Possible Adverse Health Effects of Bisphenol A

 
Bisphenol A (BPA) is a chemical used to manufacture many polycarbonate plastics and epoxy resins. Small amounts are found in such products as baby bottles, food containers, backpack water containers, in the lining of cans and bottles used for food storage and dental sealants. Small amounts of BPA have been found in the urine of over 80% of US children and adults.

Bisphenol A is a chemical which mimics the effects of estrogen in the body and has potential endocrine (hormone) disrupting effects.  Studies with humans, lab animals and cell culture has indicated that moderate exposures to BPA are linked to breast and testicular cancer. Exposure to BPA has also been associated with early puberty in young women.  (A good overall review of the health effects of Bisphenol A (BPA) is provided by Vandenberg et al. in the March 2009 Endocrinology Reviews).

A recent Chinese study reported that heavy exposure to BPA greatly increased the risk of sexual dysfunction among 164 male workers in a BPA plant as compared to 386 unexposed control workers.  Compared to the unexposed workers, the heavily exposed BPA workers had a 3.9 fold greater risk of reduced sexual desire, 4.5 fold greater risk of erectile dysfunction and a 7.1 fold greater risk of ejaculation dysfunction. Results were statistically significant and were adjusted for such factors as age, smoking, alcohol consumption and diabetes. (This work by Li et al. is now in Press in the journal Human Reproduction.)

Much more research on the health effects of BPA and other endocrine disrupting chemicals is needed.  While moderate exposures of BPA are certainly harmful to health, it is not certain whether very low doses are harmful or whether a “threshold dose” exists below which adverse health effects are unlikely.

How can exposure to BPA be reduced?  Glass containers generally contain no BPA, although glass has a danger of breakage. BPA levels in plastic containers such as baby bottles, plastic glasses, food containers, and backpack water containers can be reduced by soaking them in water for several days and then rinsing before use.  This allows much of the BPA to leach out.  Some people are suggesting the banning of BPA containing food containers.  Canada has banned the use of BPA in baby bottles.