The endocrine disruption theory evolved from concern that low-level environmental exposures to hormonally active naturally occurring (such as phytoestrogens) and synthetic compounds are adversely affecting (disrupting) the endocrine systems of wildlife and humans.
Endocrine disruptors have been described as substances that may affect the production, release, transport, metabolism, binding, action, or elimination of hormones in the body. The science (validated screens and tests) and risk assessment policy, to differentiate between endocrine modulation, non-adverse fluctuations in hormone levels, actual endocrine disruptions, and adverse reproductive and developmental hormonally mediated outcomes, are still under debate. Although nongovernmental organizations and some governments have published lists of suspected endocrine-disrupting chemicals, these findings have been criticized because the interpretation of the data is not robust or the supporting evidence was not based on validated screens and tests.
The issue has fostered global public health and regulatory concerns since the early 1990s and led to legislative mandates in the United States, including the Food Quality Protection Act (FQPA) of 1996 and the 1996 Safe Drinking Water Act (SDWA) Amendments, as well as international cooperation to develop and validate new endocrine screens and tests.
The Food Quality Protection Act amended the Federal Food, Drug, and Cosmetic Act (FFDCA) to require the U.S. Environmental Protection Agency (EPA or the Agency) to develop a screening program using validated assays to identify pesticides that may have estrogenic effects. The amendments also authorized EPA to include other endocrine effects and to include non-pesticide chemicals that have “an effect cumulative to that of a pesticide” and to which a substantial human population may be exposed. Amendments to the Safe Drinking Water Act allow EPA to require testing of chemical substances found in sources of drinking water, if a substantial human population may be exposed.
EPA established the endocrine disruptor screening program in 1999. The program’s three major components are to: develop and validate assays, develop a priority-setting approach for chemical selection, and develop program policies and procedures to require testing.
EPA expects to complete validation of Tier 1 and Tier 2 assays in 2010. The Agency published a draft list of chemicals for initial screening in 2007; the list will be finalized in 2008. The draft list consisted of pesticide active ingredients and high production volume inerts. EPA is in an ongoing process internally and with stakeholders to develop the policies and procedures that will be followed when the program is implemented.
Exponent’s multi-disciplinary team has the background, experience and expertise to work with individual companies, industry groups and others to deal effectively with technical and scientific questions in the toxicology, ecotoxicology and exposure areas, and to respond properly to regulatory and risk communications issues that will arise as the Agency’s program is refined and implemented.
Exponent’s scientific and regulatory consultants can work with clients to evaluate whether study requirements are justified, determine if existing data can meet study needs, place and monitor studies, interpret study results, conduct risk assessments, attend regulatory proceedings, and coordinate with communications specialists to develop materials that are based on sound science and are understandable to the intended audiences.