Are Potomac River Fish Addicted to Drugs?

Written By: Heather Nortz

How many prescription or over the counter drugs are currently in your medicine cabinet? Did you know that your body doesn’t absorb 100% of the drugs you take? What do you do with your expired or unused drugs? Do you think wastewater treatment or drinking water plants remove pharmaceuticals from water before they release it into the environment or to your well or water tower?

These are the types of questions I have been thinking about for the past 8 weeks. Much to my surprise, 50 percent of Americans have taken one prescription drug over the last 30 days, twenty percent have taken 3 or more, and ten percent have taken five or more (US 2017). Absorption rates are different for every individual and are altered by a multitude of physiological factors. Many people dispose of their expired or unused drugs down drains and toilets sending them directly to wastewater treatment plants, which do not remove any pharmaceuticals or personal care products from the water whatsoever.

As the human dimensions researcher on PEREC’s Summer 2017 OSCAR team, in addition to collecting fish, invertebrate, water and sediment samples, my task is to identify the societal drivers and human actions that lead to the presence of pharmaceuticals in the Potomac River where fish are unknowingly consuming them.

Heather Nortz Aides in Data collection at Gunston Cove.

Societal drivers are defined as ways in which society or culture creates a market for pharmaceuticals. Societal drivers that I have discovered are improved healthcare benefits, innovations in the manufacturing process, intensive food production techniques, and societal expectations. These drivers create the incentive for pharmaceuticals to be created, sold, and ultimately ingested, excreted, transported to wastewater treatment plants and then released into water bodies like the Potomac River.

Increased insurance and healthcare coverage of over-the-counter and prescribed drugs has made pharmaceuticals and personal care products more financially attainable, creating an incentive for people to acquire medications they normally would do without due to unaffordable prices or inconsequential symptoms.

Advancements in technologies have led to the creation of new and more effective medicines, which in turn increases demand.

A large segment of the drug market caters to the food industry. Antibacterial medications and other pharmaceuticals are often given to chicken, cattle, pigs, and other food animals to ensure longevity and health. According to the FDA, about 80% of antimicrobials used in the US in 2010 were given to food animals (Kar 2010).

Along with bigger, better food items, American society also strives for more efficient workers. Societal expectations for people to work harder for longer hours is common, thus people often turn to artificial energy sources like caffeine and other stimulants. Caffeine, which is not removed at wastewater treatment plants, has also been detected in our waterways, giving fish a caffeine addiction they cannot combat.

I have also found, through my research, the human behaviors causing an influx of pharmaceuticals into the Potomac are improper disposal of drugs, excretion of unabsorbed drugs from the body, lack of wastewater treatment plant regulations, and the use of contaminated effluent.

Heather Nortz at Hunting Creek Sampling location, the City of Alexandria in the background.

The common practice to dispose of unused or expired drugs down the drain stems from inaccurate knowledge that there are other ways of disposal. Even disposal of drugs into the garbage can be harmful to the environment. Once they get to the landfill, drugs can dissolve into leachate that leaks into groundwater. Groundwater accounts for 51% of the total US population’s water supply (Groundwater 2017). So, not only are we unknowingly feeding pharmaceuticals to fish, but to ourselves and our families as well.

Absorption rates are different for every individual and are altered by a multitude of factors. Solubility and release rate of the drug, drug interaction with other digested drugs or foods, rate of metabolism, gastric emptying rate, health of gastrointestinal tract, age, gender, and many other characteristics come into play as a pharmaceutical chemical travels through the body (Bioavailability 2017). Due to these non-uniformities, it is difficult for doctors to prescribe dosages that will result in 100% absorption and zero excretion. Therefore, partial excretion of drugs in all animals, including humans, is inevitable.

Because pharmaceuticals and personal care products in wastewater have only recently been studied and are only present in minute concentrations, treatment guidelines have not yet been developed. Under their current permits, wastewater treatment plants are responsible for the removal of solid waste, small particulates, nutrients, mainly nitrogen and phosphorous, and heavy metals, not pharmaceuticals (Alex Renew Water Treatment Plant 2017).

The mass amount of effluent that enters the environment from agriculture, treatment plants and landfills not only impacts aquatic organisms living downstream from effluent release sites in the Potomac River, but for humans consuming water or food that has been in contact with contaminated effluent as well. Veterinary and animal farm medicines are released into soil and groundwater when manure is used as fertilizer, wastewater treatment plants release effluent directly into water bodies, and digested organic solids are disposed of in landfills, used for irrigation, and the production of biosolids in agriculture (Al Maadheed 2016, Golovko 2014).


I am identifying societal drivers and human behaviors leading to ecosystem impacts, so that solutions can be crafted to prevent pharmaceuticals from entering the environment. All of the drivers and human behaviors above can be altered to reduce their severity of impact. In order to create real change in human impact and therefore the state of the ecosystem, changes must be made in national policy. In order to achieve credibility for a policy change, consistent monitoring of the state of the environment must occur over time. The drive to create new policies will come when there is hard evidence of a problem. Once sufficient evidence exists, solutions can arise from new wastewater treatment technologies, innovative mitigation strategies such as dose specialization to reduce excretion rates, and incentives to encourage proper pharmaceutical disposal habits. As implementation of the solutions reduce the flow of pharmaceuticals into the Potomac and other waterways, the fish living there can finally start rehab programs for all of the drugs they have been taking.


Works Cited and Referenced  

Al Maadheed, Shuaa Turki,Al Ali. (2016). Determination of antibiotics and caffeine in hospital wastewater and wastewater treatment plants (WWTPs) in doha, qatar (Order No. 10190503). Available from ProQuest Dissertations & Theses Global: Science & Technology. (1853729302). Retrieved from

Alexandria Renew Enterprises. (2017). Frequently Asked Questions. Retrieved July 07, 2017, from

Bioavailability. (2017, April 19). Retrieved July 07, 2017, from

Cliffie’s Notes. pillsfishshrp. Retrieved July 26, 2017, from

Golovko, O., Kumar, V., Fedorova, G., Randak, T., & Grabic, R. (2014). Seasonal changes in antibiotics, antidepressants/psychiatric drugs, antihistamines and lipid regulators in a wastewater treatment plant. Chemosphere, 111 , 418-426. doi:

Groundwater Foundation. (2017). What is Groundwater. Retrieved July 07, 2017, from

Kar, S., & Roy, K. (2010). First report on interspecies quantitative correlation of ecotoxicity of pharmaceuticals. Chemosphere, 81 (6), 738-747. doi:

Obimakinde, S., Fatoki, O., Opeolu, B., & Olatunji, O. (2017). Veterinary pharmaceuticals in aqueous systems and associated effects: An update. Environmental Science and Pollution Research International, 24 (4), 3274-3297. doi:

US Department of Health and Human Services. (2017, May 03). National Center for Health Statistics. Retrieved July 07, 2017, from

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