Perchlorate Environmental Contamination

Perchlorate Environmental Contamination

Author:

Publisher:

Published: 2002

Total Pages:

ISBN-13:

DOWNLOAD EBOOK

Perchlorate (ClO4- ) is an anion that originates as a contaminant in ground water and surface waters when the salts of ammonium, potassium, magnesium, or sodium dissolve in water. One major source of contamination is the manufacture or improper disposal of ammonium perchlorate that is used as the primary component in solid propellant for rockets, missiles, and fireworks. The external review draft of the revised document, "Perchlorate Environmental Contamination: Toxicological Review and Risk Characterization" responds to those recommendations and incorporates results from extensive laboratory and field studies performed since 1999.


Ecotoxicology, Ecological Risk Assessment and Multiple Stressors

Ecotoxicology, Ecological Risk Assessment and Multiple Stressors

Author: Gerassimos Arapis

Publisher: Springer Science & Business Media

Published: 2006-02-09

Total Pages: 376

ISBN-13: 1402044763

DOWNLOAD EBOOK

The science of ecotoxicology and the practice of ecological risk assessment are evolving rapidly. Ecotoxicology as a subject area came into prominence in the 1960s after the publication of Rachel Carson's book on the impact of pesticides on the environment. The rise of public and scientific concern for the effects of chemical pollutants on the environment in the 1960s and 1970s led to the development of the discipline of ecotoxicology, a science that takes into account the effects of chemicals in the context of ecology. Until the early 1980s, in spite of public concern and interest among scientists, the assessment of ecological risks associated with natural or synthetic pollutants was not considered a priority issue by most government. However, as the years passed, a better understanding of the importance of ecotoxicology emerged and with it, in some countries, the progressive formalization of an ecological risk assessment process. Ecological risk assessment is a conceptual tool for organizing and analyzing data and information to evaluate the likelihood that one or more stressors are causing or will cause adverse ecological effects. Ecological risk assessment allows risk managers to consider available scientific information when selecting a course of action, in addition to other factors that may affect their decision (e. g. , social, legal, political, or economic). Ecological risk assessment includes three phases (problem formulation, analysis, and risk characterization).


Health Implications of Perchlorate Ingestion

Health Implications of Perchlorate Ingestion

Author: National Research Council

Publisher: National Academies Press

Published: 2005-04-18

Total Pages: 276

ISBN-13: 0309181356

DOWNLOAD EBOOK

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.