National
Report
on
Human
Exposure
to
Environmental
Chemicals
Centers
for
Disease
Control
and
Prevention
Atlanta,
Georgia
March
2001
TM
National
Report
on
Human
Exposure
to
Environmental
Chemicals
Centers
for
Disease
Control
and
Prevention
March
2001
Contents
Executive
Summary
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viii
Introduction
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1
Data
Sources
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5
Major
Findings
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7
Toxicology
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Health­
Risk
Information
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11
Results
By
Chemical
Group
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15
Metals
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15
Lead
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15
Mercury
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17
Cadmium
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19
Cobalt
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21
Uranium
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22
Antimony
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23
Barium
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24
Beryllium
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25
Cesium
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26
Molybdenum
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27
Platinum
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28
Thallium
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29
Tungsten
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30
Tobacco
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33
Cotinine
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Organophosphate
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35
Dimethylphosphate
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37
Dimethylthiophosphate
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38
Dimethyldithiophosphate
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38
Diethylphosphate
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39
Diethylthiophosphate
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39
Diethyldithiophosphate
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40
Phthalates
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41
Mono­
ethyl
Phthalate
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42
Mono­
butyl
Phthalate
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42
Mono­
benzyl
Phthalate
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Mono­
cyclohexyl
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44
Mono­
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ethylhexyl
Phthalate
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Mono­
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octyl
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Mono­
isononyl
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46
References
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47
References
for
Analytical
Methods
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49
Glossary
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51
Executive
Summary
Introduction
The
National
Report
on
Human
Exposure
to
Environmental
Chemicals
is
a
new
publication
that
provides
an
ongoing
assessment
of
the
exposure
of
the
U.
S.
population
to
environmental
chemicals
using
biomonitoring.
For
this
Report,
an
environmental
chemical
means
a
chemical
compound
or
chemical
element
present
in
air,
water,
soil,
dust,
food,
or
other
environmental
media.
Biomonitoring
is
the
assessment
of
human
exposure
to
chemicals
by
measuring
the
chemicals
or
their
metabolites
(
i.
e.,
breakdown
products)
in
human
specimens,
such
as
blood
or
urine.

The
Report
provides
exposure
information
about
people
participating
in
an
ongoing
national
survey
of
the
general
U.
S.
population
 
the
National
Health
and
Nutrition
Examination
Survey
(
NHANES).
The
survey
is
conducted
by
the
National
Center
for
Health
Statistics
of
the
Centers
for
Disease
Control
and
Prevention
(
CDC).
This
survey
is
unique
in
its
ability
to
examine
public
health
issues
that
can
best
be
addressed
through
physical
and
laboratory
examinations
of
the
U.
S.
population.
The
first
release
of
the
Report
is
restricted
to
general
U.
S.
population
data
for
the
year
1999
from
NHANES.

This
first
Report
provides
information
about
levels
of
27
environmental
chemicals
measured
in
the
U.
S.
population.
These
chemicals
include
metals,
such
as
lead,
mercury,
and
uranium;
organophosphate
pesticide
metabolites;
phthalate
metabolites;
and
cotinine,
a
marker
of
exposure
to
tobacco
smoke.
Tables
on
the
following
pages
summarize
results
of
CDC's
Environmental
Health
Laboratory
measurements.

Public
Health
Uses
of
the
Report
The
overall
purpose
of
the
Report
is
to
provide
unique
exposure
information
to
scientists,
physicians,
and
health
officials
to
help
prevent
disease
that
results
from
exposure
to
environmental
chemicals.
Specific
uses
of
information
contained
in
the
Report
are
discussed
elsewhere
in
this
document.

Interpreting
Data
Contained
in
the
Report
This
first
report
presents
data
for
the
general
U.
S.
population
for
1999
from
CDC's
NHANES.
Because
the
sample
size
in
any
one
year
of
NHANES
is
relatively
small
and
for
1999
the
survey
was
conducted
in
only
12
locations
across
the
country,
and
because
most
analyses
were
conducted
in
subsamples
of
the
population,
more
data
will
be
needed
to
confirm
these
findings
and
to
allow
more
detailed
analysis
to
describe
exposure
levels
in
population
subgroups.

Just
because
people
have
an
environmental
chemical
in
their
blood
or
urine
does
not
mean
that
the
chemical
causes
disease.
Advances
in
analytical
methods
allow
us
to
measure
low
levels
of
environmental
chemicals
in
people,
but
studies
of
varying
exposure
levels
and
health
effects
are
needed
to
determine
which
blood
or
urine
levels
result
in
disease.
These
studies
must
also
ii
consider
other
factors
such
as
duration
of
exposure.

The
Report
will
contain
new
data
each
year.
Next
year,
CDC
will
combine
the
1999
and
2000
data
from
NHANES
to
provide
updated
national
estimates.
In
the
future,
the
Report
will
also
include
data
from
other
large
exposure
studies
and
studies
of
exposure
of
special­
population
groups
within
the
United
States.

Major
Findings
of
the
Report
First­
time
information
about
exposure
levels
for
the
U.
S.
population
The
1999
Report
provides
measures
of
exposure
for
levels
of
27
chemicals
in
the
U.
S.
population
that
are
based
on
blood
and
urine
samples
obtained
from
people
participating
in
NHANES
1999.
For
three
chemicals
 
lead,
cadmium,
and
cotinine
 
CDC
has
previously
assessed
the
population's
exposure
through
NHANES,
and
this
Report
provides
new
data
for
the
1999
calendar
year.
The
Report
provides
information
for
the
first
time
about
the
U.
S.
population's
exposure
to
24
additional
environmental
chemicals
(
metals,
organophosphate
pesticides,
and
phthalates).
Because
the
sample
size
in
one
year
of
NHANES
is
relatively
small
and
because
the
1999
survey
was
conducted
only
in
12
locations
across
the
country,
data
from
additional
years
of
the
survey
will
be
needed
to
confirm
these
findings.

Reference
range
values
for
physicians
and
health
researchers
Physicians
use
"
normal"
ranges
for
laboratory
results
to
determine
whether
their
patients
have
high
or
low
values
that
would
indicate
a
health
problem.
These
ranges
are
obtained
from
people
who
are
generally
healthy.
In
the
Report,
CDC
determined
reference
ranges
for
24
environmental
chemicals
from
a
group
of
people
not
known
to
have
any
specific
exposure
to
the
chemicals
beyond
that
experienced
in
the
general
population.
Sometimes
these
reference
ranges
are
referred
to
as
"
background­
exposure
levels."

Reference
ranges
are
extremely
helpful
to
physicians
and
health
researchers
because
levels
above
the
reference
range
usually
indicate
exposure
to
a
particular
source.
For
example,
if
a
physician
was
concerned
about
a
patient's
potential
exposure
to
cadmium
and
measured
a
cadmium
level
in
the
patient's
urine,
the
results
could
be
compared
with
the
population
reference
range
in
the
Report.
A
cadmium
level
similar
to
those
found
in
the
Report
would
indicate
exposure
no
different
from
those
levels
found
in
the
general
population,
and
a
level
much
higher
than
those
found
in
the
Report
would
indicate
that
there
may
have
been
an
unusual
exposure
to
cadmium
worthy
of
further
investigation.

Decline
in
blood
lead
levels
among
children
since
1991­
1994
Since
1976,
CDC
has
measured
blood
lead
levels
as
part
of
NHANES.
Results
presented
in
the
Report
for
1999
show
that
the
geometric
mean
blood
lead
level
for
children
aged
1­
5
years
has
decreased
to
2.0
micrograms
per
deciliter
(
µ
g/
dL),
from
2.7
µ
g/
dL,
the
geometric
mean
for
the
period
1991­
1994.
This
decrease
documents
that
blood
lead
levels
continue
to
decline
among
U.
S.
children
when
considered
as
a
group,
highlighting
the
success
of
public
health
efforts
to
decrease
the
exposure
of
children
to
lead.
However,
special
populations
of
children
at
high
risk
iii
for
lead
exposure
(
e.
g.,
those
living
in
homes
containing
lead­
based
paint
or
lead­
contaminated
dust)
remain
a
public
health
concern.

Reduced
exposure
of
the
U.
S.
population
to
environmental
tobacco
smoke
Cotinine
is
a
metabolite
of
nicotine
that
tracks
exposure
to
environmental
tobacco
smoke
(
ETS)
among
nonsmokers.
Higher
cotinine
levels
reflect
more
exposure
to
ETS,
which
has
been
identified
as
a
known
human
carcinogen.
From
1988
through
1991,
as
part
of
NHANES
III,
CDC
determined
that
the
median
level
(
50th
percentile)
of
cotinine
among
nonsmokers
in
the
United
States
was
0.20
nanograms
per
milliliter
(
ng/
mL).
Results
from
the
1999
Report
showed
that
the
median
cotinine
level
among
people
aged
3
years
and
older
has
decreased
to
less
than
0.050
ng/
mL
 
more
than
a
75%
decrease.
This
reduction
in
cotinine
levels
objectively
documents
a
dramatic
reduction
in
exposure
of
the
general
population
to
ETS
since
1988­
1991.
However,
since
more
than
half
of
American
youth
are
still
exposed,
ETS
remains
a
major
public
health
concern.

Better
assessment
of
children's
and
women's
exposure
to
mercury
The
1999
Report
provides
important
new
data
about
blood
mercury
levels
among
children
aged
1­
5
years
and
among
women
of
childbearing
age
(
16­
49
years
old).
The
geometric
mean
of
blood
mercury
levels
among
children
(
0.3
µ
g/
L)
was
about
25%
of
the
geometric
mean
of
blood
mercury
levels
among
women
of
childbearing
age
(
1.2
µ
g/
L).
Compared
with
an
adult,
the
fetus
and
child
are
usually
more
vulnerable
to
the
effects
of
metals.
Consequently,
when
addressing
mercury
exposures,
health
officials
are
particularly
careful
to
protect
the
fetus
and
child.
The
Report
provides
data
for
children
and
levels
for
women
of
childbearing
age
that
reflect
levels
of
mercury
to
which
the
fetus
is
exposed.
Scientists
will
use
these
new
data
to
better
estimate
health
risks
for
the
fetus,
children,
and
women
of
childbearing
age
from
potential
sources
of
mercury
exposure.

Setting
priorities
for
research
on
phthalates
Phthalates
are
compounds
commonly
used
in
consumer
products
such
as
soap,
shampoo,
hair
spray,
and
many
types
of
nail
polish.
Some
phthalates
are
used
in
flexible
plastics
such
as
blood
bags
and
tubing.
Animal
research
has
focused
on
evaluating
reproductive
effects
of
phthalates.
For
the
1999
Report,
CDC
scientists
measured
metabolites
of
seven
major
phthalates.
Di­
2­
ethylhexyl
phthalate
(
DEHP)
and
di­
isononyl
phthalate
(
DINP)
are
the
two
phthalates
produced
in
greatest
quantity,
with
diethyl
phthalate
(
DEP)
and
dibutyl
phthalate(
DBP)
produced
in
much
lower
quantities.
However,
data
from
the
Report
showed
that
levels
of
metabolites
of
DEP
and
DBP
were
much
higher
in
the
population
than
levels
of
metabolites
of
either
DEHP
or
DINP.

These
new
data
have
prompted
CDC
to
conduct
additional
studies
to
explain
these
findings
by
examining
the
pathways
by
which
these
phthalates
get
into
people's
bodies.
The
data
also
indicate
that
health
research
needs
to
focus
on
DEP
and
DBP,
given
that
levels
of
their
metabolites
are
much
higher
in
the
general
population
than
metabolite
levels
of
phthalates
produced
in
the
largest
quantities.
iv
Future
Plans
The
National
Report
on
Human
Exposure
to
Environmental
Chemicals
will
be
updated
each
year
with
new
data
for
the
general
population.
Next
year,
CDC
will
combine
the
1999
and
2000
data
from
NHANES
to
provide
updated
national
estimates.
For
the
general
population,
current
plans
are
for
the
Report
to
continue
to
measure
these
27
chemicals
and
gradually
expand
the
number
until
approximately
100
environmental
chemicals
are
measured
each
year.
Chemicals
under
consideration
for
future
Reports
include
volatile
organic
compounds,
polyaromatic
hydrocarbons,
dioxins,
furans,
polychlorinated
biphenyls,
trihalomethanes,
haloacetic
acids,
carbamate
pesticides,
and
organochlorine
pesticides.

Future
editions
of
the
Report
will
provide
more
detailed
assessments
of
exposure
levels
among
different
population
groups
defined
by
sex,
race
or
ethnicity,
age,
urban
or
rural
residence,
education
levels,
income,
and
other
characteristics.
In
addition,
over
time
CDC
will
be
able
to
track
trends
in
exposure
levels.
Future
reports
will
also
include
exposure
information
for
specialexposure
populations
from
studies
of
people
exposed
from
localized
or
point­
source
exposures
(
e.
g.,
people
who
eat
mercury­
contaminated
fish
from
a
polluted
river)
and
studies
of
adverse
health
effects
resulting
from
exposure
to
varying
levels
of
environmental
chemicals.

Data
provided
in
future
reports
will
help
us
answer
the
following
questions:

#
Are
exposure
levels
increasing
or
decreasing
over
time?
#
Are
public
health
efforts
to
reduce
exposure
working?
#
Do
certain
groups
of
people
have
higher
levels
of
exposure
than
others?
v
Table
1.
Selected
percentiles
and
geometric
means
of
blood
and
urine
levels
of
environmental
chemicals
(
or
metabolites),
National
Health
and
Nutrition
Examination
Survey,
United
States,
1999
Sample
size
Units
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
Metals1
Cadmium
3,189
µ
g/
L
*
<
LOD
<
LOD
0.3
(
0.2­
0.3)
0.5
(
0.4­
0.6)
0.9
(
0.7­
1.1)

Lead
3,189
µ
g/
dL
1.6
(
1.4­
1.8)
0.7
(
0.6­
0.7)
1.0
(
0.9­
1.1)
1.5
(
1.4­
1.7)
2.3
(
2.2­
2.6)
3.7
(
3.2­
4.3)

Mercury
Children
1­
5
years
Females,
16­
49
years
248
679
µ
g/
L
µ
g/
L
0.3
(
0.2­
0.4)

1.2
(
0.9­
1.6)
<
LOD
0.2
(
0.1­
0.3)
<
LOD
0.5
(
0.4­
0.7)
0.2
(
0.2­
0.3)

1.2
(
0.8­
1.6)
0.5
(
0.4­
0.8)

2.7
(
1.8­
4.5)
1.42
(
0.7­
4.8)

6.2
(
4.7­
7.9)

Metals3
Antimony
912
µ
g/
L
0.1
(
0.09­
0.12)
<
LOD
0.05
(
0.03­
0.07)
0.1
(
0.09­
0.12)
0.19
(
0.16­
0.21)
0.29
(
0.27­
0.34)

Barium
779
µ
g/
L
1.6
(
1.5­
1.7)
0.3
(
0.3­
0.4)
0.8
(
0.7­
0.9)
1.7
(
1.5­
1.9)
2.9
(
2.7­
3.3)
5.5
(
4.2­
6.2)

Beryllium
1,007
µ
g/
L
*
<
LOD
<
LOD
<
LOD
<
LOD
<
LOD
Cadmium
1,007
µ
g/
L
0.32
(
0.30­
0.33)
0.10
(
0.08­
0.12)
0.18
(
0.15­
0.19)
0.33
(
0.29­
0.35)
0.57
(
0.52­
0.62)
0.95
(
0.85­
1.04)

Cesium
1,006
µ
g/
L
4.7
(
4.2­
5.2)
1.8
(
1.4­
2.2)
3.3
(
2.9­
3.6)
5.3
(
4.7­
5.8)
7.2
(
6.7­
8.0)
9.6
(
8.5­
11.6)

Cobalt
1,007
µ
g/
L
0.36
(
0.32­
0.40)
0.11
(
0.08­
0.14)
0.23
(
0.19­
0.26)
0.40
(
0.35­
0.41)
0.60
(
0.54­
0.68)
0.89
(
0.79­
1.10)

Lead
1,007
µ
g/
L
0.80
(
0.68­
0.91)
0.21
(
0.15­
0.26)
0.42
(
0.34­
0.51)
0.80
(
0.72­
0.88)
1.36
(
1.17­
1.69)
2.21
(
1.89­
2.72)

Molybdenum
904
µ
g/
L
48.4
(
43.6­
53.2)
13.1
(
10.8­
17.3)
27.6
(
23.4­
32.8)
53.3
(
47.3­
61.5)
86.6
(
78.6­
97.5)
140
(
120­
174)

Platinum
1,007
µ
g/
L
*
<
LOD
<
LOD
<
LOD
<
LOD
<
LOD
Thallium
974
µ
g/
L
0.19
(
0.17­
0.20)
0.07
(
0.06­
0.07)
0.12
(
0.10­
0.13)
0.21
(
0.19­
0.23)
0.30
(
0.28­
0.33)
0.42
(
0.39­
0.45)
Sample
size
Units
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
vi
Tungsten
892
µ
g/
L
0.10
(
0.09­
0.12)
<
LOD
0.05
(
0.03­
0.06)
0.10
(
0.08­
0.11)
0.18
(
0.16­
0.22)
0.32
(
0.27­
0.45)

Uranium
1,006
µ
g/
L
0.008
(
0.006­
0.011)
<
LOD
<
LOD
0.007
(
0.004­
0.010)
0.014
(
0.009­
0.030)
0.034
(
0.022­
0.053)

<
LOD
means
below
the
limit
of
detection
of
the
analytical
method.
*
Not
calculated.
Proportion
of
results
below
the
limit
of
detection
was
too
high
to
provide
a
valid
result.
1
Lead
and
cadmium
are
measured
in
blood
among
people
aged
1
year
and
older;
mercury
is
measured
in
blood
among
age
groups
specified
above.
Blood
levels
by
selected
demographic
groups
are
available
elsewhere
in
this
document
and
at
www.
cdc.
gov/
nceh/
dls/
report
2
Estimate
meets
minimum
standards
of
reliability
but
should
be
interpreted
with
caution.
3
Measured
in
urine
in
a
subset
of
people
aged
6
years
and
older.
vii
Table
2.
Selected
percentiles
and
geometric
means
of
blood
and
urine
levels
of
environmental
chemicals
(
or
metabolites),
National
Health
and
Nutrition
Examination
Survey,
United
States,
1999
Sample
size
Units
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
Organophosphate
Pesticide
Metabolites1
Dimethylphosphate
703
µ
g/
L
1.84
(
1.10­
2.59)
<
LOD
0.80
(
0.36­
1.11)
1.67
(
1.04­
2.86)
3.79
(
2.38­
7.46)
7.43
(
5.43­
17.3)

Diethylphosphate
703
µ
g/
L
2.55
(
1.33­
3.78)
0.78
(
0.70­
0.90)
1.09
(
0.93­
1.31)
1.85
(
1.19­
4.11)
4.87
(
2.58­
14.0)
10.62
(
6.29)

Dimethylthiophosphate
703
µ
g/
L
2.61
(
1.77­
3.45)
<
LOD
0.72
(
0.13­
1.73)
3.80
(
2.93­
4.53)
9.00
(
7.35­
12.3)
22.9
(
18.7­
30.7)

Diethylthiophosphate
703
µ
g/
L
0.81
(
0.69­
0.94)
0.51
(
0.41­
0.53)
0.58
(
0.55­
0.59)
0.70
(
0.64­
0.78)
0.98
(
0.78­
1.45)
1.52
(
1.16­
2.91)

Dimethyldithiophosphate
703
µ
g/
L
0.51
(
0.39­
0.62)
<
LOD
<
LOD
0.60
(
0.39­
0.78)
2.05
(
1.65­
2.42)
5.43
(
3.16­
10.3)

