Last month the US Centers for Disease Control and Prevention (CDC) reported they had found 15 brands of powdered infant formula were contaminated with perchlorate, a component of rocket fuel that has been found in drinking water in 28 states and territories, and thought mostly to be a legacy of the Cold War because of rocket and missile trials.

The findings were published in the March issue of the Journal of Exposure Science and Environmental Epidemiology but did not come to public attention until the Washington DC-based advocacy organization Environmental Working Group (EWG) alerted the press late last week.

First author of the CDC study was Dr Joshua G Shier of the Division of Environmental Hazards and Health Effects, National Center for Environmental Health, Centers for Disease Control and Prevention, in Atlanta, Georgia.

Shier and colleagues did not identify the 15 brands they tested, but said that 2 of them accounted for 87 per cent of the US powdered infant formula market in 2000.

They found that all the powdered infant formulas they tested were contaminated with perchlorate, and that the cow's milk based formulas with lactose "had a significantly higher perchlorate concentration perchlorate than soy, lactose-free, and elemental PIFs [powdered infant formulas]".

However, the conclusion that probably captured the most attention was:

"The perchlorate RfD may be exceeded when certain bovine [cow's] milk-based PIFs are ingested and/or when PIFs are reconstituted with perchlorate-contaminated water."

RfD is the Environmental Protection Agency "safety limit" for perchlorate (the reference dose, or RfD) which is currently 0…