 Early-age exposure to the chemical bisphenol A (BPA), a component found in soup and other food can liners, and in some plastics, can increase the possibility of asthma in children. First to report this BPA-exposure and childhood-asthma connection are researchers at the Columbia Center for Children's Environmental Health at the Mailman School of Public Health , with results to be published in the March edition of the Journal of Allergy and Clinical Immunology . 'Asthma prevalence has increased dramatically over the past 30 years, which suggests that some as-yet-undiscovered environmental exposures may be implicated. Our study indicates that one such exposure may be BPA,' said lead author Kathleen Donohue, MD, an investigator at the Center for Children's Environmental Health and assistant professor of medicine at Columbia University College of Physicians and Surgeons . The levels of BPA exposure was measured by taking urine samples from expectant mothers during their third trimester, as well as in the children of the 568 moms at the ages of three, five and seven. A BPA metabolite found in urine acts as an indicator towards the level of exposure. The results indicated that increased risk of asthma and wheezing was linked to the exposure of BPA during the early years of the child's life. Reducing BPA exposure Recommendations from the National Institute of Environmental Health Sciences (NIEHS) to reduce exposure to BPA include: avoidance of plastic numbers three and seven. Many include number six in the 'plastics to avoid' category. Also recommended by the NIEHS is to choose glass, porcelain or stainless steel containers over plastic, especially when storing food items in the freezer, or when used for hot foods or liquids. An ABC News report from early 2011 showed a statistic pulled from the Centers for Disease Control and Prevention indicating that '93 percent of Americans have BPA in their bodies,' and suggested to eat fresh produce (as opposed to frozen produce in plastic bags), and to eat in more often (because it's difficult to know how the food is prepped or defrosted in the restaurant kitchen). 