附註:Includes bibliographical references.
Summary -- 1. Introduction -- 2. The thyroid and disruption of thyroid function in humans -- 3. Epidemiologic studies of occupational and environmental exposures to perchlorate -- 4. Animal studies -- 5. Risk characterization of perchlorate -- 6. Research recommendations -- Appendix A. Biographic information on the Committee to Assess the Health Implications of Perchlorate Ingestion -- Appendix B. Glossary -- Appendix C. Participants at public sessions -- Appendix D. Sensitivity of perchlorate-induced iodide uptake inhibition to serum iodide concentrations -- Appendix E. Physiologically based pharmacokinetic modeling.
摘要:Perchlorate a powerful oxidant used in solid rocket fuels by the military and aerospace industry has been detected in public drinking water supplies of over 11 million people at concentrations of at least 4 parts per billion (ppb). High doses of perchlorate can decrease thyroid hormone production by inhibiting the uptake of iodide by the thyroid. Thyroid hormones are critical for normal growth and development of the central nervous system of fetuses and infants. This report evaluates the potential health effects of perchlorate and the scientific underpinnings of the 2002 draft risk assessment issued by the U.S. Environmental Protection Agency (EPA). The report finds that the body can compensate for iodide deficiency, and that iodide uptake would likely have to be reduced by at least 75% for months or longer for adverse health effects, such as hypothryroidism, to occur. The report recommends using clinical studies of iodide uptake in humans as the basis for determining a reference dose rather than using studies of adverse health effects in rats that serve as EPA s basis. The report suggests that daily ingestion of 0.0007 milligrams of perchlorate per kilograms of body weight an amount more than 20 times the reference dose proposed by EPA should not threaten the health of even the most sensitive populations.
