By Richard Lenti
On the heels of a United Nations report warning of health hazards from hormone disrupting chemicals, comes a new study linking exposure to bisphenol A (BPA) to an elevated risk for asthma in young children. BPA is widely used in plastic food and beverage containers.
“Asthma prevalence has increased dramatically over the past 30 years, which suggests that some as-yet-undiscovered environmental exposures may be implicated,” said lead author Kathleen Donohue, MD, an assistant professor of Medicine at Columbia University College of Physicians and Surgeons. “Our study indicates that one such exposure may be BPA.”
The study appears in the March edition of The Journal of Allergy and Clinical Immunology.
BPA has been used for over 40 years in a range of products including the linings of aluminum cans to protect them from corrosion, and plastics such as bottles, tableware and food storage containers.
Researchers at the Columbia Center for Children’s Environmental Health followed 568 women enrolled in a study of mothers and their babies. The mothers’ BPA exposure was determined by measuring levels of a BPA metabolite in urine samples taken during their third trimester of pregnancy. BPA was also measured in the children at ages 3, 5, and 7.
While researchers found that post-natal exposure to BPA was associated with increased risk of wheezing and asthma, exposure during the third trimester of pregnancy was not linked with wheezing at age 5. That finding was in contrast to a previous study which found that BPA exposure during the second trimester was positively linked with childhood asthma.
More than 90% of the children in the study had detectable levels of BPA in their bodies, a finding that is in line with previous research. But Donahue cautions that does not mean they will all develop asthma.
“Just as smoking increases the risk of lung cancer but not everyone who smokes gets lung cancer, not every child exposed to BPA will develop asthma,” she said.
Although the biological mechanism between BPA and asthma is unclear, the new study builds on existing evidence linking BPA exposure to a range of health problems including potentially dangerous effects on a child’s developing nervous system, as well as obesity, glucose intolerance, respiratory problems and behavioral issues.
“It is very important to have solid epidemiologic research like ours to give the regulators the best possible information on which to base their decisions about the safety of BPA,” said senior author Dr. Robin Whyatt, professor of Environmental Health Sciences and deputy director of the Columbia Center for Children’s Environmental Health.
To reduce exposure to BPA, the National Institute of Environmental Health Sciences recommends eating less canned food, avoiding plastic containers that have the recycling numbers 3 and 7, and using glass, porcelain or stainless steel containers — especially for hot food and liquids.
BPA is banned in the European Union and Canada, but the U.S. Food and Drug Administration has only banned the chemical from baby bottles and sippy cups, as of July, 2012.