Following a published report that the Bush Administration is holding
up a study that shows most Americans carry a toxic rocket fuel chemical in their
bodies at levels close to federal safety limits, Environmental Working Group
(EWG) is calling for the immediate release of the study so EPA and state agencies
can take steps to protect the public.
Risk Policy Report, an independent newsletter, reported Feb. 28 that the White
House Office of Science & Technology Policy is pressuring the Centers for
Disease Control 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.
Perchlorate, the explosive ingredient in solid rocket fuel, has contaminated
drinking water and soil in at least 35 states, with most of the known contamination
coming from military bases and defense contractors. Tests by EWG, academic scientists
in Texas and Arizona, state officials in California and the U.S. Food and Drug
Administration have found perchlorate in milk, produce and many other foods
and animal feed crops from coast to coast. Perchlorate is a thyroid toxin, and
animal tests show that even small amounts can disrupt normal growth and development
in fetuses, infants and children.
The NHANES study is a followup to a CDC study last year that found perchlorate
in the urine of every one of 61 Atlanta residents tested, even though concentrations
of perchlorate in the cityÕs drinking water are very low. Last year,
scientists at Texas Tech University also found perchlorate in every sample of
human milk from 36 mothers.
In a letter to Dr. Julie Gerberding, director of the CDC, EWG Senior Vice President
Richard Wiles said the results of the study of Atlanta residents "indicate
that food is likely a major source of perchlorate exposure, and that perchlorate
exposure is likely to be widespread in the general population."
Although the EPA has no timetable for developing a national drinking water
standard for perchlorate, both Massachusetts and California are moving forward
with their own safety standards. The proposed standards — 1 part per billion
in Massachusetts and 6 ppb in California — are far below EPA's recently
adopted risk limit of 24.5 ppb, which is a level used as a guidance for cleaning
up perchlorate- contaminated sites. When the EPA announced the risk limit, it
acknowledged the need for "national guidance on relative source contribution"
— exactly the information the NHANES data could provide.
"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," wrote Wiles. "The NHANES
perchlorate data should be released immediately."