/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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