Drugs generated by the pharmaceutical industry recently discovered to have infiltrated fresh, marine and waste waters have been found to negatively impact a variety of organisms and the environment as a whole. Samples examined from sewage effluent, surface water, groundwater and drinking water have been determined to contain trace amounts of a variety of medicines spanning from antibiotics to endocrine hormones (Bound and Voulvoulis 1705), suggesting the possibility of a widespread and sustained deleterious impact on the environment. Although eco-toxicological consequences aren’t perfectly clear, studies have shown that excessive introduction of drugs to the environment could lead to feminization of fish and bacterial resistance. According to Melody Peterson, New York Times journalist and author of Our Daily Meds, actual negative changes in the ecosystem can be linked to a “witch’s brew of pharmaceuticals flowing through the nation’s waters” (Petersen 257). After evaluating the ‘spells’ of this “witch’s brew” on microbes, aquatic animals, humans and the overarching environment, Petersen and other scholars conclude that ‘prescription water’ may have vast consequences. Drugs in the water cycle have many detrimental effects.
Research suggests that certain drugs in wastewater can lead to declines in the populations of several species of animals. One of the most prevalent and extensively studied chemicals found in wastewater is the hormone estrogen (Bound and Voulvoulis 1707). Biological (natural) estrogens as well as synthetic estrogens from oral contraceptives (estradiol), both found predominately in the urine of female vertebrates, are difficult to filter and thus freely seep through municipal wastewater management systems into the environment (1707). Numerous studies have shown that several species of male fish including bass, lake trout, northern pike, walleye and fathead minnows, become ‘feminized’ when exposed to low concentrations of natural and synthetic estrogens, because exposure to the female hormones causes development of ova-testes (testes with eggs)(Kidd et al. 8897). In one seven-year study, a small lake in Ontario, Canada, was manipulated to mimic the effects of the ongoing deluge of hormones entering our waters. After a period of only one year, four out of nine males caught had ova-testes (8898) leading to a decrease in fertilization success (8897). By the middle of the second year, the population had collapsed because of reproductive failure (8899). These alarming results indicate that maintaining or increasing current levels of estrogens in municipal wastewaters could decrease the reproductive success and sustainability of fish populations, which, Kidd explains, could ultimately bring the food chain asunder and induce ecological disaster (8897).
Indeed, while it may not be surprising that organisms constantly confined to contaminated wastewater with elevated hormone levels are in danger, Vicki Blazer, marine biologist at the National Fish Health Research Laboratory of the US, has found that hormones are also affecting insects. Studies on hormones in wastewater and the wild roach also demonstrated an increase in intersex males (Blazer 22). In experiments, male roaches were found with a reduced percentage of motile sperm, on average only about half the amount of normal seminal fluid levels, and a lowered ability of their sperm to successfully fertilize eggs and produce viable offspring (22). This drastic reduction in reproductive capability of a species as robust as the cockroach alludes to the possibility of population decline if current hormones levels in wastewater are maintained or augmented.
While hormones endanger fish and roach populations, several other aquatic populations are threatened by antidepressants. Numerous studies have shown that aquatic animals including mosquito fish, frogs and freshwater mussels are adversely affected by living in water contaminated with minute amounts of psychotropic drugs such as antidepressants. In Our Daily Meds, Melody Petersen describes several studies that found stunted growth, dis-coordination and lethargy in frogs and mosquito fish living in antidepressant tainted water (257). In a separate study conducted in 2010 at the University of North Carolina, researchers found that fluoxetine, the active ingredient in the antidepressant Prozac, interfered with numerous aspects of reproductive function in endangered freshwater mussels (Bringolf et al. 1311). By altering the endocrine activities in the mollusks, serotonin, the “key mediator for a wide variety of physiological functions” was affected such that mantle flap display behavior, egg maturation and parturition (the release of parasitic larvae unto the gills of a host fish) all decreased the likelihood of producing normal amounts of viable offspring (1312). Parturition is integral to larval development, and its success rate is largely dependent on mantle flap display behavior (where a mussel uses its mantle as a lure for unsuspecting fish)(1312). When both of these acts are adversely affected, the rate of reproductive success lowers, which could cause the population to decrease (1315-1316). Given the profound effects of hormone-infused waters on other organisms, many researchers and others in the field, including Petersen, are also beginning to ponder about the effects of ‘pharmaceutical water’ on humans (Petersen 257).
