/REPORT ON OPTS AMBIENT MONITORING ACTIVITIES
prepared for the
DAA TASK GROUP ON MONITORING AND INFORMATION MANAGEMENT
December 3, 1979
INTRODUCTION
Background
The Office of Pesticides and Toxic Substances (OPTS) currently
has five ambient monitoring networks: the National
Human Monitoring Program, the National Surface Water Monitoring
Program, the National Soils Monitoring Program, the National
Estuarine Monitoring Program, and the Suburban Air Monitoring
Studies. These programs, along with short-term, problem-
oriented studies for specific chemicals, monitor for selected
pesticides and- industrial chemicals. They are operated in the
Office of Program Information and Integration's Survey and Analysis
Division to fulfill the human and environmental monitoring mandates
of both the Federal Insecticide, Fungicide, and Rodenticide Act,
as amended (FIFRA) and the Toxic Substances Control Act (TSCA).
The networks were primarily designed to monitor chlorinated
hydrocarbon pesticides, and were located in various Federal
agencies before 1970. The networks were initiated in the mid-
sixties in response to recommendations of the President's Science
Advisory Committee that the Federal government should "develop a
continuing network to monitor (pesticide) residue levels ....".
The individual programs were transferred to different parts of
EPA in 1970 and then transferred to the Office of Pesticide
Programs in 1972. During FY 1979, these ambient networks were
transferred again to OPII's Survey and Analysis Division to
organizationally centralize chemical monitoring responsibilities
for FIFRA and TSCA. Presently, these networks monitor primarily
for pesticide chemicals, but a few, selected industrial dhe.nrafl^a.ls
are also monitored.
Objectives
The objectives of the OPTS ambient monitoring networks include:
• the assessment of actual or potential human environmental
levels of exposure to pesticides and other toxic
chemicals
• the establishment of baseline information on the levels
of chemicals in humans and environmental media;
• , the identification of trends in these levels over
time;
• the identification of chemical problems or "hot spots";
• the demonstration of reduction of exposure levels as
a result of chemical regulation under TSCA or FIFRA.
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FIFRA/TSCA Regulatory Differences
A review of ambient monitoring as a supporting function of FIFRA
and TSCA must necessarily take into account the use of the
concept of risk/benefit analysis which is unique to these two
laws. Other legislation administered by the Agency utilizes the
concept of pollutant load reduction or elimination. Under
FIFRA and TSCA, the Agency must weigh the risks associated
with the use of a chemical against the benefits derived from
that use. The ambient levels of a chemical resulting from
several acceptable uses (i.e., where benefits outweigh
risks) may vary widely.
Another unique feature of the amended FIFRA, as compared to
other EPA legislative mandates, is the regulation by special
pesticide use. Certain of the ambient pesticide monitoring
programs are oriented to reflect this regulatory mode. Although
human monitoring activities are directed toward general population
exposure assessments for public health considerations, several
programs provide exposure data via specific use categories.
Both the agricultural soils and suburban/urban air monitoring
programs are designed to develop data on environmental exposure
on a specific use basis.
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CONCLUSIONS
MONITORING PROGRAM EVALUATION
Results and Data Validity
A necessarily brief but thorough review the monitoring data from
the OPTS ambient networks was performed for this report. A
copy of that review is appended to this document (Appendix A).
The major conclusions of that review are:
• Presently/ only the National Human Monitoring
Program (Adipose Tissue Survey) may be used
to make statistically significant inferences about
the entire U.S. (the HANES II Survey of human blood
serum and urine will also allow a national analysis
when completed; the data base is incomplete at this
time).
• The networks do have the potential to monitor
trends in pesticide levels in the various media
over time and by geographic area.
• The data from the various networks cannot be
matched for multi-media statistical analyses.
• The NHMP Adipose Tissue Survey indicates several
statistically significant differences by race,
age, sex, census division and year for several
chemicals examimed. (Although practical significance
may vary).
"Statistical" versus "Practical" Significance
An important concept to understand, when a data set or
monitoring program is assessed, is the difference between
"statistical" and "practical" significance. As an example,
a data set is analyzed to determine the significance of a
trend over time and the data are assumed to be error-free
(i.e., no sampling or analysis error). It is determined that
the trends are statistically significant; what does this
mean? Very little, until the various errors involved with
the sampling design, actual sampling collection, analytical
error, etc. are quantified and compared to the level of
statistical significance. The result of this analysis is
the determination of practical significance. The level of
practical significance should dictate the type or magnitude
of decisions made based on the data. As part of the extensive
evaluation now underway, the practical significance of the
various network data is being determined.
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Past Use of Ambient Data
In the past, data generated by the ambient monitoring networks
were used extensively by the Office of Pesticide Programs.
Specific examples are explained in the following section.
Within OPP, monitoring data were used frequently by the Special
Pesticide Review Division (SPRD) for both RPAR (rebuttable
presumption against registration) and Generic Standards
(re-registration) activities. The Hazard Evaluation Division (HED)
utilized ambient monitoring data for exposure estimates as part
of the Risk Assessment process. Data were utilized least by the
Registration Division.
