Children who are exposed to the chemical bisphenol A, or BPA, are at an increased risk for asthma, according to a new study published in Journal of Allergy and Clinical Immunology.

A group of researchers at the Columbia Center for Children’s Environment Health at the Mailman School of Public Health are the first to document a clear link between exposure as a child to BPA and a raised risk for asthma during childhood.

BPA is found in some plastics and in food can liners as well as store receipts.

Lead author Kathleen Donohue, MD, an assistant professor of Medicine at Columbia University College of Physicians and Surgeons and an investigator at the Center for Children’s Environmental Health, said:

“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.”

The investigative team tracked 568 women enrolled in the Mothers and Newborns study that analyzed environmental exposures. Exposure to BPA was calculated by measuring levels of a BPA metabolite via urine samples. Samples were taken during the third trimester of pregnancy, and in kids ages 3, 5, and 7.

Doctors diagnosed asthma during the ages 5 to 12 based on symptoms of asthma, medical history, and a pulmonary function test. A certified survey was used to examine wheeze.

The research team adjusted for secondhand smoke and other risk factors linked to asthma. They revealed that childhood exposure to BPA was linked to increased risk of wheeze and asthma.

Exposure to BPA during the third trimester of pregnancy showed an inverse relationship with the risk of wheeze at age five.

Surprisingly, this finding is in contrast to the outcomes of an earlier study that showed a link between BPA exposure during the second trimester – a crucial time for the development of the immune system and airways of a fetus – and the risk of asthma.

Elevated risk for wheeze and asthma was shown at “fairly routine, low doses of exposure to BPA. Like most other scientists studying BPA, we do not see a straightforward linear dose-response relationship,” according to Dr. Donohue.

During all three time periods, over 90 percent of kids in the study had detectable rates of BPA metabolite in their bodies, an outcome that also confirms earlier research.

Dr. Donohue points out this does not mean all of these children will develop asthma, however it does increase their risk.

Exactly what causes this relationship between asthma and BPA is still unknown. This study found no significant evidence that the exposure to BPA elevated the risk that the immune system may develop more antibodies to airborne allergens.

Dr. Donohue said, “Other possible pathways may include changes to the innate immune system, but this remains an open question.”

This study confirms previous evidence linking BPA exposure and respiratory issues.

BPA exposure is also associated with other health problems such as:

  • impaired glucose tolerance
  • behavioral issues
  • obesity

In September of last year a study found that BPA in food packaging was linked to childhood and adolescent obesity.

Senior author Robin Whyatt, DrPH, professor of Environmental Health Sciences and deputy director of the Columbia Center for Children’s Environmental Health, says:

“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.”

The National Institute of Environmental Health Sciences (NIEHS) recommends eating less canned food, choosing glass or stainless steel containers especially for hot foods and liquids, and avoiding plastic containers numbers 3 and 7, in an effort to decreased exposure to BPA.

Written by Kelly Fitzgerald