I think about plastics a great deal, especially since my children are surrounded by plastic toys, cups, pens, plates, and other paraphernalia, including a plastic tea set that they play with in the bath. The topic was on my mind recently while reporting an article for the journal Nature on replacements for the ubiquitous chemical bisphenol A (BPA), a component of many plastic devices that mimics the hormone estrogen. It has been linked to a range of adverse health effects, including male genital abnormalities, diabetes, and heart disease.
In 2011, Delilah Lithner, then a doctoral student in environmental science at the University of Gothenburg in Sweden, published her thesis. Of 83 plastic products she tested, one-third leached chemicals that were toxic to the water flea (Daphnia magna). Five of these flea-poisoning products were items designed for children: a child’s handbag, bathtub squirt toys, inflatable arm pads, a bathing ring, and diaper-coating material.
Although BPA has been withdrawn from baby bottles and sippy cups, it is still found in a slew of other items, Steve Hentges of the American Chemistry Council told me, including incubators for premature babies, eyeglass lenses, sports helmets, and electronic equipment. Preliminary studies have also shown that the chemical that replaced BPA in baby bottles, bisphenol S (BPS), has a similar structure and some of the same estrogen-mimicking properties.
Hentges maintains that BPA is safe. But no U.S. law requires manufacturers to test industrial chemicals for safety before putting them in such products as shampoos, paints, detergents, plastic toys, and flame retardants found in couches, baby car seats, and diaper-changing pads. (By contrast, pharmaceutical companies and pesticide companies must provide mounds of data on the safety of their drugs and sprays before selling them.) The 1976 Toxic Substances Control Act mandates that the Environmental Protection Agency (EPA) determine that a chemical presents an “unreasonable risk” to health or the environment before the chemical can be regulated. In more than 30 years, the Natural Resources Defense Council reports, the EPA has tested only 200 chemicals and has partially regulated only five. More than 62,000 chemicals already on the market when the law passed were permitted to remain in use with no testing.
A Senate bill introduced a year ago by Frank R. Lautenberg and David Vitter would update the 1976 law. According to the Environmental Defense Fund, that bill (the Chemical Safety Improvement Act of 2013) includes “notable improvements,” including mandatory “safety evaluations for all chemicals in active commerce” and a requirement that new chemicals be deemed safe before going on the market.
But change comes slowly, and long-term effects of these chemicals—especially on children—are difficult to predict. Both BPA and BPS “clearly have biological effects on multiple cell receptors” as well as physiological systems in animals, says Eric Prossnitz, professor of cell biology and physiology at the University of New Mexico Health Sciences Center in Albuquerque. “The effects of chronic (now lifelong and even in utero during development) exposure are highly complex, but again, even shorter term exposure can have effects later in life,” he wrote to me in an email, adding that any new plastics and chemical additives “need to be extensively tested before public ‘consumption,’ as we already know that these compounds will become endemic to all biological organisms on Earth.”