A new study released by researchers at Stanford University and the Johns Hopkins University's Bloomberg School of Public Health suggests that school lunches may contain unsafe levels of BPA, or bisphenol A.
The chemical, most often found in canned foods and plastic packaging, mimics human hormones and can be harmful for the developing brains of fetuses, infants and children.
"There are known sources of BPA being used in school food," said Jennifer C. Hartle, a postdoctoral research fellow at Stanford and lead author of the study, which was recently published in the Journal of Exposure Science and Environmental Epidemiology.
Hartle added that parents should push for their school systems to use fresh ingredients rather than canned or prepackaged foods when serving lunches to their children.
"Everybody knows about pesticides as a potential problem with food," she said. "Well, the packaging is something else to consider."
However, the head of the Maryland-based School Nutrition Association and a spokesman for the chemical industry disagrees with the findings, noting that the levels of BPA found in the study were all below established safety limits, writes Timothy B. Wheeler for The Baltimore Sun.
Hartle did acknowledge that the levels of BPA a student might receive from one meal would be well below the threshold set by the federal government. However, that standard was set by the Environmental Protection Agency in 1988. She added that since that time over 100 studies have been performed, finding that much lower doses of BPA have resulted in negative health effects in animals.
For the study, researchers interviewed food service managers and also visited school kitchens and cafeterias in an effort to determine what foods are served and how they are kept. Using other studies that found BPA can enter food from cans and plastic packaging, they calculated how much of the chemical students may be ingesting in a single meal.
Although plastic packaging and utensils have been found to contain BPA, canned foods still remain the most common source for BPA. While government nutrition standards and health advocates have continued to fight to reduce the amount of pizza served at schools, the study maintains that this alone is not reducing the amount of BPA children are ingesting.
Despite more fruits and vegetables being served at schools, canned foods are still frequently used. Even at salad bars, added as a result of efforts to create more nutritious school lunches, canned and prepackaged beans, fruits and other items are offered.
Estimates by researchers suggest that although around 12% of food is thrown out uneaten by students, what they do ingest could result in negligible amounts of BPA or as much as 1.19 micrograms per kilogram of body weight. While the EPA places the safe-intake level at 50 micrograms per kilo of body weight, the European food safety authority recently lowered its limit to 4 micrograms based on new research, writes Susanna Pilny for RedOrbit.
"This lunch is only part of the exposures a child will get during the day," said Andrea Gore, a pharmacology professor at the University of Texas at Austin and lead author of the Endocrine Society's statement on the matter. They could also be getting BPA, she added, in "what they eat for dinner, what they eat for snacks, what they're exposed to beyond just the food."