An Associated Press (AP) investigation in 2007 revealed that most municipal drinking water is contaminated with a wide variety of prescription drugs, from painkillers to antibiotics to antipsychotic drugs and even pet medications. The AP report helped bring to light a problem that scientists had been worrying about for years—all the medications that we take are winding up in our waterways.
Most of the efforts to counteract this problem have focused on proper drug disposal, which usually means throwing old or expired medications out in the land trash or returning them to a pharmacy as part of a drug take-back program. But a new study presented at a recent meeting of the American Chemical Society finds that those efforts may address only a tiny fraction of the problem. The research, presented by Ilene S. Ruhoy, MD, PhD, assistant professor and director of the Institute for Environmental Medicine at Touro University in Nevada, finds that our daily showers and baths could be contributing heavily to the problem, as residues from all those steroidal creams (cortisone, for instance), acne medications, antibiotic ointments, prescription shampoos, and painkilling or birth-control patches we use get washed down the drain.
THE DETAILS: The two authors conducted a literature review of numerous studies that looked at how drugs are metabolized in the body to figure out if topical drugs being washed off in baths and showers could pose a significant environmental hazard, and they discovered that indeed they do. "We had been part of the national dialogue regarding pharmaceuticals in the environment for several years," she says. "Then we realized that if we're going to have a true discussion about the issue that we needed to look at all potential sources." Many drugs, such as steroidal and antimicrobial creams, remain on the surface of the skin and could conceivably be washed away if not absorbed by the body. Her review also revealed that drugs taken internally can be excreted through sweat, which is absorbed by clothing, making laundry another potential source of pharmaceuticals in the environment.
WHAT IT MEANS: Dr. Ruhoy wasn't able to determine how many of the pharmaceuticals that are winding up in rivers, oceans, and drinking water come from topical products, compared with drugs flushed down the toilet or drugs that we ingest and then excrete naturally. "It's a very complex problem, and not an easy one to solve," she says. "But one of the main reasons we did our study was to educate people and make them more aware of the issue."
The effect of these chemicals on humans is still considered to be fairly minor, she notes, and water treatment technologies being installed by some municipalities are getting better at trapping pharmaceuticals before they make it into our drinking water. But birds, fish, and other aquatic animals suffer in more profound ways. The chemicals in birth control pills are being found to turn fish into hermaphrodites, and cholesterol medications can interfere with animals' metabolic rates. Steroidal creams can interfere with hormones, says Dr. Ruhoy, as can birth control pills, and with antimicrobial creams, there's always the concern that bacteria and viruses could be developing antimicrobial resistance.