May 2nd, 2011
08:35 AM ET
A new study is adding to rising concerns about the safety of bisphenol A (BPA), a chemical used to manufacture plastics and found in hundreds of household products, including plastic food containers, soda cans and reusable cups.
Research presented Sunday at the Pediatric Academic Societies annual meeting finds the higher the amount of BPA an expecting mother is exposed to early in her pregnancy, the more likely her newborn will experience wheezing during the first 3 years of life.
According to Dr. Adam Spanier, a pediatrician with Penn State’s Hershey Medical Center and lead author of the study, fetuses exposed to high levels of BPA at 16 weeks of gestation had an increased risk of transient wheeze. At 6 months the infants were twice as likely to wheeze; the condition persisted for 3 years then cleared up. If moms-to-be were exposed to BPA later in pregnancy, researchers did not see the same effect.
“The challenge with dealing with BPA is that it has such a broad range, from zero to several thousand,” Spanier explains. “We were just looking to see if any exposure was associated with wheezing.” At 16 weeks of gestation the women in this study tested positive for BPA levels ranging from 0.4 to 37.5 micrograms per liter.
Previous studies – done mainly on mice – have linked BPA to potential side effects on the brain, behavior and prostate gland of fetuses, infants and children, according to the Food and Drug Administration. But officials with the Environmental Protection Agency say there remains uncertainty in the extrapolation of dose levels from animals to humans. Still, last year the FDA concluded that there is “reason for some concern” and beefed up measures to reduce human exposure to the chemical. In particular, the governement warned parents to limit infants' use of products that contain bisphenol-A.
In response to the study, Steven Hentges, executive director of the Polycarbonate/BPA Global Group with the American Chemistry Council said this: “This small-scale study, which has not been peer-reviewed or published in the scientific literature, is inherently incapable of establishing a cause-effect relationship between any causative agent and wheezing. The statistical associations reported in this study have not been verified or corroborated by any other study on BPA, which is one of the best tested substances in commerce. Based on the full weight of scientific evidence, government agencies around the world have determined that BPA is safe for use.”
Spanier also notes that this investigation, which included 367 pairs of mothers and infants whose BPA levels were tested at 16 and 26 weeks of gestation and again during the delivery, was the first to evaluate the link between BPA and wheezing and the research needs to be replicated in another study population. In this study, 99% of the mothers in the study had detectable levels of urinary BPA at some point during the study. Factors associated with the increased levels in these women included working as a cashier, eating canned vegetables and exposure to tobacco smoke.
Health officials say there are several things that consumers can do to limit their exposure.
The Department of Health and Human Services recommends purchasing plastic containers marked at the bottom with recycle codes 1, 2, 4, 5, and 6 because they are very unlikely to contain BPA. You can also look for the "BPA-Free" label when shopping for canned goods and various household items.
Experts from the National Institutes of Health recommend consumers avoid putting polycarbonate plastic food containers into the microwave because high temperatures may break down the chemical and increase the chances of BPA entering your food.
The National Toxicology Program also provides a list of ways to reduce exposure, including opting for fresh or frozen fruits and vegetables instead of canned goods. The lining of the cans are often made with BPAs. They suggest using glass, porcelain or stainless steel containers to store food.
They also recommend consumers beware of the sales receipts you receive particularly at grocery stores and ATMs, as the developer used for dyes in thermal paper may contain levels of BPA which could pose a risk for human exposure. An NIH spokesperson suggests not taking a receipt unless you have to while the government continues to investigate.
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