As you stroll your neighborhood streets these days, you might see an unlikely new form of lawn ornament: a boxful of shiny, reusable polycarbonate water bottles with a "free" sign propped against it. Sustainability expert Corky Parker has run across three such offerings on her walks around Seattle recently. "Succumb not to temptation!" Parker warns. There’s a reason people are jettisoning once beloved Nalgene and other brand-name reusable water bottles. Polycarbonate plastic containers have been shown to leach an estrogen-mimicking synthetic chemical called bisphenol-A—alias BPA—aka "that water-bottle chemical."
BPA’s presence in baby bottles has triggered the loudest public outcry, and babies are certainly the age group at highest risk. Research on pregnant laboratory animals has shown that the artificial estrogen can permanently change the way mammalian organs develop, setting the infants up for problems ranging from infertility to obesity. The research results have prompted Canada, the European Union, and several cities and states in the United States—though not, as yet, the federal government—to ban the chemical’s use in baby products.
But infants aren’t the only ones at risk; even infinitesimal amounts of the chemical can contribute to health problems at any age, including in mature adults. What kind of health problems? Some of the ones we worry about most, says Fred vom Saal, a pioneering endocrinologist at the University of Missouri.
"Exposure to low doses of BPA in adult monkeys resulted in a significant decrease in the number of connections between nerve cells in the area of the brain associated with memory, which is what is typically seen in people with dementia. BPA is also associated with a decrease in testosterone in adults. Low levels of testosterone are associated with low energy level, depression, low libido, and loss of muscle mass," vom Saal says.
Findings from the CDC’s U.S. National Health and Nutrition Examination Survey show a significant relationship between bisphenol-A levels and a number of diseases, including heart attack and stroke, insulin resistance and type 2 diabetes, and abnormal liver enzyme levels. The CDC detected BPA in 95 percent of adults tested.
Where’s all that BPA coming from? Reusable polycarbonate plastic food containers and bottles are one source. Canned food and drinks are another, the BPA leaching from the epoxy-resin coatings inside the cans. The ink on pressure-printed receipts contains BPA, too, which rubs off on to your hands and is absorbed through your skin. "Other than that, we can’t say for sure, because manufacturers aren’t required to list BPA on labels," vom Saal says.
Nevertheless there are ways to reduce your exposure. Avoid plastic bottles and containers marked with the recycling identification codes 3 and 7. Don’t microwave food in them, and don’t wash them in the dishwasher, where hot water and harsh detergent hasten breakdown of plastics. Minimize your consumption of canned food and drinks; buy fresh or flash-frozen food instead. Store leftovers in reusable glass containers; you can accumulate glass peanut butter and jelly jars with tight-fitting lids, pick up glass boxes with lids at yard sales, or buy them new at kitchen stores.
And if you like to carry a reusable bottle around to keep yourself hydrated, a number of companies make handsome and sturdy lightweight steel ones these days.