Perchlorate, a hazardous chemical in rocket fuel, has been found at potentially dangerous levels in powdered infant formula, according to a study (pdf) by a group of U.S. Centers for Disease Control scientists. The study, published last month by The Journal of Exposure Science & Environmental Epidemiology, has intensified the years-long debate about whether or how the federal government should regulate perchlorate in the nation’s drinking water.
According to the CDC, perchlorate exposure can damage the thyroid, which can hinder brain development among infants. For nearly a decade, Democratic members of Congress, the Department of Defense, the White House and the Environmental Protection Agency have been fighting about how much perchlorate in water is too much.
In the new study, CDC scientists tested 15 brands of infant formula and found perchlorate in all of them. The names of the brands weren’t revealed because the CDC says the study "was not designed to compare brands." But the study does say that the formulas with the highest perchlorate levels are the most popular. The most contaminated brands were lactose-based as opposed to soy-based and accounted for 87% of the infant formulas on the market in 2000, the latest data available from the U.S. Department of Agriculture.
The study points out that when perchlorate-contaminated powdered formula is mixed with water that also contains traces of the chemical, as many drinking water sources around the country do, the final concoction can become particularly harmful to babies.
"As this unprecedented study demonstrates, infants fed cow’s milk- based powdered formula could be exposed to perchlorate from two sources – tap water and formula. That suggests that millions of American babies are potentially at risk," said Anila Jacob, a physician and a senior scientist with Environmental Working Group, a Washington, D.C., nonprofit that posted the study on its Web site.
In December the EPA released an interim health advisory (pdf) suggesting that water with a level of perchlorate limited to 15 parts per billion (ppb) is safe to drink.The level is not an enforceable standard, but is meant to provide guidance to states and local governments seeking to develop their own regulations.
Keeping perchlorate beneath that level would ensure that the amount of daily oral exposure would remain beneath a threshold called a reference dose, the EPA said. That is the amount of perchlorate humans could consistently consume over the course of a lifetime without increasing their risk of harm. Environmentalists argue that the EPA reference dose is too high.
The CDC study found that, hypothetically, 54% of infants consuming the perchlorate-contaminated formula would exceed EPA’s reference dose, if the formula were mixed with water containing perchlorate at four ppb.
Perchlorate has been found at that level in drinking water sources of at least 26 states and two territories, according to a study the CDC referenced in the report.
Perchlorate’s effect on individual infants will vary, the CDC scientists said, according to their weight and the amount of iodine in their diet.Iodine can counteract the harmful effects of perchlorate and is an ingredient in many brands of baby formula, the scientists said.
In a statement sent to reporters last night, Sen. Barbara Boxer, chair of the Environment and Public Works committee, said the study prompted her to ask the Food and Drug Administration to inform the public "how best to protect children from perchlorate." As she has done in the past, Boxer called on the EPA to "overrule the Bush Administration’s policy which was to walk away from setting a safe drinking water standard for perchlorate in our water supply."