The five-year study on 634 workers in factories in China found that those exposed to BPA had quadruple the risk of erectile dysfunction and seven times more risk of ejaculation difficulty compared to workers where no BPA was present. The research was carried out by Kaiser Permanente.
The research arm of the company said the study was the first to look at the effect of BPA on the male reproductive system in humans. Previous animal studies have shown that BPA has a detrimental effect on male reproductive system in mice and rats.
The project compared 230 employees exposed to high levels of BPA in their work as packagers, technical supervisors, laboratory technicians and maintenance workers in one BPA manufacturing facility and three facilities using BPA to manufacture epoxy resin, in several regions near Shanghai, to a control group of 404 workers in the same city from factories where no BPA exposure in the workplace was recorded. Workers from the two groups were matched by age, education, gender, and employment history.
BPA levels were gauged using a range of methods including spot air sampling, walk-through evaluations and by reviewing factory records. A group of workers also provided urine samples for testing to confirm the higher BPA levels among the workers with occupational BPA exposure.
Researchers measured sexual function and, after adjusting for age, education, marital status, current smoking status, a history of chronic diseases and exposure to other chemicals, and employment history, found the BPA-exposed workers had a significantly higher risk of sexual dysfunction compared to the unexposed workers
“The BPA-exposed workers had a nearly four-fold increased risk of reduced sexual desire and overall satisfaction with their sex life, greater than four-fold increased risk of erection difficulty, and more than seven-fold increased risk of ejaculation difficulty”, said a statement from the researchers.
More research needed
The levels of exposure experienced by the Chinese workers were 50 times higher than those faced by the average worker in the US, said the research as it called for further investigation into the issue.
"Because the BPA levels in this study were very high, more research needs to be done to see how low a level of BPA exposure may have effects on our reproductive system," said lead author Dr De-Kun Li, a reproductive and perinatal epidemiologist at Kaiser Permanente's Division of Research. "This study raises the question: Is there a safe level for BPA exposure, and what is that level? More studies like this, which examine the effect of BPA on humans, are critically needed to help establish prevention strategies and regulatory policies."
He added the study could have implications beyond male impotence as this could be a “sensitive early indicator for adverse BPA effects than other disease endpoints that are more difficult to study, such as cancer or metabolic diseases”.
Occupational exposure to bisphenol-A (BPA) and the risk of Self-Reported Male Sexual Dysfunction by D. Li1, Z. Zhou et al is published in the Human Reproduction journal