Taking Showers Could Contaminate Drinking Water

THE GIST:

• Taking showers and doing laundry could wash pharmaceuticals into the water supply.
• Babies and people with compromised immune systems could be most at risk.
• Although the health consequences are still unclear, knowing the source of pollution could help reduce its impact.

With every shower you take, you may be unwittingly polluting the environment.

As you scrub off dirt, you also wipe off medicines from your skin and pharmaceuticals excreted in sweat, according to a new study. Those chemicals pass through the sewage system and might even end up in our drinking water.

"We are raising an alarm in that pharmaceuticals are not meant to be in our water," said Ilene Ruhoy, director of the Institute for Environmental Medicine at the Touro University College of Osteopathic Medicine in Henderson, Nev. She presented her work this week at the American Chemical Society meeting in San Francisco.

WATCH VIDEO: You can save 10,000 gallons of water every year just by taking a shower that is one minute shorter.

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"If you think about other people exposed to these drugs that are intended for a particular population," she said, "that could be a concern."

Scientists have already recognized toilets as the biggest source of pharmaceuticals in the environment. After swallowing and digesting medicines, our bodies excrete metabolized versions of them through urine and feces. Often, people flush unwanted or unused pills as well, without thinking about where the drugs will end up.

Ruhoy suspected that toilets weren't the only way that pharmaceuticals escape from the medicine cabinet. For the first time, she and colleagues considered overlooked sources of drugs in the environment.

Their research revealed that human skin fails to absorb much of the medicine that is applied topically, such as antibiotic ointments and steroid creams. Showers, baths and laundry wash those drugs directly into the sewage system. Chemically, these compounds often remain whole, unlike the broken-down versions in feces and urine.

The scientists also found that a significant percentage of the medicine we swallow end up coming out in our sweat. Those chemicals go down the drain, too.

It's not yet clear how pharmaceutical residues in the environment will affect the health of animals or people, especially because concentrations for now are low. Still, tiny doses can add up after years and years of exposure. It's a phenomenon that scientists have become increasingly worried about.

Studies have already found female features, such as eggs, in male fish that live near sewage effluents. Among the concerns, the migration of antibiotics into the environment could lead to more drug-resistant infections. Babies and people with compromised immune systems would be most at risk.

"There's potential for an incredible number of compounds to be entering the environment, and we don't really know what mixtures of those chemicals can do, either individually or together," said Michael Fulton, an environmental toxicologist with the National Oceanic and Atmospheric Administration in Charleston, S.C.

"Work is really just sort of beginning," he added, "to try and identify what compounds are getting into the environment in high enough concentrations to produce an effect in some animal living out there."

Knowing where pollution is coming from is an important first step toward preventing it from entering the environment in the first place, Ruhoy said. She recommends using the minimal necessary dose of topical ointments instead of slathering them on. Precautionary measures like wiping down with a towel before stepping into the shower might help, too.

"Let's just be aware that what we do has an effect on the environment," she said. "The environment and human health are intricately connected."