Human exposure to oestrogens in water is disrupting healthy endocrine function (Dibb 27). An increasing amount of evidence has been inculpating chemicals that mimic estrogen hormones with reproductive and development disorders, reduced fertility and cancers in both sexes (27). Sue Dibb, writer for The Ecologist, explains in “Swimming in a Sea of Oestrogens: Chemical Hormone Disrupters,” that oestrogen mimics are found in many environmental chemicals that eventually seep into the water supply (27). According to the British Medical Journal, the gradual increased presence of these chemicals in the environment has coincided with a steady increase in testicular cancer, breast cancer, endometriosis and a decrease in the average sperm counts of men (by 50 per cent) since 1940 (Dibb 27). Although oestrogens seem to be quite malignant and persuasive as evidence for the danger of pharmaceuticals in water, studies on the effects of many drugs on humans are not yet conclusive. Currently the more demonstrable threat to human life is antibiotic resistant bacteria.
Antibiotics in wastewater contribute to the formation of antibiotic resistant strains for bacteria—a serious threat to humans and animals everywhere. The growing presence of antibiotics in the environment leads to resistant strains because the longer bacteria are exposed to antibiotics, the faster the rate of resistant strain selection and proliferation. This is why antibiotic resistant bacteria were first seen in hospitals: when bacteria are frequently exposed to antibiotics, the antibiotic sensitive strains die, leaving the resistant strains to proliferate (Rosenblatt-Farrell 246).
Sources of antibiotics in the environment come from excrement and improper disposal (Bound and Voulvoulis 1705). In fact, in a study on how improperly disposed of medications pose a significant risk to children, researchers found that 35.4% of Americans disposed of their drugs via the sink or toilet, while 54% threw them away with conventional trash (Kuspis and Krenzelok). As Forbes Magazine recently named the antibiotic azithromycin the fifth most popular, overused prescription drug in America, these statistics allude to large amounts of antibiotics entering the environment via trash (Herper). In addition to azithromycin, the most widely used agricultural antibiotic, tetracycline, is routinely added to the food and water of cattle, swine and farmed fish, and is subsequently the most prevalent antibiotic found in water and soil (MacKay). Antibiotics pass through humans, animals and water filtration systems largely unaltered and invariably find their way from the toilet, soil or trashcan into the water cycle (Bound and Voulvoulis 1705). In fact, “more than 60% of ingested antibiotics are excreted by livestock and eventually enter the nation’s waterways” (MacKay). They are then spread via natural water routes and human wastewater management systems (Rosenblatt-Farrell 247). This problem is further aggravated by the fact these resistant strains are spread over large areas when the animal excrement is used as fertilizer, and when flies that associate with antibiotic-treated animals or their byproducts carry the bacteria elsewhere (247). In “The Landscape of Antibiotic Resistance,” Noah Rosenblatt-Farrell illuminates the reality of the spread of antibiotic resistance when he explains how even in the Arctic, wild animals have been found with drug-resistant strains of E. coli (247). Even when chicken breast samples from American grocery stores were tested between 2002 and 2006, “an average of 51.1% tested positive for Campylobacter, 11.9% for Salmonella, 97.7% for E. coli, and 82.6% for Enterococcus… many of which tested positive for resistance to one or more drugs” (247).
The overwhelming presence of antibiotics in the water has caused many to lose their efficacy and contribute to the emergence of dangerous antibiotic resistant bacterial strains (Rosenblatt-Farrell 245). An example of one such strain is Methicillin-resistant Staphylococcus aureus (MRSA)(246). Over the last 20 years, MRSA has spread in prevalence from affecting mostly inpatients (hospital-related risks) to also affecting healthy individuals through everyday touching (246). MRSA treatment is lengthy, difficult and more often than not results in fatality (246). Petersen devotes an entire section of Our Daily Meds to the devastating effects antibiotic resistant bacteria can have on children in the section ‘Revenge of The Germs.’ She explains how “drug resistance threatens to reverse medical progress,” and how “curable diseases—from sore throats and ear infections to TB and malaria—are in danger of becoming incurable,” by quoting World Health Organization (WHO) and numerous physicians describing the crisis (Petersen 279-280). Over the last decade there has been an alarming increase in the percentage of people being found with samples of MRSA, evidence of the increasing amount of antibiotics in the environment (Rosenblatt-Farrell 246).
