Endocrine disruption, diabetes, obesity — to the list of ills potentially associated with exposure to the chemical bisphenol-A (BPA), you can add one more: childhood asthma.
In a new study presented over the weekend at the Pediatric Academic Societies annual meeting in Denver, researchers from the Penn State College of Medicine found that if pregnant women are exposed to BPA, their children may end up at a higher risk for developing asthma early in life.
In a study of 367 pairs of mothers and infants, researchers measured levels of BPA in the urine of pregnant women at 16 weeks of gestation and 26 weeks, as well as at the time of birth. Afterward, mothers were asked every six months for three years whether their child was showing symptoms of asthma. The results indicated, among other things, that BPA exposure was almost universal — 99% of children were born to mothers who had detectable levels of BPA at some point during their pregnancy.
(More on Time.com: Pregnant Women Awash in Chemicals. Is That Bad for Baby?)
The connection to asthma, though, was a little less clear-cut. At 6 months old, infants whose mothers had high levels of BPA were twice as likely to show wheezing as babies whose mothers who had low levels. But that difference disappeared as the children aged. Interestingly, though, the scientists also found that high levels of BPA detected in mothers at 16 weeks of gestation were associated with asthma in their kids, but high levels later in pregnancy or at birth showed little association. That lends some credence to the idea that the impact of BPA — like other hormone-disrupting chemicals — may be dependent on the timing of exposure for pregnant women, not just the level of exposure.
Still, it’s important to note that this study is correlative — it shows a possible association between BPA and asthma, not a cause — and that it has not yet been peer-reviewed. As the chemical industry has pointed out repeatedly, there have been no conclusive studies proving the dangers of BPA, and indeed, the federal government has made no move yet against the chemical, which is used in many plastics. But foreign countries and states have already moved to ban BPA from products used by young children, and the pressure to remove the chemical is increasing. (Interestingly, however, Coca-Cola has recently resisted shareholder pressure to eliminate BPA from its can linings.)
(More on Time.com: Want to Reduce Your Exposure to BPA? Cut Out Canned, Packaged Foods)
This isn’t the first study to make the connection between asthma and BPA — another piece of research, published last year in the journal Environmental Health Perspectives, found evidence that mice exposed to BPA were more likely to give birth to pups that developed breathing problems. The case hasn’t yet been made, but expect the worries about BPA to only keep growing.
More on TIME.com on Environmental Chemicals:
Exposure to Pesticides in Pregnancy Can Lower Children’s IQ
Even BPA-Free Plastics Leach Endocrine-Disrupting Chemicals