Bathing and showering: Underappreciated sources of water pollution from medicines

Mar 24, 2010
Showering and bathing wash medicated creams and ointments off the skin, down the drain, and into the environment. Credit: Wikimedia Commons; photo by DO’Neil

That bracing morning shower and soothing bedtime soak in the tub are potentially important but until now unrecognized sources of the hormones, antibiotics, and other pharmaceuticals that pollute the environment, scientists reported here today at the 239th National Meeting of the American Chemical Society. The first-ever evaluation, they said, could lead to new ways to control environmental pollution from active pharmaceutical ingredients (APIs), which has been the source of growing concern.

Ilene Ruhoy, M.D., Ph.D., who co-authored the study, said that scientists have long known that bathrooms are a portal for release of APIs into the environment. An active ingredient in a pill is the medicine, usually combined with binders to hold the pill together, stabilizers, and other inactive ingredients. However, scientists and pollution control officials assumed that toilets were the main culprit, with APIs excreted in urine and feces and flushed into sewers and sewage treatment plants. APIs may go right through the disinfection process at those plants, and enter lakes, rivers, and oceans. Some also end up in the environment when people flush unused drugs down the toilet. Scientists have found traces of the active ingredients of birth control pills, antidepressants, and scores of other drugs in waterways. Some end up in drinking water - at extremely low, trace levels.

"We've long assumed that the active ingredients from medications enter the environment primarily as a result of their excretion via urine and feces," said Dr. Ruhoy. She directs the Institute for at Touro University in Henderson, Nev., and did the research with Christian Daughton, Ph.D., of the U.S. Environmental Protection Agency's National Exposure Research Laboratory in Las Vegas. "However, for the first time, we have identified potential alternative routes for the entry into the environment by way of bathing, showering, and laundering. These routes may be important for certain APIs found in medications that are applied topically, which means to the skin. They include creams, lotions, ointments, gels, and skin patches."

Ruhoy and Daughton identified this potential new source of APIs through a comprehensive review of hundreds of scientific studies on the metabolism and use of medications. They focused on APIs in medications that are applied to the skin or excreted from the body via sweat glands. These two sources can result in residues being washed off the body and down bathroom drains. These include steroids (such as cortisone and testosterone), acne medicine, antimicrobials, narcotics, and other substances.

Another previously unrecognized route by which APIs may reach the environment includes perspiration (many APIs are released in sweat) and laundering of clothing that has come into contact with topical medications from their dermal application or from sweating.

Ruhoy explained that some APIs in topical medications enter the environment in a form that has the potential for having greater impact than those released in feces and urine. While some medications are excreted substantially unchanged, and therefore enter the environment as the parent compound, other APIs, prior to excretion from the body, are largely metabolized, or broken down, in the liver and kidneys.

"Topical APIs, from bathing and showering, however, are released unmetabolized and intact, in their full-strength form," Ruhoy said. "Therefore, their potential as a source of pharmaceutical residues in the environment is increased."

Ruhoy cited steps by which consumers can reduce the potential environmental impact of these skin-based pharmaceuticals by following directions and applying only the recommended amount, rather than thinking that "if a little is good, more must be better." Doctors can help by prescribing the lowest possible dose for the shortest period of time necessary. Scientists should continue efforts to develop better drug delivery systems for topical medications so that APIs, for instance, are absorbed faster and more completely, she said. Design of dermal patches so that less API residue remains after use would be particularly helpful in reducing accidental poisonings from carelessly discarded patches and the quantities of APIs flushed down toilets.

"We need to be more aware of how our use of pharmaceuticals can have unwanted environmental effects," Ruhoy said. "Identifying the major pathways in which APIs enter the is an important step toward the goal of minimizing their environmental impact."

Explore further: Dead floppy drive: Kenya recycles global e-waste

Related Stories

Study: Range of pharmaceuticals in fish across US

Mar 25, 2009

(AP) -- Fish caught near wastewater treatment plants serving five major U.S. cities had residues of pharmaceuticals in them, including medicines used to treat high cholesterol, allergies, high blood pressure, bipolar disorder ...

Even if you're careful, drugs can end up in water

Feb 08, 2010

(AP) -- The federal government advises throwing most unused or expired medications into the trash instead of down the drain, but they can end up in the water anyway, a study from Maine suggests.

NoMix toilets get thumbs-up in 7 European countries

Mar 10, 2010

People in seven European countries have positive attitudes toward a new eco-friendly toilet that could substantially reduce pollution problems and conserve water and nutrients, scientists in Switzerland are ...

Feds mull regulating drugs in water

Dec 22, 2009

(AP) -- Federal regulators under President Barack Obama have sharply shifted course on long-standing policy toward pharmaceutical residues in the nation's drinking water, taking a critical first step toward regulating some ...

Recommended for you

Dead floppy drive: Kenya recycles global e-waste

22 hours ago

In an industrial area outside Kenya's capital city, workers in hard hats and white masks take shiny new power drills to computer parts. This assembly line is not assembling, though. It is dismantling some ...

New paper calls for more carbon capture and storage research

Aug 22, 2014

Federal efforts to reduce greenhouse gas emissions must involve increased investment in research and development of carbon capture and storage technologies, according to a new paper published by the University of Wyoming's ...

Coal gas boom in China holds climate change risks

Aug 22, 2014

Deep in the hilly grasslands of remote Inner Mongolia, twin smoke stacks rise more than 200 feet into the sky, their steam and sulfur billowing over herds of sheep and cattle. Both day and night, the rumble ...

User comments : 3

Adjust slider to filter visible comments by rank

Display comments: newest first

hadbanger
not rated yet Mar 24, 2010
The best thing that we should do right now is to educate people about the possible risks involved. Even though the levels are miniscule; they shouldn't be taken lightly.
Research will hopefully minimize risks to exposure to these API's
3432682
1 / 5 (1) Mar 25, 2010
This is more about the wonderful advances in the sensitivity of detection equipment than any danger from the chemicals. Some discussion of the rate of breakdown is needed, too, to put this in perspective. The sky is not falling.
rwinners
not rated yet Mar 26, 2010
I'd guess that, 90+ percent of the time, the material ends up in the same drain. The end result is the same.