Infants Exposed to Unsafe Levels of Thyroid Toxin
Researchers from the Centers for Disease Control and Prevention (CDC) have found that 15 brands of powdered infant formula are contaminated with perchlorate, a rocket fuel component detected in drinking water in 28 states and territories.
The two most contaminated brands, made from cow’s milk, accounted for 87 percent of the U.S. powdered formula market in 2000, the scientists said.
The CDC scientists did not identify the formula brands they tested.
The CDC findings, published in the March 2009 edition of the Journal of Exposure Science and Environmental Epidemiology, raise new concerns about perchlorate pollution, a legacy of Cold War rocket and missile tests. Studies have established that the chemical is a potent thyroid toxin that may interfere with fetal and infant brain development.
The CDC study said that reconstituting cow’s milk/lactose formula with water contaminated with perchlorate at just 4 parts per billion (ppb) would cause 54 percent of the infants consuming the mix to exceed the so-called “safe” dose set by the Environmental Protection Agency (EPA). Many scientists contend that the EPA “safe” level is too high to protect public health.
“Perchlorate contamination of drinking water is a very serious concern, particularly for infants,” said Anila Jacob, M.D., M.P.H., a senior scientist with Environmental Working Group (EWG). “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.”
While these findings are of concern, the CDC scientists also noted that FDA requires infant formula to be supplemented with iodine, a nutrient that can counteract the negative effects of perchlorate on the thyroid gland. The range of required iodine concentrations in formula is between 5 and 75 micrograms per 100kcal of energy.
Iodine supplements at higher levels may offer some protection from the toxic effects of perchlorate.
But the CDC scientists estimated that those brands that contain only the minimum iodine concentration of 5 micrograms would leave infants iodine-deficient and thus more vulnerable to the toxic effects of perchlorate. A scenario in which formula contained 40 micrograms of iodine (per 100kcal of energy) would offer more protection for infants, but the scientists stressed that even adequate iodine intake among formula-fed infants is not guaranteed to prevent “perchlorate-induced thyroid dysfunction.”
These findings underscore the need for the EPA to scrap Bush era perchlorate policies that shielded defense contractors and other big polluters from the costs of cleaning up perchlorate-contaminated water by setting a legally enforceable safe drinking water level that protects pregnant women, infants and others who are most vulnerable to the effects of this harmful chemical.
Last fall, EPA officials declared that perchlorate in drinking water posed no threat to most Americans and did not need to be regulated as a water pollutant. EPA’s decision was widely viewed as a major victory for the Pentagon and the defense and aerospace industries unwilling to mount a nationwide perchlorate cleanup estimated to cost hundreds of millions of dollars.
In response to criticisms from scientists, health professionals and consumer advocates, in January 8, EPA issued a non-binding “health advisory” on perchlorate and asked the National Academy of Sciences to review the issue.
EWG dismissed EPA’s action as – nothing more than an effort to dodge the issue and buy time for the defense, aerospace and chemical industries.”
Years of federal inaction have prompted some states to set their own mandatory limits for perchlorate in drinking water: California, at 6 ppb and Massachusetts at 2 ppb. While recent scientific research has shown these standards to be too weak to protect public health adequately, they are far more stringent than EPA’s action in January.
At her confirmation hearing, EPA administrator Lisa Jackson pledged that she would act “immediately” to reduce perchlorate contamination in drinking water.
Since then, EWG has called on Jackson to fulfill that promise, but so far the agency has not made public a plan of action.
The new CDC study provides some of the strongest evidence yet that a legally enforceable safe drinking water level for perchlorate should be a priority for the Obama administration.
- EWG is a nonprofit research organization based in Washington, DC that uses the power of information to protect human health and the environment.