Diethyldithiophosphate
703
µ
g/
L
0.19
(
0.14­
0.23)
0.08
(
0.07­
0.08)
0.09
(
0.09­
0.09)
0.14
(
0.09­
0.26)
0.30
(
0.25­
0.39)
0.54
(
0.44­
0.86)

Phthalate
Metabolites1
Mono­
benzyl
phthalate
1,029
µ
g/
L
17.4
(
14.1­
20.7)
3.5
(
2.2­
4.5)
8.0
(
5.9­
9.8)
18.5
(
15.4­
22.6)
38.6
(
31.5­
48.7)
82.3
(
64.0­
101)

Mono­
butyl
phthalate
1,029
µ
g/
L
26.7
(
23.9­
29.4)
5.9
(
4.6­
7.3)
13.2
(
10.5­
15.4)
27.5
(
24.6­
31.5)
53.8
(
51.2­
59.7)
98.6
(
89.1­
122)

Mono­
cyclohexyl
phthalate
1,029
µ
g/
L
*
<
LOD
<
LOD
<
LOD
<
LOD
<
LOD
Mono­
ethyl
phthalate
1,029
µ
g/
L
176.0
(
132­
220)
27.7
(
17.5­
38.3)
61.5
(
43.1­
80.0)
171
(
121­
226)
424
(
362­
563)
1,160
(
971­
1,350)

Mono­
2­
ethylhexyl
phthalate
1,029
µ
g/
L
3.5
(
3.0­
4.0)
<
LOD
1.5
(
0.8­
1.9)
3.3
(
3.0­
3.8)
7.7
(
6.1­
9.6)
13.6
(
11.2­
17.3)

Mono­
isononyl
phthalate
1,029
µ
g/
L
*
<
LOD
<
LOD
<
LOD
<
LOD
4.3
(
0.6­
22.3)

Mono­
n­
octyl
phthalate
1,029
µ
g/
L
*
<
LOD
<
LOD
<
LOD
<
LOD
1.9
(
1.2­
3.5)
Sample
size
Units
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
viii
Cotinine3
2,263
ng/
mL
*
<
LOD
<
LOD
<
LOD
0.15
(
0.11­
0.23)
0.52
(
0.38­
1.01)

<
LOD
means
below
the
limit
of
detection
of
the
analytical
method.
*
Not
calculated.
Proportion
of
results
below
the
limit
of
detection
was
too
high
to
provide
a
valid
result.
1Organophosphate
pesticide
metabolites
are
measured
in
urine
in
a
subset
of
people
aged
6
to
59
years.
Phthalate
metabolites
are
measured
in
urine
in
a
subset
of
people
aged
6
years
and
older.
2
Upper
end
of
the
95%
confidence
interval
cannot
be
estimated
reliably.
3
Measured
in
serum
among
nonsmokers
aged
3
years
and
older.
Serum
levels
of
cotinine
for
selected
demographic
groups
are
available
elsewhere
in
this
document
and
at
www.
cdc.
gov/
nceh/
dls/
report
1
Introduction
The
National
Report
on
Human
Exposure
to
Environmental
Chemicals
is
a
new
publication
that
provides
an
ongoing
assessment
of
the
U.
S.
population's
exposure
to
environmental
chemicals
using
biomonitoring.
For
this
Report,
an
environmental
chemical
means
a
chemical
compound
or
chemical
element
present
in
air,
water,
soil,
dust,
or
other
environmental
media.
Biomonitoring
is
the
assessment
of
human
exposure
to
chemicals
by
measuring
the
chemicals
or
their
metabolites
in
human
specimens,
such
as
blood
or
urine.
This
report
presents
data
for
the
noninstitutionalized,
civilian
U.
S.
population
for
1999
from
CDC's
National
Health
and
Nutrition
Examination
Survey
(
NHANES).
NHANES
is
a
series
of
surveys
designed
to
collect
data
on
the
health
and
nutritional
status
of
the
U.
S.
population.

Currently,
the
Report
includes
data
for
exposure
of
the
general
population
to
these
27
environmental
chemicals:

#
Metals
°
Lead
°
Mercury
°
Cadmium
°
Cobalt
°
Uranium
°
Antimony
°
Barium
°
Beryllium
°
Cesium
°
Molybdenum
°
Platinum
°
Thallium
°
Tungsten
#
Tobacco
smoke
°
Cotinine
(
a
metabolite
of
nicotine)

#
Organophosphate
pesticides:
urine
metabolites
of
28
pesticides,
including
chlorpyrifos,
diazinon,
fenthion,
malathion,
parathion,
disulfoton,
phosmet,
phorate,
temephos,
and
methyl
parathion:
°
Dimethylphosphate
°
Dimethylthiophosphate
°
Dimethyldithiophosphate
°
Diethylphosphate
°
Diethylthiophosphate
°
Diethyldithiophosphate
#
Phthalates:
urine
metabolites
of
seven
phthalates:
°
Mono­
ethyl
phthalate
°
Mono­
isononyl
phthalate
°
Mono­
butyl
phthalate
°
Mono­
cyclohexyl
phthalate
°
Mono­
2­
ethylhexyl
phthalate
°
Mono­
benzyl
phthalate
°
Mono­
n­
octyl
phthalate
2
Data
Presented
for
Each
Environmental
Chemical
The
Report
presents
descriptive
statistics
on
the
distribution
of
blood
or
urine
levels
for
each
environmental
chemical.
Statistics
include
geometric
means
and
percentiles
with
confidence
intervals.
Geometric
means
are
calculated
by
taking
the
log
of
each
concentration,
then
calculating
the
mean
of
those
log
values,
and
finally
taking
the
antilog
of
that
mean
(
the
calculation
can
be
done
using
log
base
e
or
log
base
10).
A
geometric
mean
provides
a
better
estimate
of
central
tendency
for
data
that
are
distributed
with
a
long
tail
at
the
upper
end
of
the
distribution.
This
type
of
distribution
is
common
when
measuring
environmental
chemicals
in
blood
or
urine.
The
geometric
mean
is
less
influenced
by
high
values
than
is
the
arithmetic
mean.
Percentiles
(
10th,
25th,
50th,
75th,
and
90th
)
are
given
to
provide
additional
information
about
the
shape
of
the
distribution.
For
urine
measurements,
data
are
shown
for
both
the
concentration
in
urine
and
the
concentration
corrected
for
urine­
creatinine
level.

When
sample
sizes
are
adequate,
the
Report
also
presents
data
for
the
population
and
population
subgroups
defined
by
demographic
variables
such
as
age,
sex,
and
race
or
ethnicity.

First­
Time
Information
The
Report
is
a
new
publication
that
provides
information
to
scientists,
public
health
officials,
and
the
public
about
exposure
to
environmental
chemicals
in
the
U.
S.
population.
For
24
of
the
27
environmental
chemicals
listed
in
the
Report,
this
is
the
first
time
this
type
of
exposure
information
has
been
available
for
the
general
U.
S.
population.
CDC
has
previously
assessed
the
population's
exposure
to
three
chemicals
(
lead,
cadmium,
and
cotinine),
1­
5
and
this
Report
provides
new
data
about
these
chemicals
for
the
1999
calendar
year.

Interpreting
Report
Exposure
Data:
Important
Factors
Research
studies,
separate
from
the
Report,
are
required
to
determine
which
blood
or
urine
levels
are
safe
and
which
cause
disease.

The
measurement
of
an
environmental
chemical
in
a
person's
blood
or
urine
does
not
by
itself
mean
that
the
chemical
causes
disease.
Advances
in
analytical
methods
allow
us
to
measure
low
levels
of
environmental
chemicals
in
people,
but
studies
of
varying
exposure
levels
and
health
effects
are
needed
to
determine
which
blood
or
urine
levels
result
in
disease.
These
studies
must
also
consider
other
factors
such
as
duration
of
exposure.
The
Report
does
not
present
new
data
on
health
risks
from
different
exposures.

For
some
environmental
chemicals,
such
as
lead,
research
studies
have
given
us
a
good
understanding
of
the
health
risks
associated
with
different
blood
lead
levels.
However,
for
many
environmental
chemicals,
we
need
more
research
to
assess
health
risks
from
different
blood
or
urine
levels
of
a
chemical.
The
results
shown
in
the
Report
should
help
prioritize
and
foster
research
on
human
health
risks
that
result
from
exposure
to
environmental
chemicals.
See
the
section
titled
"
Toxicology
and
Health­
Risk
Information,"
which
lists
Internet
sites
providing
health
3
information
about
environmental
chemicals.
Each
environmental
chemical
can
be
searched
in
databases
at
these
Web
sites
using
the
chemical
name
or
the
chemical's
Chemical
Abstract
Service
(
CAS)
number,
which
is
provided
in
the
Report.
If
available
for
the
chemical
of
interest,
the
Agency
for
Toxic
Substances
and
Disease
Registry
(
ATSDR)
ToxFAQs
provide
a
good
summary
of
the
chemical's
toxicology,
as
well
as
answers
to
common
questions
about
exposure
and
health
effects.

Blood
and
urine
levels
of
a
chemical
should
not
be
confused
with
levels
of
the
chemical
in
air,
water,
soil,
dust
or
food.

Concentrations
of
environmental
chemicals
in
blood
or
urine
are
not
the
same
as
those
in
air,
water,
soil,
dust,
or
food.
For
example,
a
chemical
concentration
of
10
micrograms
per
liter
(
µ
g/
L)
in
water
does
not
produce
a
level
of
10
µ
g/
L
in
blood
or
urine.
In
fact,
blood
or
urine
levels
may
result
from
exposure
to
chemicals
in
more
than
one
environmental
medium.
Blood
lead
levels
reflect
exposure
from
lead
in
air,
water,
soil,
dust,
and
food.
The
blood
and
urine
levels
shown
in
the
Report
cannot
be
quantitatively
extrapolated
to
specific
air,
water,
soil,
dust,
or
food
levels.

The
1999
Report
results
are
for
the
general
U.
S.
population.
Future
Reports
will
include
data
for
both
the
general
population
and
populations
in
special­
exposure
situations.

The
1999
Report
data
are
for
the
general
U.
S.
population
and
should
not
be
interpreted
as
representing
groups
of
people
in
special­
exposure
situations.
Future
releases
of
the
Report
will
include
data
from
CDC
studies
of
special­
exposure
populations.
The
1999
Report
contains
results
from
a
sample
of
people
representing
the
civilian,
noninstitutionalized
U.
S.
population.
Groups
of
people
in
special­
exposure
situations
(
e.
g.,
pesticide
applicators,
people
living
near
hazardous
waste
sites,
people
working
in
lead
smelters)
are
not
targeted
in
this
set
of
results.
For
example,
people
working
in
lead
smelters
likely
have
a
different
distribution
of
blood
lead
levels
than
people
in
the
general
population.
A
specific
study
of
people
working
in
lead
smelters
would
be
needed
to
describe
the
distribution
of
blood
lead
levels
in
that
group.

The
1999
Report
Results
are
based
on
1
year
of
NHANES
data.

Because
the
sample
size
in
any
one
year
of
NHANES
is
relatively
small
and
for
1999
the
survey
was
conducted
in
only
12
locations
across
the
country,
and
because
most
analyses
were
conducted
in
subsamples
of
the
population,
more
data
will
be
needed
to
confirm
these
findings
and
to
allow
more
detailed
analysis
to
describe
exposure
levels
in
population
subgroups.
Data
from
additional
sites
are
also
needed
to
evaluate
the
potential
influence
of
geographic
clustering
on
blood
and
urine
levels
of
chemicals.

CDC
will
update
the
Report
each
year.
Next
year,
CDC
will
combine
the
1999
and
2000
data
from
NHANES
to
provide
new
national
estimates.
In
the
future,
the
Report
will
also
include
data
from
other
large
exposure
studies
and
studies
of
exposure
of
special­
population
groups
within
the
United
States.
4
Biomonitoring
Exposure
Measurements
The
biomonitoring
exposure
measurements
presented
in
the
Report
were
made
at
CDC's
Environmental
Health
Laboratory
(
Division
of
Laboratory
Sciences,
National
Center
for
Environmental
Health).
The
analytical
methods
used
for
measuring
these
environmental
chemicals
or
their
metabolites
in
blood
and
urine
were
isotope
dilution
mass
spectrometry,
inductively
coupled
plasma
mass
spectrometry,
or
graphite
furnace
atomic
absorption
spectrometry.
Information
about
the
analytical
methods
used
appears
in
the
"
References
for
Analytical
Methods"
section
of
this
document.
5
Data
Sources
The
National
Health
and
Nutrition
Examination
Survey
The
National
Health
and
Nutrition
Examination
Survey
(
NHANES)
is
a
series
of
surveys
conducted
by
CDC's
National
Center
for
Health
Statistics
(
NCHS)
that
is
designed
to
collect
data
on
the
health
and
nutritional
status
of
the
U.
S.
population.
NHANES
is
unique
in
its
ability
to
examine
public
health
issues
that
can
best
be
addressed
through
physical
and
laboratory
examinations
of
the
U.
S.
population.
NHANES
collects
information
about
a
wide
range
of
topics,
from
the
prevalence
of
infectious
diseases
to
risk
factors
for
cardiovascular
disease.
Beginning
in
1999,
NHANES
became
a
continuous
and
annual
survey.
The
sampling
plan
for
each
year
follows
a
complex,
stratified,
multistage,
probability­
cluster
design
to
select
a
representative
sample
of
the
civilian,
noninstitutionalized
population.

The
current
sample
design
includes
oversampling
of
African
Americans,
Mexican
Americans,
adolescents
(
12­
19
years
old),
older
Americans
(
60
years
old
and
older),
and
pregnant
women
to
produce
more
reliable
estimates
for
these
groups.
The
NHANES
protocol
includes
a
home
interview
followed
by
a
standardized
physical
examination
in
a
mobile
examination
center.
As
part
of
the
examination
protocol,
blood
is
obtained
by
venipuncture
for
participants
aged
1
year
and
older,
and
urine
specimens
are
collected
for
people
aged
6
years
and
older.
The
1999
NHANES
was
conducted
in
12
counties
across
the
United
States.
From
these
locations,
5,325
people
were
selected
to
participate
in
the
survey.
Of
these,
3,812
(
71%)
participated
in
the
examination
component.

Environmental
chemicals
were
measured
either
in
blood
or
urine
specimens
collected
as
part
of
the
examination
component.
The
age
range
for
which
a
chemical
was
measured
varied.
Because
of
the
availability
of
samples
and
the
speed
of
analytical
measurements,
some
environmental
chemicals
(
metals,
phthalate
metabolites,
and
organophosphate
metabolites)
were
measured
only
in
randomly
selected
subsamples
within
specific
age
groups.

Blood
lead
and
cadmium
levels
were
measured
in
all
people
aged
1
year
and
older.
Serum
cotinine
was
measured
in
all
people
aged
3
years
and
older.
Blood
mercury
was
measured
in
children
aged
1­
5
years
and
in
women
16­
49
years
of
age.
Urine
measurements
for
metals
and
phthalates
were
conducted
for
random
one­
third
samples
of
people
aged
6
years
and
older.
Urine
organophosphate
pesticide
metabolites
were
measured
in
a
random
one­
half
sample
of
children
aged
6
through
11
years
and
in
a
random
one­
quarter
sample
of
people
aged
12­
59
years.
Age
groups
and
sample
sizes
for
each
exposure
measurement
are
shown
in
the
tables.

NHANES
Data
Analysis
Because
the
NHANES
sample
design
is
complex,
sample
weights
must
be
used
to
account
for
the
unequal
probability
of
selection
into
the
survey.
Sample
weights
are
also
used
to
adjust
for
possible
bias
resulting
from
nonresponse
and
are
post­
stratified
to
U.
S.
Census
Bureau
estimates
of
the
6
U.
S.
population.
All
data
analyses
were
conducted
at
NCHS
using
the
statistical
software
package,
WESVAR,
which
uses
sample
weights
and
calculates
variance
estimates
that
account
for
the
complex
survey
design.
Selected
percentiles
and
geometric
means
of
analyte
concentrations
are
presented.
For
each
estimate,
95%
confidence
intervals
are
shown.
Results
are
shown
for
the
total
population.
For
analytes
that
were
measured
in
the
full
sample
of
people,
results
are
also
shown
by
age,
sex,
and
race
or
ethnicity.

For
these
analyses,
race
or
ethnicity
is
categorized
as
non­
Hispanic
black,
Mexican
American,
and
all
others
(
most
are
non­
Hispanic
white).
Analyte­
concentration
levels
less
than
the
limit
of
detection
were
assigned
a
value
equal
to
the
detection
limit
divided
by
the
square
root
of
2
for
calculation
of
geometric
means.
If
the
proportion
of
results
below
the
limit
of
detection
was
greater
than
40%,
geometric
means
were
not
calculated.
For
urine
measures,
the
Report
shows
data
for
both
the
concentration
in
urine
and
the
concentration
corrected
for
urine­
creatinine
level.
Creatinine­
corrected
values
for
results
below
the
limit
of
detection
were
calculated
only
if
the
proportion
of
results
below
the
limit
of
detection
was
less
than
10%.
In
those
cases,
the
fill
value
used
to
calculate
geometric
means
was
used
in
the
calculation.

Limitations
On
Estimates
of
Chemical
Exposures
From
One
Year
of
Data
Although
the
current
NHANES
is
conducted
using
annual
samples
that
are
nationally
representative,
the
sample
size
in
any
one
year
is
relatively
small,
resulting
in
large
variability
for
estimates,
especially
those
for
detailed
demographic
groups
or
other
detailed
analyses.
NHANES
is
designed
to
increase
precision
by
combining
data
across
calendar
years.
Because
of
the
small
sample
size
in
1999,
a
number
of
survey
participants
have
large
sample
weights,
and
the
potential
exists
that
these
sample
weights
may
strongly
influence
estimates.
This
factor
is
particularly
important
for
chemical
results
that
were
only
measured
in
subsamples
of
the
population.

Another
analytic
limitation
of
the
NHANES
sample
is
that
it
is
selected
from
a
relatively
small
number
of
sampling
units
(
PSUs)
or
counties;
the
1999
sample
was
planned
for
only
12
PSUs.
With
a
small
number
of
PSUs,
variance
estimates
that
account
for
the
complex
design
will
be
relatively
unstable,
a
factor
which
introduces
a
higher
level
of
uncertainty
in
the
annual
estimates.
Although
the
annual
NHANES
is
nationally
representative,
it
is
not
possible
to
produce
environmental
exposure
estimates
by
geographic
region.
Because
the
number
of
geographic
sites
sampled
each
year
is
small
and
because
environmental
exposure
measures
may
vary
geographically,
national
estimates
based
on
one
year
of
data
may
be
highly
variable.

These
limitations
related
to
measuring
environmental
exposures
from
a
single
year
of
NHANES
will
be
addressed
as
more
data
become
available
from
the
ongoing
survey.
More
detailed
analyses
by
demographic
groups
and
other
variables
will
be
possible
with
increased
sample
size
and
with
a
larger
number
of
geographic
locations.
7
Major
Findings
First­
Time
Information
About
Exposure
Levels
in
the
U.
S.
Population
The
Report
provides
information
to
scientists,
public
health
officials,
and
the
public
about
exposure
to
environmental
chemicals
in
the
U.
S.
population.
It
provides
measures
of
exposure
for
27
chemicals
in
the
U.
S.
population
based
on
blood
and
urine
samples
from
people
participating
in
the
1999
NHANES.
CDC
has
previously
assessed
the
exposure
of
the
population
through
NHANES
for
three
chemicals:
lead,
cadmium,
and
cotinine.
The
Report
provides
new
data
on
these
chemicals
for
the
1999
calendar
year
as
well
as
data
on
24
additional
environmental
chemicals
(
metals,
organophosphate
pesticides,
and
phthalates).
Because
the
sample
size
in
any
one
year
of
NHANES
is
relatively
small
and
because
the
1999
survey
was
only
conducted
in
12
locations
across
the
country,
data
from
additional
years
of
the
survey
will
be
needed
to
confirm
these
findings.

