Pharmaceutical Pollution: The Invisible Threat in Our Waterways
Modern medicine relies on a range of pharmaceuticals. And, with advances in medical science, more of these critical drugs are being developed all the time. While pharmaceuticals are necessary for human health, they can also do great harm when they are not disposed of properly. Here’s what you need to know about what happens when medicines are released into ecosystems.
The scale of the problem
Chemical residue from drugs is found in water around the world. This includes lakes, rivers, and groundwater, where active pharmaceutical ingredients (APIs) are a serious issue for the environment. The problem has only escalated as the pace of drug discovery continues to increase and more drugs come to market. Worldwide, we rely on about 4,000 APIs in medicine and veterinary care.
A report in 2016 by the United Nations found 631 pharmaceuticals or related products in the natural environment in 71 countries. By 2020, 89 counties had detected traces of these drugs in nature—including antibiotics, painkillers, hormones, and drugs that act on blood lipids. In the US, a study of wastewater treatment plants found that every sample contained at least one API. Higher concentrations of these chemicals are found in urban areas with larger populations.
Although these substances likely have been in water systems for years, they’ve only been detected relatively recently. Better monitoring has revealed the extent of this type of pollution. A global study from 2022 that analyzed river samples in 104 countries confirmed drug contamination on every continent.
Treating wastewater significantly reduces the concentration of pharmaceutical pollutants in water, making it safe for human use. But technology hasn’t advanced to the point where pharmaceutical residues can be totally removed. Because treatment can’t eliminate the problem, the trace amounts that persist can harm aquatic species—and over the long term, humans.
How we got here
There are several ways medications can pollute ecosystems. When people ingest drugs, there is some remnant the body cannot metabolize, and this is excreted as waste. Improper disposal of medication is the other culprit when it comes to pharmaceutical pollution. It’s common for people to pour old medications down their kitchen or bathroom sinks or flush them down the toilet, sending large amounts directly into the sewage treatment system.
Another common method of discarding expired or unused medication is throwing them in the garbage. This approach isn’t safe either, because these chemicals can leach from landfills into the soil and nearby groundwater.
Since most wastewater treatment facilities cannot completely remove drug compounds, the chemical residue survives in the treated water and is discharged into waterways. Companies that manufacture drugs contribute to the problem too. Wastewater treatment plants that process discharges from pharmaceutical factories can be dealing with chemical residue concentrations up to 1,000 times higher than facilities that don’t receive pharmaceutical effluent.
Agriculture also creates pharmaceutical pollution. Raising livestock often involves the use of antibiotics, hormones, and other drugs to promote growth and treat illness in herds. These medications end up in cattle manure. Fertilizing crops with manure leads to pharmaceutical compounds being deposited in the soil and entering waterways through irrigation runoff.
Health impacts
The potential long-term effects on ecosystems are concerning. While they may persist in low concentrations, APIs can upset natural biological processes. Although this is an emerging area of research, there are some well-documented cases raising the alarm. For example, lab-produced hormones in contraceptives have been found to disrupt the endocrine system in fish, altering their reproductive systems with male fish becoming feminized or developing female traits.
Another instance was uncovered in South Asia where the painkiller diclofenac, used by veterinarians, almost decimated the vulture population in the 1900s and 2000s. The birds that fed on the carcasses of livestock that had been administered the drug died of kidney failure and 95% of them were gone over a 10-year period.
Research has uncovered other environmental issues. Since antibiotics are made to kill living organisms, they can readily kill aquatic vegetation. In addition, common over-the-counter medications such as aspirin, ibuprofen, and naproxen can cause oxidative cell stress for aquatic species, changing behavior, growth, and reproductive patterns.
In terms of human health, there is now more awareness that this type of pollution may contribute to the growth of drug-resistant bacteria. Antibiotics present in ecosystems can encourage the evolution of this kind of bacteria. The World Health Organization (WHO) has already identified the emergence of these “superbugs” as a major risk to health globally.
How you can help
Pharmaceutical pollution is a worldwide problem that can’t be solved by one person. Still, there are ways you can help:
Dispose of unused medicines safely: Don’t flush them down the toilet or sink. Use community take-back programs. In the US, you can find kiosks at major drugstore chains, including CVS, Rite Aid, and Walgreens, where you can safely deposit unused or expired drugs. Search online for “safe drug disposal near me” to find drop-off sites in your area. Some police or law enforcement stations have safe disposal kiosks, too.
If you can’t find a safe disposal site: You can dispose of unused drugs in household trash by mixing them with something unappealing (coffee grounds, pet litter, or something an animal will not want to eat), sealing it in a container, and then throwing it away.
Advocate for safe drug disposal in your community: If there are no safe disposal sites in your community, raise awareness about the problem and see what can be done.
Live a healthy lifestyle: No one has complete control over their health, and everyone needs medicines at some point. But making healthy choices—like quitting smoking, eating nutritious foods, exercising, and getting enough sleep—can reduce your risk of chronic disease and therefore your need to take medications.