19 April 2008

BPA in Plastic Baby Bottles

Overreaction or a prudent decision?
The Canadian government moved Friday to ban polycarbonate infant bottles, the most popular variety on the market, after it officially declared one of their chemical ingredients toxic.

The action, by the departments of health and environment, is the first taken by any government against bisphenol-a, or BPA, a widely used chemical that mimics a human hormone. It has induced long-term changes in animals exposed to it through tests.

[New York Times, 19 April 2008]

BPA, or Bisphenol-A is a compound used to make polycarbonate plastic and epoxy resin materials. Because it is tansparent, clear, and almost shatter-proof, polycarbonate plastic is used to make a variety of products like baby and water bottles. The problem is, according to a published report last February 2008:
When the bottles were heated to 175 degrees F (80 degrees C), every one of them leached bisphenol A at about 5 to 7 parts per billion. The report also suggested that because of the chemical makeup of bisphenol A, it may leach more in fatty or acidic liquids, such as milk or apple juice, than in water. [TIME, 08 Feb 2008]

The concern arises because BPA, even at low dose exposures, can mimic the hormone estrogen, and induce a number of hormone-related effects like early puberty, miscarriage, breast and prostate cancer, immune system changes, and low sperm counts.

There's an ongoing debate on its safety, however, because some scientific reports give conflicting findings:
In a 2006 summary explaining its review of bisphenol A safety, the European Food Safety Authority argued that animal trials of the chemical simply don't tell us very much about humans. For one thing, when humans ingest the compound, it's quickly excreted through the urine; when rats and mice eat it, it's released into the bloodstream and remains in the body much longer --- with much more time to throw off the body's sex-hormone balance, causing nasty effects. [TIME, 08 Feb 2008]

Meanwhile, Canada is not waiting for any more debates. Toxic or not, it is banning the plastic baby bottles.

1 reactions:

mesiamd said...

Bisphenol A illustrates (again) that we're swimming in a pool of chemicals (some are harmful to human beings) that we know little about. The opportunity for investigation is wide, but our scientists have their hands full with many to study. This makes us wonder how much blindspots we have in terms of learning about toxic agents.

When the verdicts aren't definitive, surely it pays to be prudent. But can we be sure we can escape bisphenol, a common plastics chemical in our household products?