Reporter deprives listeners of reliable BPA science coverage.

Posted by Negin P. Martin, Ph. D at Nov 11, 2009 04:40 PM |

NPR science correspondent oversteps study's conclusions in a blog about BPA science.

Jon Hamilton, a science correspondent at National Public Radio, posted a health blog entitled “BPA safer than contraceptives in rat study” on October 30.

Hamilton reports on the results of a recent study published in the journal Toxicological Sciences. The government-funded study examined the effects of low-dose exposure to bisphenol A (BPA) and ethinyl estradiol (EE) – an estrogen hormone used in oral contraceptives – on the development of reproductive organs in male rats. The researchers chose BPA and EE because of their established estrogenic effects.
In the study, the male rats born to pregnant mothers that were given the higher oral doses of EE had smaller reproductive organs and reduced sperm counts. In contrast, the oral exposure to the different doses selected for the BPA treatments yielded no significant effect on the Longs Evans strain of male rats used in the study.  Based on that result, Hamilton’s article concludes: “The plastic additive bisphenol A (BPA) may not be so bad after all.”
The authors themselves do not confirm that statement. While they report that they saw no effects with developmental exposure to BPA on this strain of rat at the doses tested, they do not conclude or expound on the chemical's health safety or risks.

In that way, Hamilton's interpretation goes further than the authors' conclusions and ignores a large body of published research. More than 90 percent of government-funded studies report significant effects from low dose BPA exposure. About 10 percent don’t see an effect.

One common way to address this type of narrow reporting of a single study is to interview other scientists who are experts in the field yet were not associated with the study. These independent voices are necessary to objectively critique the the study's strengths, conclusions and how it fits with prior research.

For Hamilton to draw a conclusion based on a single study – while ignoring the majority of other government-funded studies and failing to include comments from other scientific experts – is careless and may mislead readers about the health concerns over BPA. Hamilton's presentation deprives NPR readers from reliable coverage about BPA science.

(Updated Nov 12, 2009)