Thursday, February 7, 2008

Endocrine Disruptors

We wrote about this in the course of a review of the Leonard Sax book Boys Adrift in December. It's a very disturbing story given the ubiquitous use of plastic bottles in our society:

BPA is one of many man-made chemicals classified as endocrine disruptors, which alter the function of the endocrine system by mimicking the role of the body's natural hormones. Hormones are secreted through endocrine glands and serve different functions throughout the body.

The chemical-which is widely used in products such as reusable water bottles, food can linings, water pipes and dental sealants-has been shown to affect reproduction and brain development in animal studies.

"There is a large body of scientific evidence demonstrating the harmful effects of very small amounts of BPA in laboratory and animal studies, but little clinical evidence related to humans," explains Belcher. "There is a very strong suspicion in the scientific community, however, that this chemical has harmful effects on humans."

When these plastics were exposed to boiling water BPA leached into the water at high rates:

Prior to boiling water exposure, the rate of release from individual bottles ranged from 0.2 to 0.8 nanograms per hour. After exposure, rates increased to 8 to 32 nanograms per hour.

One question that the article doesn't answer is whether boiling causes the bottle to leach out BPA continuously after the plastic has been heated or whether the leaching only occurs during the boiling. It would also be helpful to know whether and how the "normal" amount of BPA leached by these bottles affects the body.

RLC