Over the last several decades, water quality researchers have started to gain an understanding that there are increasing amounts of pharmaceutical compounds seeping into drinking water. The bulk of this is thought to be coming from pharmaceutical manufacturing facilities, human waste, and individual pharmaceutical waste.
You might think that these compounds would be filtered out at wastewater treatment plants, but that isn't the case. And that is because it is nearly impossible to do so.
Between 2004 and 2009, the U.S. Geological Survey, USGS, found that treatment plants that received discharges from pharmaceutical facilities had 10 to 1000 times higher concentrations of pharmaceuticals than wastewater treatment plants located elsewhere. The pharmaceutical compounds from these treatment plants, which often discharge their treated water into streams or rivers, could be found up to 30 kilometers downstream from the plant-based on simple detection and measurement of water samples.
For many years, the concentrations of pharmaceuticals in water has been known, but it was felt that --considering the relatively small amounts of pollutants, and the relatively vast amounts of water involved-- dilution would mitigate any damage caused. However, over time, these concentrations have built up in various sources of water, and thus the pharmaceutical compounds are making their way back into humans through drinking water.
While we mentioned one example of high concentrations found in effluent from plants that treat pharmaceutical waste, it's also important to note that humans are one of the most common sources of pharmaceutical compounds in wastewater. Most drugs we ingest are not fully metabolized in our bodies, meaning that some of the compounds end up making their way back out through our waste. This means that they eventually make their way back to the wastewater treatment plant where no modern process is capable of removing them at scale.
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Uncontrolled drug disposal, such as discarding drugs into toilets, and agricultural runoff from livestock manure are also causes of increasing levels of pharmaceuticals in drinking water.
To understand this problem in a greater scope, let's take a closer look.
Pharmaceuticals in water
Across the US, and to varying degrees the world, public water systems are closely monitored for a variety of harmful substances. Each water treatment plant will have a permit that indicates the level of certain chemicals they are allowed to have in their water. This is generally set by a regulating agency and generally works well.
However, there are thousands of potentially harmful substances that can make their way into drinking water. It is not possible to test for all of these, or to measure their concentration. Getting accurate data is compounded by the need to run specific tests and use different sampling measures to get accurate data on the levels of different pollutants in the water.
According to the World Health Organization, "Practical difficulties associated with implementing monitoring programmes for pharmaceuticals include the lack of standardized sampling and analysis protocols, high costs and the limited availability of the analytical instruments required to measure the diverse range of pharmaceuticals that may be present."
While routine monitoring for pharmaceuticals in water sources and drinking-water on a national basis is not feasible, where local circumstances warrant, such as the existence of a manufacturing facility with uncontrolled effluent discharge, it is more reasonable to conduct investigative monitoring of certain chemicals.
A typical wastewater treatment plant, Source: Nick Allen/Wikimedia Commons
Currently, there's no confirmed data that indicates low levels of pharmaceuticals in water are harming humans – yet – but we do have data indicating that concentrations of pharmaceuticals in water are harming wildlife and fish. Pharmaceuticals showing up in fish becomes a particularly worrisome prospect when you consider humans eat fish, and that fish essentially function as filters for the water they breathe, slowly absorbing the chemicals in which they live.
If you eat a fish that has been living in water with high concentrations of pharmaceuticals from wastewater effluent, you might start seeing the consequential negative side effects.
What is the extent of the problem?
Studies dating back now roughly two decades found measurable amounts of medication in 80% of water samples from streams in the US. This essentially means that nearly every water source (at least in the US, but likely also in much of the rest of the developed world) is polluted with pharmaceuticals to some extent.
In most cases though, it's not one drug, rather a slew of drugs, including antibiotics, antidepressants, heart medications, hormones, and painkillers, to name a few of the compounds researchers have found.
The current water treatment network is not designed to remove and treat for pharmaceuticals in water. Because concentrations vary constantly, from one water source to another, and from plant to plant, there is no way to treat the removal of pharmaceuticals in a one-size-fits-all manner, like many other wastewater treatment processes. Rather treating pharmaceuticals in water might require boutique wastewater treatment outfits in every municipality. This would drive your water costs way up.
One thing you might not be thinking about is this: pharmaceuticals making their way into your food through fertilizer.
While it may seem unsettling, many wastewater treatment plants sell their filtered sludge back to agricultural producers, to use as fertilizer. If that solid sludge from the wastewater plant has high concentrations of pharmaceuticals, they can in turn make their way into crops, and thus to your dinner table.
There is some positive news though. Research is currently being conducted into the removal of pharmaceuticals in wastewater. Researchers have found that one of the most common disinfectants, chlorine, does seem to have some effect on degrading compounds like acetaminophen, codeine, and some antibiotics.
This is a good sign, as it means modern treatment processes do work for some common pharmaceuticals, but it doesn't really address the problem at hand. Chlorine has been used for decades, meaning that as we're now detecting high levels of pharmaceuticals in water, much of that data is usually post-chlorine disinfection or post-treatment.
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In 2008, a series of articles was published by the Associated Press that found that pharmaceuticals were found in treated drinking water. These are chemicals like antidepressants, antipsychotics, and beta-blockers. The study didn't find any of these compounds in a therapeutically significant amount, but it did find them. Since many of these compounds don't naturally degrade in the environment, it means that over time we may be facing a dangerous buildup.
While it's rather hard for us to study the potential side effects of pharmaceuticals in drinking water on humans, it's easier to examine their effect on fish and other aquatic wildlife.
Several studies have concluded that estrogen and other hormone-influencing chemicals found in water can "feminize" fish, causing populations to have skewed ratios of males to females than what's seen as a standard. All of these hormones are likely coming from women who take birth control pills and other types of hormone treatments.
Their waste contains some level of the drug, which makes its way to the water treatment plant, where it then goes through the treatment process without removing the chemicals, and they are eventually discharged into a river or stream where they can be taken up by fish.
What can we do?
While civil engineers will likely have to figure out a solution to pharmaceutical treatment of wastewater within the next several decades, one of the best solutions is to start being proactive about pharmaceutical pollution now.
Make sure to never dump your drugs into the toilet or down the sink when you are done with them or they expire. Be sure to take your medication back to the pharmacy or other places that have pharmaceutical recycling programs.
This ensures that the chemicals and products are disposed of safely and don't end up switching a fish's biological sex a few streams down the line.
Farmers can do even more to help, by working to ensure that fertilizer runoff does not end up in the water system.
Regulating agencies are also trying to get a handle on the situation as well. The first step to solving the problem is educating the public that this is indeed a problem. Chances are, reading this article is one of the first times you've heard about pharmaceutical pollution in streams and drinking water from humans. While it's not the largest problem in the world right now, it's growing.
The EPA has added 10 pharmaceutical compounds to its list of possibly harmful contaminants in water that will require greater investigation by researchers. It's likely that a compound on this list will become one of the first that is mandated to be treated by water treatment plants across the world.
Aside from stopping the pollution in households and farms, and working on better water treatment methods, researchers are also urging pharmaceutical companies to design drugs that either degrade faster or are more ecologically friendly. Getting the pharmaceutical companies to change their step is a great first step to effectively managing the growing pharmaceutical pollution problem we have on our hands.
