The worrisome, hormone-disrupting chemical BPA showed up in every urine sample taken from more than 80 preschoolers in two states, reported a recent study of kids, ages 2 through 5.
And even though BPA often appears in samples of dust, air and surfaces of objects, the new study found that most of the BPA that got into the little kids came from their food.
The researchers weren't able to determine which foods delivered the largest doses of BPA. But the chemical often appears in the linings of cans and in hard, clear polycarbonate plastic containers. Recent studies have also documented the migration of the chemical from packaging into foods.
Levels of BPA detected in the kids' urine fell well below declared safe limits. Still, the findings suggest that caregivers could reduce the chemical burden of children they care for by paying more attention to the packaging their food comes in.
"Knowledge is power," said lead researcher Marsha Morgan, a research environmental health scientist at the Environmental Protection Agency in Research Triangle Park, N.C.
"I really believe that parents should be aware of containers that contain BPA or that microwaving can cause BPA to migrate when you heat up containers," she said. "They may want to use alternatives like glass or BPA-free containers."
The new results are the latest findings from an ongoing study on 257 preschoolers in North Carolina and Ohio. Over a 48-hour period in 2001, researchers originally took samples from dust, air, surfaces, food and drinks in the children's homes and daycares. They also collected urine samples.
Among other outcomes, the project has found that little kids are exposed to dozens of pollutants, including BPA. Many of those pollutants end up in their bodies. And even though adults live and work in the same spaces, children experience higher levels of exposure.
In the new study, Morgan and colleagues found BPA in the urine of each of the 81 kids whose urine they looked at, the researchers reported in the journal Environmental Science & Technology.
The scientists were also able to track the source of more than 95 percent of that BPA to the food that all 257 of the original kids were eating. Levels of BPA in solid foods were seven times higher than levels in liquids that the kids drank.
At the beginning of the study, the researchers had mixed together all of the food the kids ate over the two-day period, and they mixed liquids separately. That gave them the ability to compare foods with drinks, but they couldn't isolate the effects of any particular menu item. All of the foods had come from ordinary grocery stores.
According to the study, levels of the chemical in the kids' urine were 10 times lower than limits declared safe by the EPA. But some scientists have been strongly arguing that those limits are way too high, said Arnold Schecter, a public health physician at the University of Texas School of Public Health in Dallas.
BPA may also interact with other chemicals in foods to multiply potential health risks, which are especially concerning for developing young brains and bodies. Schecter and colleagues have been systematically documenting the presence of pesticides, plasticizers, flame-retardants and all sorts of other chemicals in our food supply.
"If you were considering this one chemical alone, this amount would not exceed what is considered by some government agencies at this time to be an allowable or safe dose," Schecter said. "But of course, BPA is not the only toxic chemical being ingested. They not only interact with each other; they can cause similar endocrine disruption."
Because his work has shown that BPA levels are higher in canned foods than in other products, Schecter said that eliminating canned foods from kids' diets would go a long way towards reducing their exposure. It may also help to use glass or other alternatives instead of the hard, clear polycarbonate containers for food and drinks.
Some companies, such as the Eden Organic brand, already use BPA-free linings for their canned beans. In reaction to pressure from consumers, other companies may follow suit.
"This is avoidable," Schecter said. "Cans do not need to be lined with BPA, nor do bottles need to contain BPA."