A heated debate over the safety of biphenyl-A (BPA), a plastic additive used in many common household products from baby products to food liners, has been going on for quite some time now. The chemical mimics the hormone estrogen, and has been linked to numerous problems in animal studies. The FDA claims it is safe; most of the scientific community disagrees.
Human studies are only beginning to come out, since the research is relatively new and it's much more difficult to study exposure in humans (and more expensive). Despite these challenges, some human research is starting to trickle in. A recent study by Joe Braun of the University of North Carolina at Chapel Hill, and Bruce Lanphear of Simon Fraser University in Burnaby, Canada, and their colleagues monitored BPA exposures in 249 women, beginning early in their pregnancies. They've continued to study the children, who currently range in age from 3 to 5 years, and were able to find a link between prenatal BPA exposure and later behavioral issues.
More than 99% of the pregnant women in the study tested positive for BPA in at least one of their three urine tests. This isn't surprising . . . we've known for some time that exposure is pretty much automatic, since BPA is used in so much of what we consume. Using this data, the team was able to find a correlation between a mother's BPA levels and later gender-specific abnormal behavior. The higher the level of BPA in the mother during the first 16 weeks of pregnancy, the more likely the child was to display atypical behavior. In girls, this was marked by heightened aggression. In boys, it meant they tended to become more anxious and withdrawn.
The behavioral deviations from the norm averaged about 2 to 6 points higher (as measured on the 100-point 'Behavioral Assessment System for Children-2' scale) for every 10 – fold increase in the early BPA levels of mom. The team also found that BPA levels later than 16 weeks of pregnancy did not appear to link in any way with later behavior. Lanphear notes that the significance of these changes is similar to the subtle IQ drops caused by lead exposure in U.S. children.
Of particular concern is that these findings replicate what has been found in animal studies. Research in rats has found that rat pups who were prenatally exposed to BPA tend to show more aggression and hyperactivity than those who aren't exposed. This seems to indicate that the chemical affects humans in the same way as it does rats, which means that all those scary animal studies produced might be just as threatening towards humans. Other studies have shown everything fro reproductive problems, early puberty in girls, and cancer and obesity risk from the chemical.
You can learn more about the potential dangers of BPA, and what parents can do to limit their family's exposure, in our article: “The BPA Debate: Are Plastics Poisoning Your Children?” available on our website. We'll also continue to keep you posted on any future developments on this blog.