Draft Toxicological Profile For Perchlorates

The development of analytical methods for identifying widespread perchlorate contamination brought about an explosion of research into the environmental problems and their potential solutions along with a corresponding increase in the availability of information. Unlike reference works that focus on only a few aspects of this contaminant, Perchlora

Emerging Contaminants: Anticipating Developments examines the factors that have led "new" environmental contaminants to emerge in the past and combines the lessons learned to anticipate potential new developments. The analyses described in this book originate in multiple disciplines: the science of toxicology; environmental law and regulation; the field of product stewardship; and the social science which explains why ideas take hold. Over a dozen case studies of contaminants that emerged as environmental issues over the last hundred years illustrate crucial points. The results of the analyses in this book support a step-by-step method to assess the potential for a contaminant to emerge, and a framework to apply those conclusions to managing site liabilities. Features: Describes an unprecedented understanding of why contaminants emerge as issues, based on a multidisciplinary analysis Makes abstract concepts tangible, basing analyses on data and illustrating key points with case studies Enables readers to anticipate and prepare to manage future challenges associated with emerging chemicals Presents an analytical framework for companies to assess and manage business risks Written for regulators, policymakers, industry professionals with responsibility for contaminated site management, as well as attorneys, and consultants, this book provides a framework for anticipating the emergence of new contaminants so that the risks–whether to human health and the environment or to a business–can be anticipated and appropriately managed.

Perchlorateâ€"a powerful oxidant used in solid rocket fuels by the military and aerospace industryâ€"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 weightâ€"an amount more than 20 times the reference dose proposed by EPAâ€"should not threaten the health of even the most sensitive populations.