The pesticide and plastics industry have a lot invested in the safety of chemicals like bisphenol A and atrazine. Such "endocrine-disrupting" chemicals mimic human hormones, and research has tied them to health problems like cancer and infertility. But these industries have always held up studies that look at exposure to huge doses of endocrine disruptors. In massive quantities, the industries point out, these chemicals don’t cause problems. Therefore, they must be safe.
But those huge doses may actually obscure the chemicals' effects, a new study argues. Endocrine-disrupting compounds "can have effects at low doses that are not predicted by effects at higher doses," the authors write. In other words, low levels of exposure to these chemicals -- like the levels that you'd get from, say, drinking water out of a BPA-laced plastic bottle -- can have worse effects than high levels of exposure.