Safely Dispose of Leftover Pills and Keep Drugs out of Drinking Water

Monica Purmalek, Sarah Miller, & Annika Schmid, National Center for Health Research

In a country where so many people are prescribed medications, properly disposing of unused medications has become a  challenging issue. Although the Food and Drug Administration advises flushing away certain dangerous drugs, research shows that unused medication that is disposed of this way has the potential to end up in our water and harm human health. The FDA has a “Flush List” of drugs considered dangerous because of their potential for misuse/abuse or because of their ability to result in death from just one dose. The list contains 10 opioids and 3 non-opioids.1 A full list can be found on the FDA’s website here.  This article will explain the issues of different chemicals in the water and how to dispose of dangerous medication in a way that best protects human health.

How Do Drugs End Up in Our Water?

Medicines get into our water when people take them and then excrete them in their urine. Excretions of drugs that have been processed by the body are somewhat less of a concern. However, conventional water treatment practices are not able to fully remove these metabolized drugs before they reach our drinking water. When some drugs enter the water supply, they are there to stay.2

Another way medicine gets into the water is when people wash off ointments and creams. However, what comes out of our bodies and off our skin is very diluted. 

The biggest concern is when people flush medicines down the toilet, which introduces drugs into the water supply in their full concentration. It is actually what the FDA has been recommending for drugs that can be abused or lethal in one dose, such as OxyContin, Percocet, and morphine—but that means they end up in our drinking water.3

An investigation by the Associated Press in 2008 found that municipal water supplies in several areas were contaminated with antibiotics, hormones from birth control pills, seizure medications, blood pressure medications, and antidepressants.4 A 2014 study found an average of 6 pharmaceuticals, such as medication for diabetes, seizures, and a local anesthetic at detectable levels in 59 streams in the southeastern United States.5

And there are a lot of leftover medications out there because of the rate at which Americans use and are prescribed drugs. According to the Centers for Disease Control and Prevention (CDC), 48% of Americans surveyed in 2015 and 2016 reported using at least one prescription drug in the past month.6 This means that about 150 million Americans use prescription drugs at any given time. This could translate to hundreds of thousands if not millions of pounds of unused drugs per year, and those drugs have the potential to end up contaminating water.

How Can Drugs in the Water Affect Our Health?

The good news is that the amounts of drugs currently detected in drinking water are probably too small to have a short-term effect on human health.7 However, current research cannot tell us  what the effects on humans are of long-term daily exposure to drugs at these levels. We know, for instance, that chemicals in our drinking water that act like hormones actually do more harm to our health at low doses than at high doses.8 These chemicals (endocrine disrupting compounds or EDCs) are used mainly in plastics, shampoos, and lotions. 

Common EDC’s that you may already be familiar with are Bisphenol A (BPA) and phthalates. Both of these chemicals are introduced to drinking water by humans and do not occur naturally. BPA and phthalates have a known effect on human reproductive health.9 In males, BPA is linked to a difference in sexual function and sperm health. In females, BPA and phthalates increase the likelihood of polycystic ovary syndrome (PCOS) and endometriosis, both chronic and painful conditions.  

EDC’s may also contribute to a person’s risk of obesity, Type 2 diabetes, and heart disease by increasing the body’s tendency to store fat.10 These changes to our biology are theorized to be a permanent result of exposure to EDC’s through the modification of gene expression and can even be passed down through generations. This means that the safety of our drinking water can have a multi-generational effect on human health. For more information on how chemicals can contribute to obesity, you can read this article. 

