Bisphenol-A in your polycarbonate water bottle

Somewhere along the way, I picked up the idea that polycarbonate plastic was safer to use in beverage and food containers than plastics like PET, that it didn't leach toxic chemicals.

Oops.

Polycarbonate plastic molecules are made up of strings of Bisphenol A (BPA), which was originally created as a synthetic hormone. As polycarbonate ages, wears, or is exposed to heat, acids, or bases, BPA leaches out.

Polycarbonate is everywhere, used to coat children's teeth (as an anti-cavity measure), and metal cans (to prevent the metal from contact with food contents). It's also the primary component of food containers; refrigerator shelves; baby bottles; water, juice, and milk bottles; microwave cookware; and eating utensils. And it's used industrially in a wide variety of applications.

BPA has been linked to breast cancer, insulin resistance (a precursor to diabetes), miscarriage, obesity, prostate enlargement, early onset of sexual maturation, hyperactivity, and increased aggressiveness - all at low doses. (In fact, when dealing with endocrine disruptors like BPA, low doses can stimulate a response that high doses might inhibit. Our bodies' reaction to hormones and to chemicals that mimic them is not a simple monotonically increasing function.)

In a CDC study, 95% of urine samples from people in the United States had measurable BPA levels.

One Charlottesville shop has stopped carrying popular Nalgene brand bottles. (As Nalgene also makes vivisection equipment, there's good reason to boycott them anyway.) If you own a Nalgene bottle, be aware that the manufacturer's care suggestions increase the risk of BPA leaching.

Of course, a website run by the American Plastics Council, the Association of Plastics Manufacturers in Europe, and the Japan Chemical Industry Association tells us that everything is just fine.

But then, a paper in the journal Environmental Health Perspectives notes that it depends who's funding the research:

Source of funding is highly correlated with positive or negative findings in published articles. For government-funded published studies, 94 of 104 (90%) report significant effects at doses of BPA < 50 mg/kg/day. No industry-funded studies (0 of 11, or 0%) report significant effects at these same doses.