Information
About
U.
S.
Population­
Based
Reference
Ranges
for
Physicians
and
Health
Researchers
The
1999
Report
provides
unique
reference
range
values
that
are
based
on
a
sampling
of
the
U.
S.
population.
CDC
had
previously
determined
U.
S.
population­
based
reference
ranges
for
lead,
cadmium,
and
cotinine
using
NHANES
data;
the
1999
Report
provides
U.
S.
population­
based
reference­
range
results
for
24
additional
environmental
chemicals.

Physicians
use
"
normal"
ranges
for
laboratory
results
to
determine
whether
their
patients
have
high
or
low
values
that
would
indicate
that
a
health
problem
exists.
These
normal
ranges
are
obtained
from
people
who
are
generally
healthy.
In
the
1999
Report,
CDC
determined
reference
ranges
for
24
environmental
chemicals
from
a
group
of
people
in
the
general
population
who
were
selected
without
regard
to
known
exposure
to
these
chemicals.
Sometimes
these
reference
ranges
are
referred
to
as
"
background
exposure
levels."

Reference
ranges
are
extremely
helpful
to
physicians
and
health
researchers
because
levels
above
the
reference
range
usually
indicate
exposure
to
a
particular
source.
For
example,
if
a
physician
was
concerned
about
a
patient's
potential
exposure
to
cadmium
and
measured
a
cadmium
level
in
the
patient's
urine,
the
results
could
be
compared
with
the
population
reference
range
shown
in
the
1999
Report.
A
cadmium
level
similar
to
those
found
in
the
Report
would
indicate
exposure
no
different
from
those
found
in
the
general
population,
and
a
level
much
higher
than
those
in
the
Report
would
indicate
that
there
may
have
been
an
unusual
exposure
to
cadmium
worthy
of
further
investigation.

Decline
in
Blood
Lead
Levels
Among
Children
Since
1991­
1994
Since
1976,
CDC
has
measured
levels
of
lead
in
blood
as
part
of
NHANES.
Results
presented
in
the
1999
Report
show
that
the
geometric
mean
blood
lead
level
for
children
aged
1­
5
years
has
8
decreased
to
2.0
micrograms
per
deciliter
(
µ
g/
dL)
from
2.7
µ
g/
dL,
the
geometric
mean
for
the
period
1991­
1994.
This
decrease
documents
that
blood
lead
levels
continue
to
decline
among
U.
S.
children
when
considered
as
a
group
and
highlights
the
success
of
public
health
efforts
to
decrease
the
exposure
of
children
to
lead.
Nevertheless,
special
populations
of
children
at
high
risk
for
lead
exposure
(
e.
g.,
those
living
in
homes
containing
lead­
based
paint
or
lead­
contaminated
dust)
remain
a
major
public
health
concern.

Better
Assessment
of
Children's
and
Women's
Exposure
to
Mercury
The
1999
Report
provides
important
new
data
on
levels
of
mercury
in
blood
among
children
1
to
5
years
old
and
among
women
of
childbearing
age
(
16­
49
years
old).
The
geometric
mean
of
blood
mercury
levels
among
children
(
0.3
µ
g/
L)
was
about
25%
of
the
geometric
mean
of
blood
mercury
levels
among
women
of
childbearing
age
(
1.2
µ
g/
L).
Compared
with
an
adult,
the
fetus
or
child
is
usually
more
vulnerable
to
the
effects
of
metals.
Consequently,
when
addressing
mercury
exposures,
health
officials
are
particularly
careful
to
protect
the
fetus
and
child.
The
Report
provides
data
for
children
and
levels
for
women
of
childbearing
age
that
reflect
levels
of
mercury
to
which
the
fetus
is
exposed.
Scientists
will
use
these
new
data
to
better
estimate
health
risks
for
the
fetus,
children,
and
women
of
childbearing
age
from
potential
sources
of
mercury
exposure.

Setting
Priorities
for
Research
on
Phthalates
Phthalates
are
compounds
commonly
used
in
such
consumer
products
as
soap,
shampoo,
hair
spray,
and
many
types
of
nail
polish.
Some
phthalates
are
used
in
flexible
plastics
such
as
blood
bags
and
tubing.
Animal
research
has
focused
on
the
reproductive
effects
of
phthalates.
For
the
1999
Report,
CDC
scientists
measured
metabolites
of
seven
major
phthalates.
Di­
2­
ethylhexyl
phthalate
(
DEHP)
and
di­
isononyl
phthalate
(
DINP)
are
the
two
phthalates
produced
in
greatest
quantity,
with
diethyl
phthalate
(
DEP)
and
dibutyl
phthalate
(
DBP)
produced
in
much
lower
quantities.
However,
data
from
the
1999
Report
showed
that
levels
of
metabolites
of
DEP
and
DBP
were
much
higher
in
the
population
than
metabolites
of
either
DEHP
or
DINP.

These
new
data
have
prompted
CDC
to
conduct
additional
studies
to
explain
these
findings
by
examining
the
pathways
by
which
these
phthalates
get
into
people's
bodies.
The
data
also
indicate
that
health
research
needs
to
focus
on
DEP
and
DBP,
given
that
the
levels
of
their
metabolites
are
much
higher
in
the
U.
S.
population.

Reduced
Exposure
of
the
U.
S.
Population
to
Environmental
Tobacco
Smoke
Cotinine
is
a
metabolite
of
nicotine
that
tracks
exposure
to
environmental
tobacco
smoke
(
ETS)
among
nonsmokers;
higher
cotinine
levels
reflect
more
exposure
to
ETS,
which
has
been
identified
as
a
known
human
carcinogen.
From
1988
through
1991,
as
part
of
NHANES
III,
CDC
determined
that
the
median
level
(
50th
percentile)
of
cotinine
among
nonsmokers
in
the
United
States
was
0.2
nanograms
per
milliliter
(
ng/
mL).
Results
from
the
1999
Report
showed
that
the
9
median
cotinine
level
among
people
aged
3
years
and
older
has
decreased
to
less
than
0.050
ng/
mL
 
more
than
a
75%
decrease.
This
reduction
in
cotinine
levels
objectively
documents
a
dramatic
reduction
in
exposure
of
the
general
U.
S.
population
to
ETS
since
the
period
1988­
1991.
However,
since
more
than
half
of
American
youth
are
still
exposed,
ETS
remains
a
major
public
health
concern.
11
Toxicology
and
Health­
Risk
Information
The
Report
presents
new
data
on
the
exposure
of
the
U.
S.
population
to
environmental
chemicals.
This
new
information
can
be
used
to
promote
and
prioritize
research
to
determine
health
risks
from
different
exposure
levels
of
these
chemicals
when
the
risks
are
not
known.
One
important
factor
to
include
in
such
research
is
duration
of
exposure.
The
measurement
of
an
environmental
chemical
in
a
person's
blood
or
urine
does
not
by
itself
mean
that
the
chemical
causes
disease.
Advances
in
analytical
methods
allow
us
to
measure
lower
and
lower
levels
of
environmental
chemicals
in
people,
but
studies
of
varying
exposure
levels
and
health
effects
are
required
to
determine
which
blood
and
urine
levels
are
safe
and
which
result
in
disease.

Information
Available
on
the
Internet
Links
to
non­
federal
organizations
are
provided
solely
as
a
service
to
our
readers.
These
links
do
not
constitute
an
endorsement
of
these
organizations
or
their
programs
by
CDC
or
the
federal
government,
and
none
should
be
inferred.
CDC
is
not
responsible
for
the
content
of
the
individual
organization's
Web
pages
found
at
these
links.
For
information
about
toxicology
and
health
risks,
see
the
following
sites:

Federal
and
Non­
Federal
Internet
Links
#
ATSDR
ToxFAQs:
www.
atsdr.
cdc.
gov/
toxfaq.
html
or
www.
atsdr.
cdc.
gov/
toxprofiles
#
National
Institute
for
Occupational
Safety
and
Health
(
NIOSH),
Occupational
Health
and
Safety
Guidelines
for
Chemical
Hazards:
www.
cdc.
gov/
niosh/
81­
123.
html
#
National
Toxicology
Program
Report
on
Carcinogens:
http://
ehis.
niehs.
nih.
gov/
roc/
#
EPA
Integrated
Risk­
Information
System
(
IRIS):
www.
epa.
gov/
iris/
#
International
Programme
on
Chemical
Safety
(
IPCS):
www.
who.
int/
pcs
#
Chemfinder:
www.
chemfinder.
com
#
Material
Safety
Data
Sheets:
www.
hazard.
com/
msds/
index.
html
U.
S.
Government­
Related
Internet
Links
Centers
for
Disease
Control
and
Prevention
(
CDC)
#
NIOSH
Pocket
Guide
to
Chemical
Hazards:
www.
cdc.
gov/
niosh/
npg/
npgd0000.
html
#
Registry
of
Toxic
Effects
of
Chemical
Substances
(
RTECS):
www.
cdc.
gov/
niosh/
rtecs.
html
#
CDC's
Tobacco
Information
and
Prevention
Source:
www.
cdc.
gov/
tobacco/
#
CDC's
National
Center
for
Health
Statistics:
www.
cdc.
gov/
nchs
#
National
Health
and
Nutrition
Examination
Survey:
www.
cdc.
gov/
nchs/
nhanes.
htm
#
CDC's
Childhood
Lead
Poisoning
Prevention
Program:
www.
cdc.
gov/
nceh/
lead/
lead.
htm
#
Pesticides
and
Public
Health:
Integrated
Methods
of
Mosquito
Management:
www.
cdc.
gov/
ncidod/
eid/
vol7no1/
rose.
htm
U.
S.
Department
of
Health
and
Human
Services
(
HHS)
#
Environmental
Health
Policy
Committee:
http://
web.
health.
gov/
environment
12
U.
S.
Food
and
Drug
Administration
(
FDA)
#
Center
for
Devices
and
Radiological
Health:
www.
fda.
gov/
cdrh
#
Center
for
Food
Safety
and
Applied
Nutrition:
www.
cfsan.
fda.
gov/
#
Center
for
Toxicological
Research:
www.
fda.
gov/
nctr/

National
Institutes
of
Health
(
NIH)
#
National
Cancer
Institute:
www.
nci.
nih.
gov
#
National
Institute
of
Child
Health
and
Human
Development:
www.
nichd.
nih.
gov
#
National
Institute
for
Environmental
Health
Sciences:
www.
niehs.
nih.
gov
#
National
Toxicology
Program
(
NTP)
Chemical
Health
and
Safety
Data:
http://
ntpserver
niehs.
nih.
gov/
Main_
Pages/
Chem­
HS.
html
#
National
Toxicology
Program
Report
on
Carcinogens:
http://
eihs.
niehs.
nih.
gov/
roc/
toc9.
html
#
Chemical
Carcinogenesis
Research
Information
System:
http://
toxnet.
nlm.
nih.
gov/
cgibin
sis/
htmlgen?
CCRIS
#
Hazardous
Susbstances
Data
Bank
(
HSDB
®
)
:
http://
toxnet.
nlm.
nih.
gov/
cgibin
sis/
htmlgen?
HSDB
U.
S.
Environmental
Protection
Agency
(
EPA)
#
Office
of
Air
and
Radiation
Organizational
Chart:
www.
epa.
gov/
oar/
#
Office
of
Environmental
Information
(
OEI):
www.
epa.
gov/
oei/
#
Office
of
Prevention,
Pesticides,
and
Toxic
Substances
(
OPPTS):
www.
epa.
gov/
opptsfrs/
home/
opptsim.
htm
#
Office
of
Research
and
Development
(
ORD):
www.
epa.
gov/
ORD
#
Office
of
Water
(
OW):
www.
epa.
gov/
OW/
#
Office
of
Pesticide
Programs:
www.
epa.
gov/
pesticides
#
EPA
Integrated
Risk­
Information
System
(
IRIS):
www.
epa.
gov/
iris
#
EPA
Envirofacts:
www.
epa.
gov/
enviro/
index_
java.
html
#
Organophosphate
pesticide
common
and
trade
names:
www.
epa.
gov/
oppbead1/
matrices/
oplist.
htm
#
Lead:
www.
epa.
gov/
OGWDW/
dwh/
c­
ioc/
lead.
html
U.
S.
Department
of
Agriculture
(
USDA)
#
Food
Safety
and
Inspection
Service:
http://
www.
fsis.
usda.
gov
#
USDA,
Forest
Service
Pesticide
Fact
Sheets:
http://
svinet2.
fs.
fed.
us/
foresthealth/
pesticide
U.
S.
Department
of
Energy
#
Office
of
Environment,
Safety
and
Health:
http://
tis.
eh.
doe.
gov/
portal/
home.
htm
U.
S.
Department
of
Housing
and
Urban
Development
(
HUD)
#
Office
of
Healthy
Homes
and
Lead­
Hazard
Control:
www.
hud.
gov/
offices/
lead/

U.
S.
Consumer
Product
Safety
Commission
(
CPSC)
#
www.
cpsc.
gov/
13
U.
S.
Department
of
Transportation
(
DOT)
#
Hazardous
Materials
Emergency­
Response
Guidebook:
http://
hazmat.
dot.
gov/
erg2000/
psnsort.
htm
U.
S.
Department
of
Labor,
Occupational
Safety
and
Health
Administration
(
OSHA):
#
http://
www.
osha.
gov/
index.
html
Other
Related
Internet
Sites
#
American
College
of
Occupational
and
Environmental
Medicine:
http://
www.
acoem.
org/
#
Association
of
Occupational
and
Environmental
Clinics:
http://
www.
aoec.
org/
#
Association
of
Public
Health
Laboratories:
http://
www.
aphl.
org
#
International
Chemical
Safety
Cards:
http://
www.
ilo.
org/
public/
english/
protection/
safework/
cis/
products/
icsc/
dtasht/
index.
htm
#
NRC
Mercury
Report:
http://
books.
nap.
edu/
books/
0309071402/
html/
index.
html
15
Results
By
Chemical
Group
Metals
Lead
(
CAS
No.
7439­
92­
1)
General
Information
Elemental
lead
is
a
naturally
occurring,
blue­
gray
metal
found
in
small
amounts
in
rock
and
soil.
Lead
has
no
distinctive
taste
or
smell.
Lead
and
lead
compounds
are
used
in
storage
batteries,
ammunition,
metal
products
(
solder
and
pipes),
roofing,
gasoline,
and
devices
to
shield
people
from
X­
rays.
Because
of
health
concerns,
lead
had
been
banned
from
gasoline,
ceramic
products,
paints
for
residential
use,
and
solder
used
on
food
cans.

Industrially,
lead
and
lead­
contaminated
dusts
are
released
into
the
environment
from
the
burning
of
fossil
fuels
or
waste.
Workplace
exposures
come
mostly
from
dusty
environments.
Lead­
based
paint
and
lead­
contaminated
dust
from
this
type
of
paint
are
the
primary
sources
of
lead
exposure
in
the
home.
Preventing
adverse
health
effects
to
children
resulting
from
lead
exposure
remains
a
major
public
health
effort.

Interpreting
Lead
Levels
Reported
in
Tables
Table
1
presents
blood
lead
results,
and
Table
2
shows
urine
lead
results.
Because
of
lead's
adverse
effects
on
cognitive
development,
CDC
has
defined
an
elevated
blood
lead
level
as
equal
to
or
greater
than
(>)
10
µ
g/
dL
for
children
younger
than
6
years
of
age.
Data
from
NHANES
III,
Phase
2
(
1991­
1994)
6
showed
that
the
geometric
mean
blood
lead
level
for
children
1­
5
years
old
was
2.7
µ
g/
dL
(
95%
confidence
interval:
2.5
µ
g/
dL
 
3.0
µ
g/
dL).
Results
in
this
1999
Report
for
the
same
age
group
show
that
the
geometric
mean
blood
lead
level
has
decreased
to
2.0
µ
g/
dL
(
95%
confidence
interval
1.7
µ
g/
dL
 
2.3
µ
g/
dL).
The
sample
size
in
the
Report
for
1999
is
too
small
to
provide
reliable
estimates
of
the
percentage
of
children
with
blood
lead
levels
>
10
µ
g/
dL.
In
future
Reports,
more
data
about
blood
lead
levels
will
be
available
for
this
group,
thus
permitting
reliable
estimates
of
the
percentage
of
children
with
elevated
blood
lead
levels.

For
other
age
and
population
groups
defined
by
sex
and
race
or
ethnicity,
the
1999
Report
data
show
consistently
lower
levels
than
those
measured
in
the
1991­
1994
period,
3
and
the
relation
of
blood
lead
levels
to
age
is
consistent
with
that
seen
previously
as
well.
3
A
recent
CDC
publication6
included
data
from
the
1999
Report
for
children
1­
5
years
old
and
additional
state
and
local
surveillance
data
for
elevated
blood
lead
levels
among
children.
The
article
notes
that
although
blood
lead
levels
are
dropping
in
these
children
when
considered
as
a
group,
elevated
blood
lead
levels
among
children
continue
to
be
a
major
public
health
concern.

Table
2
presents
urine
lead
levels.
Measuring
lead
in
urine
is
used
less
often
to
gauge
lead
exposure.
Percentiles
shown
in
Table
2
will
serve
as
reference
levels
so
that
urine
results
for
individual
patients
can
be
compared
with
background
levels
found
in
the
U.
S.
population
in
1999.
16
Table
1.
Geometric
mean
and
selected
percentiles
of
blood
lead
concentrations
(
in
µ
g/
dL)
for
the
U.
S.
population,
aged
1
year
and
older,
by
selected
demographic
groups,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
Total,
age
1
and
older
3,189
1.6
(
1.4­
1.8)
0.7
(
0.6­
0.7)
1.0
(
0.9­
1.1)
1.5
(
1.4­
1.7)
2.3
(
2.2­
2.6)
3.7
(
3.2­
4.3)

Gender
Male
1,594
1.9
(
1.7­
2.1)
0.8
(
0.7­
0.9)
1.2
(
1.1­
1.4)
1.8
(
1.7­
2.0)
2.7
(
2.5­
3.1)
4.3
(
3.7­
5.3)

Females
1,595
1.3
(
1.2­
1.5)
0.6
(
0.4­
0.7)
0.8
(
0.7­
0.9)
1.2
(
1.1­
1.4)
1.9
(
1.7­
2.1)
3.0
(
2.6­
3.5)

Race/
Ethnicity
Black,
non­
Hispanic
693
1.7
(
1.5­
2.0)
0.8
(
0.6­
0.8)
1.1
(
0.9­
1.3)
1.6
(
1.4­
1.8)
2.5
(
2.2­
3.0)
4.2
(
3.3­
5.2)

Mexican
American
1,289
1.8
(
1.6­
2.0)
0.7
(
0.6­
0.8)
1.1
(
0.9­
1.2)
1.6
(
1.4­
1.9)
2.8
(
2.3­
3.3)
4.1
(
3.8­
5.2)

White,
non­
Hispanic*
1,207
1.5
(
1.4­
1.7)
0.6
(
0.5­
0.7)
1.0
(
0.8­
1.1)
1.5
(
1.3­
1.6)
2.3
(
2.1­
2.5)
3.5
(
3.1­
4.1)

Age
Group
1­
5
years
254
2.0
(
1.7­
2.3)
0.9**
(
0.5­
1.1)
1.3
(
1.1­
1.5)
1.9
(
1.6­
2.1)
2.7
(
2.2­
4.4)
4.7**
(
3.5­
9.8)

6­
11
years
419
1.3
(
1.0­
1.6)
0.6
(
0.5­
0.7)
0.8
(
0.7­
1.0)
1.2
(
1.0­
1.5)
1.7
(
1.4­
2.2)
2.7
(
1.9­
4.7)

12­
19
years
868
1.0
(
0.8­
1.2)
0.4
(
0.2­
0.5)
0.6
(
0.5­
0.8)
0.9
(
0.8­
1.1)
1.4
(
1.2­
1.6)
2.1
(
1.9­
2.4)

20­
39
years
595
1.4
(
1.2­
1.5)
0.6
(
0.5­
0.7)
0.8
(
0.8­
1.0)
1.3
(
1.1­
1.5)
2.0
(
1.7­
2.2)
2.8
(
2.5­
3.2)

40­
59
years
471
1.9
(
1.7­
2.0)
0.9
(
0.7­
1.0)
1.2
(
1.1­
1.3)
1.8
(
1.6­
1.9)
2.7
(
2.4­
3.2)
3.8
(
3.6­
4.4)

60+
years
582
2.5
(
2.2­
2.8)
1.2
(
1.1­
1.3)
1.6
(
1.5­
1.9)
2.3
(
2.1­
2.7)
3.5
(
3.0­
4.3)
5.0
(
4.5­
6.4)

Numbers
in
parentheses
are
95%
confidence
intervals.
*
Includes
other
racial/
ethnic
groups.
**
Estimate
meets
minimum
standards
of
reliability
but
should
be
interpreted
with
caution.
17
Table
2.
Geometric
mean
and
selected
percentiles
of
urine
lead
concentrations
and
creatinine­
adjusted
levels
for
the
U.
S.
population
aged
6
years
and
older,
National
Health
and
Nutrition
Examination
Survey,
1999
Sample
size
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
µ
g/
L
of
urine
1,007
0.80
(
0.68­
0.91)
0.21
(
0.15­
0.26)
0.42
(
0.34­
0.51)
0.80
(
0.72­
0.88)
1.36
(
1.17­
1.69)
2.21
(
1.98­
2.72)

µ
g/
L
of
creatinine*
1,007
0.72
(
0.62­
0.83)
0.31
(
0.23­
0.36)
0.45
(
0.39­
0.50)
0.69
(
0.61­
0.79)
1.11
(
0.96­
1.35)
1.67
(
1.47­
2.31)

Numbers
in
parentheses
are
95%
confidence
intervals.
*
µ
g
per
gram
of
creatinine
in
urine.