Because of their exposure due to living in the water, fish serve as an important way for researchers to study the health effects of medications in our water. Since the early 2000s, studies have shown that medications in water can harm animals living in water contaminated with the medication. A 2004 study found that when an estrogen commonly used in birth control pills was put in water, it reduced the ability of the fish to reproduce.11 This was not only true for the exposed fish, but also for the offspring of the exposed fish. Scientists continue to study the effect of pharmaceutical estrogen in zebra fish. A 2021 paper looked specifically at the chronic effects that chemicals in water had on these fish. The study showed that water contaminated with estrogens led to the early development of female sex organs and the late developement of male sex organs. The estrogen was also linked to an abundance of females being born.12 In 2011, a study published in the Journal of Environmental Science and Technology found that drugs in the water can build up in the brains of fish and cause changes in their behavior.13 We still have much to learn about the long-term effects on fish and other animals (some of which we eat). 

If drugs in our water are affecting fish, could drugs in drinking water affect our children? Young children drink more water for their size than adults, so the amount of drugs they are ingesting by drinking water is much larger, pound for pound.13 For all of these reasons it is important to dispose of drugs in a way that minimizes the risk to our drinking water. 

Can I Toss Them in the Garbage?

Instead of flushing unused medications, can you throw them in the trash? Yes, but this will not prevent groundwater contamination entirely. For medications not on their flush list, the FDA recommends removing the medications from their original container and mixing them with undesirable substances like coffee grounds or cat litter.3 This makes the medication less recognizable to someone searching for potentially dangerous drugs like painkillers in the garbage, as well as  less likely to cause an accidental poisoning of children and pets. The FDA also suggests that you put the drug mixture into a sealable bag or container to prevent the medication from leaking. While this is better than flushing pills down the toilet, the drugs can still leech into the groundwater. For example, the bag or container can get punctured on the way to the landfill and the drugs can leach into the water in the ground below the landfill.

What Is the Best Way to Dispose of My Medications?

Drug “take-back” programs are currently the best way for you to safely dispose of your unused medications both those on and off the flush list. They are often sponsored by hospitals, the Drug Enforcement Administration (DEA), or your community. The DEA holds a National Drug Take-Back Initiative once a year in over 5,000 locations. In 2021, the DEA collected a total of 840,000 pounds of drugs on National Take-back Day.15 You can search for year round disposal sites here.  Many police stations also host drug take-back events or have drop-off boxes where you can leave your unused medications. Most pharmacies will take back your medications for a small fee.

The drugs that are collected using take-back programs are usually sent to pharmaceutical companies to be incinerated. Some research shows that incineration can produce toxic chemicals called dioxins that can be released into the air. The leftover ash is put into regular landfills so it is possible that it can leach into the soil and groundwater.16 However, compared to other drug disposal methods, take-back programs are still the safest way to dispose of your unused drugs.

What Else Can I Do to Keep Medicines Out of the Water Supply?

Why do we even have leftover pills? Healthcare professionals are usually required to fill prescriptions in certain units, regardless of whether or not you need to finish taking all of the medicine in the prescription.17

Some prescription drugs—pain killers, for instance—are taken on an as-needed basis so you can end up with a lot of leftover pills. Doctors and pharmacies should develop strategies to reduce the amounts of unused drugs. Meanwhile, you can do your part by talking to your doctor about how many pills you expect to need and properly disposing of your leftover pills.

If you are buying over-the-counter medications, don’t purchase more medicine than you can use before the expiration date. This will save you from wasting money and save you from having expired medicine in your house.

The Bottom Line

Drugs are entering our waterways, often by being flushed down the toilet. The introduction of pharmaceuticals into water has known, immediate health effects on humans and wildlife, but even more concerning are the unknown long-term health effects which are only beginning to be studied. We can mitigate the issue by disposing of medications in the garbage, or even better, by turning them in at drug disposal sites in police stations and pharmacies. Preventative measures can help as well, so make sure you are not over-buying or being over-prescribed medication. 

All articles are reviewed and approved by Dr. Diana Zuckerman and other senior staff.

The National Center for Health Research is a nonprofit, nonpartisan research, education and advocacy organization that analyzes and explains the latest medical research and speaks out on policies and programs. We do not accept funding from pharmaceutical companies or medical device manufacturers. Find out how you can support us here.

