Siniififl St
F nvironmpntal Prptprtinn
NHATS
National Human Adipose"; issue Survey
A c.
-------
NHATS
National Human Adipose Tissue Survey
BACKGROUND
The U.S. Environmental Protection Agency (EPA) through the National
Human Monitoring Program (NHMP) has conducted a number of
programs to monitor pesticides and other toxic substances in human
tissues and fluids since the early 1970s. The National Human Adipose
Tissue Survey (NHATS) is EPA's primary program under the NHMP.
Monitoring data are used in exposure assessments and are important
elements in the quantitative evaluations of hazard and risk.
PURPOSE
To Collect Human Adipose Tissue for Research Purposes.
Researchers use the adipose tissue to monitor the prevalence and
levels of selected toxic substances in the general United States
population. Data collected are used to provide average baseline levels
in the general population, identify trends in exposure, and assess
the effects of regulatory action.
DESIGN
Specimens are collected in 47 metropolitan statistical areas (MSAs)
according to a statistically determined survey design. The design
specifications are based on the age, sex, and race of the U.S. Census
population figures for the census division to which the MSA belongs.
The geographic stratification used in the design ensures a represen-
tative sample for all regions of the country for use in determining
estimates of levels of toxic substances in the adipose tissue.
-------
1990 Survey Design
Age Group
Sex
Census Region
North Central
Northeast
South
West
Number of Specimens Collected
0-14 Years
Male Female
45 45
30 30
53 48
30 30
15-44 Years
Male Female
90 90
60 60
96 98
66 70
45+ Years
Male Female
60 75
40 50
64 73
34 40
'Noncaucasians constitute 8% of the 1,377 total specimens
More Than 90 Pathologists and Medical Examiners
in 47 Metropolitan Statistical Areas
Northeast Region
1 New England
2 Middle Atlantic
South Region
3 South Atlantic
4 East South Central
5 West South Central
North Central Region
6 East North Central
7 West North Centra]
West Region
8 Mountain
9 Pacific
-------
RESULTS
ORGANOCHLORINE PESTICIDES AND PCBs
EPA through the NH ATS program has conducted human monitoring efforts since
the early 1 970's designed to estimate average concentrations of organochlorine
pesticides and other toxic substances (specifically PCBs) in the general popula-
tion. The results of these surveys have shown that almost all of the general
population contained low levels of these environmentally persistent compounds.
More recent monitoring efforts have demonstrated that as a result of restriction
or ban of specific compounds there is a corresponding reduction in body burden
levels of these substances.
Estimated Time Trends of
Concentration Levels
Percent of Population Having
Levels of PCBs Greater Than 3 ppm
75 76
Fiscal Year
a
I
Median Concentration Levels of Total DDT (ppm)
72
75
76 77
Fiscal Year
3
78
79
83
-------
Comparison
Concentrati
Across Age Groups
70 71 72 73 74 75 76 77 78 79
0.15
Median Concentration Levels of Oxychlordane (ppm)
81 82 83
0-14 years
45+ years
15-44 years
0.44
0.39
0.34
0.29
c
a
=0 0.24
0.19
0.14
0.09
0.04
Median Concentration Levels of I3-BHC (ppm)
70 71 72 73 74 75 76 77 78 79 80 81 82 83
Rscal Year
0-14 years
45+ years
15-44 years
-------
i of Chemical
ition Levels
Across Census Regions
fcj
I
0.043
Median Concentration Levels of Hexachlorobenzene (ppm)
70 71 72 73 74 75 76 77 78 79 80 81 82 83
Fiscal Year
North Central
South
North East
West
0.6
0.3
0.2
0.1
0.0
Median Concentration Levels of 8-BHC (ppm)
70 71 72 73 74 75 76 77 78 79 80 81 82 83
Fiscal Year
North Central
South
North East
West
-------
DiOXINS AND FURANS
Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) have been
the subject of much concern in recent years as a result of the extreme toxicity
of some of the isomers. The compound 2,3,7,8-Tetrachlorodibenzo-p-dioxin
(TCDD), commonly referred to as "dioxin", has been demonstrated to be one
of the most highly toxic compounds evaluated in animal studies.
The dioxins and furans originate from multiple sources which include commercial
products (contaminants in herbicides such as Agent Orange and 2,4,5-T; wood
preservatives such as pentachlorophenol; trichlorophenols; etc.), emissions from
incineration sources (municipal refuse incinerators, hospital waste incinerators,
metal reclamation facilities, automobiles, and wood stoves) and bleaching proces-
ses used in the pulp and paper industry.
The NHATS program has generated data on the background & levels of these
chemicals in the general U.S. population. Examples of the results for TCDDs
showing trends from 1971 to 1987, levels across age categories and a comparison
between Vietnam veterans, non-Vietnam veterans, and civilians are shown below.
Log TCDD Level in pg/g (ppt)
Histogram of 2,3,7,8-TCDD Levels
by Study Group After Log Transformation
Results:
8
I
THTTT^-. r^ — ^
0 .2 .4 .6 .8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0 4.6
-------
Mean 2,3,7,8-TCDD Concentration for Samples Collected
from 1971 through 1987 (15-44 Age Group)
Concentration
pg/g Lipid
Analyzed as individual specimens
CD Analyzed as composite specimens
71-73 74-76 77-78 80-82 FY82 FY87
Concentration
pg/g Lipid
16
Ranges of 2,3,7,8-TCDD Concentrations for the FY87
NHATS Composites by Age Category
14
12
101
8
6
4
0-14
15-44
Age Category
45 +
-------
SPECIAL STUDY
As part of an effort to expand the capabilities of EPA's unique human monitoring
program, special studies were conducted. One of these studies involved the
further evaluation of the specimens collected in FY1982 for the presence of
compounds that are cited in the Superfund Amendments and Reauthorization
Act (SARA) as chemicals of interest or identified at hazardous waste sites. Some
of the results for the determination of SARA related compounds and other
frequently detected chemicals are shown in the table below.
Volatile Compounds
Compound
Trichloroethylene
Dichlorobenzene
Styrene
Xylene
Chloroform
Benzene
Toluene
Ethyl Isovalerate
Limonene
Pentyl Alcohol
Biphenyl
2-Phenyl phenol
Bis(ethylhexyl)
Phthalate
Cresol
Diphenyl ether
Frequency of
Detection (°/o) Sources
43 Solvent for fats, waxes, resins, etc. Used for sol-J
vent extraction in many industries. Also used as |
degreasing agent in dry cleaning.
81 Active ingredient in moth balls.
100 Used in the manufacture of plastics.
100 Solvent.
76 Used as a solvent for fats, oils, rubber, waxes,
and resin; cleaning agent.
96 Used in the manufacture of medicinal chemicals,
dyes, and many other organic compounds.
91 Used in the manufacture of dyes, explosives, and
other organic compounds; a solvent for paints,
lacquer, and resins.
96 Used in alcoholic solution for flavoring confec-
tionary and beverages.
100 Found in various ethereal oils, particularly oils of
lemon and orange. Lemon-like odor. Used as a
solvent in the manufacture of resins, and as a
wetting and dispersing agent.
83 Solvent.
Semivolatile Compounds
20
48
91
88
91
Used as a heat transfer agent, fungistat for
oranges (applied to inside of shipping container or
wrappers).
Used as germicide and fungicide.
Plasticizer, vacuum pump oil.
Used as local antiseptic, parasiticide, disinfectant,
in photographic developing solutions, in manufac-
ture of explosives.
Used as a heat transfer medium and in perfuming
soaps.
------- |