Pharmaceuticals In Our Water Supplies

Pharmaceuticals In Our Water Supplies

Pharmaceuticals In Our Water Supplies
Are “Drugged Waters” a Water Quality Threat?

By Arizona Water Resource, July-August 2000, Volume 9, Number 1

Developed to promote human health and well being, certain pharmaceuticals are now attracting attention as a potentially new class of water pollutants. Such drugs as antibiotics, anti-depressants, birth control pills, seizure medication, cancer treatments, pain killers, tranquilizers and cholesterol-lowering compounds have been detected in varied water sources.

Where do they come from? Pharmaceutical industries, hospitals and other medical facilities are obvious sources, but households also contribute a significant share. People often dispose of unused medicines by flushing them down toilets, and human excreta can contain varied incompletely metabolized medicines. These drugs can pass intact through conventional sewage treatment facilities, into waterways, lakes and even aquifers. Further, discarded pharmaceuticals often end up at dumps and land fills, posing a threat to underlying groundwater.

Farm animals also are a source of pharmaceuticals entering the environment, through their ingestion of hormones, antibiotics and veterinary medicines. (About 40 percent of U.S.-produced antibiotics are fed to livestock as growth enhancers.) Manure containing traces of such pharmaceuticals is spread on land and can then wash off into surface water and even percolate into groundwater.

Along with pharmaceuticals, personal care products also are showing up in water. Generally these chemicals are the active ingredients or preservatives in cosmetics, toiletries or fragrances. For example, nitro musks, used as a fragrance in many cosmetics, detergents, toiletries and other personal care products, have attracted concern because of their persistence and possible adverse environmental impacts. Some countries have taken action to ban nitro musks. Also, sun screen agents have been detected in lakes and fish.

Researchers Christian G. Daughton and Thomas A. Ternes reported in the December issue of “Environmental Health Perspectives” that the amount of pharmaceuticals and personal care products entering the environment annually is about equal to the amount of pesticides used each year.

Concern about the water quality impacts of these chemicals first gained prominence in Europe, where for over a decade scientists have been checking lakes, streams, and groundwater for pharmaceutical contamination. American officials and scientists are taking note, with two recent U.S. professional organizations — the National Ground Water Associations and the American Chemical Society — addressing the issue at their annual meetings this summer.

What risk does chronic exposure to trace concentrations of pharmaceuticals pose to humans or wildlife? Some scientists believe pharmaceuticals do not pose problems to humans since they occur at low concentrations in water. Other scientists say long-term and synergistic effects of pharmaceuticals and similar chemicals on humans are not known and advise caution. They are concerned that many of these drugs have the potential of interfering with hormone production. Chemicals with this effect are called endocrine disrupters and are attracting the attention of water quality experts.

To some scientists the release of antibiotics into waterways is particularly worrisome. They fear the release may result in disease-causing bacteria to become immune to treatment and that drug-resistant diseases will develop.

Scientists generally agree that aquatic life is most at risk, its life cycle, from birth to death, occurring within potentially drug-contaminated waters. For example, anti-depressants have been blamed for altering sperm levels and spawning patterns in marine life. Most studies of pharmaceutical and pharmaceutically active chemicals in water have mostly focused on aquatic animals.

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