Mercury
(
CAS
No.
7439­
97­
6)
General
Information
Mercury
is
a
naturally
occurring
metal
that
has
several
forms.
Metallic
mercury
is
a
shiny,
silverwhite
odorless
liquid.
If
heated,
it
forms
a
colorless,
odorless
gas.
Mercury
combines
with
other
elements,
such
as
chlorine,
sulfur,
or
oxygen
to
form
inorganic
mercury
compounds
or
salts
that
are
usually
white
powders
or
crystals.
Mercury
also
combines
with
carbon
to
make
organic
mercury
compounds.
The
most
common
of
these,
methylmercury,
is
produced
mainly
by
small
organisms
in
water
and
soil.
Increased
levels
of
mercury
in
the
environment
can
increase
the
amount
of
methylmercury
that
these
small
organisms
produce.
Metallic
mercury
is
used
to
produce
chlorine
gas
and
caustic
soda.
It
is
also
used
in
thermometers,
dental
fillings,
and
batteries.

Inorganic
mercury
(
metallic
mercury
and
mercury
compounds)
enters
the
air
from
the
mining
of
ore
deposits,
the
burning
of
coal,
and
the
incineration
of
waste.
It
also
enters
the
water
or
soil
from
natural
deposits,
disposal
of
wastes,
and
volcanic
activity.
Methylmercury
concentrates
in
the
food
chain.
Fish
contaminated
with
mercury
are
a
major
source
of
methylmercury.
Organic
mercury
is
more
toxic
than
inorganic
mercury.
The
blood
mercury
level
in
the
Report
is
total
blood
mercury
and
thus
includes
both
organic
and
inorganic
mercury.
Most
measures
of
inorganic
mercury
were
below
the
limit
of
detection;
therefore,
these
measurements
are
a
good
indication
of
methylmercury
exposure.

Interpreting
Mercury
Levels
Reported
in
the
Table
Total
blood
mercury
levels
shown
in
Table
3
are
for
children
selected
to
represent
the
general
U.
S.
population
aged
1­
5
years
and
women
aged
16­
49
years.
Extremely
limited
information
has
been
available
about
children's
exposure
to
mercury
and
how
it
relates
to
levels
in
adults.
The
geometric
mean
of
blood
mercury
levels
among
children
(
0.3
µ
g/
L)
was
about
25%
of
the
geometric
mean
of
18
blood
mercury
levels
among
women
of
childbearing
age
(
1.2
µ
g/
L).
Levels
among
women
of
childbearing
age
are
particularly
important
because
they
reflect
levels
of
mercury
to
which
the
fetus
is
exposed.
7
The
National
Research
Council
(
NRC)
recently
completed
a
toxicologic
review
of
mercury
levels.
7
The
NRC
calculated
a
benchmark
dose
(
BMD),
which
was
an
estimate
of
a
methylmercury
exposure
to
the
fetus
associated
with
an
increase
in
abnormal
scores
on
cognitive
function
tests
among
children.
7
The
lower
95%
confidence
bound
of
the
BMD
was
59
µ
g/
L.
The
90th
percentiles
of
mercury
levels
among
children
1­
5
years
old
and
women
of
childbearing
age
are
below
this
level.
Approximately
10%
of
women
have
mercury
levels
within
one­
tenth
of
this
level.

Table
3.
Geometric
mean
and
selected
percentiles
of
total
blood
mercury
concentrations
(
in
µ
g/
L)
for
U.
S.
children
aged
1­
5
years
and
women
aged
16­
49
years,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
Children,
aged
1­
5
years,
males
and
females
248
0.3
(
0.2­
0.4)
<
LOD*
<
LOD
0.2
(
0.2­
0.3)
0.5
(
0.4­
0.8)
1.4**
(
0.7­
4.8)

Females,
16­
49
years
679
1.2
(
0.9­
1.6)
0.2
(
0.1­
0.3)
0.5
(
0.4­
0.7)
1.2
(
0.8­
1.6)
2.7
(
1.8­
4.5)
6.2
(
4.7­
7.9)

Numbers
in
parentheses
are
95%
confidence
intervals.
<
LOD
means
below
the
limit
of
detection
of
the
analytical
method.
*
Less
than
the
limit
of
detection
of
0.1
µ
g/
L
blood.
**
Estimate
meets
minimum
standards
of
reliability
but
should
be
interpreted
with
caution.
19
Cadmium
(
CAS
No.
7440­
43­
9)
General
Information
Elemental
cadmium
is
a
silver­
white
metal.
In
nature,
it
is
usually
found
combined
with
other
elements
such
as
oxygen
(
cadmium
oxide),
chlorine
(
cadmium
chloride),
or
sulfur
(
cadmium
sulfate,
cadmium
sulfide).
Cadmium
does
not
corrode
easily
and
has
many
uses.
In
industry
and
consumer
products,
it
is
used
for
batteries,
pigments,
metal
coatings,
and
plastics.
Cadmium
or
its
compounds
have
no
definite
taste
or
odor.

Cadmium
gets
into
the
environment
from
the
weathering
of
rocks
and
minerals
that
contain
cadmium.
Exposure
to
cadmium
can
occur
in
industries,
such
as
mining
or
electroplating,
that
commonly
use
or
produce
the
chemical.
Cadmium
exposure
can
also
occur
from
exposure
to
cigarette
smoke.

Interpreting
Blood
and
Urine
Cadmium
Levels
Reported
in
the
Tables
In
the
1999
Report,
blood
cadmium
levels
were
measured
in
people
1
year
old
and
older,
and
urine
cadmium
levels
were
measured
in
a
sample
of
people
6
years
old
and
older.
Blood
cadmium
results
are
shown
in
Table
4
and
urine
cadmium
results
in
Table
5,
expressed
as
urine
concentration
and
urine
concentration
adjusted
for
creatinine.
Blood
and
urine
cadmium
levels
in
these
tables
are
for
people
selected
to
represent
the
general
U.
S.
population.
Measuring
cadmium
at
these
levels
in
blood
and
urine
is
possible
because
of
advances
in
analytical
chemistry.
Finding
a
measurable
amount
of
cadmium
in
the
blood
or
urine
does
not
mean
that
the
level
of
cadmium
causes
an
adverse
health
effect.

The
Occupational
Safety
and
Health
Administration
(
OSHA)
has
developed
criteria
for
evaluating
occupational
exposures.
For
blood
cadmium,
the
criterion
is
5
micrograms
per
liter
(
µ
g/
L)
of
blood;
for
urine
cadmium,
the
criterion
is
3
µ
g/
gram.
8
Occupational
criteria
are
provided
here
for
comparison
only,
not
to
imply
a
safety
level
for
general
population
exposure.
The
90th
percentile
for
blood
cadmium
reported
in
Table
4
is
less
than
the
OSHA
blood
cadmium
level,
and
the
90th
percentile
for
urine
cadmium
shown
in
Table
5
is
less
that
the
OSHA
urine
cadmium
level.
Whether
cadmium
at
the
levels
reported
here
is
a
cause
for
health
concern
is
not
yet
known;
more
research
is
needed.

The
blood
cadmium
data
indicate
that
exposure
is
similar
among
males
and
females
as
well
as
among
the
racial
or
ethnic
groups
sampled.
Levels
were
higher
among
people
20
years
old
and
older
than
among
people
aged
1
through
19
years.

These
data
provide
physicians
with
a
reference
range
so
that
they
can
determine
whether
people
have
been
exposed
to
higher
levels
of
cadmium
than
those
found
in
the
general
population.
These
data
will
also
help
scientists
plan
and
conduct
research
about
cadmium
exposure
and
health
effects.
20
Table
4.
Geometric
mean
and
selected
percentiles
of
blood
cadmium
concentrations
(
in
µ
g/
L)
for
the
U.
S.
population,
aged
1
year
and
older,
by
selected
demographic
groups,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
Total,
age
1
year
and
older
3,189
<
LOD**
<
LOD
0.3
(
0.2­
0.3)
0.5
(
0.4­
0.6)
0.9
(
0.7­
1.1)

Gender
Males
Females
1,594
1,595
<
LOD
<
LOD
<
LOD
<
LOD
<
LOD
0.3
(
0.2­
0.3)
0.5
(
0.4­
0.6)
0.5
(
0.4­
0.6)
0.9
(
0.8­
1.1)
0.9
(
0.7­
1.2)

Race/
Ethnicity
Black,
non­
Hispanic
693
<
LOD
<
LOD
<
LOD
0.5
(
0.4­
0.6)
0.9
(
0.7­
1.2)

Mexican
American
1,289
<
LOD
<
LOD
0.3
(
0.2­
0.4)
0.5
(
0.4­
0.5)
0.7
(
0.6­
1.0)

White,
non­
Hispanic*
1,207
<
LOD
<
LOD
0.3
(
0.2­
0.3)
0.5
(
0.4­
0.6)
0.9
(
0.7­
1.1)

Age
Group
1­
19
years
1,541
<
LOD
<
LOD
<
LOD
<
LOD
0.4
(
0.3­
1.0)

20+
years
1,648
<
LOD
<
LOD
0.3
(
0.3­
0.4)
0.6
(
0.5­
0.7)
1.0
(
0.8­
1.3)
Numbers
in
parentheses
are
95%
confidence
intervals.
*
Includes
other
racial/
ethnic
groups.
**
Less
than
the
limit
of
detection
of
the
analytical
method.
21
Table
5.
Geometric
mean
and
selected
percentiles
of
urine
cadmium
concentrations
and
creatinineadjusted
levels
for
the
U.
S.
population
aged
6
years
and
older,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95
%
confidence
interval)

10th
25th
50th
75th
90th
µ
g/
L
of
urine
1,007
0.32
(
0.30­
0.33)
0.10
(
0.08­
0.12)
0.18
(
0.15­
0.19)
0.33
(
0.29­
0.35)
0.57
(
0.52­
0.62)
0.95
(
0.85­
1.04)

µ
g/
g
of
creatinine*
1,007
0.29
(
0.27­
0.31)
0.11
(
0.10­
0.13)
0.17
(
0.15­
0.19)
0.27
(
0.26­
0.30)
0.46
(
0.43­
0.50)
0.74
(
0.66­
0.79)

Numbers
in
parentheses
are
95%
confidence
intervals.
*
µ
g
per
gram
of
creatinine
in
urine.

Cobalt
(
CAS
No.
7440­
48­
4)
General
Information
Cobalt
is
an
element
that
occurs
in
nature
either
as
a
steel­
gray,
shiny,
hard
metal
or
combined
with
other
elements.
The
cobalt
used
in
U.
S.
industry
is
imported
or
obtained
by
recycling
scrap
metal
that
contains
cobalt.
Among
its
many
uses
are
making
alloys
(
mixtures
of
metals),
colored
pigments,
and
fertilizers.
It
is
also
used
as
a
drier
for
paint
and
porcelain
enamel
used
on
steel
bathroom
fixtures,
large
appliances,
and
kitchenware.
Small
amounts
of
cobalt
naturally
occur
in
food.
In
addition,
vitamin
B
12
is
a
cobalt­
containing
compound
that
is
essential
for
good
health.

Cobalt
occurs
naturally
in
dust,
seawater,
and
many
types
of
soil.
It
is
also
emitted
into
the
environment
from
burning
coal
and
oil
and
from
car
and
truck
exhaust.

Interpreting
Urine
Cobalt
Levels
Reported
in
the
Table
Urine
cobalt
levels
were
measured
in
a
subsample
of
NHANES
participants
aged
6
years
and
older
who
were
selected
to
be
representative
of
the
U.
S.
population.
Measuring
cobalt
at
these
levels
in
urine
is
possible
because
of
advances
in
analytical
chemistry.
Finding
a
measurable
amount
of
cobalt
in
urine
does
not
mean
that
the
level
of
cobalt
causes
an
adverse
health
effect.

There
are
no
OSHA
criteria
for
occupational
levels
of
cobalt
in
blood
or
urine.
The
American
Conference
of
Governmental
Industrial
Hygienists
(
ACGIH),
a
private
organization,
publishes
biological
exposure
indices
(
BEIs)
and
has
determined
that
the
BEI
"
generally
indicate
a
concentration
below
which
nearly
all
workers
should
not
experience
adverse
health
effects."
9
The
BEIs
generally
correspond
to
the
uptake
levels
expected
when
workers
are
exposed
at
airexposure
limits
set
by
ACGIH.
This
organization
notes
that
these
values
are
for
workers
and
that
it
is
not
appropriate
to
apply
them
to
the
general
population.
Information
about
the
BEI
level
is
22
provided
here
for
comparison,
not
to
imply
that
the
BEI
is
a
safety
level
for
general
population
exposure.
For
urine
cobalt,
the
BEI
is
15
µ
g/
L.
9
The
90th
percentile
of
urine
cobalt
levels
reported
in
Table
6
is
less
than
this
level.
Whether
cobalt
at
the
levels
reported
here
is
a
cause
for
health
concern
is
not
yet
known;
more
research
is
needed.

These
data
provide
physicians
with
a
reference
range
so
that
they
can
determine
whether
people
have
been
exposed
to
higher
levels
of
cobalt
than
those
found
in
the
general
population.
These
data
will
also
help
scientists
plan
and
conduct
research
about
cobalt
exposure
and
health
effects.

Table
6.
Geometric
mean
and
selected
percentiles
of
urine
cobalt
concentrations
and
creatinineadjusted
levels
for
the
U.
S.
population
aged
6
years
and
older,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Geometric
mean
(
95%
confidence
interval)
Selected
Percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
µ
g/
L
of
urine
1,007
0.36
(
0.32­
0.40)
0.11
(
0.08­
0.14)
0.23
(
0.19­
0.26)
0.40
(
0.35­
0.41)
0.60
(
0.54­
0.68)
0.89
(
0.79­
1.10)

µ
g/
g
of
creatinine*
1,007
0.33
(
0.29­
0.36)
0.14
(
0.12­
0.16)
0.20
(
0.18­
0.22)
0.30
(
0.27­
0.34)
0.47
(
0.42­
0.54)
0.80
(
0.63­
1.11)

Numbers
in
parentheses
are
95%
confidence
intervals.
*
µ
g
per
gram
of
creatinine
in
urine.

Uranium
(
CAS
No.
7439­
97­
6)
General
Information
Uranium
is
a
silver­
white,
extremely
dense
radioactive
metal.
It
almost
never
occurs
as
an
uncombined
metal
but
rather
as
a
compound
with
oxygen,
chlorine,
or
fluorine.
Uranium
has
many
commercial
uses,
including
its
use
in
nuclear
weapons,
nuclear
fuel,
armor­
piercing
shells,
and
in
colored
glass
and
ceramics.

Uranium
exposure
generally
is
associated
with
its
commercial
uses,
occurring
mostly
by
inhaling
dust
and
other
small
particles.
Some
uranium
can
be
absorbed
from
food
and
water,
especially
in
areas
where
large
amounts
of
uranium
occur
naturally.

Interpreting
Uranium
Levels
Reported
in
the
Table
Urine
uranium
levels
were
measured
in
a
subsample
of
NHANES
participants
6
years
old
and
older
who
were
selected
to
be
representative
of
the
U.
S.
population.
The
analytical
method
used
measured
levels
of
the
U
238
isotope,
not
levels
of
the
U
235
isotope
(
the
form
of
uranium
used
as
23
nuclear
fuel).
More
than
99%
of
naturally
occurring
uranium
is
U
238.
Measuring
uranium
at
these
levels
in
urine
is
possible
because
of
advances
in
analytical
chemistry.
Finding
a
measurable
amount
of
uranium
in
urine
does
not
mean
that
the
level
of
uranium
causes
an
adverse
health
effect.
The
United
States
Nuclear
Regulatory
Commission
has
set
an
action
level
for
uranium
in
urine
to
protect
workers
occupationally
exposed
to
uranium.
10
This
urine
uranium
level
is
15
µ
g/
L.
The
90th
percentile
of
urine
uranium
levels
in
Table
7
is
below
this
level.
Whether
uranium
at
the
levels
reported
here
is
cause
for
health
concern
is
not
yet
known;
more
research
is
needed.

These
urine
uranium
data
provide
physicians
with
a
reference
range
so
that
they
can
determine
whether
people
have
been
exposed
to
higher
levels
of
uranium
than
those
found
in
the
general
population.
These
data
will
also
help
scientists
plan
and
conduct
research
about
uranium
exposure
and
health
effects.

Table
7.
Geometric
mean
and
selected
percentiles
of
uranium
urine
concentrations
and
creatinineadjusted
levels
for
the
U.
S.
population
aged
6
years
and
older,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Geometric
Mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
intervals)

10th
25th
50th
75th
90th
µ
g/
L
of
urine
1,006
0.008
(
0.006­
0.011)
<
LOD**
<
LOD
0.007
(
0.004­
0.010)
0.014
(
0.009­
0.030)
0.034
(
0.022­
0.053)

µ
g/
g
of
creatinine*
1,006
­­­
<
LOD
<
LOD
(
0.005)
(
0.002­
0.009)
0.011
(
0.005­
0.026)
0.024
(
0.015­
0.109)

Numbers
in
parentheses
are
95%
confidence
intervals.
*
µ
g
per
gram
of
creatinine
in
urine.
**
Less
than
the
limit
of
detection
of
0.004
µ
g/
L
in
urine.

Antimony
(
CAS
No.
7440­
36­
0)
General
Information
Elemental
antimony
is
a
silver­
white
metal.
In
nature,
antimony
can
be
found
in
ores
or
other
minerals,
usually
combined
with
oxygen
to
form
antimony
oxide.
Antimony
is
used
in
storage
batteries,
solder,
sheet
and
pipe
metal,
bearings,
castings,
and
pewter.
Antimony
oxide
is
added
to
textiles
and
plastics
to
prevent
them
from
catching
fire.
It
is
also
used
in
paints;
ceramics;
fireworks;
and
in
enamels
for
plastics,
metal,
and
glass.

