For an industrial chemical released into the environment at more than 1 million pounds a year, it shouldn’t come as much of a surprise that bisphenol A also shows up in humans. Four years ago, researchers discovered that BPA, which is used in plastic manufacturing, was present in nearly 93 percent of the US population’s urine.
So it’s disturbing that a growing body of scientific literature suggests that BPA disrupts the body’s hormones. Exposure to the chemical has been associated with risk for obesity, breast cancer, prostate cancer, cardiovascular disease, infertility, diabetes, thyroid dysfunction, and neurological problems.
But the worst part for researchers can be trying to narrow down confounding factors and figure out how BPA makes its way into the body. If these chemicals are everywhere at once—in can linings, soft plastic, as well as leaching into the air and food—how can we even begin to study exposure?