Data were also provided upon request to other parts of EPA;
the Office of Research and Development, the Office of General
Counsel, the Office of Air Planning and Standards, the old
Office of Toxic Substances. Additionally, data were provided to
various Federal, State, and local agencies and EPA Regions,
upon request.
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Future Assessment Plans
Presently, planning is ongoing to review and upgrade the
monitoring networks. This includes:
• an in-depth review of the statistical design for
each ambient network, scheduled for completion in
recommendations for network improvements. (see
Appendix B.).
* An extensive evaluation of past and possible future
uses of monitoring data will be performed. This will
include interviews with personnel at all levels in
OPP and OGC.
• A program to provide improved computer support to the
networks in FY 80 to 1) edit existing data bases;
2) provide timely data input; and 3) facilitate report
generation.
« The implementation of a computerized sample tracking
system for all network samples.
• Initiation of anticipatory monitoring efforts by:
1) determining the presence and identification of
unknown non-pesticidal organic compounds in networ]
samplesl and 2) additional analyses for known
non-pesticidal compounds in network samples.
• Inclusion of existing hazard signaling mechanisms
into the present monitoring data base to provide a
more responsive system of problem identification.
POLICY QUESTIONS RELATING TO OPERATING PROGRAMS
Data from the ambient monitoring networks have been used widely
as inputs to the OPP decision making process, both in facilitating
regulatory decisions and documenting regulation results.
• Support of the DDT Decision:
Data from the monitoring networks have demonstrated
decreases in DDT levels in human adipose tissue and
environmental media on a national basis since about
1970. Monitoring data have also shown that the DDT
substitutes are not accumulating in adipose tissue.
• Support of Hearings initiated under FIFRA.
Monitoring data from the pesticides networks have
played a prominent role in cancellation and/or
suspension hearings initiated under FIFRA since 1973.
These include the aldrin/dieldrin hearings and the
chlordane/heptachlor hearings. Presently, monitoring
data are being summarized for use in the upcoming
2,4,5-T.Silvex hearing, as well as proceedings on
DBCP (dibromochloropropane). Regulatory action on the
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insecticide aldicarb is possible if the results of an
ongoing monitoring study indicate significant human
exposure.
• Use of Ambient Data as Baseline Information.
Data on pesticides from the OPTS networks are also
utilized extensively as baseline levels against which
data from pesticide exposure incidents can be compared
and evaluated. Recent examples of such uses of network
data include:
~ Use of pentachlorophenol (PGP)levels in human
urine from the HANES II Survey (cooperative with
PHS) to compare with the results of samples being
collected in the Richmond, Kentucky area. There,
alleged high exposures to PGP from treated wood
from the Army's Blue Grass Depot have possibly
led to a high incidence of luekemia among the
population. OPTS and the Center for Disease
Control (CDC). Atlanta will be cooperating in this
study. Resulting data will also be used in the
PCP RPAR.
- Use of human and environmental data on DDT in
evaluating the ongoing studies by CDC in the
Triana, Alabama area. This area is contaminated
with high levels of DDT resulting from the
washout of DDT from an old waste dump near a
former DDT-manufacturing plant at the Army's
Redstone Arsenal.
ENVIRONMENTAL ASSESSMENT AND TRENDS
Trend assessments can be made using data from the human adipose
survey. Several residues have exbhiited trends which are
significant to past and present regulatory initiatives. Sevel
of these have been selected for presentation here.
DDT
All agricultural uses of DDT as all insecticide were cancelled
as of the end of 1972. Pesticide use information indicate
that usage of this chemical began decreasing several years
prior to this regulation. The following graph presents a
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summary of human DDT exposure by year from 1970 to 1977,
100%'
99% •
3
•J
O
o
0% -
% Positive
geometric Mean
- 8.0
- 6.0
- 4.0
-2.0
s
a
a
1970 1971 1972 1973 1974 1975 1976 1977
The above graph shows a statistically-significant decline in
the mean levels of DDT and its analogs in human adipose tissue.
This indicates the effectiveness of the FIFRA regulation of this
chemical.
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Aldrin/Dieldrin
Both aldrin and dieldrin are closely-related insecticides
which were regulated in 1975, with initial proceedings
commencing in 1973. The decision to cancel all major
agricultural uses of these chemicals was upheld by the
Court of Appeals. The following graph presents a summary
of deldrin/dieIdrin exposure as detected by the human
adipose tissue survey.
3
-J
t)
o
a
100% -
95% -
90% -
0% -
T
T
1970 1971
.—
1972
'—I 1—
1973 1974
.19
s
HI
-.16 =
-.13
.10
o
-j
CJ
1975
1976
1977
The decline represents another example of the environmental
improvement caused by FIFRA regulation.
® Polychlorinated Biphenyls (PCBs)
Residues of PCBs have been detected in human tissue adipose
since 1972. These groups of chemicals have exhibited a
marked increased and their usage has been the subject of a
current EPA regulation. The following graph shows the
yearly occurrence and percentage of samples with 3 parts
per million or more of PCBs.
75%-
50%'
Parcenc Positive
•« Percent >3ppm
1970
1971
1972
1973 1974
1975
—i r~
1976 1977
•15.00%
-11.25%
I- 7.50%
. 3.75%-
• 0%
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