New research has found a significant association between workplace exposure to the chemical Bisphenol A, widely used in coatings, and decreased sperm count and function—the first research to make that connection in humans.
A study of Chinese factory workers found that BPA was “statistically significantly associated with” decreased sperm count, vitality, motility and concentration.
“These results provide the first epidemiologic evidence of an adverse effect of BPA on semen quality,” study author Dr. De-Kun Li, MD, PhD, reports in an article published online Thursday (Oct. 28) in the journal Fertility and Sterility.
“Compared with men who did not have detectable urine BPA levels, those with detectable urine BPA had more than three times the risk of lowered sperm concentration and lower sperm vitality, more than four times the risk of lower sperm count, and more than twice the risk of lower sperm motility,” concluded Li, a scientist at the Kaiser Permanente Division of Research in Oakland, CA.
Furthermore, although the study focused on high-level workplace exposures, “similar dose-response associations were observed among men with environmental BPA exposure at levels comparable with those in the U.S population,” Li found.
The study, funded by the National Institute of Occupational Safety and Health, did not determine whether the relatively low sperm counts and other signs of poor semen quality translated to reduced fertility.
In a separate study earlier this year, Li also found that increasing levels of BPA in urine were associated with “worsening male sexual functioning”—specifically, decreased sexual desire, more difficulty having an erection, lower ejaculation strength, and lower level of overall satisfaction with sex life.
Furthermore, that five-year study of 427 factory workers found that the results remained consistent even among men with no occupational exposure “and at levels lower than the urine BPA in average Americans,” Li reported.
BPA is a key component in the epoxy resins that are used to make coatings of every type, from protective and marine coatings for ship hulls, tank linings and oil platforms; to powder coatings for automotive parts, metal roofing and gardening tools; to anti-slip and industrial floor coatings; to—most controversial—linings of food cans.
BPA is also a key component in the production of polycarbonate plastic, which is used to make a huge variety of products, from baby bottles to bullet-resistant shielding, bicycle helmets, kidney dialysis machines, incubators, face shields and safety glasses, and adhesives for home and construction use.
The safety of BPA has been the subject of growing recent global debate. The government of Canada recently added the chemical to its Schedule 1 list of Toxic Substances under the Canadian Environmental Protection Act, over the consternation of the chemical industry, which said the risk of BPA had been exaggerated.
The European Food Safety Authority announced Sept. 30 that it would not lower the official limit on accepted exposure to Bisphenol A, despite requests by some European countries to do so. France, German, Denmark and Sweden all have taken steps to rein in BPA exposure.
The U.S. Food & Drug Administration has declined to regulate BPA but recently acknowledged that the chemical raises health concerns.
The World Health Organization and U.N. Food & Agriculture Organization have scheduled a meeting Monday (Nov. 1) in Ottawa to discuss BPA safety.