12 November 2009
Plastics workers risk impotence, ejaculation difficulties
by Kate Melville
A groundbreaking study into Bisphenol-A (BPA) exposure amongst Chinese factory workers has found that men working in environments where the chemical was present had quadruple the risk of erectile dysfunction and seven times more risk of ejaculation difficulty. This is the first study to look at the effect of BPA on the male reproductive system in humans. Previous animal studies have shown BPA to have a detrimental effect on the male reproductive system in rodents.
The five-year study, published in Human Reproduction, examined 634 Chinese factory workers, comparing those in BPA manufacturing facilities with a control group of workers in factories where no BPA was present. BPA is used in the production of polycarbonated plastics and epoxy resins found in baby bottles, plastic containers, the lining of cans used for food and beverages, and in dental sealants.
BPA is believed by some to be a powerful human endocrine disrupter, affecting both male and female reproductive systems. This first epidemiological study of BPA effects on the male reproductive system provides evidence that has been lacking as the U.S. Food and Drug Administration, and various U.S. government panels have explored this controversial topic.
The researchers estimated that the BPA levels experienced by the exposed factory workers in the study were 50 times higher than what the average American male might experience. "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 the study's lead author De-Kun Li, from 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."
The study was conducted using air sampling, personal air sample monitoring and walk-through evaluations, reviewing factory records and interviewing factory leaders and workers about personal hygiene habits, use of protective equipment, and exposures to other chemicals. A group of workers also provided urine samples for assaying urine BPA level to confirm the higher BPA exposure level among the workers with occupational BPA exposure.
Sexual function measurements were based on in-person interviews using a standard male sexual function inventory that measures four categories of male sexual function including erectile function, ejaculation capability, sexual desire, and overall satisfaction with sex life.
After adjusting for age, education, marital status, current smoking status, a history of chronic diseases and exposure to other chemicals, 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.
Dr. Li concludes by pointing out that the findings might hint at deeper adverse BPA effects beyond male sexual dysfunction. "Male sexual dysfunction could be a more sensitive early indicator for adverse BPA effects than other disease endpoints that are more difficult to study, such as cancer or metabolic diseases," he noted.
BPA found to have "dramatic" effect on adult hormone levels
Fresh concerns about BPA
Decomposing plastic refuse releasing BPA into oceans
Experts demand FDA act on BPA report
California Mulls Estrogen-Plastic Ban
Estrogen contamination in bottled water "just the tip of the iceberg," say scientists