There is evidence that domestic animals and wildlife have suffered adverse consequences from exposure to environmental chemicals that interact with the endocrine system. These problems have been identified primarily in species exposed to relatively high concentrations of organochlorine pesticides, PCBs, dioxins, as well as synthetic and plant-derived estrogens. Whether similar effects are occurring in the general human or wildlife populations from exposures to ambient environmental concentrations is unknown. For example, while there have been reports of declines in the quantity and quality of sperm production in humans over the last four decades, other studies show no decrease. Reported increases in incidences of certain cancers (breast, testes, prostate) may also be related to endocrine disruption. Because the endocrine system plays a critical role in normal growth, development, and reproduction, even small disturbances in endocrine function may have profound and lasting effects. This is especially true during highly sensitive prenatal periods, such that small changes in endocrine status may have delayed consequences that are evident much later in adult life or in a subsequent generation. Furthermore, the potential for synergistic effects from multiple contaminants exists. The seriousness of the endocrine disruptor hypothesis and the many scientific uncertainties associated with the issue are sufficient to warrant a coordinated federal research effort.
Federal Activities Under the National Science and Technology Council (NSTC)
The NSTC Committee on Environment and Natural Resources (CENR) identified endocrine disruptors as an initiative in November 1995. The NSTC is a cabinet-level council chaired by President Clinton that serves as the principal means for coordinating science and technology issues across the Federal government.
The CENR established a Working Group on endocrine disruptors that is chaired by the Environmental Protection Agency with vice chairs from the Department of the Interior and the National Institute of Environmental Health Sciences. Other participating agencies include the National Oceanic and Atmospheric Administration, the National Science Foundation, the Food and Drug Administration, the
Centers for Disease Control, the Agency for Toxic Substances and Disease Registry, the National Cancer Institute, the Smithsonian Institution, the Departments of Agriculture and Energy, and the Office of Science and Technology Policy.
The Working Group established three objectives for developing an integrated research strategy across the federal agencies: ( 1) Develop a planning framework for federal research related to the human health and ecological effects of endocrine disrupting chemicals; (2) Conduct an inventory of on-going federally funded research on endocrine disruptors; and (3) Identify research gaps and facilitate a coordinated interagency research plan to address them.
Progress by the CENR Working Group
The first two objectives of the Working Group have been completed. A planning framework, The Health and Ecological Effects of Endocrine Disrupting Chemicals: A Framework for Planning, and a research inventory describing nearly 400 projects have been published. Both the framework document and the inventory can be accessed on the internet (www.epa.gov/endocrine).
Analysis of the current research effort indicates that the majority of federally funded research projects focus on human health effects; fewer are devoted to ecological effects or exposure assessment. The largest number of studies focus on reproductive development followed by carcinogenesis, then neurologic and immunologic effects. Dioxins and PCBs are the most studied test chemicals. Most of the research can be categorized as supporting either methods development for hazard identification or basic research on mechansims of endocrine action. An overlay of the inventory and the research framework will be used to complete the third and final objective of the working group, prioritization of critical unmeet research needs, during the summer of 1997.
For additional information contact:
Office of Science and Technology Policy
Executive Office of the President
(202) 456-6020 FAX (202) 456-6019