The next time that you happen to fill a prescription, take a moment to peruse the list of potential side effects. I suspect that you will not find “possible contamination of ground water” anywhere on the list. Perhaps it should be added, given the following article by Cornelia Dean in the New York Times:

Drugs Are in the Water. Does It Matter?

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.

The pharmaceutical and personal care products, or P.P.C.P.’s, are being flushed into the nation’s rivers from sewage treatment plants or leaching into groundwater from septic systems. According to the Environmental Protection Agency, researchers have found these substances, called “emerging contaminants,� almost everywhere they have looked for them.

Most experts say their discovery reflects better sensing technology as much as anything else. Still, as Hal Zenick of the agency’s office of research and development put it in an e-mail message, “there is uncertainty as to the risk to humans.�

In part, that is because the extent and consequences of human exposure to these compounds, especially in combination, are “unknown,� the Food and Drug Administration said in a review issued in 2005. And aging and increasingly medicated Americans are using more of these products than ever. [full text]