WASHINGTON, March 15 — In a sharp rebuke to the Bush Administration, a federal advisory committee on children's health warns that the EPA's recommended cleanup level for a rocket fuel chemical fails to protect children, fetuses and mothers. The warning comes as Massachusetts, pointedly rejecting the EPA guidelines, is setting the nation's first enforceable safety standards for the chemical—12 times more stringent than the federal cleanup level.
In a letter to EPA Administrator Stephen Johnson, the Children's Health Protection Advisory Committee said the agency's preliminary remediation goal (PRG) for perchlorate could expose nursing infants to levels 5 to 10 times higher than the EPA's reference dose (RfD). The RfD is an estimate of a safe daily exposure level, but like the cleanup goal, is not a legally enforceable standard. The Committee urged EPA to lower the PRG to account for "infant exposures and susceptibility," to move quickly to establish a national standard for perchlorate in drinking water, and in the interim issue a health advisory for a drinking water level that will protect children.
"The PRG is not supported by the underlying science and can result in exposures that pose neurodevelopmental risks in early life," said the committee, chaired by Dr. Melanie A. Marty of California's Office of Environmental Health Hazard Assessment. [CHPAC letter, pdf]
Perchlorate is the explosive ingredient in solid rocket fuel. It has been found in drinking water, groundwater and soil in at least 40 states, with most known contamination coming from military bases and defense industry plants. Even small doses have been found in animal studies to disrupt proper functioning of the thyroid gland. For fetuses, infants and children, changes in thyroid hormone levels can cause lowered IQ, mental retardation, loss of hearing and speech, and motor skill deficits.
The advisory committee said it is troubled that the EPA's recently set remediation goal does not attempt to account for exposures to perchlorate from sources other than drinking water, "an obvious concern given the recent widespread detection of perchlorate in lettuce and milk." Tests by the Environmental Working Group, journalists, academic scientists, the states of California and Utah, and the Food and Drug Administration, have found the chemical in fresh produce, supermarket milk and cheese, human breast milk and a variety of animal feed crops. The committee noted that the proposed drinking water standards in Massachusetts, New Jersey and California all took into account exposures from food and other sources.
Yesterday the Massachusetts Department of Environmental Protection (DEP) released proposed drinking water and waste site cleanup standards of 2 parts per billion (ppb) for perchlorate, which has been found in drinking water sources at 10 locations across the state. The regulations also require regular testing for perchlorate in all public water systems.
The proposed standard, still subject to public hearings, is a pointed rejection of the EPA's RfD, which the agency translated into a cleanup "guidance" of 24.5 ppb. The state said the standard will protect public health "especially for sensitive populations, such as pregnant women, nursing mothers, infants, and individuals with low levels of thyroid hormones." DEP said the standard was "based on a thorough review of the scientific data available on perchlorate, including analysis performed by independent scientists at the National Academy of Sciences."
The controversial NAS study was also the the basis for the EPA's RfD. But like the Children's Health Protection Advisory Committee, health officials in Massachusetts and other states argue that EPA ignored exposures from food when setting the RfD and cleanup level, leaving infants and fetuses vulnerable. California has proposed a drinking water standard of 6 ppb, while New Jersey is considering a standard of 5 ppb.
"It's time for the EPA to wake up and listen to what the states and its own advisors are saying: Perchlorate is a threat to children at very small doses," said Renee Sharp, an Environmental Working Group scientist who has studied the chemical for six years. "The Bush Administration has given no sign that it's going to set a national drinking water standard, and the EPA's recommendations leave children at risk. A non-enforceable 'standard' that doesn't protect the most vulnerable populations is worth nothing."
EPA says it can't set a national standard without more information about levels of perchlorate in food. Yet the Bush Administration is holding up release of a study by the Centers for Disease Control that found perchlorate in the blood of most Americans at levels close to the EPA's RfD. Since the CDC tests included people from cities with little or no perchlorate in their drinking water, those findings indicate that perchlorate is widespread in the food supply.
Risk Policy Report, an independent newsletter, reported Feb. 28 that the White House Office of Science & Technology Policy is pressuring the CDC to delay the release of a study that tested for perchlorate in human blood samples from the National Health and Nutrition Examination Survey (NHANES). An EPA source told the newsletter that CDC has found levels of perchlorate that "leave no margin of safety" for the public, compared to EPA's current risk limit.
"In the absence of national safety standards, the CDC should not be sitting on data so clearly needed to protect the public from a chemical that appears to be widespread in drinking water and food," said Sharp. "Once again, in the face of inaction by the Bush Administration, states such as Massachusetts and California are stepping forward to protect public health."