Antimony
gets
into
the
environment
from
natural
sources
and
from
industry.
Exposure
to
antimony
can
come
from
food,
drinking
water,
or
air.
Workplace
exposure
occurs
as
a
result
of
breathing
the
air
near
industries
such
as
smelters,
coal­
fired
plants,
and
refuse
incinerators
that
process
or
release
antimony.
24
Interpreting
Antimony
Levels
Reported
in
the
Table
Urine
antimony
levels
were
measured
in
a
subsample
of
NHANES
participants
aged
6
years
and
older
who
were
selected
to
be
representative
of
the
U.
S.
population.
Measuring
antimony
at
these
levels
in
urine
is
possible
because
of
advances
in
analytical
chemistry.
Finding
a
measurable
amount
of
antimony
in
urine
does
not
mean
that
the
level
of
antimony
causes
an
adverse
health
effect.
Whether
antimony
at
the
levels
reported
here
is
a
cause
for
health
concern
is
not
yet
known;
more
research
is
needed.

These
urine
antimony
data
provide
physicians
with
a
reference
range
so
that
they
can
determine
whether
people
have
been
exposed
to
higher
levels
of
antimony
than
those
found
in
the
general
population.
These
data
will
also
help
scientists
plan
and
conduct
research
about
exposure
to
antimony
and
health
effects.

Table
8.
Geometric
mean
and
selected
percentiles
of
urine
antimony
concentrations
and
creatinineadjusted
levels
for
the
U.
S.
population
aged
6
years
and
older,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
intervals)

10th
25th
50th
75th
90th
µ
g/
L
of
urine
912
0.10
(
0.09­
0.12)
<
LOD**
0.05
(
0.03­
0.07)
0.10
(
0.09­
0.12)
0.19
(
0.16­
0.21)
0.29
(
0.27­
0.34)

µ
g/
g
of
creatinine*
912
­­­
<
LOD
0.4
(***­
0.05)
0.08
(
0.07­
0.09)
0.13
(
0.10­
0.16)
0.19
(
0.17­
0.24)

Numbers
in
parentheses
are
95%
confidence
intervals.
*
µ
g
per
gram
of
creatinine
in
urine.
**
Less
than
the
limit
of
detection
of
0.04
µ
g/
L
of
urine
***
Results
that
were
below
the
limit
of
detection
were
not
adjusted
for
creatinine.
The
lower
confidence
interval
is
not
defined;
the
estimate
is
below
the
limit
of
detection.

Barium
(
CAS
No.
7440­
39­
3)
General
Information
Elemental
barium
is
a
silver­
white
metal.
In
nature,
it
combines
with
other
chemicals
such
as
sulfur
or
carbon
and
oxygen.
Barium
compounds
are
used
by
the
oil
and
gas
industries
to
make
drilling
muds.
These
compounds
are
also
produced
commercially
for
use
in
paint,
bricks,
tiles,
glass,
and
rubber.
Barium
sulfate
is
used
by
doctors
to
perform
medical
tests
and
as
a
contrast
medium
for
taking
X­
rays
of
the
gastrointestinal
tract.

People
are
exposed
to
barium
in
air,
water,
and
food.
Workers
employed
by
industries
that
make
or
use
barium
compounds
are
exposed
to
barium
dust.
The
health
effects
of
the
different
barium
25
compounds
depend
on
how
well
the
compound
dissolves
in
water.

Interpreting
Barium
Levels
Reported
in
the
Table
Urine
barium
levels
were
measured
in
a
subsample
of
NHANES
participants
aged
6
years
and
older
who
were
selected
to
be
representative
of
the
U.
S.
population.
Measuring
barium
at
these
levels
in
urine
is
possible
because
of
advances
in
analytical
chemistry.
Finding
a
measurable
amount
of
barium
in
urine
does
not
mean
that
the
level
of
barium
causes
an
adverse
health
effect.
Whether
barium
at
the
levels
reported
here
is
a
cause
for
health
concern
is
not
yet
known;
more
research
is
needed.

These
urine
barium
data
provide
physicians
with
a
reference
range
so
that
they
can
determine
whether
people
have
been
exposed
to
higher
levels
of
barium
than
those
found
in
the
general
population.
These
data
will
also
help
scientists
plan
and
conduct
research
about
exposure
to
barium
and
health
effects.

Table
9.
Geometric
mean
and
selected
percentiles
of
urine
barium
concentrations
and
creatinineadjusted
levels
for
the
U.
S.
population
aged
6
years
and
older,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
µ
g/
L
of
urine
779
1.6
(
1.5­
1.7)
0.3
(
0.3­
0.4)
0.8
(
0.7­
0.9)
1.7
(
1.5­
1.9)
2.9
(
2.7­
3.3)
5.5
(
4.2­
6.2)

µ
g/
g
of
creatinine*
779
1.5
(
1.3­
1.6)
0.4
(
0.4­
0.6)
0.9
(
0.8­
1.0)
1.5
(
1.4­
1.6)
2.4
(
2.1­
2.8)
4.5
(
3.9­
5.1)

Numbers
in
parentheses
are
95%
confidence
intervals.
*
µ
g
per
gram
of
creatinine
in
urine.

Beryllium
(
CAS
No.
7440­
41­
7)
General
Information
Pure
beryllium
is
a
hard,
gray
metal.
In
nature,
beryllium
can
be
found
in
mineral
rocks,
coal,
soil,
and
volcanic
dust.
Beryllium
compounds
are
commercially
mined,
and
the
beryllium
is
purified
for
use
in
mirrors;
nuclear
weapons;
and
electrical,
aircraft,
and
machine
parts.
Beryllium
compounds
have
no
distinctive
smell.
Beryllium
dust
gets
into
ambient
air
from
burning
coal
and
oil.
Exposure
to
beryllium
occurs
mostly
in
the
workplace,
near
some
hazardous
waste
sites,
and
from
breathing
tobacco
smoke.
26
Interpreting
Beryllium
Results
Reported
in
the
Table
Urine
beryllium
levels
were
measured
in
a
subsample
of
NHANES
participants
aged
6
years
old
and
older
who
were
selected
to
be
representative
of
the
U.
S.
population.
All
of
the
levels
in
the
table
are
below
the
limit
of
detection
of
the
analytical
method
for
beryllium,
which
was
0.13
µ
g/
L.

Table
10.
Geometric
mean
and
selected
percentiles
of
urine
beryllium
concentrations
and
creatinineadjusted
levels
for
the
U.
S.
population
aged
6
years
and
older,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
µ
g/
L
of
urine
1,007
­­­
<
LOD**
<
LOD
<
LOD
<
LOD
<
LOD
µ
g/
g
of
creatinine*
1,007
­­­
<
LOD
<
LOD
<
LOD
<
LOD
<
LOD
*
µ
g
per
gram
of
creatinine
in
urine.
**
Less
than
the
limit
of
detection
of
0.13
µ
g/
L
in
urine.

Cesium
(
CAS
No.
7440­
46­
2)
General
Information
Cesium
is
a
silver­
white
metal
that
ignites
on
contact
with
air
and
reacts
explosively
with
water.
Cesium
can
be
found
naturally
in
rock,
soil,
and
clay.
It
occurs
as
an
aluminosilicate
(
pollucite
and
lepidolite)
and
as
a
borate
(
rhodizite).
Cesium
compounds
are
commonly
used
in
photomultipliers,
vacuum
tubes,
scintillation
counters,
infrared
lamps,
semiconductors,
high­
power
gas­
ion
devices,
and
photographic
emulsions.
11,
12
Interpreting
Cesium
Levels
Reported
in
the
Table
Urine
cesium
levels
were
measured
in
a
subsample
of
NHANES
participants
aged
6
years
and
older
who
were
selected
to
be
representative
of
the
U.
S.
population.
Measuring
cesium
at
these
levels
in
urine
is
possible
because
of
advances
in
analytical
chemistry.
Finding
a
measurable
amount
of
cesium
in
urine
does
not
mean
that
the
level
of
cesium
causes
an
adverse
health
effect.

Whether
cesium
at
the
levels
reported
here
is
cause
for
health
concern
is
not
yet
known;
more
research
is
needed.
These
urine
cesium
data
provide
physicians
with
a
reference
range
so
that
they
can
determine
whether
people
have
been
exposed
to
higher
levels
of
cesium
than
those
found
in
the
general
population.
These
data
will
also
help
scientists
plan
and
conduct
research
about
exposure
to
cesium
and
health
effects.
27
Table
11.
Geometric
mean
and
selected
percentiles
of
urine
cesium
concentrations
and
creatinineadjusted
levels
for
the
U.
S.
population
aged
6
years
and
older,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
µ
g/
L
of
urine
1,006
4.7
(
4.2­
5.2)
1.8
(
1.4­
2.2)
3.3
(
2.9­
3.6)
5.3
(
4.7­
5.8)
7.2
(
6.7­
8.0)
9.6
(
8.5­
11.6)

µ
g/
g
of
creatinine*
1,006
4.3
(
3.8­
4.7)
2.5
(
2.1­
2.7)
3.2
(
2.9­
3.5)
4.2
(
3.8­
4.6)
5.4
(
4.9­
6.3)
7.1
(
6.5­
8.7)

*
µ
g
per
gram
of
creatinine
in
urine.
Numbers
in
parentheses
are
95%
confidence
intervals.

Molybdenum
(
CAS
No.
7439­
98­
7)
General
Information
Molybdenum
occurs
naturally
in
compounds
with
other
elements.
Elemental
molybdenum
is
a
silver­
white,
hard
metal
with
many
commercial
uses,
including
the
production
of
metal
alloys.
Molybdenum
is
also
a
nutritionally
essential
trace
element.

Molybdenum
enters
the
environment
from
the
weathering
of
ores
that
contain
it
and
from
water
containing
the
metal
in
its
soluble
forms.
In
industry,
the
dust
and
other
fine
particles
produced
in
refining
or
shaping
molybdenum
are
the
most
important
sources
of
exposure.

Interpreting
Molybdenum
Levels
Reported
in
the
Table
Urine
molybdenum
levels
were
measured
in
a
subsample
of
NHANES
participants
aged
6
years
and
older
who
were
selected
to
be
representative
of
the
U.
S.
population.
Measuring
molybdenum
at
these
levels
is
possible
because
of
advances
in
analytical
chemistry.
Finding
a
measurable
amount
of
molybdenum
in
urine
does
not
mean
that
the
level
of
molybdenum
causes
an
adverse
health
effect.
Whether
molybdenum
at
the
levels
reported
here
is
cause
for
health
concern
is
not
yet
known;
more
research
is
needed.

These
urine
molybdenum
data
provide
physicians
with
a
reference
range
so
that
they
can
determine
whether
people
have
been
exposed
to
higher
levels
of
molybdenum
than
those
found
in
the
general
population.
These
data
will
also
help
scientists
plan
and
conduct
research
about
molybdenum
exposure
and
health
effects.
28
Table
12.
Geometric
mean
and
selected
percentiles
of
molybdenum
urine
concentrations
and
creatinine­
adjusted
levels
for
the
U.
S.
population
aged
6
years
and
older,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
µ
g/
L
of
urine
904
48.4
(
43.6­
53.2)
13.1
(
10.8­
17.3)
27.6
(
23.4­
32.8)
53.3
(
47.3­
61.5)
86.6
(
78.6­
97.5)
140
(
120­
174)

µ
g/
g
of
creatinine*
904
43.9
(
40.6­
47.2)
19.0
(
15.4­
23.3)
28.4
(
26.6­
29.3)
41.1
(
38.6­
44.9)
65.2
(
61.4­
71.5)
113
(
90.6­
126)

*
µ
g
per
gram
of
creatinine
in
urine.
Numbers
in
parentheses
are
95%
confidence
intervals.

Platinum
(
CAS
No.
7440­
06­
4)
General
Information
Platinum
is
a
silver­
gray,
lustrous,
malleable
metal
found
naturally
in
the
earth's
crust
and
typically
is
associated
with
nickel,
copper,
or
iron­
sulfide
seams.
Important
properties
of
platinum
and
the
compounds
it
forms
are
resistance
to
corrosion,
strength
at
high
temperatures,
and
high
catalytic
activity.

Platinum­
rhodium
and
platinum­
palladium
crystals
are
used
to
reduce
automobile­
exhaust
emissions.
Platinum­
rhodium
compounds
are
used
in
glass
and
glass­
fiber
manufacture
and
in
hightemperature
thermocouples.
Other
platinum
compounds
have
a
variety
of
uses,
including
anticancer
treatments.
Platinum
compounds
are
also
used
in
electrodes
and
jewelry,
as
oxidation
catalysts
in
chemical
manufacturing,
and
in
thick­
film
circuits
printed
on
ceramic
substrates.
11,
12
Interpreting
Platinum
Levels
Reported
in
the
Table
Urine
platinum
levels
were
measured
in
a
subsample
of
NHANES
participants
aged
6
years
and
older
who
were
selected
to
be
representative
of
the
U.
S.
population.
All
of
the
levels
in
the
table
are
below
the
limit
of
detection
of
the
analytical
method
for
platinum,
which
was
0.04
µ
g/
L.
29
Table
13.
Geometric
mean
and
selected
percentiles
of
platinum
urine
concentrations
and
creatinineadjusted
levels
for
the
U.
S.
population
aged
6
years
and
older,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
µ
g/
L
of
urine
1,007
­­­
<
LOD**
<
LOD
<
LOD
<
LOD
<
LOD
µ
g/
g
of
creatinine*
1,007
­­­
<
LOD
<
LOD
<
LOD
<
LOD
<
LOD
*
µ
g
per
gram
of
creatinine
in
urine.
**
Less
than
the
limit
of
detection
of
0.04
µ
g/
L
in
urine.

Thallium
(
CAS
No.
7440­
28­
0)
General
Information
Elemental
thallium
is
a
blue­
white
metal
that
is
found
in
small
amounts
in
soil
and
rocks.
In
the
past,
thallium
was
obtained
as
a
byproduct
of
smelting
other
metals;
however,
it
has
not
been
produced
in
the
United
States
since
1984.
Thallium
and
most
of
its
compounds
are
odorless
and
tasteless.

Thallium
exposure
occurs
primarily
from
commercial
processes
such
as
coal­
burning
and
smelting.
In
these
and
other
sources,
thallium
is
produced
in
fine
particles
that
can
then
be
absorbed
by
breathing.
One
rare,
but
significant,
accidental
exposure
to
thallium
can
occur
by
eating
rat
poison
that
contains
water­
soluble
thallium
salts.
In
the
United
States,
thallium
has
been
banned
for
use
in
rat
poisons.

Interpreting
Thallium
Levels
Reported
in
the
Table
Urine
thallium
levels
were
measured
in
a
subsample
of
NHANES
participants
aged
6
years
and
older
who
were
selected
to
be
representative
of
the
U.
S.
population.
Measuring
thallium
at
these
levels
in
urine
is
possible
because
of
advances
in
analytical
chemistry.
Finding
a
measurable
amount
of
thallium
in
urine
does
not
mean
that
the
level
of
thallium
causes
an
adverse
health
effect.
Whether
thallium
at
the
levels
reported
here
is
a
cause
for
health
concern
is
not
yet
known;
more
research
is
needed.

These
urine
thallium
data
provide
physicians
with
a
reference
range
so
that
they
can
determine
whether
people
have
been
exposed
to
higher
levels
of
thallium
than
those
found
in
the
general
population.
These
data
will
also
help
scientists
plan
and
conduct
research
about
thallium
exposure
and
health
effects.
30
Table
14.
Geometric
mean
and
selected
percentiles
of
urine
thallium
concentrations
and
creatinineadjusted
levels
for
the
U.
S.
population
aged
6
years
and
older,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
µ
g/
L
of
urine
974
0.19
(
0.17­
0.20)
0.07
(
0.06­
0.07)
0.12
(
0.10­
0.13)
0.21
(
0.19­
0.23)
0.30
(
0.28­
0.33)
0.42
(
0.39­
0.45)

µ
g/
g
of
creatinine*
974
0.17
(
0.16­
0.18)
0.09
(
0.08­
0.09)
0.13
(
0.11­
0.14)
0.17
(
0.16­
0.18)
0.22
(
0.21­
0.24)
0.29
(
0.27­
0.35)

Numbers
in
parentheses
are
95%
confidence
intervals.
*
µ
g
per
gram
of
creatinine
in
urine.

Tungsten
(
CAS
No.
7440­
33­
7)
General
Information
Tungsten,
also
known
as
wolfram,
is
a
steel­
gray
to
tin­
white
metal
naturally
occurring
in
the
earth's
crust,
mainly
as
scheelite
(
CaWO
4).
A
major
use
of
tungsten
is
in
the
production
of
hard
metals
(
i.
e.,
tungsten
carbide,
which
is
common
in
rock
drills
and
metal­
cutting
tools;
or
ferrotungsten,
which
is
used
in
the
steel
industry).
Additionally,
tungsten
compounds
are
used
as
catalysts
in
the
petroleum
industry,
as
lubricating
agents,
in
filaments
for
incandescent
lamps,
and
as
bronzes
in
pigments.
11,
12
Interpreting
Tungsten
Levels
Reported
in
the
Table
Urine
tungsten
levels
were
measured
in
a
subsample
of
NHANES
participants
aged
6
years
and
older
who
were
selected
to
be
representative
of
the
U.
S.
population.
Measuring
tungsten
at
these
levels
in
urine
is
possible
because
of
advances
in
analytical
chemistry.
Finding
a
measurable
amount
of
tungsten
in
urine
does
not
mean
that
the
level
of
tungsten
causes
an
adverse
health
effect.
Whether
tungsten
at
the
levels
reported
here
is
a
cause
for
health
concern
is
not
yet
known;
more
research
is
needed.

These
urine
tungsten
data
provide
physicians
with
a
reference
range
so
that
they
can
determine
whether
people
have
been
expose
to
higher
levels
of
tungsten
than
those
found
in
the
general
population.
These
data
will
also
help
scientists
plan
and
conduct
research
about
tungsten
exposure
and
health
effects.
31
Table
15.
Geometric
mean
and
selected
percentiles
of
tungsten
urine
concentrations
and
creatinineadjusted
levels
in
the
U.
S.
population
aged
6
years
and
older,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
µ
g/
L
of
urine
892
0.10
(
0.09­
0.12)
<
LOD**
0.05
(
0.03­
0.06)
0.10
(
0.08­
0.11)
0.18
(
0.16­
0.22)
0.32
(
0.27­
0.45)

µ
g/
g
of
creatinine*
892
­­­
<
LOD
0.03
(***­
0.05)
0.07
(
0.06­
0.09)
0.14
(
0.11­
0.18)
0.23
(
0.19­
0.38)

Numbers
in
parentheses
are
95%
confidence
intervals.
*
µ
g
per
gram
of
creatinine
in
urine.
**
Less
than
the
limit
of
detection
of
0.04
µ
g/
L
of
urine.
***
Results
that
were
below
the
limit
of
detection
were
not
adjusted
for
creatinine.
The
lower
confidence
interval
is
not
defined;
the
estimate
is
below
the
limit
of
detection.
33
Tobacco
Smoke
Cotinine
(
CAS
No.
486­
56­
6)
General
Information
Tobacco
use
is
the
most
important,
preventable
cause
of
premature
morbidity
and
mortality
in
the
United
States.
The
consequences
of
smoking
and
the
use
of
smokeless
tobacco
products
are
well
known
and
include,
but
are
not
limited
to,
an
increased
risk
for
cancer,
emphysema,
and
cardiovascular
disease.
For
example,
lung
cancer
is
the
number­
one
cancer
killer
of
both
men
and
women
in
the
United
States,
and
smoking
is
by
far
the
leading
cause
of
lung
cancer.
Environmental
tobacco
smoke
(
ETS)
is
a
known
human
carcinogen,
and
persistent
exposure
to
ETS
is
associated
with
an
increased
risk
for
lung
cancer
and
other
disease.
Children
are
at
particular
risk
from
ETS,
which
may
exacerbate
asthma
among
susceptible
children
and
also
greatly
increase
the
risk
for
lower
respiratory­
tract
illness,
such
as
bronchitis
and
pneumonia,
among
young
children.

