A study from researchers at the Johns Hopkins Bloomberg School of Public Health and School of Medicine has revealed that children having of the synthetic chemical BPA (Bisphenol A) in their urine carry more risk of asthma symptoms.
The study is based on the research conducted on children in low-income neighborhoods in Baltimore.
For their analysis, the researchers examined clinical data and urine samples, taken at three-month intervals over a year, from 148 predominantly Black children in Baltimore.
They found consistent links between higher BPA levels in urine and measures of recent asthma severity.
While some products, including baby bottles, no longer contain BPA, exposures to BPA remain almost universal, and there are still concerns that, especially in childhood, those exposures might have a health impact.
The researchers found no statistically significant link between BPA levels and asthma symptoms among the girls in the study.
The researchers also found that higher levels of two common chemicals closely related to BPA — BPS and BPF — were not consistently associated with more asthma symptoms.
Like BPA, BPS and BPF are found in many consumer products, including food cans and beverage bottles.
The study, published July 28 in the Journal of Allergy and Clinical Immunology, is thought to be the first to examine children’s environmental exposures to BPA, BPS, and BPF and their associations with asthma severity.
The study suggests that additional studies are needed to examine this BPA-asthma link, given the high burden of pediatric asthma and widespread exposure to BPA in the United States.
What Is BPA?
BPA is a chemical building block used to make polycarbonate plastic as well as some epoxies. Produced at the rate of about 7 million tons per year worldwide, it can leach from polycarbonate bottles into the liquids they contain, and from epoxies that line cans of soup and other food items.
A 2011 study published found that eating soup from cans lined with BPA-containing epoxy caused study participants’ BPA levels to rise by a factor of almost 20.
BPA can activate estrogen receptors on cells, which suggests that it may have hormone-like effects — disrupting human biology even at very small exposure levels.
Animal studies have found evidence that the chemical can have pro-inflammatory effects.
Epidemiological studies have found that people with higher BPA levels in their urine are more likely to have cardiovascular disease, diabetes, asthma, and some other conditions.
Children are in principle more vulnerable, to the extent that they use BPA-containing products more often than adults do.
Due to consumer concerns, companies stopped making BPA-containing baby bottles and sippy cups more than a decade ago, and have largely switched to non-BPA can epoxies.
BPS and BPF are close chemical relatives, or analogs, of BPA, and are found, for example, in can-linings and thermal-printer receipts — often as replacements for BPA. They too can interact with estrogen receptors, although very little is known about their health impacts at current exposure levels.