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DEVELOPING TOOLS FOR EVALUATING RISK MANAGEMENT OF ENDOCRINE DISRUPTING CHEMICALS
Citation:
ACHESON, C. M., R. C. BRENNER, P. T. MCCAULEY, M. MILLS, STEVE HUTCHINS, C. V. OWENS, K. M. SCHENCK, T. F. SPETH, D. A. GORDON, M. MEDINA-VERA, J. GUNDERSEN, AND L. ZINTEK. DEVELOPING TOOLS FOR EVALUATING RISK MANAGEMENT OF ENDOCRINE DISRUPTING CHEMICALS. Presented at US Board of Scientific Counselors, Endocrine Disrupting Chemicals Subcommittee Review, Research Triangle Park, NC, December 13 - 15, 2004.
Impact/Purpose:
To develop quantitative methods to determine: 1) how unreasonable risks can be managed; 2) what are the major sources and environmental fates of EDCs; 3) the levels of EDCs in environmental matrices; and 4) if the changes in chemical concentrations correlate to changes in biological activity.
Description:
The goal of endocrine disrupting chemical (EDC) risk management (RM) is to minimize the release of EDCs into the environment or to minimize the exposure of humans or wildlife to EDCs already present in the environment. RM research projects may involve: substituting more innocuous chemicals for EDCs in current use, developing strategies to remove EDCs before they enter the environment, or developing techniques to degrade EDCs found in the environment. To evaluate the performance of RM techniques, the concentrations of the chemicals of concern (COCs) are often measured. The Office and Research and Development's RM research has focused on known or highly suspected EDCs including reproductive steroid hormones and alkylphenolic compounds (APs). These chemicals may be present in environmental matrices such as water, soil, sediment, biosolids, or air. Chemical analysis techniques are available for some suspected EDCs compounds, such as PCBs and chlorinated pesticides, but for others, suitable analytical techniques are not available for environmental matrices. Thus, before evaluating the effectiveness of RM strategies, methods to measure COCs in the applicable matrices and at relevant concentrations are needed. Specific challenges for some analyte/matrix pairs are matrix interferences and sample throughput. This effort to develop quantitative methods is ongoing. Analytical methods are improved as better analytical equipment and techniques become available, and new methods are developed as new EDCs are identified. In addition, the understanding of RM effectiveness is more robust when biological assays supplement chemical data. Chemical data demonstrate changes in COC concentrations while bioassays demonstrate changes in biological effect or activity. Due to the limited knowledge about the endocrine activity of various chemicals, their degradation products, and their behavior in mixtures, the combination of chemical measurements and bioassays are even more important in evaluating the performance of EDC risk management approaches. While many EDC bioassays have been developed, these bioassays are often expensive and require specialized skills and equipment. To cost effectively incorporate EDC bioassays in RM projects, RM researchers have formed collaborations with exposure and effects researchers. Through these collaborations, data is being gathered to evaluate the correlation between EDC concentrations and biological effects and to identify endocrine activity in samples. As RM research grows, these collaborations are expected to continue. Impacts and Outcomes: The chemical analysis methods developed to date are used by EPA/ORD RM projects and Region 5. Since most EDC RM projects involve steroid hormones as COCs, these projects could not proceed without these analytical methods. Bioassays strengthen the evaluation of RM research by providing data to demonstrate biological effects. Since EPA/ORD is leading EDC RM research, these tools may be used by many other groups as EDC RM research expands. The precedent of including chemical and biological measures in evaluating RM is uncommon but appropriate based on current knowledge. In addition, tools from this research may be used by regulators and the regulated community to effectively monitor and manage EDC's. Tool development has resulted in scientific papers and presentations at technical conferences.