Cotinine
is
a
major
metabolite
of
nicotine
and
is
currently
regarded
as
the
best
biomarker
for
exposure
of
active
smokers
and
nonsmokers
to
ETS.
Measuring
cotinine
is
preferred
over
measuring
nicotine
because,
although
both
are
specific
for
exposure
to
tobacco,
cotinine
is
retained
in
the
body
much
longer
than
nicotine.
Cotinine
can
be
measured
in
blood
(
i.
e.,
in
serum),
urine,
saliva,
and
hair.
Nonsmokers
exposed
to
typical
levels
of
ETS
have
cotinine
levels
of
less
than
1
ng/
mL,
with
heavy
exposure
to
ETS
producing
levels
in
the
1­
15
ng/
mL
range.
Active
smokers
almost
always
have
levels
higher
than
15
ng/
mL
and
sometimes
greater
than
500
ng/
mL.

Interpreting
Cotinine
Levels
Reported
in
the
Table
Table
16
presents
data
for
the
U.
S.
nonsmoking
population
aged
3
years
and
older.
For
these
results,
nonsmoking
is
defined
as
a
serum
cotinine
level
less
than
or
equal
to
(<)
15
ng/
mL,
and
for
people
12
years
and
older,
no
reported
use
of
tobacco
or
nicotine­
containing
products
in
the
last
5
days.
The
limit
of
detection
(
LOD)
for
these
measurements
was
0.050
ng/
mL.

From
1988
through
1991,
as
part
of
NHANES
III,
CDC
determined
that
the
median
level
(
50th
percentile)
of
cotinine
among
nonsmokers
in
the
United
States
was
0.20
ng/
mL.
5
Results
shown
in
Table
16
show
that
the
median
cotinine
level
in
1999
has
decreased
to
less
than
0.050
ng/
mL
 
more
than
a
75%
decrease.
This
reduction
in
cotinine
levels
objectively
documents
a
dramatic
reduction
in
exposure
of
the
general
U.
S.
population
to
ETS
since
the
period
1988­
1991.

Compared
with
results
for
the
period
1988­
1991
for
population
groups
defined
by
age,
sex,
and
race
or
ethnicity,
5
all
results
in
Table
16
show
declines
in
cotinine
levels.
Previously,
higher
levels
of
cotinine
have
been
noted
for
non­
Hispanic
blacks,
13
and
although
levels
for
this
population
group
have
declined,
they
are
still
higher
than
those
of
other
racial
or
ethnic
groups.
As
seen
previously,
5
males
continue
to
have
higher
levels
than
females,
and
people
20
years
old
and
older
have
lower
levels
than
those
younger
than
20
years
of
age.
Table
16
appears
on
the
next
page.
34
Table
16.
Selected
percentile
of
serum
cotinine
concentrations
(
in
ng/
mL)
for
the
U.
S.
nonsmoking
population
aged
3
years
and
older,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Selected
percentiles
(
95%
confidence
intervals)

10th
25th
50th
75th
90th
Total,
age
3
years
and
older
2,263
<
LOD***
<
LOD
<
LOD
0.15
(
0.11­
0.23)
0.52
(
0.38­
1.01)

Gender
Males
1,075
<
LOD
<
LOD
0.6
(
0.04­
0.09)
0.20
(
0.13­
0.31)
0.61
(
0.41­
1.46)

Females
1,188
<
LOD
<
LOD
<
LOD
0.12
(
0.09­
0.17)
0.46
(
0.30­
0.93)

Race/
Ethnicity
Black,
non­
Hispanic*
467
<
LOD
<
LOD
0.12
(
0.10­
0.14)
0.50
(
0.42­
0.67)
1.59
(
1.14­
2.16)

Mexican
American
937
<
LOD
<
LOD
<
LOD
0.12
(
0.08­
0.24)
0.34
(
0.21­
1.01)

White,
non­
Hispanic**
859
<
LOD
<
LOD
<
LOD
0.12
(
0.09­
0.21)
0.45
(
0.30­
1.01)

Age
Group
3­
19
years
1,152
<
LOD
<
LOD
0.07
(
0.04­
0.13)
0.32
(
0.16­
0.63)
1.13
(
0.58­
2.77)

20+
years
937
<
LOD
<
LOD
<
LOD
0.12
(
0.09­
0.15)
0.38
(
0.30­
0.56)
Numbers
in
parentheses
are
95%
confidence
intervals.
*
Research
in
progress
to
determine
whether
levels
for
black,
non­
Hispanic
people
may
be
affected
by
biological
factors.
**
Includes
other
racial/
ethnic
groups.
***
Less
than
the
limit
of
detection
of
0.05ng/
mL
in
serum.
35
Organophosphate
Pesticides
General
Information
Organophosphate
pesticides
account
for
about
half
of
the
insecticides
used
in
the
United
States.
Approximately
60
million
pounds
of
organophosphate
pesticides
are
applied
to
about
60
million
acres
of
U.
S.
agricultural
crops
annually;
nonagricultural
uses
account
for
about
17
million
pounds
per
year.
14
Organophosphate
pesticides
are
active
against
a
broad
spectrum
of
insects
and
are
used
on
food
crops
as
well
as
in
residential
and
commercial
buildings
and
on
ornamental
plants
and
lawns.
Exposure
of
the
general
population
to
these
pesticides
occurs
primarily
from
ingestion
of
food
products
or
from
residential
use.

About
75%
of
the
registered
pesticides
metabolize
to
the
dialkyl
phosphate
metabolites.
15
This
Report
provides
measurements
in
urine
for
the
following
six
urinary
metabolites
of
organophosphate
pesticides:
#
Dimethylphosphate
(
DMP).
#
Dimethylthiophosphate
(
DMTP).
#
Dimethyldithiophosphate
(
DMDTP).
#
Diethylphosphate
(
DEP).
#
Diethylthiophosphate
(
DEPT).
#
Diethyldithiophosphate
(
DEDTP).

Table
17
shows
the
six
urinary
metabolites
and
their
parent
organophosphate
pesticides.
For
example,
chlorpyrifos
metabolizes
to
diethylphosphate
and
diethythiophosphate.
Measurement
of
these
metabolites
reflects
exposure
to
organophosphate
pesticides
that
has
occurred
predominantly
in
the
last
few
days.
Note
that
each
of
the
six
urinary
metabolites
can
be
produced
from
the
metabolism
of
more
than
one
organophosphate
pesticide.
In
addition
to
reflecting
exposure
to
the
parent
pesticides,
the
level
of
the
metabolite
in
a
person's
urine
may
also
reflect
exposure
to
the
metabolite
itself
if
it
was
present
in
the
person's
environment.

The
mechanism
of
toxicity
of
the
organophosphate
pesticides
is
inhibition
of
acetylcholinesterase,
which
catalyzes
the
deacetylation
of
acetylcholine.
Acetylcholine
helps
transfer
nerve
impulses
between
nerve
cells
or
from
a
nerve
cell
to
other
types
of
cells,
such
as
muscle
cells.
Inhibition
of
the
enzyme
acetylcholinesterase
leads
to
the
build­
up
of
acetylcholine,
which
then
overstimulates
muscles,
causing
symptoms
such
as
weakness
and
sometimes
paralysis.

Interpreting
Organophosphate
Metabolite
Levels
in
the
Tables
Urine
levels
of
metabolites
of
organophosphate
pesticides
were
measured
in
a
subsample
of
NHANES
participants
6
through
59
years
of
age
who
were
selected
to
be
representative
of
the
U.
S.
population.
As
noted
above,
a
particular
metabolite
may
come
from
multiple
parent
organophosphate
pesticides.
Measuring
these
metabolites
at
these
levels
in
urine
is
possible
because
of
advances
in
analytical
chemistry.
Finding
a
measurable
amount
of
one
or
more
metabolites
in
urine
does
not
mean
that
the
level
of
the
organophosphates
causes
an
adverse
health
effect.
Whether
organophosphate
pesticides
at
the
levels
of
metabolites
reported
here
are
a
cause
36
for
health
concern
is
not
known;
more
research
is
needed.

These
data
provide
physicians
with
a
reference
range
so
that
they
can
determine
whether
people
have
been
exposed
to
higher
levels
of
organophosphate
pesticides
than
those
experienced
in
the
general
population.
Tables
18­
23
summarize
results
of
these
tests.
These
data
will
help
scientists
plan
and
conduct
research
about
exposure
to
organophosphate
pesticides
and
health
effects.

Table
17.
Organophosphate
pesticides
and
their
metabolites
Pesticide
DMP*
DMTP
DMDTP
DEP
DEPT
DEDTP
Azinphos
methyl
X
X
X
Chlorethoxyphos
X
X
Chlorpyrifos
X
X
Chlorpyrifos
methyl
X
X
Coumaphos
X
X
Dichlorvos
(
DDVP)
X
Diazinon
X
X
Dicrotophos
X
Dimethoate
X
X
Disulfoton
X
X
X
Ethion
X
X
X
Fenitrothion
X
X
Fenthion
X
X
Isazaphos­
methyl
X
X
Malathion
X
X
X
Methidathion
X
X
X
Methyl
parathion
X
X
Naled
X
Oxydemeton­
methyl
X
X
Parathion
X
X
Phorate
X
X
X
Phosmet
X
X
X
Pirimiphos­
methyl
X
X
37
Pesticide
DMP*
DMTP
DMDTP
DEP
DEPT
DEDTP
Sulfotepp
X
X
Temephos
X
X
Terbufos
X
X
X
Tetrachlorviphos
X
Trichlorfon
X
Dimethylphosphate
(
CAS
No.
813­
78­
5)

Table
18.
Geometric
mean
and
selected
percentiles
of
dimethylphosphate
urine
concentrations
and
creatinine­
adjusted
levels
for
the
U.
S.
population
aged
6­
59
years,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
µ
g/
L
of
urine
703
1.84
(
1.10­
2.59)
<
LOD**
0.80
(
0.36­
1.11)
1.67
(
1.04­
2.86)
3.79
(
2.38­
7.46)
7.43
(
5.43­
17.3)

µ
g/
g
of
creatinine*
703
­­­
<
LOD
0.49
(***­
0.80)
1.56
(
0.83­
2.84)
4.02
(
2.96­
7.76)
10.1
(
7.47­
19.7)

Numbers
in
parentheses
are
95%
confidence
intervals.
*
µ
g
per
gram
of
creatinine
in
urine.
**
Less
than
the
limit
of
detection
of
0.51
µ
g/
L
of
urine.
***
Results
that
were
below
the
limit
of
detection
were
not
adjusted
for
creatinine.
The
lower
confidence
interval
is
not
defined;
the
estimate
is
below
the
limit
of
detection.
38
Dimethylthiophosphate
(
CAS
No.
1112­
38­
5)

Table
19.
Geometric
mean
and
selected
percentiles
of
dimethylthiophosphate
urine
concentrations
and
creatinine­
adjusted
levels
for
the
U.
S.
population
aged
6­
59
years,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
µ
g/
L
of
urine
703
2.61
(
1.77­
3.45)
<
LOD**
0.72
(
0.13­
1.73)
3.80
(
2.93­
4.53)
9.00
(
7.35­
12.3)
22.9
(
18.7­
30.7)

µ
g/
g
of
creatinine*
703
­­­
<
LOD**
0.59
(***­
0.42)
3.08
(
2.33­
3.53)
7.87
(
6.16­
11.5)
23.6
(
17.0­
27.2)

Numbers
in
parentheses
are
95%
confidence
intervals.
*
µ
g
per
gram
of
creatinine
in
urine.
**
Less
than
the
limit
of
detection
of
0.18
µ
g/
L
in
urine.
***
Results
that
were
below
the
limit
of
detection
were
not
adjusted
for
creatinine.
The
lower
end
of
the
confidence
interval
is
not
defined;
the
estimate
is
below
the
limit
of
detection.

Dimethyl
dithiophosphate
(
CAS
No.
756­
80­
9)

Table
20.
Geometric
mean
and
selected
percentiles
of
dimethyldithiophosphate
urine
concentrations
and
creatinine­
adjusted
levels
for
the
U.
S.
population
aged
6­
59
years,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
µ
g/
L
of
urine
703
0.51
(
0.39­
0.62)
<
LOD**
<
LOD
0.60
(
0.39­
0.78)
2.05
(
1.65­
2.42)
5.43
(
3.16­
10.3)

µ
g/
g
of
creatinine*
703
­­­
<
LOD
<
LOD
0.42
(
0.31­
0.55)
1.57
(
1.31­
2.00)
5.33
(
3.99­
6.72)

Numbers
in
parentheses
are
95%
confidence
intervals.
*
µ
g
per
gram
of
creatinine
in
urine.
**
Less
than
the
limit
of
detection
of
0.08
µ
g/
L
in
urine.
39
Diethylphosphate
(
CAS
No.
598­
02­
7)

Table
21.
Geometric
mean
and
selected
percentiles
of
diethylphosphate
urine
concentrations
and
creatinine­
adjusted
levels
for
the
U.
S.
population
aged
6­
59
years,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
µ
g/
L
of
urine
703
2.55
(
1.33­
3.78)
0.78
(
0.70­
0.90)
1.09
(
0.93­
1.31)
1.85
(
1.19­
4.11)
4.87
(
2.58­
14.0)
10.6
(
6.29­**)

µ
g/
g
of
creatinine*
703
2.24
(
1.11­
3.37)
0.43
(
0.40­
0.49)
0.81
(
0.48­
1.25)
1.87
(
1.12­
4.13)
5.85
(
2.77­
12.1)
12.13
(
8.69­
26.9)

Numbers
in
parentheses
are
95%
confidence
intervals.
*
µ
g
per
gram
of
creatinine
in
urine.
**
Upper
end
of
confidence
interval
cannot
be
reliably
estimated.

Diethylthiophosphate
(
CAS
No.
5871­
17­
0)

Table
22.
Geometric
mean
and
selected
percentiles
of
diethylthiophosphate
urine
concentrations
and
creatinine­
adjusted
levels
for
the
U.
S.
population
aged
6­
59
years,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
µ
g/
L
of
urine
703
0.81
(
0.69­
0.94)
0.51
(
0.41­
0.53)
0.58
(
0.55­
0.59
0.70
(
0.64­
0.78)
0.98
(
0.78­
1.45)
1.52
(
1.16­
2.91)

µ
g/
g
of
creatinine*
703
0.71
(
0.56­
0.87)
0.26
(
0.24­
0.29)
0.38
(
0.33­
0.42)
0.64
(
0.47­
0.84)
1.25
(
0.91­
1.90)
2.32
(
1.85­
3.00)

Numbers
in
parentheses
are
95%
confidence
intervals.
*
µ
g
per
gram
of
creatinine
in
urine.
40
Diethyldithiophosphate
(
CAS
No.
298­
06­
6)

Table
23.
Geometric
mean
and
selected
percentiles
of
diethyldithiophosphate
urine
concentrations
and
creatinine­
adjusted
levels
for
the
U.
S.
population
aged
6­
59
years,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
µ
g/
L
of
urine
703
0.19
(
0.14­
0.23)
0.08
(
0.07­
0.08)
0.09
(
0.09­
0.09)
0.14
(
0.09­
0.26)
0.30
(
0.25­
0.39)
0.54
(
0.44­
0.86)

µ
g/
g
of
creatinine*
703
0.16
(
0.12­
0.21)
0.04
(
0.04­
0.05)
0.07
(
0.05­
0.09)
0.14
(
0.10­
0.21)
0.33
(
0.22­
0.49)
0.70
(
0.55­
0.91)

Numbers
in
parentheses
are
95%
confidence
intervals.
*
µ
g
per
gram
of
creatinine
in
urine.
41
Phthalates
General
Information
Phthalates
are
industrial
chemicals
commonly
found
in
many
consumer
products,
including
vinyl
flooring
and
wall
covering;
detergents;
lubricating
oils;
solvents;
food
packaging;
and
personal­
care
products
such
as
soaps,
shampoo,
hair
spray,
and
nail
polish.
Other
phthalates
are
used
in
flexible
plastics,
such
as
blood
bags,
tubing,
or
children's
toys,
and
in
some
pharmaceutical
and
pesticide
formulations.

Results
of
animal
studies
have
found
that
some
phthalates
given
at
very
high
doses
to
animals
during
pregnancy
produce
birth
defects
among
offspring.
16,
17
Table
24
shows
the
relation
between
phthalates
and
their
metabolites
and
also
includes
their
commonly
used
abbreviations.

Table
24.
Phthalates
and
their
metabolites
Phthalate
name
Abbreviation
CAS
Number
Primary
urine
metabolite
Diethyl
phthalate
DEP
84­
66­
2
Mono­
ethyl
phthalate
Dibutyl
phthalate
DBP
84­
74­
2
Mono­
butyl
phthalate
Benzylbutyl
phthalate
BzBP
85­
68­
7
Mono­
benzyl
phthalate
Dicyclohexyl
phthalate
DCHP
84­
61­
7
Mono­
cyclohexyl
phthalate
Di­
2­
ethylhexyl
phthalate
DEHP
117­
81­
7
Mono­
2­
ethylhexyl
phthalate
Dioctyl
phthalate
DOP
117­
84­
0
Mono­
n­
octyl
phthalate
Di­
isononyl
phthalate
DINP
28553­
12­
0
Mono­
isononyl
phthalate
Interpreting
Phthalate
Metabolite
Levels
Reported
in
the
Tables
Urine
levels
of
phthalates
were
measured
in
a
subsample
of
NHANES
participants
aged
6
years
and
older
who
were
selected
to
be
representative
of
the
U.
S.
population.
Results
are
presented
in
tables
25­
31.
Measuring
phthalate
metabolites
at
these
levels
in
urine
is
possible
because
of
advances
in
analytical
chemistry.
Finding
a
measurable
amount
of
one
or
more
phthalate
metabolites
in
urine
does
not
mean
that
the
level
of
one
or
more
of
these
causes
an
adverse
health
effect.
Whether
phthalates
at
the
levels
of
metabolites
reported
here
are
a
cause
for
health
concern
is
not
yet
known;
more
research
is
needed.

These
levels
of
phthalate
metabolites
in
urine
provide
physicians
with
a
reference
range
so
that
they
can
determine
whether
people
have
been
exposed
to
higher
levels
of
phthalates
than
those
experienced
in
the
general
population.
These
data
will
also
help
scientists
plan
and
conduct
research
on
phthalate
exposure
and
health
effects.
42
Mono­
ethyl
Phthalate
(
CAS
No.
2306­
33­
4)
(
Metabolized
from
diethyl
phthalate,
CAS
No.
84­
66­
2)

People
exposed
to
diethyl
phthalate
will
excrete
mono­
ethyl
phthalate
in
their
urine.
The
amount
of
mono­
ethyl
phthalate
is
an
indicator
of
how
much
contact
with
diethyl
phthalate
has
occurred.
Diethyl
phthalate
is
an
industrial
solvent
used
in
many
consumer
products,
particularly
those
containing
fragrances.
Products
that
may
contain
diethyl
phthalate
include
perfume,
cologne,
soap,
shampoo,
and
hand
lotion.

Table
25.
Geometric
mean
and
selected
percentiles
of
mono­
ethyl
phthalate
urine
concentrations
and
creatinine­
adjusted
levels
for
the
U.
S.
population,
aged
6
years
and
older,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
µ
g/
L
of
urine
1,024
176.0
(
132­
220)
27.7
(
17.5­
38.3)
61.5
(
43.1­
80.0)
171
(
121­
226)
424
(
362­
563)
1160
(
971­
1,350)

µ
g/
g
of
creatinine*
1,024
151.5
(
121­
182)
30.8
(
20.5­
42.7)
63.9
(
45.6­
84.3)
134
(
112­
152)
337
(
265­
402)
892
(
716­
1,400)

Numbers
in
parentheses
are
95%
confidence
intervals.
*
µ
g
per
gram
of
creatinine
in
urine.

