to infants is not known. In the United States formulas must contain iodine which counteracts perchlorate's effects. The chemical is not listed on the ingredients on formula labels.
The small study tested 15 powdered formulas and all were found to have the chemical in them. The formulas ranged from milk-based, soy-based, lactose-free or "elemental," which are made with synthetic amino acids for babies who can't digest standard formulas. Formulas derived from cow's milk had the largest amounts of perchlorate. The researchers would not release the brand names of the formulas to the Associated Press.
The study did not measure the levels of perchlorate in infants. That study is considered essential because it would tell if infants are absorbing the perchlorate to which they may be exposed.
"Perchlorate contamination of drinking water is a very serious concern, particularly for infants," Dr. Anila Jacob, a senior scientist with Environmental Working Group, said in a statement. "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."
say that when the formula is mixed with water containing trace amounts of perchlorate there could be potentially dangerous levels. According to the scientists significant amounts of the chemical can affect thyroid function. Fetal and infant brain development can also be affected by thyroid problems.
, the new administrator of the Environmental Protection Agency, has pledged to act quickly to reduce perchlorate contamination in drinking water. Perchlorate has been found in drinking water in 28 states and territories, according to the Environmental Working Group.