A new BPA study presented by US researcher Justin Teeguarden of the Pacific Northwest National Laboratory, Richland, WA, U.S. on February 16, 2013 at the American Association for the Advancement of Science (AAAS) annual meeting in Boston, U.S. modeled BPA exposure in the general population and concluded that levels are too low to cause health effects related to endocrine disruption (Teeguarden et al. 2013). The researcher estimated BPA exposure of 30 000 individuals based on external exposure estimates, urinary BPA measurements, the urine-to-blood concentration ratio and the fraction of BPA in its unconjugated form, which he assumes to be exceedingly low (~0.1%). The levels calculated did not correspond to the levels at which toxicological effects are commonly seen in animals but where around a thousand fold lower. Teeguarden concludes that studies that were indeed able to measure higher levels of BPA in human blood point to very high exposures, contamination of samples or measurement artifacts.
However, Teeguarden’s assessment has also sparked criticism. Criticism mostly refers to the fact that Teeguarden’s data are based on models relying on estimates, rather than actual biomonitoring. BPA researcher Laura Vandenberg from Tufts University says it is unlikely that all 25 studies, which have measured BPA in human blood, were false measurements. Further she contends that many of the levels measured in human blood correspond to dose levels administrated in toxicological low dose studies, where they have been found to cause adverse health effects (see Environmental Health News and Science News).
Teeguarden, JG et al. (2013). "Estrogen receptor activation potential of internal concentrations of BPA in humans. American Association for the Advancement of Science annual meeting." Presented February 16, 2013.
Note March 19, 2013: In a recent opinion piece by the journalist Tom Philpott published March 13, 2013 it was criticzed that the study has not been published in a peer-reviewed journal and that it is not clear whether it has been submitted for publication. To read more, click here.