Monday, June 27, 2011

BisPhenol A Makes Boys More Girly - Literally

Bis-phenol A feminizes mice.
Bis-phenol A BPA is back in the news.

Depth of Processing fans know that bis-phenol A is common industrial chemical used in packaging materials that happens to be a weak synthetic estrogen, and that it feminizes males including male mice. BPA reduces sperm counts, shrinks male parts, and produces early onset of puberty in girls.

What does that mean? This has shown up a variety of ways, and in a recent study, BPA fed to a pregnant mouse made her male offspring less attractive to females. Presumably by changing their secondary male mouse characteristics -- probably pheromones. This is interesting because the baby mouse got normal food. It was his mom that got the BPA.

Cheryl Rosenfeld at U-Missouri - Columbia showed that feeding BPA affects  the unborn male mouse fetuses to make them less likely to mate. This fits the pattern that BPA feminizes as described above. Rosenfeld specializes in sexual differentiation en utero with other related studies.

BPA used to be in re-usable clear plastic bottles, but that has stopped now that polycarbonate is no longer used for baby bottles, pitchers, and water bottles in the US and Canada.

All this is worrisome because BPA is still used in most soda can liners. I would not worry too much because BPA is bound pretty tightly in these liners, but this is more evidence that will eventually lead to an industry-wide shift away from BPA based can liners.

Read my previous post on BPA, and the one before that.