A Bitter Pill to Swallow
First published in 1994, the best selling book Prozac Nation highlighted the growing numbers of Americans taking antidepressant drugs. Basically, it is an indictment about the liberal way medications are doled out to people. Along with the higher use of antidepressants in our nation, there is also an explosion in the number of people taking other kinds of pharmaceuticals, such as oral contraceptives, high blood pressure medications, and cholesterol-lowering drugs. The irony is that, while the increased use of modern drugs is having an overall positive impact on people's health at the individual level, the cumulative effect of the byproducts from these substances may end up being quite negative for our environment.
A variety of compounds, known as pharmaceuticals and personal care products (PPCPs), are omnipresent but unregulated pollutants in our nation's waters. These include prescription and over-the-counter drugs, cosmetics, fragrances, veterinary drugs, sunscreens, and DEET insect repellants. Beginning in the late 1990s, the compounds began to attract more attention from U.S. researchers after the development of more sensitive testing methods that can detect trace levels of the compounds in water at the parts-per-billion or even parts-per-trillion levels.
A number of researchers have found that many pharmaceuticals are only partially metabolized by humans before the compounds are released into the sewage systems. Most of the PPCPs enter the wastewater systems because they are washed off during bathing or excreted by the human body into drains and then collected in sewer systems. Unfortunately, the compounds often survive the biodegradation process of wastewater treatment and are thereafter passed downstream, where they could impact waterborne organisms, such as fish. As well, the compounds can be drawn into water treatment intake pipes for drinking water.
On March 15, University of Buffalo (UB) chemists announced they have for the first time identified in the effluent from several wastewater treatment plants the metabolites of two antibiotics and a medical imaging agent. A metabolite is any substance produced or used during metabolism (digestion). In drug use, the term refers to the end products that remain after metabolism. For additional information about the study, go to www.chem.buffalo.edu/aga.php.
"The lesson is that not detecting active ingredients in the effluent doesn't mean the water is clean. The pharmaceuticals we monitored are not degraded completely in the treatment plants; most of them are just transformed into other compounds that still may have adverse ecotoxicological effects," Dr. Diana Aga, the leader of the UB research team said.
In August 2005, the U.S. Environmental Protection Agency (EPA) sponsored a conference entitled "Meeting on Pharmaceuticals in the Environment" at the agency's Las Vegas laboratory. At the closing session of the conference, EPA representatives recommended that the agency should develop regulatory guidance for wastewater treatment plants on the best treatment technologies to attack many drugs and other compounds before the treated effluent is returned to the waterways. Researchers and EPA officials agreed the agency needs to work harder to develop accepted testing methods for PPCPs. However, EPA officials admitted that a coordinated regulatory approach to such unregulated compounds is probably years away, given strained agency resources.
Other participants at the conference said more research is needed to determine the cumulative ecological impacts on fish and other aquatic organisms. Of particular interest among the PPCP class of compounds are chemicals known to disrupt or alter sexual development in animals, as well as various plant and animal steroids that can affect hormonal development.
Currently, EPA is conducting several research projects related to PPCPs. For example, within EPA's Region 1 office in New England, researchers are working on analytical methods for detecting steroid hormones in treated wastewater from 40 wastewater treatment plants. EPA's Region 3 office is focusing on the environmental effects of veterinary pharmaceuticals, particularly those that have antimicrobial effects that may alter the antibiotic resistance in certain organisms. EPA's Region 8 office, in conjunction with the agency's water office, is funding a study on the potential link between effluent from wastewater treatment plants and any endocrine disrupting effects in the white suckerfish. In a different vein, EPA's Region 10 office is evaluating the impact on marine organisms of cruise ships discharging large amounts of wastewater into the oceans. For more information about research being conducted concerning the environmental impacts of PPCPs, check out EPA's Web site at www.epa.gov.esd/chemistry/pharm.
The possibility that PPCPs, which are used in some form or other by virtually all modern societies, may have adverse effects on our environment is alarming. Our leaders need to deal aggressively with this issue as soon as possible so our nation's water supply doesn't become a vast pharmaceutical cocktail. We must say no to pollution from drugs now in order to prevent PPCPs from having a destructive impact on us and other living organisms.