EPA: Why Impose Limits on Toxicant Levels in the Water Supply?
Image courtesy of Mel B. via flickr
When questioned by the Senate Committee on Environment and Public Works yesterday about the potential health risks posed by perchlorate, a chemical used in solid rocket fuel, Benjamin H. Grumbles, the EPA's assistant administrator for water, said: "We know that perchlorate can have an adverse effect and we're concerned about that."
Yet, when further pressed by Senator Barbara Boxer (D-CA), who chairs the committee, on whether the agency would take action to limit the amount of perchlorate in water -- a no-brainer, you'd think, right? -- Grumbles answered that there was a "distinct possibility" (read: almost guaranteed) that it would not, reports the LAT's Marla Cone. Not that Grumbles' response was surprising in the least: The EPA has been dragging its feet for years now over a decision to set perchlorate standards -- despite the chemical having already contaminated the water supplies of at least 11 million people. Its adverse health effects are especially pernicious in infants or developing fetuses; even at low levels, the chemical can block the thyroid gland's ability to absorb iodide from the bloodstream -- inhibiting normal brain development. An EPA study determined that low perchlorate levels were present in both drinking water and ground water in 35 states.
In adults, perchlorate can interfere with metabolism. The EPA, relying on evidence obtained by a landmark National Academy of Sciences study, has argued that, at low levels, the chemical does not pose a threat to human health and that its effects on the thyroid gland are reversed once exposure stops. However, more recent scientific studies have shown that the health risks may be significant enough to consider imposing limits on its concentration.
In 2005, scientists reported that perchlorate was present in food crops and in "virtually all" human breast milk samples they tested. California is the only state to have taken the initiative in regulating perchlorate, saying it was concerned about the level of contamination in the Colorado River, which supplies a large portion of Southern California.
Because it is mainly found in solid rocket fuel, most of the contamination has been traced to military bases and aerospace plants, which have intensively been lobbying against a federal standard, citing the NAS study to argue perchlorate lacks any demonstrable health effects. Sen. Boxer has introduced two bills that would require the testing of water supplies and force the EPA to set a standard by next year.
Given the current political make-up, that means we probably won't see any action on this front until at least post-January 20, 2009 -- in other words, don't hold your breaths.