Agency is Protecting the Defense Department and its Contractors, Not Public Health, NRDC Charges
WASHINGTON (February 18, 2005) -- The Environmental Protection Agency (EPA) today issued a new public health goal for rocket fuel-contaminated drinking water that fails to protect infants and unborn children, according to NRDC (Natural Resources Defense Council). The group said the agency is aware that it will have to revise its goal for the rocket-fuel ingredient perchlorate to a more protective level, but announcing a higher acceptable level could make it easier for the Department of Defense and its contractors to oppose stricter cleanup standards.
"The EPA's new drinking water goal will not protect millions of Americans, especially infants and babies in the womb who are exposed to rocket fuel," said Erik D. Olson, an NRDC senior attorney. Perchlorate, which has been found in water and food supplies nationally, attacks the thyroid gland.
Specifically, EPA today announced a "Drinking Water Equivalent Level," or DWEL, for perchlorate of 24.5 parts per billion (ppb) in water, which it qualified by stating that "exposures above the DWEL are not necessarily considered unsafe." This level is 24.5 times higher than the 1 ppb level that the agency proposed in its January 2003 risk assessment. In calculating the new level, EPA ignored the fact that children, infants and fetuses weigh less than adults, as well as the fact that the widespread contaminant also is found in lettuce, milk and other foods.
A DWEL is not an enforceable standard. However, it is likely to be cited by industry and the Pentagon when they oppose stricter cleanup standards than the DWEL. Moreover, EPA uses DWELs when it establishes drinking water standards.
EPA also issued a second calculation for perchlorate, called a reference cose (RfD), which is the level at which exposure to perchlorate is considered safe. It is expressed as an amount of perchlorate per unit of body weight per day (milligrams per kilogram of body weight per day, or mg/kg-d). EPA's RfD is identical to the one suggested in the January 2005 report by the National Academy of Sciences (NAS), "Health Implications of Perchlorate Ingestion." (For more information about the NAS study, click here.) EPA ultimately will use the RfD with the DWEL if it establishes an enforceable drinking water standard.
For more than 20 years, the EPA has adjusted an RfD for the body weight of a particular vulnerable population -- in this case infants and fetuses -- and also for human exposure from food so that drinking water alone does not over-expose people to a toxin. If the EPA follows this standard scientific practice, NRDC experts said, the actual enforceable drinking water standard using the agency's new RfD would be about 1 ppb. However, EPA has not made its intentions clear as to when, or if, it intends to set a drinking water standard for perchlorate that accounts for the lower weights of infants and fetuses and the fact that perchlorate-contaminated water contaminates the food supply.
"People don't just drink perchlorate, they eat it too," said Dr. Gina Solomon, an NRDC senior scientist. "This chemical is in lettuce and milk, yet EPA today misleadingly suggests that our only exposure is from water, thereby putting millions of Americans at risk."