The study was done in urban, suburban and rural schools in the San Francisco Bay area by Stanford's Prevention Research Center and the Johns Hopkins Bloomberg School of Public Health, and was published in the Journal of Exposure Science and Environmental Epidemiology.
Researcher Jennifer Hartle told Miller, "During school site visits, I was shocked to see that virtually everything in school meals came from a can or plastic packaging. Meat came frozen, pre-packaged, pre-cooked and pre-seasoned. Salads were pre-cut and pre-bagged. Corn, peaches and green beans came in cans. The only items not packaged in plastic were oranges, apples and bananas."
Researchers track BPA intake in terms of micrograms per kilogram of body weight per day. Rodents experience toxicity at 2 mcg/kg, but the toxic level for humans is unknown because it's also unknown how humans metabolize BPA, Miller writes. In 1988, the Environmental Protection Agency "defined safe BPA consumption levels as 50 micrograms or less per kilogram of body weight per day," Miller writes. "Since then, hundreds of scientific papers have found detrimental biological effects of BPA at levels lower than the EPA standard. The European Food Safety Authority recently updated its standards for safe BPA intake to 4 micrograms per kilogram of body weight per day."
The study found that a student consuming pizza and milk with canned fruits and vegetables could take in anywhere from minimal levels of BPA up to 1.19 mcg/kg each school day. "While most students would not consume the maximum amount, those who do would take in more than half of the dose shown to be toxic in animal studies in just one meal," Miller writes.
Study co-author Robert Lawrence of Johns Hopkins told Miller, "With endocrine-disrupting chemicals particularly, there is so much uncertainty. We can't tie a specific dose to a specific response like we can with lead. But we know BPA is impacting human health. Animal models are showing there can be a whole range of health effects. This research shows we should take a precautionary approach." (Read more)