Nov 15, 2008

Perchlorate Problem Proves Persistent near DC Reservoir

More testing for groundwater problems in Northwest Washington neighborhoods where the U.S. Army researched chemical weapons during World War I has found new locations of perchlorate contamination, at some of the highest levels detected to date, according to officials. Undetermined is whether the contamination could end up in the Dalecarlia Reservoir or the Washington Aqueduct, both of which supply drinking water to more than 1 million people in the metropolitan area ... Perchlorate, a compound that was used nine decades ago in tests with mustard agent and screening smokes, can disrupt thyroid function and can contribute to developmental delays and infertility.

Given that two of the wells are just west of major disposal pits, the December findings were not surprising. They showed levels of 60 and 70 parts per billion, which exceed the previous high of 58 parts per billion detected in 2003 on the grounds of Sibley Memorial Hospital and are more than double a federal recommendation for perchlorate cleanup. Much more unexpected, however, was the 48 parts per billion reading from the third well, about 1,000 feet south of Dalecarlia at Loughboro Road and MacArthur Boulevard.
Washington Post
February 18, 2006: pg. B-2

As the clock runs out on the Bush administration, officials at the Environmental Protection Agency are trying to hand industry yet another victory by refusing to set safety standards for the toxic rocket fuel ingredient perchlorate ... Based on Centers for Disease Control data, the Environmental Working Group estimated that as many as 44 million women who are pregnant, thyroid deficient or have low iodine levels are at heightened risk of exposure to the chemical.

Other CDC studies have found perchlorate in the urine of every person tested and have discovered that children between 6 and 11 had perchlorate levels 1.6 times higher than adults. These CDC reports have aroused great concern because tests show that the chemical disrupts production of thyroid hormones at these levels, and adequate thyroid hormones are crucial to normal brain development and growth in infants and children.
Perchlorate in Groundwater near Dalecarlia Reservoir

In a letter last week, the heads of EPA's Science Advisory Board and its drinking water committee urged EPA Administrator Stephen L. Johnson to extend the public comment period on its preliminary determination to not regulate perchlorate. That decision is set to become final next month. Perchlorate, which is present in the water systems of 35 states, accumulates in the body from consuming water, milk, lettuce and other common products and has been linked in scientific studies to thyroid problems in pregnant women, newborns and infants ... "It seemed premature to go ahead and make a decision on perchlorate when they didn't have all the science in," [Advisory Board Chairwoman Deborah] Swackhamer said ... A 2006 CDC study of 1,000 women found that one third had experienced significant changes in thyroid hormone levels at an exposure rate of 7 parts per billion.
Washington Post

November 14, 2008: pg. A-8
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