School meals may contain unsafe levels of bisphenol A (BPA), according to a study led by Jennifer Hartle, DrPh, a postdoctoral researcher at Stanford University’s Prevention Research Center and a Center for a Livable Future-Lerner Fellow (2013). BPA – a chemical commonly found in canned goods and plastic packaging – can disrupt human hormones and has been linked to adverse health effects including cancer. Current federal standards for school meals focus on nutrition and overlook exposure to toxic chemicals. Researchers say this exposure is of serious concern for low-income children since they are more likely to eat federally funded meals instead of bringing lunch from home.
“During school site visits, I was shocked to see that virtually everything in school meals came from a can or plastic packaging,” Hartle said. “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.” The uptick in packaging is a result of schools’ efforts to streamline food preparation and meet federal nutrition standards while keeping costs low.
To better assess BPA exposure through school meals, Hartle, along with researchers from the Johns Hopkins Center for a Livable Future (CLF), interviewed school food service personnel, visited school kitchens and cafeterias in the San Francisco Bay Area and analyzed studies on BPA food concentration values. They found that BPA exposure varies depending on what students eat, but a student consuming pizza and milk with canned fruits and vegetables could take in anywhere from minimal levels to 1.19 micrograms of BPA per kilogram of body weight per day. While most students would not consume the maximum amount, those who do would take in more than half the dose shown to be toxic in animal studies in just one meal.
“With endocrine-disrupting chemicals particularly, there is so much uncertainty,” said Robert Lawrence, MD, co-author of the study and director of the CLF. “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 wide range of health effects. This research shows we should take a precautionary approach and limit school meal exposure to BPA by serving students more fresh fruits and vegetables.”
“Probabilistic modeling of school meals for potential bisphenol A (BPA) exposure,” was written by Jennifer C. Hartle, Mary A. Fox, and Robert S. Lawrence.