News Alert: Report on Perchlorate Distorts Relevance of Scientific Findings

Tuesday, March 1, 2005
Unnecessary alarm, controversy created

A report released on Feb. 23 from Texas Tech University on perchlorate in breast milk created the false impression that nursing mothers and their infants were at immediate risk and that sensitive populations hadn't been considered by the nation's leading experts on the subject.

The Texas Tech breast milk report failed to acknowledge the fact that the National Academy of Sciences' (NAS) expert panel's report on perchlorate dealt squarely with the issue of safety to pregnant women, fetuses and infants in crafting its recommendations, and included several unprecedented safety factors. (See NAS report at http://books.nap.edu/books/0309095689/html/9.html) The U.S. Environmental Protection Agency (EPA) followed NAS' lead in setting its reference dose on Feb. 18, and in calculating the drinking water equivalent level for the reference dose at 24.5 parts per billion.

In a Feb. 25, 2005 news report, Dr. Richard B. Johnston, associate dean for research at the University of Colorado School of Medicine, a pediatrician and head of the NAS panel on perchlorate, told the Rocky Mountain News that NAS researchers applied conservative safety factors specifically to protect the most vulnerable populations. Dr. Johnston was quoted as follows: "Based on the science in the (NAS) report and the committee's interpretation of science, (the levels found in breast milk) wouldn't be considered unsafe."

The NAS, the EPA and California's Office of Environmental Health Hazard Assessment each already considered the types of exposures studied in the Texas Tech report. Their evaluations for safe doses of perchlorate provided appropriate safety factors and other adjustments in recent scientific and regulatory reviews to ensure that recommended exposure levels were safe for all populations, including pregnant women, their fetuses and nursing infants.

In addition, data relating to breast milk was made available as a matter of public record to all three of these entities based upon previous human studies conducted in Chile. The findings in Chile were consistent with those in the Texas Tech study.