A new study supported by NTP was the first to investigate occupational exposure to BPA (bisphenol A) among manufacturing workers in the United States. Researchers at NIOSH led the study, which appeared January 1, 2017, in the journal "Annals of Work Exposures and Health." NIOSH is a member agency of NTP, and the study was conducted as part of an ongoing collaboration between the two agencies.
The NIOSH study included six U.S. companies that make BPA or manufacture or use resins and waxes containing BPA. Of the 78 workers participating in the study, most were white males. Over two days, participants provided seven urine samples. The participants also answered questions about food and beverage products they consumed in the previous 24 hours.
Researchers at the Centers for Disease Control and Prevention (CDC) have found BPA in the urine of nearly all people tested, indicating widespread exposure in the U.S. population. Diet is thought to be the main nonoccupational source of BPA exposure. Workers who participated in the new study handled raw BPA, often in large quantities, and—unlike the general population—were exposed to BPA mainly by inhalation and absorption through the skin.
NIOSH researchers found that BPA levels in the urine of workers were, on average, about 70 times higher than that of most adults in the United States. Certain job categories were associated with average urine levels more than 300 times greater than in the general population. Workers who handled sacks of BPA and carried process or bulk samples containing BPA for quality control testing, for example, had increased urinary BPA levels. Among the highest exposed workers were those who worked with molten casting wax that contained BPA. The lowest urinary BPA levels (trace amounts) were found in workers who handled a resin product. The study did not evaluate the health of the participating workers.
The NIOSH Science Blog provides more information about this study and ways to reduce exposure.