The Impact of Medication Disposal on the Environment

Anna K. Morin, Pharm.D.

While the therapeutic and adverse effects of medications on human health are extensively studied, the potential environmental impacts of the manufacturing, use, and disposal of medications are not well understood. Medications can enter the environment by various routes. Residues released during the manufacturing process can enter the air and surface waters. After administration, human medicines are absorbed, metabolized, and then excreted. Other routes of entry include the disposal of unused medicines and medical waste. When medications and other substances are disposed of in the trash or into wastewater disposal systems, they can find their way into the environment. Many wastewater treatment facilities are not designed to remove medications or metabolites from the water supply and federal regulations regarding medication disposal on the environment are absent.

Various studies have highlighted the ecological and human health concerns of medication disposal. Of particular concern is that active ingredients from prescription drugs have been found in streams, lakes, rivers, and the public water supply in the United States (US) (1,2). A 2008 study found a number of medications in US drinking water, including antibiotics (i.e., amoxicillin, azithromycin, sulfamethoxazole, and tetracycline), anticonvulsants (i.e., carbamazepine and phenytoin), pain medications (i.e., acetaminophen, ibuprofen, naproxen, and codeine), and sex hormones (estrone, estradiol, and prednisone) (1). In 2014, a study found hydrochlorothiazide in every sample taken from 50 large wastewater treatment plants. Other medications such as metoprolol, atenolol, and carbamazepine were found in more than 90% of the samples (2). While the majority of these medications were found in very small concentrations, the public health impact can be significant. Unwanted effects range from infertility in fish and surrounding wildlife to the decreased growth or elimination of plant species. The current overall effects in humans are unknown, but concern exists that prolonged exposure to trace quantities of medications could lead to detrimental health outcomes such as antibiotic resistance and abnormal hormonal effects (1,2).

In addition to expiration of medications, there are many reasons why consumers may need to dispose of medications. Problems with medication adherence and compliance, inappropriate prescribing and dispensing, adverse drug reactions or dosage changes that result in less than anticipated overall usage, and unused medications following a patient’s death can all lead to the accumulation of unused or unwanted medications. Improper storage and disposal of medications have the potential for negative consequences, including harm to the environment, accidental poisonings, and drug diversion. The safe and responsible use and disposal of medications requires the cooperation of both consumers and healthcare providers. Flushing medications down the toilet or sink or disposing of medications in the household trash allows these pharmaceuticals to pass through wastewater facilities and leach into the soil and water supplies. In addition to consumer medication disposal, healthcare facilities, such as medical offices, nursing homes, and hospitals, also generate a significant amount of medical waste that can cause environmental damage (3).

Pharmacists can play an important role in educating consumers regarding safe and responsible methods to dispose of medications. In addition, the US Food and Drug Administration (FDA), the United States Environmental Protection Agency (EPA), and the Drug Enforcement Administration (DEA) provide resources and guidance regarding the appropriate disposal of unwanted or expired medications on their websites (4-7). The current preferred method to dispose of medications are drug take-back programs that facilitate the collection and destruction of medications. Consumers can contact their healthcare providers, pharmacy, local law enforcement, or the DEA to learn what take-back options are available in their community.

References

1. Donn J, Mendoza M, and Pritchard J. Associated Press. Drugs found in drinking water. USA Today. September 12, 2008. http://www.h2oengineeringllc.com/doc_library/Drugs%20found%20 in%20drinking%20water%20-%20USATODAY.pdf (Accessed 01/25/21).

2. Kostich, MS, Batt, AL, and Lazorchak, JM. Concentrations of prioritized pharmaceuticals in effluents from 50 large wastewater treatment plants in the US and implications for risk estimation. Environmental Pollutution 2014; 184: 354–359.

3. Manzoor J and Sharma M. Impact of biomedical waste on environment and human health. Environmental Claims Journal 2019;31(4):311-324.

4. US Food and Drug Administration (FDA): Disposal of Unused Medicines: What You Should Know. https://www.fda.gov/drugs/safe-disposal-medicines/disposal-unused-medicines-what-youshould-know (accessed 01/25/21).

5. FDA Consumer Health Information: Where and How to Dispose of Unused Medicines. https:// www.fda.gov/consumers/consumer-updates/whereand-how-dispose-unused-medicines (accessed 01/25/21).

6. US Environmental Protection Agency: Collecting and Disposing of Unwanted Medicines: What to do with Unwanted or Expired Medicines. https://www. epa.gov/hwgenerators/collecting-and-disposing-unwanted-medicines (accessed 01/25/21).

7. US Department of Justice Drug Enforcement Administration: Drug Disposal Information. https://www.deadiversion.usdoj.gov/drug_disposal/ index.html (accessed 01/25/21).