The first study focusing on the chemical bisphenol (BPA) and children was recently published in the journal Environmental Health Perspectives. Investigators reported that the amount of BPA that women were exposed to during pregnancy was significantly associated with parents’ views of their child’s behavior when they were 2 years old. Here, we talk to David Bellinger, PhD, of Children’s Hospital Boston’s Neurology Department, about the findings.
Lately, it’s been widely reported that many plastic consumer products, including some baby bottles, contain a chemical called bisphenol A (BPA) that can leach out and be ingested. Although BPA can be detected in the urine of most people (more than 90 percent of the U.S. population according to the Centers for Disease Control and Prevention), whether it poses a health risk is unclear. To date, all of the research on potential health effects of BPA has involved animals, and has shown that BPA disrupts the endocrine system, mimicking estrogen.
The results this study—the first focusing on children—are fairly complicated. The association was seen in girls, but not boys. Not all behaviors were associated with mothers’ BPA exposure, only hyperactivity and aggression. And finally, BPA levels measured earlier in pregnancy (before 16 weeks) were more strongly related to these behaviors than BPA levels measured later in pregnancy or at birth.
These findings are potentially important, but it’s important to remember that this is the first published study of BPA and child development. No single study ever settles an issue once and for all. These studies are hard to do well and are subject to a variety of biases and uncertainties. Even the best study doesn’t prove causation, so the question of whether current levels of BPA exposure represent a true health hazard to children remains open.
We will have to see if this BPA-behavior association holds up in other studies that try to reproduce the findings. It will also be important for the investigators of the study to follow the children they studied to an age older than 2 to see whether the associations persist or disappear. In my view, the importance of this study is that it provides a warning that there might be something here that warrants greater scrutiny. The sizes of the associations observed were modest. That is, although the more highly exposed children were rated, on average, as being more active, this doesn’t mean that they would warrant a diagnosis of ADHD. But the worry is that the apparent BPA effects observed are only “the tip of the iceberg.” This is why additional studies are necessary so that we can better understand the scope and severity of any effects of BPA on children.
In the face of the lack of scientific consensus on the effects of BPA, if any, different countries are taking different approaches. In October 2008, Canada became the first country to ban the import or sale of polycarbonate baby bottles containing BPA, although this was done largely as a precautionary measure. The U.S. Food and Drug Administration is currently evaluating the safety of BPA. In the meantime, they are not recommending that consumers discontinue using products that contain BPA.
Watch a video of Children’s late Michael Shannon, MD, MPH, discussing BPA and plastic baby bottles.