Acetaminophen from painkillers, triclosan from antimicrobial soaps and caffeine from the morning java jolt, among other chemicals, are showing up daily on the banks of U.S. streams. The compounds, derived from substances that we excrete or use in our homes, farms and factories, were found by the first national stream survey designed to look for "contaminants of emerging concern"--tough-to-measure, relative newcomers to pollution monitoring.
Most of the chemical concentrations are tiny--less than one part per billion. But mixtures of many different chemicals are "surprisingly common," says U.S. Geological Survey hydrologist Dana W. Kolpin, who led the study that discovered seven or more compounds in half of the 139 streams. This snapshot is a worst-case scenario because the samples were taken downstream of sewage treatment plants and livestock feedlots, although a few contaminants turned up in more pristine sites.
This article was originally published with the title Drams of Drugs and Dregs.