Richard Denison, Ph.D., is a Senior Scientist.
As reported by Rob Stein in the Washington Post this morning, a NIOSH-funded study of male Chinese workers conducted by researchers at Kaiser-Permanente in Oakland, California has found that exposure to the endocrine-disrupting chemical bisphenol A (BPA) significantly increases the incidence of low sperm counts and concentrations, as well as lowered sperm motility and higher mortality.
The 5-year study, published in the peer-reviewed journal Fertility and Sterility (that's a title only slightly more cheery than the CDC's publication Morbidity and Mortality!), shows that the same kinds of adverse effects of BPA on sperm already observed in animal studies also occur in humans with detectable levels of BPA in their urine.
And while the most pronounced effects were observed in highly exposed workers, the authors of the study note:
Similar dose-response associations were observed among participants with only environmental BPA exposure at levels comparable to men in the general United States population.
Despite a markedly reduced sample size in this group of men exposed only to low environmental BPA sources, the inverse correlation between increased urine BPA level and decreased sperm concentration and total sperm count remain statistically significant.