Mono­
butyl
Phthalate
(
CAS
No.
131­
70­
4)
(
Metabolized
from
dibutyl
phthalate,
CAS
No.
84­
66­
2)

People
exposed
to
dibutyl
phthalate
will
excrete
mono­
butyl
phthalate
in
their
urine.
The
amount
of
mono­
butyl
phthalate
is
an
indicator
of
how
much
contact
with
dibutyl
phthalate
has
occurred.
Dibutyl
phthalate
is
an
industrial
solvent
used
in
many
consumer
products
such
as
nail
polish,
cosmetics,
and
insecticides.
43
Table
26.
Geometric
mean
and
selected
percentiles
of
mono­
butyl
phthalate
urine
concentrations
and
creatinine­
adjusted
levels
for
the
U.
S.
population
aged
6
years
and
older,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
µ
g/
L
of
urine
1,029
26.7
(
23.9­
29.4)
5.9
(
4.6­
7.3)
13.2
(
10.5­
15.4)
27.5
(
24.6­
31.5)
53.8
(
51.2­
59.7)
98.6
(
89.1­
122)

µ
g/
g
of
creatinine*
1,029
23.0
(
20.9­
25.0)
8.2
(
6.2­
9.5)
13.0
(
11.9­
14.6)
22.0
(
19.4­
24.6)
38.7
(
34.2­
42.6)
69.0
(
56.2­
93.0)

Numbers
in
parentheses
are
95%
confidence
intervals.
*
µ
g
per
gram
of
creatinine
in
urine.

Mono­
benzyl
Phthalate
(
CAS
No.
2528­
16­
7)
(
Metabolized
from
benzylbutyl
phthalate,
CAS
No.
85­
68­
7)

People
exposed
to
benzylbutyl
phthalate
will
excrete
mono­
benzyl
phthalate
in
their
urine.
The
amount
of
mono­
benzyl
phthalate
is
an
indicator
of
how
much
contact
with
dibutyl
phthalate
has
occurred.
Benzylbutyl
phthalate
is
an
industrial
solvent
used
in
many
consumer
products
such
as
adhesives,
sealants,
cosmetics,
and
car­
care
products.

Table
27.
Geometric
mean
and
selected
percentiles
of
mono­
benzyl
phthalate
urine
concentrations
and
creatinine­
adjusted
levels
for
the
U.
S.
population
aged
6
years
and
older,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
µ
g/
L
of
urine
1.029
17.4
(
14.1­
20.7)
3.5
(
2.2­
4.5)
8.0
(
5.9­
9.8)
18.5
(
15.4­
22.6)
38.6
(
31.5­
48.7)
82.3
(
64.0­
101)

µ
g/
g
of
creatinine*
1,029
15.0
(
12.8­
17.2)
4.7
(
3.9­
5.2)
8.0
(
6.3­
9.5)
14.2
(
12.3­
16.0)
25.7
(
23.2­
30.3)
57.5
(
44.0­
72.7)

Numbers
in
parentheses
are
95%
confidence
intervals.
*
µ
g
per
gram
of
creatinine
in
urine.
44
Mono­
cyclohexyl
Phthalate
(
CAS
No.
7517­
36­
4)
(
Metabolized
from
dicyclohexyl
phthalate,
CAS
No.
84­
61­
7)

People
exposed
to
dicyclohexyl
phthalate
will
excrete
mono­
cyclohexyl
phthalate
in
their
urine.
The
amount
of
mono­
cyclohexyl
phthalate
is
an
indicator
of
how
much
contact
with
dicyclohexyl
phthalate
has
occurred.
Dicyclohexyl
phthalate
is
used
primarily
in
research
laboratories.

Table
28.
Geometric
mean
and
selected
percentiles
of
mono­
cyclohexyl
phthalate
urine
concentrations
and
creatinine­
adjusted
levels
for
the
U.
S.
population
aged
6
years
and
older,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
µ
g/
L
of
urine
1,029
­­­
<
LOD**
<
LOD
<
LOD
<
LOD
<
LOD
µ
g/
g
of
creatinine*
1,029
­­­
<
LOD
<
LOD
<
LOD
<
LOD
<
LOD
*
µ
g
per
gram
of
creatinine
in
urine.
**
Less
than
the
limit
of
detection
of
0.7
µ
g/
L
of
urine
Mono­
2­
ethylhexyl
Phthalate
(
CAS
No.
4376­
20­
9)
(
Metabolized
from
di­
2­
ethylhexyl
phthalate,
CAS
No.
117­
81­
7)

People
exposed
to
di­
2­
ethylhexyl
phthalate
will
excrete
mono­
2­
ethylhexyl
phthalate
in
their
urine.
The
amount
of
mono­
2­
ethylhexyl
phthalate
is
an
indicator
of
how
much
contact
with
di­
2­
ethylhexyl
phthalate
has
occurred.
Di­
2­
ethylhexyl
phthalate
is
primarily
used
to
produce
flexible
plastics,
such
as
PVC
tubing
and
blood
bags.
Di­
2­
ethylhexyl
phthalate
has
been
removed
from
most
children's
toys
and
food
packaging
in
the
United
States.
45
Table
29.
Geometric
mean
and
selected
percentiles
of
mono­
2­
ethylhexyl
phthalate
urine
concentrations
and
creatinine­
adjusted
levels
for
the
U.
S.
population
aged
6
years
and
older,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
µ
g/
L
of
urine
1,029
3.5
(
3.0­
4.0)
<
LOD**
1.5
(
0.8­
1.9)
3.3
(
3.0­
3.8)
7.7
(
6.1­
9.6)
13.6
(
11.2­
17.3)

µ
g/
g
of
creatinine*
1,029
­­­
<
LOD
1.1
(
0.7­
1.3)
2.8
(
2.3­
3.3)
5.2
(
4.5­
6.2)
9.1
(
7.4­
11.2)

Numbers
in
parentheses
are
95%
confidence
intervals.
*
µ
g
per
gram
of
creatinine
in
urine.
**
Less
than
the
limit
of
detection
of
1.2
F
g/
L
of
urine
Mono­
n­
octyl
Phthalate
(
CAS
No.
5393­
19­
1)
(
Metabolized
from
dioctyl
phthalate,
CAS
No.
117­
84­
0)

People
exposed
to
dioctyl
phthalate
will
excrete
mono­
n­
octyl
phthalate
in
their
urine.
The
amount
of
mono­
n­
octyl
phthalate
is
an
indicator
of
how
much
contact
with
dioctyl
phthalate
has
occurred.
Dioctyl
phthalate
is
used
primarily
to
produce
flexible
plastics.

Table
30.
Geometric
mean
and
selected
percentiles
of
mono­
n­
octyl
phthalate
urine
concentrations
and
creatinine­
adjusted
levels
for
the
U.
S.
population
aged
6
years
and
older,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
µ
g/
L
of
urine
1,029
­­­
<
LOD**
<
LOD
<
LOD
<
LOD
1.9
(
1.2­
3.5)

µ
g/
g
of
creatinine*
1,029
­­­
<
LOD
<
LOD
<
LOD
<
LOD
1.3
(
0.7­
2.9)

Numbers
in
parentheses
are
95%
confidence
intervals.
*
µ
g
per
gram
of
creatinine
in
urine.
**
Less
than
the
limit
of
detection
of
0.9
µ
g/
L
of
urine
46
Mono­
isononyl
Phthalate
(
Metabolized
from
di­
isononyl
phthalate,
CAS
No.
28553­
12­
0)

People
exposed
to
di­
isononyl
phthalate
will
excrete
mono­
isononyl
phthalate
in
their
urine.
The
amount
of
mono­
isononyl
phthalate
is
an
indicator
of
how
much
contact
with
di­
isononyl
phthalate
has
occurred.
Di­
isononyl
phthalate
is
actually
a
mixture
of
many
compounds.
These
compounds
are
produced
with
side
alkyl
chains
of
C8,
C9,
and
C10
isomers.
Di­
isononyl
phthalate
is
primarily
used
to
produce
flexible
plastics.

Table
31.
Geometric
mean
and
selected
percentiles
of
mono­
isononyl
phthalate
urine
concentrations
and
creatinine­
adjusted
levels
for
the
U.
S.
population
aged
6
years
and
older,
National
Health
and
Nutrition
Examination
Survey,
1999.

Sample
size
Geometric
mean
(
95%
confidence
interval)
Selected
percentiles
(
95%
confidence
interval)

10th
25th
50th
75th
90th
µ
g/
L
of
urine
1,029
­­­
<
LOD**
<
LOD
<
LOD
0.6
(
0.6­
0.9)
4.3
(
0.6­
22.3)

µ
g/
g
of
creatinine*
1,029
­­­
<
LOD
<
LOD
<
LOD
<
LOD
3.8
(
0.2­
12.1)

Numbers
in
parentheses
are
95%
confidence
intervals.
*
µ
g
per
gram
of
creatinine
in
urine.
**
Less
than
the
limit
of
detection
of
0.8
µ
g/
L
of
urine
47
References
1.
Brody
D,
Pirkle
JL,
Kramer
R,
Gunter
EW,
Matte
TD,
Paschal
DC,
Flegal
KM.
Blood
lead
levels
in
the
U.
S.
population:
Phase
I
of
the
Third
National
Health
and
Nutrition
Examination
Survey.
JAMA
1994;
272:
277­
83.

2.
Pirkle
JL,
Brody
D,
Gunter
EW,
Pashcal
DC,
Flegal
KM,
Matte
TD.
The
decline
in
blood
lead
levels
in
the
United
States:
The
National
Health
and
Nutrition
Examination
Surveys.
JAMA
1994;
272:
284­
91.

3.
Pirkle
JL,
Kaufmann
RB,
Brody
DJ,
Hickman
T,
Gunter
EW,
Paschal
DC.
Exposure
of
the
U.
S.
population
to
lead:
1991­
1994.
Environ
Health
Perspect
1998;
106:
745­
50.

4.
Paschal
DC,
Burse
V,
Gunter
EW,
Pirkle
JL,
Sampson
EJ,
Miller
DT,
Jackson
RJ,
Caudill
SP.
Exposure
of
the
U.
S.
population
aged
6
years
and
older
to
cadmium:
1988­
1994.
Arch
Environ
Contam
Toxicol
2000;
38:
377­
83.

5.
Pirkle
JL,
Flegal
KM,
Bernert
JT,
Brody
DJ,
Etzel
RA,
Maurer
KR.
Exposure
of
the
U.
S.
population
to
environmental
tobacco
smoke:
The
Third
National
Health
and
Nutrition
Examination
Survey,
1988­
1991.
JAMA
1996;
275:
1233­
40.

6.
Centers
for
Disease
Control
and
Prevention.
Blood
lead
levels
in
young
children
 
United
States
and
selected
states,
1996
 
1999.
MMWR
Morb
Mortal
Wkly
Rep
;
49(
50):
1133­
7.

7.
National
Academy
of
Sciences.
Toxicologic
effects
of
methylmercury.
Washington
(
D.
C.):
National
Research
Council;
2000.

8.
Occupational
Safety
and
Health
Administration.
OSHA
29
CFR
1910.1127,
Section
1
 
Medical
Surveillance.
Washington
(
D.
C.):
OSHA;
1992.

9.
American
Conference
of
Government
Industrial
Hygienists.
2000
TLVs
and
BEIs:
Threshold
limit
values
for
chemical
substances
and
physical
agents
and
biological
exposure
indices.
Cincinnati
(
OH):
ACGHI;
2000.
p.
91,
97.

10.
U.
S.
Nuclear
Regulatory
Commission.
U.
S.
Nuclear
Regulatory
Commission
(
NRC)
Guide
8.22
 
Bioassay
at
Uranium
Mills.
Washington
(
D.
C.):
NRC;
July
1978.

11.
Seiler
HG,
Sigel
H,
Sigel
A,
eds.
Handbook
on
toxicity
of
inorganic
compounds.
New
York:
Mardel
Decker,
1988.
p.
217­
21.

12.
Budavari
S,
ed.
The
Merck
Index.
11th
ed.
Rahway
(
NJ):
Merck
&
Co.,
Inc;
1989.
p.
308­
9.

13.
Caraballo
R,
Giovino
G,
Pechacek
TF,
Mowery
PD,
Richter
PA,
Strauss
WJ,
Sharp
DJ,
Eriksen
MP,
Pirkle
JL,
Maurer
KR.
Racial/
ethnic
differences
in
serum
cotinine
levels
among
U.
S.
adult
cigarette
smokers:
The
Third
National
Health
and
Nutrition
Examination
Survey,
1988­
1991.
JAMA
1998;
280:
135­
140.
48
14.
U.
S.
Environmental
Protection
Agency
(
EPA),
Office
of
Pesticide
Programs.
Organophosphate
pesticides
in
food:
A
primer
on
reassessment
of
residue
limits
[
Online].
Available:
www.
epa.
gov/
pesticides/
op/
primer.
htm
[
2001,
March
16]

15.
U.
S.
Environmental
Protection
Agency
(
EPA),
Office
of
Pesticide
Programs.
Status
summary
of
the
organophosphate
review
process
[
Online].
Available:
www.
epa.
gov/
pesticides/
op/
status.
htm
[
2001,
March
16].

16.
Mylchreest
E,
Cartley
RC,
Foster
PMD.
Male
reproductive
tract
malformations
in
rats
following
gestational
and
lactational
exposure
to
dibutyl
phthalate:
an
antiandrogenic
mechanism?
Toxicol
Sci
1998;
43:
47­
60.

17.
Thomas
JA,
Thomas
MJ.
Biological
effects
of
diethylhexyl
phthalate
and
other
phthalic
acid
esters.
Crit
Rev
Toxicol
1984;
13:
283­
317.
49
References
for
Analytical
Methods
Metals
1.
Chen
HP,
Paschal
DC,
Miller
DT,
Morrow
JC.
Determination
of
total
and
inorganic
mercury
in
whole
blood
by
on­
line
digestion
with
flow
injection.
Atomic
Spectroscopy
1998;
19:
176­
9.

2.
Miller
DT,
Paschal
DC,
Gunter
EW,
Stroud
PE,
D'Angelo
J.
Determination
of
lead
in
blood
using
electrothermal
atomization
atomic
absorption
spectrometry
with
a
L'vov
platform
and
matrix
modifier.
Analyst
1987;
112:
1701­
4.

3.
Paschal
DC,
Ting
BG,
Borrow
JC,
Pirkle
JL,
Jackson
RJ,
Sampson
EJ,
Miller
DT,
Caldwell
KT.
Trace
metals
in
urine
of
United
States
residents:
reference
range
concentrations.
Environ
Res
1998;
76:
53­
9.

4.
Stoeppler
M,
Brandt
K.
Determination
of
cadmium
in
whole
blood
and
urine
by
electrothermal
atomic­
absorption
spectrophotometry.
Fresenius
A
Anal
Chem
1980;
300:
372­
80.

Tobacco
Smoke
(
Cotinine)

Bernert
JT,
Turner
WE,
Pirkle
JL,
Sosnoff
CS,
Akins
JR,
Waldrep
MK,
Ann
Q,
Covey
TR,
Whitfield
WE,
Gunter
EW,
Miller
BB,
Patterson
DG,
Needham
LL,
Hannon
WH,
Sampson
EJ.
Development
and
validation
of
a
sensitive
measurement
of
serum
cotinine
in
both
smokers
and
nonsmokers
by
liquid
chromatography/
atmospheric
pressure
ionization
tandem
mass
spectrometry.
Clin
Chem
1997;
43:
2281­
91.

Metabolites
of
Organophosphate
Pesticides
Bravo
R,
Driskell
WJ,
Whitehead
Jr
RD,
Needham
LL,
Barr
DB.
Determination
of
dialkyl
phosphate
metabolites
of
organophosphate
pesticides
in
urine
using
GC­
MS/
MS
with
stable
isotope
internal
standards.
[
Note:
This
manuscript
is
in
review
for
publication.
For
a
copy
of
the
methods,
submit
an
e­
mail
request
to
ncehdls@
cdc.
gov.

Phthalate
Metabolites
Blount
BC,
Milgram
KE,
Silva
M,
Malek
N,
Reidy
J,
Needham
LL,
Brock
JW.
Quantitative
detection
of
eight
phthalate
metabolites
in
human
urine
using
HPLC­
APCI­
MS/
MS.
Anal
Chem
2000;
72:
4127­
34.
51
Glossary
acaricide
A
chemical
agent
that
kills
mites.

acetylcholinesterase
An
enzyme
that
exists
in
skeletal
muscle,
red
blood
cells,
and
the
gray
matter
of
nerve
tissue.

alkyl
group
A
group
of
atoms
derived
from
an
alkane
(
a
hydrocarbon
with
no
carbon­
to­
carbon
multiple
bonds)
by
the
removal
of
one
hydrogen
atom.

alloy
A
substance
that
is
a
mixture
of
two
or
more
metals.
Alloys
are
often
harder,
stronger,
lighter,
or
more
durable
than
individual
metals.

analytical
method
A
laboratory
procedure
used
to
measure
a
chemical
in
a
human
specimen,
such
as
blood
or
urine.

antimony
(
CAS
No.
7440­
36­
0)
A
silver­
white
metal
found
in
the
earth's
crust.
In
nature,
antimony
can
be
found
in
ores
and
other
minerals.
Antimony
ores
are
mixed
with
other
metals
to
form
antimony
alloys,
or
they
combine
with
oxygen
to
form
antimony
oxide.

barium
(
CAS
No.
7440­
39­
3)
A
silver­
white
metal
that
exists
in
nature
and
combines
with
other
chemicals,
such
as
sulfur
or
carbon
and
oxygen.
These
combinations
are
called
compounds.
Industry
also
produces
barium
compounds.

beryllium
(
CAS
No.
7440­
41­
7)
A
hard,
gray
metal.
In
nature,
beryllium
can
combine
with
other
chemicals
in
rocks,
coal,
soil,
and
volcanic
dust.

biomonitoring
Laboratory
analysis
of
human
specimens,
such
as
blood
or
urine,
to
measure
people's
exposure
to
chemicals
in
the
environment.

blood
The
fluid
that
circulates
through
the
heart,
arteries,
veins,
and
capillaries
of
the
body.
Blood
carries
oxygen
and
nutrients
to
cells
and
removes
carbon
dioxide
and
other
waste
products
from
cells.

blood
lead
Lead
that
is
in
blood.

blood
mercury
Mercury
that
is
in
blood.

cadmium
(
CAS
No.
7440­
43­
9)
52
A
mineral
that
naturally
exists
in
the
earth's
crust.
All
soils
and
rocks,
including
coal
and
mineral
fertilizers,
have
some
cadmium
in
them.
Industry
takes
out
cadmium
during
the
production
of
other
metals
such
as
zinc,
lead,
and
copper.

carbamate
pesticides
A
group
of
organic
pesticides
that
are
used
as
herbicides,
insecticides,
and
fungicides.
These
pesticides
do
not
stay
in
the
soil
for
a
long
time.

carcinogenic
Capable
of
causing
cancer.

