Shooting Blanks

Fertility clinic studies indicated years ago that phthalates can have a negative effect on sperm quality—potentially leading to infertility. Now, a study in Chinese workers has demonstrated that BPA, or bisphenol A, can harm both sperm quality and quantity.

That BPA could harm male fertility comes as no surprise to many: laboratory studies have shown repeatedly that BPA exposure can harm male reproductive organs, including those involved in producing sperm. 

In the new study, researchers from Kaiser Permanente and their Chinese collaborators studied 218 factory workers, some of whom had occupational exposure to BPA (130 workers) and some of whom did not (88 workers). Previous studies in Chinese factory workers exposed to BPA had found a link between higher BPA exposure and greater risk of sexual dysfunction. This study measured sperm count, motility, and other factors, and found a very strong relationship between BPA exposure and lower sperm quality and sperm count. 

Compared to men who tested negative for BPA, those who tested positive:

-were more than three times as likely to have lower sperm concentrations and a lower percentage of live sperm;

-had four times the risk of lower sperm count; and

-were more than twice as likely to have lower sperm motility.

Researchers didn’t see a difference in some factors they tested, such as sperm morphology, ie whether sperm are shaped normally.

Unfortunately, these findings don’t just apply to men with very high exposures to BPA.  When the researchers examined men with no workplace exposure, they still found that the higher the BPA level, the lower the sperm count.

And American men, take note: the average BPA level found in these men was actually lower than the U.S. average.

Photo courtesy of flickr user Hafdís H