to
an
instability
in
output
numbers
related
to
fewer
3
fish/
consumption
events
being
evaluated
within
the
LifelineTM
program
than
within
the
DEEMTM
program.
For
this
reason
HED
elected
to
report
results
using
DEEMTM
only.

For
this
submitted
assessment
the
registrant
used
field
trial
data
for
residues
on
potatoes
and
cotton.
HED
used
tolerances
because
the
added
refinement
was
not
needed,
but
this
is
merely
a
difference
in
approaches
based
upon
the
lack
of
need
for
the
extra
refinement.
The
same
processing
factors
were
used
in
both
assessments.
The
submitted
assessment
assumed
that
(<)
2%
of
the
potato
and
cotton
crops
are
treated
with
endothall
while
HED's
assessment
used
an
estimate
that
1%
of
these
crops
were
treated.

Cerexagri
chose
to
use
tolerance
values
for
all
livestock
commodities
except
poultry,
which
was
set
to
zero.
HED
calculated
anticipated
residues
for
the
livestock
commodities,
including
poultry,
using
metabolism
study
data.
This
is
expected
to
lead
to
small
differences
in
exposure,
although
neither
approach
can
be
considered
to
be
a
better
option
than
the
other.

Cerexagri
estimated
residues
in
finfish
at
0.035
ppm
from
residues
found
in
a
study
in
bluefish.
Cerexagri
also
eliminated
tuna
as
a
source
of
residues,
since
it
is
not
a
freshwater
fish
likely
to
be
treated
with
endothall.
Cerexagri
similarly
estimated
residues
of
0.91
ppm
on
molluscs
and
at
0.17
ppm
in
crustaceans
even
though
they
concluded
that
neither
a
significant
proportion
of
normally
eaten
molluscs
nor
crustaceans
are
likely
to
be
consumed
by
people.
HED
used
a
proposed
tolerance
of
0.1
ppm
for
(
all)
finfish,
and
did
not
apply
residues
to
molluscs
and
crustaceans.

For
water
Cerexagri
used
a
maximum
allowed
amount
of
endothall
of
0.2
mg/
L
and
used
EPA's
1999
default
water
intakes
and
body
weights.
HED
used
the
results
of
a
PRIZM/
EXAMS
model
and
employed
these
results
directly
in
the
DEEMTM
(
and
LifelineTM)
program(
s),
thus
allowing
HED
to
refine
the
water
exposure
for
real
reported
intakes
and
real
body
weights.

As
stated
at
the
head
of
this
review,
Cerexagri
estimated
a
maximum
chronic
exposure
to
food
plus
drinking
water
to
"
children"
as
0.00451
mg/
kg/
day,
or
6.4
of
the
cPAD.
For
"
Adults"
Cerexagri
estimated
an
exposure
through
food
plus
drinking
water
of
0.000165
mg/
kg/
day,
or
2.4%
of
the
cPAD.
HED's
chronic
exposure
for
the
US
Population
through
food
plus
drinking
water
was
estimated
at
0.000137
ppm,
or
2.0%
of
the
PAD.
For
Adults
20
­
49
years
of
age
the
exposure
was
0.000112
mg/
kg/
day,
or
1.6%
of
the
cPAD.
The
most
highly
exposed
population
subgroup
was
children
3­
5
years
old
at
0.000285,
or
4.1%
of
the
PAD.
Other
subpopulation
groups
for
infants
through
children
6­
12
ranged
from
0.000208
mg/
kg/
day
(
3.0%
cPAD)
to
0.000280
mg/
kg/
day
(
4.0%
cPAD).

Thus,
for
all
of
the
minor
differences
between
these
two
assessments,
the
results
came
out
very
close
to
each
other.
