/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. ------- 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. ------- 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. ------- 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. ------- 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 ------- 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 ------- 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. ------- 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% ------- |