To immediately reduce risks to both humans and animals posed by drugs in wastewater, we must change the way we think of drug disposal. Americans should never think of the sink or toilet as acceptable ways to discard of medications. We must increase the prominence of labeling with disposal information and have doctors and pharmacists explain to patients the importance of finishing medications. While most modern landfills have membrane liners that prevent much drug-laden leachate from entering groundwater, some inevitably still makes it through, thus we must search for new disposal methods whereby drugs avoid the trash yard (Bound and Voulvoulis 1710). While it is possible for high-tech processes such as ozonation, nonfiltration and activated carbon adsorption (which actively eliminate pharmaceuticals from water) to be implemented in more facilities, simply minimizing the disposal pathway should be more effective, efficient and immediate than said expensive modifications to the wastewater management system (1710). While consumers comply with the direct user risks of drugs—such as side effects—they unknowingly contribute to environmental and indirect user risk—the risks drugs in the environment pose against wildlife and humans—when they dispose of drugs improperly. Petersen, Rosenblatt-Farrell, Kidd, and many more would all agree that there needs to be more regulation regarding pharmaceutical drugs. This regulation should not be confined only to industry practices, drug use and direct user risks, rather it should also include environmental and indirect user risks.
Blazer, Vicki S. “Intersex in Bass “Emerging” Contaminant Issues.” Chesapeake Bay Commission. Web. 2 Dec. 2010.
Bound, Jonathan P., and Nikolaos Voulvoulis. “Household Disposal of Pharmaceuticals as a Pathway for Aquatic Contamination in the United Kingdom.” Environmental Health Perspectives 113.12 (2005): 1705-711. EBSCOhost. Web. 29 Oct. 2010.
Bringolf, Robert B., Rebecca M. Heltsley, Teresa J. Newton, Chris B. Eads, Stephen J. Fraley, Damian Shea, and Gregory Cope. “Environmental Occurrence and Reproductive Effects of the Pharmaceutical Fluoxetine in Native Freshwater Mussels.” Environmental Toxicology 29.6 (2010): 1311-318. EBSCOhost. Web. 1 Dec. 2010.
Dibb, Sue. “Swimming in a Sea of Oestrogens: Chemical Hormone Disrupters.” The Ecologist 25.1 (1995): 27-31. EBSCOhost. Web. 3 Dec. 2010.
Herper, Matthew. “America’s Most Popular Drugs.” Forbes. Forbes Magazine, 5 Nov. 2010. Web. 2 Dec. 2010.
Kidd, Karen A., Paul J. Blanchfield, Kenneth H. Mills, Vince P. Palace, Robert E. Evans, James M. Lazorchak, and Robert W. Flick. “Collapse of a Fish Population after Exposure to a Synthetic Estrogen — PNAS.” Proceedings of the National Academy of Sciences. 29 Mar. 2007. Web. 28 Oct. 2010.
Kuspis, DA, and EP Krenzelok. “What Happens to Expired Medications? A Survey of Community Medication Disposal.” PubMed. NCBI, Feb. 1996. Web. 2 Dec. 2010.
MacKay, Allison. “MacKay Research Examines Impact of Antibiotics in Environment.” University of Connecticut. Web. 2 Dec. 2010.
Petersen, Melody. Our Daily Meds: How the Pharmaceutical Companies Transformed Themselves into Slick Marketing Machines and Hooked the Nation on Prescription Drugs. New York: Farrar, Straus and Giroux, 2008. Print.
Rosenblatt-Farrell, Noah. “The Landscape of Antibiotic Resistance.” Environmental Health Perspectives 117.6 (2009): 245-50. EBSCOhost. Web. 27 Oct. 2010.
*Image credit: No Drugs Down The Drain