What happens to the chemicals in drugs once they are out of our systems?

What happens to the chemicals in drugs once they are out of our systems?

Courtney Moschetta, Huntsville, AL

Every time you swallow a pill, some of that medicine follows a circuitous path through your body, down the toilet, through the sewage treatment plant (where if is often resistant to traditional treatments) and into the nearest river or lake, where it is eventually tapped again for the public drinking water supply.

According to Christian Daughton, chief of environmental chemistry at the U.S. Environmental Protection Agency’s (EPA) National Environmental Research Laboratory in Las Vegas, new technologies now allow scientists to detect extremely low levels of prescription and over-the-counter drugs, as well as compounds found in personal care products like shampoo and sun screen, in water. In Kansas City alone, more than 40 percent of stream samples analyzed recently by the U.S. Geological Survey had detectable amounts of over-the-counter-drugs like ibuprofen and acetaminophen, antibiotics, and prescription medications for high blood pressure.

While the effects on human health of drug residues in water are not yet a serious concern, new studies show that fish and other aquatic species may be affected, says Daughton. Antibiotics make some species more resistant to pathogens, steroids can cause endocrine disruption that interferes with reproductive processes, and anti-depressants make fish tranquil and more likely to succumb to predation. Considering the large variety of pharmaceuticals on the market today, our water may have a witch’s brew of very small amounts of many different kinds of drugs.

Right now there are no EPA or Food and Drug Administration regulations in place to control levels of residual drugs in water, but some environmental groups concerned with water quality want to see drug disposal policies enacted, new sewage treatment technologies developed, and source reduction efforts on the part of pharmaceutical companies and pharmacies. Daughton envisions a day when drug companies will take responsibility for the lifecycle of their products. Instead of flushing your unused prescription drugs down the toilet, you may be able to send them back to the pharmacy or return them to the maker for proper disposal. Such programs already exist in areas of Europe and Canada.

CONTACT: EPA National Environmental Research Laboratory, Environmental Sciences Division, http://www.epa.gov/nerlesd1/chemistry/pharma/overview.htm; United States Geological Survey’s Toxic Substances Hydrology Program, http://toxics.usgs.gov/regional/emc.html.