 References

  1. Food and Drug Administration. (2020, October 1). Drug Disposal: FDA’s Flush List for Certain Medicines. FDA. https://www.fda.gov/drugs/disposal-unused-medicines-what-you-should-know/drug-disposal-fdas-flush-list-certain-medicines
  2.  “Fighting Drugs In Drinking Water.” Fighting Drugs In Drinking Water | Clean Water Action. Clean Water Action, n.d. Web. 29 May 2013. <http://www.cleanwateraction.org/programinitiative/fighting-drugs-drinking-water>.
  3. “How to Dispose of Unused Medicines.” US Food and Drug Administration. FDA, n.d. Web. 23 Apr. 2013.
  4.  Donn, J; Mendoza, M; and Pritchard, J; AP: Drugs found in drinking water, USA Today. March 10, 2008. Retrieved from: https://usatoday30.usatoday.com/news/nation/2008-03-10-drugs-tap-water_N.htm
  5. Bradley, P. M., Journey, C. A., Button, D. T., Carlisle, D. M., Clark, J. M., Mahler, B. J., Nakagaki, N., Qi, S. L., Waite, I. R., & VanMetre, P. C. (2016, May 24). Metformin and Other Pharmaceuticals Widespread in Wadeable Streams of the Southeastern United States. Environmental Science and Technology Letters, 3(6), 243-249.
  6. Martin, C. B., Hales, C. M., Gu, Q., & Ogden, C. L. (2019, May). Prescription Drug Use in the United States, 2015-2016. Centers for Disease Control and Prevention. Retrieved October 7, 2021, from https://www.cdc.gov/nchs/products/databriefs/db334.htm
  7. Kumar, A and Xagagoraraki, I, Human Health Risk Assessment of Pharmaceuticals in Water: An Uncertainty Analysis of Metprobabmate, Carbamazepine, and Phenytion. Regulatory Toxicology and Pharmacology. 57(1) pp.146-56.
  8.  Vandenberg LN, Colborn T, Hayes TB, et al. “Hormones and Endocrine-disrupting Chemicals: Low-Dose Effects and Nonmonotonic Dose Responses.” Endocrine Reviews. March 2012. Web.16 Apr. 2012.
  9. Giulivo, M., Lopez de Alda, M., Capri, E., & Barcelo, D. (2016, November). Human exposure to endocrine disrupting compounds: Their role in reproductive systems, metabolic syndrome and breast cancer. A review. Environmental Research, 151, 251-264. 
  10. Janesick, A., & Blumberg, B. (2012, February 28). Obesogens, stem cells and the developmental programming of obesity. International Journal of Andrology, 35(3), 437-448. 
  11. Nash, J. P., Kime, D. E., Van der Ven, L. T. M., Wester, P. W., Brion, F., Maack, G., Stahlschmidt-Allner, P., & Tyler, C. R. (2004, December). Long-term exposure to environmental concentrations of the pharmaceutical ethynylestradiol causes reproductive failure in fish. Environmental Health Perspectives, 112(17), 1725-1733. 
  12. Cooper, R., David, A., Lange, A., & Tyler, C. R. (2021, April 30). Health Effects and Life Stage Sensitivities in Zebrafish Exposed to an Estrogenic Wastewater Treatment Works Effluent. Frontiers in Endocrinology.
  13.  Belluck, Pam. “Traces of Anxiety Drug May Affect Behavior in Fish.” The New York Times. NY Times, 14 Feb. 2013. Web. 23 Apr. 2013. <http://www.nytimes.com/2013/02/15/science/traces-of-anxiety-drug-may-affect-fish-behavior-study-shows.html>. 
  14. Bearer, CF. Environmental health hazards: How children are different from adults. The Future of Children. 5(2)pp.11-26, 1995.
  15. National Precription Drug Take Back Day is October 23. (2021, October 4). Get Smart About Drugs. Retrieved October 7, 2021, from https://www.getsmartaboutdrugs.gov/content/national-take-back-day
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