CAS
number
A
unique
number
assigned
to
a
given
compound
by
the
Chemical
Abstracts
Service,
a
division
of
the
American
Chemical
Society.
Also
known
as
CAS
registry
number,
CAS
RN,
or
CAS
#.

catalytic
activity
The
activity
of
a
catalyst,
a
substance
that
increases
the
rate
of
a
chemical
reaction.

cesium
(
CAS
No.
7440­
46­
2)
A
silver­
white
metal
that
catches
fire
when
exposed
to
air
and
that
reacts
explosively
with
water.
Cesium
is
found
naturally
in
rock,
soil,
and
clay.
Cesium
sometimes
combines
with
other
chemicals.
These
combinations
are
called
compounds.
Cesium
is
used
primarily
to
convert
and
conduct
electricity.

chlorpyrifos
(
CAS
No.
2921­
88­
2)
An
organophosphate
pesticide.

cobalt
(
CAS
No.
7440­
48­
4)
An
element
that
occurs
in
nature
either
as
a
steel­
gray,
shiny,
hard
metal
or
combined
with
other
elements.
These
combinations
are
called
compounds.
Cobalt
occurs
naturally
in
many
types
of
soil
and
in
dust
and
seawater.
Small
amounts
also
occur
naturally
in
food.

compound
A
substance
composed
of
two
or
more
elements.
For
example,
table
salt
(
sodium
chloride
or
Na
Cl)
is
a
compound
composed
of
sodium
(
Na)
and
chlorine
(
Cl).

confidence
interval
A
range
of
statistical
values
within
which
a
true
value
or
result
is
expected
to
fall
with
a
specific
probability.

copper
(
CAS
No.
7440­
50­
8)
An
element
that
occurs
in
nature
as
a
soft,
reddish,
flexible
metal.
Copper
is
an
excellent
conductor
of
electricity.

cotinine
(
CAS
No.
486­
56­
6)
A
metabolite
 
or
breakdown
product
 
of
nicotine,
one
of
the
chemicals
found
in
smoking
and
chewing
tobacco.
Cotinine
is
produced
when
the
body
takes
in
nicotine
and
breaks
it
down.
Nicotine
gets
into
people's
bodies
if
they
smoke
or
chew
tobacco
of
if
they
are
exposed
to
environmental
tobacco
smoke
(
also
called
"
secondhand"
smoke).
53
creatinine
(
CAS
No.
60­
27­
5)
A
nitrogen
compound
that
is
found
in
muscle,
blood,
and
urine.

deciliter
(
dL)
A
unit
of
volume
equal
to
one­
tenth
of
a
liter,
about
one­
half
cup
of
liquid.

detection
limit
The
amount
of
a
substance
that
a
laboratory
can
measure
reliably
in
a
sample
of
air,
water,
soil,
or
other
medium,
such
as
blood
or
urine.

diazinon
(
CAS
No.
333­
41­
5)
An
insecticide.
In
1986,
the
U.
S.
Environmental
Protection
Agency
(
EPA)
banned
its
use
in
open
areas,
such
as
sod
farms
and
golf
courses,
because
it
posed
a
danger
to
migratory
birds.
The
ban
applies
to
agricultural,
home­
lawn,
or
commercial­
establishment
uses.

diethyldithiophosphate
(
CAS
No.
298­
06­
6)
An
organophosphate
pesticide
metabolite
or
breakdown
product
that
is
formed
when
the
body
is
exposed
to
one
of
four
different
organophosphate
pesticides.
This
metabolite
can
be
measured
in
a
person's
urine
if
that
person
has
been
exposed
to
disulfoton,
ethion,
phorate,
or
terbufos.

diethylphosphate
(
CAS
No.
598­
02­
7)
An
organophosphate
pesticide
metabolite
or
breakdown
product
that
is
formed
when
the
body
is
exposed
to
one
of
ten
different
organophosphate
pesticides.
This
metabolite
can
be
measured
in
a
person's
urine
if
that
person
has
been
exposed
to
chlorethoxyphos,
chlorpyrifos,
coumaphos,
diazinon,
disulfoton,
ethion,
parathion,
phorate,
sulfotepp,
or
terbufos.

diethylthiophosphate
(
CAS
No.
5871­
17­
0)
An
organophosphate
pesticide
metabolite
or
breakdown
product
that
is
formed
when
the
body
is
exposed
to
one
of
ten
different
organophosphate
pesticides.
This
metabolite
can
be
measured
in
a
person's
urine
if
that
person
has
been
exposed
to
chlorethoxyphos,
chlorpyrifos,
coumaphos,
diazinon,
disulfoton,
ethion,
parathion,
phorate,
sulfotepp,
or
terbufos.

dimethyldithiophosphate
(
CAS
No.
756­
80­
9)
An
organophosphate
pesticide
metabolite
or
breakdown
product
that
is
formed
when
the
body
is
exposed
to
one
of
five
different
organophosphate
pesticides.
This
metabolite
can
be
measured
in
a
person's
urine
if
that
person
has
been
exposed
to
azinphos
methyl,
dimethoate,
malathion,
methidathion,
or
phosmet.

dimethylphosphate
(
CAS
No.
813­
78­
5)
An
organophosphate
pesticide
metabolite
or
breakdown
product
that
is
formed
when
the
body
is
exposed
to
one
of
18
different
organophosphate
pesticides.
This
metabolite
can
be
measured
in
a
person's
urine
if
that
person
has
been
exposed
to
azinophos
methyl,
chlorpyrifos
methyl,
dichlorvos
(
DDVP),
dicrotophos,
dimethoate,
fenitrothion,
fenthion,
isazaphos­
methyl,
malathion,
methidathion,
methyl
parathion,
naled,
oxydemeton­
methyl,
phosmet,
pirimiphos­
methyl,
temephos,
tetrachlorviphos,
or
trichlorfon.

dimethylthiophosphate
(
CAS
No.
1112­
38­
5)
An
organophosphate
pesticide
metabolite
or
breakdown
product
that
is
formed
when
the
body
is
exposed
to
one
of
13
different
organophosphate
pesticides.
This
metabolite
can
be
measured
in
a
person's
urine
if
that
54
person
has
been
exposed
to
azinphos
methyl,
chlorpyrifos
methyl,
dimethoate,
fenitrothion,
fenthion,
isazaphos­
methyl,
malathion,
methidathion,
methyl
parathion,
oxydemeton­
methyl,
phosmet,
pirimiphosmethyl
or
temephos.

dioxin
Any
of
a
family
of
compounds
known
chemically
as
dibenzo­
p­
dioxins.
Concern
about
these
compounds
arises
from
their
potential
toxicity
and
ability
to
contaminate
commercial
products.

disulfoton
(
CAS
No.
298­
04­
4)
A
pale
yellow
insecticide
used
on
some
vegetables
and
flowers.

element
A
substance
that
cannot
be
separated
into
its
constituent
parts
and
still
retain
its
chemical
identity.
An
example
of
an
element
is
sodium
(
Na).

exposure
Contact
with
a
chemical
by
swallowing,
breathing,
or
touching
(
such
as
through
the
skin
or
eyes).
Exposure
may
occur
immediately
or
over
a
longer
period.

fenthion
(
CAS
No.
55­
38­
9)
A
substance
that
is
used
as
an
insecticide
and
acaricide.

fossil
fuel
A
substance
found
in
the
layers
of
the
earth
that
can
be
burned.
Fossil
fuel
is
formed
by
the
remains
of
plants
and
animals
that
lived
millions
of
years
ago.
Oil,
natural
gas,
peat,
and
coal
are
fossil
fuels.

furan
(
CAS
No.
110­
00­
9)
A
colorless,
flammable
liquid
that
is
used
as
a
solvent.
Furan
is
also
used
to
make
polymers
such
as
nylon.

geometric
mean
A
special
mathematical
average.

gram
(
g)
A
gram
is
basic
unit
of
mass
in
the
metric
system
and
is
equal
to
the
weight
of
one
cubic
centimeter
of
water
at
4
degrees
centigrade.

inductively
coupled
plasma
mass
spectrometry
(
ICPMS)
A
method
for
analyzing
several
chemicals
at
the
same
time.

industrial
solvent
A
substance
or
liquid
that
industry
uses
to
dissolve
other
substances.

isomer
One
of
two
or
more
molecules
that
have
the
same
chemical
formula
but
have
a
different
arrangement
of
their
atoms.

lead
(
CAS
No.
7439­
92­
1)
55
A
naturally
occurring
blue­
gray
metal
found
in
the
earth's
crust.
Lead
is
found
in
small
amounts
in
rock
and
soil.
Lead
can
be
found
in
all
parts
of
the
environment.
Most
lead
comes
from
human
activities
such
as
mining,
manufacturing,
and
burning
fossil
fuels.

limit
of
detection
The
minimum
concentration
of
a
substance
being
analyzed
that
can
be
measured
with
high
confidence.

liter
(
L)
A
liter
is
the
basic
unit
of
volume
in
the
metric
system,
equal
to
1.06
liquid
quarts.

logarithmic
scale
The
power
to
which
a
base
must
be
raised
to
equal
a
given
number.
In
this
Report,
logarithms
are
expressed
using
a
base
of
10.

malathion
(
CAS
No.
121­
75­
5)
A
yellow­
brown
liquid
that
is
widely
used
as
an
insecticide.

mass
spectrometry
A
scientific
method
that
separates
organic
matter
into
basic
elements
and
compounds
and
analyzes
them
according
to
atomic
and
molecular
mass.

mean
A
mathematical
average.

median
In
a
group
of
numbers,
the
value
of
the
middle
number
when
the
numbers
are
arranged
in
ascending
order.

mercury
(
CAS
No.
7439­
97­
6)
A
naturally
occurring
metal
that
comes
in
several
forms.
Metallic
mercury
is
a
shiny,
silver­
white,
odorless
liquid.
If
heated,
mercury
forms
a
colorless,
odorless
gas.
Mercury
combines
with
other
elements
to
form
mercury
compounds.

metabolism
All
the
chemical
reactions
that
enable
the
body
to
work.
For
example,
food
is
metabolized
(
chemically
changed
or
broken
down)
to
supply
the
body
with
energy.
Chemicals
can
be
metabolized
and
made
either
more
or
less
harmful
by
the
body.

metabolite
A
byproduct
of
metabolism
that
happens
when
the
body
takes
in
a
substance,
such
as
an
environmental
chemical,
and
breaks
it
down.

metal
An
element
that
is
typically
shiny
and
conducts
heat
and
electricity.
Mercury,
lead,
and
cadmium
are
examples
of
metals.

methyl
parathion
(
CAS
No.
298­
00­
0)
Methyl
parathion
is
an
insecticide
that
comes
in
two
forms:
white
crystals
or
a
brown
liquid.
It
smells
like
56
rotten
eggs,
is
similar
to
nerve
gas,
and
is
used
to
kill
insects
on
farm
crops,
especially
cotton.
Methyl
parathion
is
a
restricted­
use
pesticide
that
only
trained
people
are
allowed
to
mix,
load,
and
spray.
It
is
banned
for
indoor
residential
use.

microgram
(
µ
g)
A
unit
of
mass
equal
to
one­
millionth
of
a
gram.

milliliter
(
mL)
A
unit
of
volume
equal
to
one­
thousandth
of
a
liter.

molybdenum
(
CAS
No.
7439­
98­
7)
A
silver­
white,
hard
metal
with
many
commercial
uses.
Molybdenum
withstands
high
temperatures
and
high
pressure
and
is
a
byproduct
of
copper
mining.

mono­
benzyl
phthalate
(
CAS
No.
2528­
16­
7)
A
metabolite
or
breakdown
product
of
benzylbutyl
phthalate.
This
product
can
be
measured
in
a
person's
urine.

mono­
butyl
phthalate
(
CAS
No.
131­
70­
4)
A
metabolite
or
breakdown
product
of
dibutyl
phthalate.
This
product
can
be
measured
in
a
person's
urine.

mono­
cyclohexyl
phthalate
(
CAS
No.
7517­
36­
4)
A
metabolite
or
breakdown
product
of
dicyclohexyl
phthalate.
This
product
can
be
measured
in
a
person's
urine.

mono­
ethyl
phthalate
(
CAS
No.
2306­
33­
4)
A
metabolite
or
breakdown
product
of
diethyl
phthalate.
This
product
can
be
measured
in
a
person's
urine.

mono­
2­
ethylhexyl
phthalate
(
CAS
No.
4376­
20­
9)
A
metabolite
or
breakdown
product
of
di­
2­
ethylhexyl
phthalate.
This
product
can
be
measured
in
a
person's
urine.

mono­
isononyl
phthalate
(
does
not
have
a
CAS
No.)
A
metabolite
or
breakdown
product
of
di­
isononyl
phthalate.
This
product
can
be
measured
in
a
person's
urine.

mono­
n­
octyl
phthalate
(
CAS
No.
5393­
19­
1)
A
metabolite
or
breakdown
product
of
dioctyl
phthalate.
This
product
can
be
measured
in
a
person's
urine.

nanogram
(
ng)
A
unit
of
mass
equal
to
one­
billionth
of
a
gram.

National
Health
and
Nutrition
Examination
Survey
(
NHANES)
A
series
of
surveys
designed
to
collect
data
on
the
health
and
nutritional
status
of
the
U.
S.
population.
In
1999,
NHANES
became
a
continuous
and
annual
survey.

nitrosamine
57
An
organic
compound
that
is
found
in
many
foods.
Nitrosamines
can
cause
cancer.

nonpersistent
pesticide
A
pesticide
that
breaks
down
into
nontoxic
components
almost
immediately
after
application
or
that
only
lasts
for
a
few
days
before
breaking
down.

organophosphate
pesticides
Pesticides
that
contain
phosphorus.
They
can
be
poisonous
to
animals
and
people
because
they
prevent
essential
nervous
system
enzymes
from
working.
Organophosphate
pesticides
are
chemically
unstable
or
nonpersistent.

parathion
(
CAS
No.
56­
38­
2)
An
organophosphate
pesticide
used
to
control
many
insects
and
mites.
Trade
names
for
parathion
include
AC
3422,
Alkron,
Alleron,
Aphamite,
Corothion,
E­
605,
ENT
15108,
Ethyl
parathion,
Etilon,
Fosferno
50,
Niran,
Orthophos,
Panthion,
Paramar,
Paraphos,
Parathene,
Parawet,
Phoskil,
Rhodiatox,
Soprathion,
Stathion,
and
Thiophos.

percentile
The
set
of
divisions
that
produce
exactly
100
equal
parts
in
a
series
of
continuous
values.

phorate
(
CAS
No.
298­
02­
2)
A
toxic,
clear
liquid
used
as
an
insecticide.

phosmet
(
CAS
No.
732­
11­
6)
An
organophosphate
pesticide
mainly
used
on
apple
trees,
although
it
is
also
used
on
a
other
fruit
crops,
ornamentals,
and
vines
to
control
aphids,
suckers,
mites,
moths,
and
fruit
flies.
The
compound
is
also
an
active
ingredient
in
some
pet
collars.
Trade
names
for
phosmet
include
Appa,
Decemtion,
Fesdan,
Imidan,
Kemolate,
Prolate,
PMC,
and
Safidon.

phthalates
A
family
of
chemicals
used
primarily
as
plasticizers
that
are
added
to
products
to
make
them
soft
or
flexible.

pigment
A
natural
or
synthetic
substance
that
is
used
to
transfer
color
to
another
substance.

platinum
(
CAS
No.
7440­
06­
4)
A
silver­
gray,
lustrous
metal
found
naturally
in
the
earth's
crust.
Platinum
and
the
compounds
it
forms
resist
corrosion
and
can
withstand
high
temperatures.

pollutant
Any
substance
or
agent
that
causes
pollution.

polyaromatic
hydrocarbons
(
PAHs)
A
group
of
more
than
100
different
chemicals
that
are
formed
during
the
incomplete
burning
of
coal,
oil,
gas,
garbage,
or
other
organic
substances,
including
tobacco
or
charbroiled
meat.
PAHs
are
found
in
soot,
coal
tar,
crude
oil,
creosote,
and
roofing
tar.
Some
PAHS
are
used
in
medicines,
dyes,
plastics,
and
pesticides.
58
polychlorinated
biphenyls
(
PCBs)
A
group
of
manufactured
organic
chemicals
that
contain
209
individual
chlorinated
chemicals
(
known
as
congeners).
PCBs
are
oily
liquids
or
solids
and
range
from
being
colorless
to
light
yellow.
Products
containing
PCBs
are
old
fluorescent
lighting
fixtures;
electrical
appliances
containing
PCB
capacitators;
old
microscope
oil;
and
hydraulic
fluids,
paints,
inks,
adhesives,
electrical
condensers,
batteries,
and
lubricants.

reference
range
A
set
of
numerical
quantities
that
serves
as
a
base
against
which
further
quantities
are
measured.

sample
A
portion
of
a
population
that
is
observed
to
make
generalizations
about
the
whole
population.

sample
size
The
number
of
units
(
such
as
people
or
animals)
in
a
population
to
be
studied.
If
a
scientist
surveys
200
people
about
their
pesticide
use,
the
sample
size
would
be
200.

serum
The
liquid
portion
of
blood
that
remains
after
the
removal
of
clotting
proteins
and
blood
cells.

substrate
A
compound
that
reacts
with
a
substance.

temephos
(
CAS
No.
3383­
96­
8)
An
organophosphate
pesticide
used
to
control
mosquito,
midge,
and
black
fly
larvae.
Temephos
is
used
on
lakes,
ponds,
and
wetlands.
It
is
also
used
to
control
fleas
on
dogs
and
cats
and
to
control
lice
on
humans.
Trade
names
for
temephos
include
Abat,
Abate,
Abathion,
Acibate,
Biothion,
Difennthos,
Ecopro,
Nimitox,
and
Swebate.

thallium
(
CAS
No.
7440­
28­
0)
A
blue­
white
metal
that
is
found
in
the
earth's
crust.
Thallium
is
found
in
small
amounts
in
soil
and
rocks.
In
the
past,
thallium
was
obtained
as
a
byproduct
of
smelting
other
metals;
however,
it
has
not
been
produced
in
the
United
States
since
1984.

thermocouple
A
device
consisting
of
two
different
metallic
conductors
that
are
connected
at
both
ends,
producing
a
loop
in
which
heat
is
converted
into
electrical
current.
A
thermocouple
is
used
to
measure
the
temperature
of
a
substance.

toxicant
A
toxic
or
poisonous
substance.

tungsten
(
CAS
No.
7440­
33­
7)
A
steel­
gray
to
tin­
white
metal
found
naturally
in
the
earth's
crust.
This
metal
is
highly
flammable
and
may
catch
fire
spontaneously
when
exposed
to
air.
Tungsten
may
be
combined
with
other
chemicals
such
as
carbon.
Tungsten
is
also
called
wolfram.
59
uranium
(
CAS
No.
7439­
97­
6)
A
silver­
white,
extremely
dense
radioactive
metal.
Uranium
almost
never
occurs
by
itself
but
rather
in
combination
with
oxygen,
chlorine,
or
fluorine.

volatile
organic
compounds
(
VOCs)
Organic
compounds
that
evaporate
readily
into
the
air.
VOCs
are
released
when
cars
or
other
machines
burn
fuel.
VOCs
contribute
significantly
to
smog
production.
VOCs
include
chemicals
such
as
benzene,
toluene,
methylene
chloride,
and
methyl
chloroform
and
can
cause
serious
health
problems.

zinc
(
CAS
No.
7440­
66­
6)
One
of
the
most
common
elements
in
the
earth's
crust.
Zinc
is
found
in
air,
soil,
and
water
and
is
present
in
all
foods.
Pure
zinc
is
a
blue­
white,
shiny
metal.
Zinc
is
used
in
coatings
to
prevent
rust
and
in
dry­
cell
batteries.
It
is
also
mixed
with
other
metals
to
make
alloys
such
as
brass
and
bronze.
A
zinc
and
copper
alloy
is
used
to
make
pennies
in
the
United
States.
Zinc
compounds
are
widely
used
in
industry
to
make
paint,
rubber,
dye,
wood
preservatives,
and
ointments.
Centers
for
Disease
Control
and
Prevention
National
Center
for
Environmental
Health
Division
of
Laboratory
Sciences
Mail
Stop
F­
20
4770
Buford
Highway,
N.
E.
Atlanta,
Georgia
30341­
3724
Telephone
(
toll­
free):
1­
866­
670­
6052
E­
mail:
ncehdls@
cdc.
gov
Web
site:
www.
cdc.
gov/
nceh/
dls/
report
March
2001
NCEH
Pub.
No.
01­
0379
