WebMD Medical News
Louise Chang, MD
April 3, 2009 -- CDC scientists have found a chemical called perchlorate in samples of powdered infant formula.
Perchlorate occurs naturally in the environment; it's also made for use in rocket propellant, explosives, fireworks, and road flares.
Perchlorate has been found in drinking water in some areas of the country, as well as in food and breast milk.
High levels of exposure to perchlorate may disrupt the function of the thyroid gland, which is needed for normal growth and development of the central nervous system, according to background information from the FDA.
The formula findings, published online in the Journal of Exposure Sciences and Environmental Epidemiology, raise more questions than answers.
Those questions include the health effects of perchlorate from powdered infant formula, whether iodine supplementation might offset perchlorate-related thyroid problems, and whether the formula samples that were tested were representative of powdered infant formula nationwide.
"It's important to note that infant formula contains iodine and that iodine would be expected to ameliorate any potential effects that perchlorate would have," Ben Blount, PhD, Chief of the CDC's Perchlorate Biomonitoring Laboratory, tells WebMD.
The researchers -- who included Blount and Joshua Schier, MD, a medical toxicologist with the CDC's National Center for Environmental Health -- bought four types of powdered infant formula at several grocery stores in one U.S. city in 2006.
Here's what they bought (no brands or companies are mentioned in the study):
After mixing the formula with perchlorate-free water, the researchers checked perchlorate levels in the formula. Then they estimated how much perchlorate babies of various ages and sizes might be exposed to, based on their feeding schedule, how much perchlorate was in local tap water, and other factors.
The results: "Perchlorate was found in all brands and types of infant formula," with the highest levels in powdered infant formulas made from cows' milk containing lactose. That's probably because mammals can store perchlorate in breast tissue during lactation, Blount notes.
And in certain hypothetical situations -- based on water levels of perchlorate and formula doses -- babies might be exposed to more perchlorate than health officials believe to be safe.
But more work is needed to see if those estimates reflect reality.
"There needs to be a closer and much more detailed analysis of how much perchlorate is actually getting into infants' bodies," Schier tells WebMD.
The U.S. Environmental Protection Agency (EPA) doesn't regulate perchlorate in drinking water, but that may change.
In January 2009, the EPA issued an interim health advisory setting an upper limit on perchlorate levels in public drinking water. The EPA is also seeking advice from the National Academy of Sciences before deciding whether to set a national regulation for perchlorate in drinking water.
Meanwhile, if you want to find out if your drinking water contains perchlorate, the EPA suggests calling your drinking water utility or state drinking water program to learn the results of past perchlorate monitoring or to find out if your state requires monitoring.
If your state doesn't require perchlorate monitoring, you can send a sample of your tap water to a lab that's certified to analyze perchlorate or similar compounds. The EPA's web site has a state-by-state list of links to drinking water labs.
Schier's study focuses on perchlorate in powdered infant formula, not in water. But if there's perchlorate in your drinking water, perchlorate would get into formula made with that water.
Background information posted on the FDA's web site states that "If you live in one of the few areas where perchlorate in the public drinking water is above 15 parts per billion, FDA recommends using water that is lower in perchlorate levels, such as bottled water or water from a home treatment device certified for perchlorate removal, to reconstitute your infant's formula."
Perchlorate can be removed from drinking water by reverse osmosis technology. But if you're considering installing a home treatment unit, the EPA recommends contacting the manufacturer to ask whether the unit can remove perchlorate from your water supply.
The FDA has also investigated perchlorate in foods. Those findings, which were published last year, are consistent with the new CDC report, are well below the EPA's level of concern, and reflect the "ubiquitous" environmental nature of perchlorate, an FDA spokesman tells WebMD.
SOURCES:Schier, J. Journal of Exposure Science and Environmental Epidemiology, March 18, 2009; advance online edition. Ben Blount, PhD, chief, Perchlorate Biomonitoring Laboratory, CDC.Joshua Schier, MD, Medical Toxicologist, National Center for Environmental Health, CDC.FDA: "For Consumers: Information About Perchlorate: Questions and Answers."U.S. Environmental Protection Agency: "Perchlorate," and "Perchlorate: Questions and Answers."FDA.News release, Environmental Working Group.
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