In an article published on January 1, 2017 in the peer-reviewed journal Annals of Work Exposures and Health, Cynthia Hines and colleagues from the U.S. National Institute for Occupational Safety and Health (NIOSH) report on the levels of occupational exposure to bisphenol A (BPA, CAS 80-05-7) in the U.S.. Seven urine samples were obtained during two consecutive days at work from 77 people employed by six different companies that make BPA, BPA-resins, or BPA-filled wax.
Compared to the general population with urine concentration of creatinine-adjusted total BPA (free plus conjugated) being 1.27 µg/g (geometric mean), approximately 70 times higher levels were found in those occupationally exposed. In some workers, contamination levels were more than 1000 times higher, up to 18,900 µg/g.
The data obtained in the study contradict the long-standing notion that all accumulated BPA would be metabolized and excreted within a day. In his article published on January 4, 2017 by Environmental Health News, editor Brian Bienkowski quoted Hines, the lead author of the study, suggesting “that BPA is taking longer to clear than would be predicted considering some oral dosing studies that have been done.” Laura Vandenberg from the University of Massachusetts, Amherst, U.S., not directly involved in the study, commented that skin absorption is the most likely route of BPA uptake in case of occupational exposures.
The levels found in the U.S. workers are higher than those observed by a series of Chinese studies where serum BPA levels measured in males exposed at the workplace were found to be associated with reduced levels of reproductive hormones, lower sperm quality, and self-reported sexual dysfunction. The U.S. study lead author Hines noted that, although the exposure data were shared with the interested workers, no specific information on associated risks could be provided to them, because in the U.S. there are no workplace exposure limits for BPA. Hence, the researchers could only “send general advice to the companies and workers to reduce exposure.”
Brian Bienkowski (January 4, 2017). “US workers making BPA have enormous loads of it in them.” Environmental Health News
Hines, C., et al. (2017). “Urinary bisphenol A (BPA) concentrations among workers in industries that manufacture and use BPA in the USA.” Annals of Work Exposures and Health (published January 1, 2017).
Zhou, Q., et al. (2013). “Serum bisphenol-A concentration and sex hormone levels in men.” Fertility and Sterility 100: 478-482.
Li, D., et al. (2011). “Urine bisphenol-A (BPA) level in relation to semen quality.” Fertility and Sterility 95: 625-630.
Li, D., et al. (2010). “Occupational exposure to bisphenol-A (BPA) and the riks of self-reported male sexual dysfunction.” Human Reproduction 25: 519-527.