Water Pollution - Drugs and Household Products in the Water Supply - Does It Matter? - New York Times

"Residues of birth control pills, antidepressants, painkillers, shampoos and a host of other compounds are finding their way into the nation’s waterways, and they have public health and environmental officials in a regulatory quandary.

On the one hand, there is no evidence the traces of the chemicals found so far are harmful to human beings. On the other hand, it would seem cavalier to ignore them.
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In a survey begun in 1999, the agency surveyed 139 streams around the country and found that 80 percent of samples contained residues of drugs like painkillers, hormones, blood pressure medicines or antibiotics. The agency said the findings suggested that the compounds were more prevalent and more persistent than had been thought."