The Washington Post reports that a toxic chemical component of rocket fuel, in concentrations 80 times what the Environmental Protection Agency considers safe for human consumption, has been found near a reservoir that supplies drinking water to the District of Columbia.
Although health officials insist there is no immediate threat to the District's drinking water supplies, the discovery – which the agency kept quiet for more than a year – sharpens the nationwide debate over the health
threats of perchlorate, which is known to contaminate water or soil in more than 40 states. At most of the hundreds of sites of known contamination, the chemical leaked from military bases or defense plants.
The EPA's preliminary risk assessment says drinking water concentrations of perchlorate of more than 1 part per billion (ppb) are unsafe, and pose a particular risk for pregnant women, fetuses and infants. The chemical can
disrupt normal functioning of the thyroid gland, which controls growth and development, leading to learning disabilities and deficiencies in motor skills.
The EPA's risk assessment is under review by the National Academy of Sciences, but officials in Massachusetts and California agree that very low levels of perchlorate are a health risk. Massachusetts has set a limit of 1 ppb in drinking water, while California's standard is 6 ppb. Both are in sharp contrast to claims by the Pentagon and defense contractors that perchlorate is safe at up to 200 ppb.
EWG, which has conducted a series of groundbreaking studies on perchlorate, argues that a drinking water standard should be no more than one-tenth the EPA's current recommendation, or 0.1 ppb. EWG's tests have found perchlorate in lettuce and milk, and other researchers have found it in a wide range of food crops.
View EWG's studies
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