You are here:
HUMAN HEALTH IMPACT OF ENVIRONMENTAL ESTROGENIC CHEMICALS
Citation:
Kavlock, R J. HUMAN HEALTH IMPACT OF ENVIRONMENTAL ESTROGENIC CHEMICALS. Presented at Environmental Mutagens and Human Exposure, Florianopolis, Brazil, May 4-8, 2003.
Description:
HUMAN HEALTH IMPACT OF ENVIRONMENTAL ESTROGENIC CHEMICALS.
Robert J. Kavlock, Reproductive Toxicology Division, NHEERL, ORD, US Environmental Protection Agency, Research Triangle Park, NC USA.
Over the past several decades a hypothesis has been put forth that a number of environmental contaminants that have estrogenic activity may be responsible for the increase in certain undesired health outcomes in the human population. Among these are breast cancer, endometriosis, altered sex ratios, testicular cancer, poor semen quality, precocious puberty, and malformations of the reproductive tract including cryptorchidism and hypospadias. Indeed, as a result of the ?endocrine disrupting chemical? (EDC) hypothesis, a large screening program has been mandated in the US to detect whether pesticides, pesticide inerts, water contaminants, and a wide variety of industrial chemicals can exert effects via modification of the estrogen, androgen and thyroid hormone signaling pathways. However, many uncertainties exist, such as what chemicals might be responsible for the observed trends, what are their potencies and dose-response relationships, and what is the nature and magnitude of human exposure. To help clarify the scientific basis of the alleged health impacts, the US EPA developed and published a research strategy in the mid 90s that identified the key research questions and has guided resource utilization since then. This presentation will focus on progress that has been in closing knowledge gaps in the EDC hypothesis and in a recent assessment of the state-of-the science on endocrine disruptors by the World Health Organization (IPCS, 2002). In assessing the validity of the overall hypothesis, a framework developed by the WHO that is patterned after the Hill criteria has proven useful for judging the strength and weaknesses of the bodies of evidence, particularly with regard to invoking a particular mode of action. An emerging picture is that exposure to some anti-androgenic agents, such as some of the phthalate acid esters, may present a more plausible hypothesis for at least some of the human health effects.
This is an abstract of a proposed presentation and does not necessarily represent US EPA policy.