Micro-pollutants, such as drugs, cannot be removed by waste treatment plants
Most drugs we take, we excrete. The remnants flow on to treatment plants, and some drugs flow out in treated water—more, it turns out, than we previously thought.
The US Geological Survey reported in 2016 that it had detected at least one out of 108 pharmaceuticals it tested for in small streams in the eastern US. The average number detected was six. Our prescription habit, it seems, has blanketed our water ways with a variable drug cocktail.
In 2008 the U.S. Geological Survey (USGS) tested water in nine states across the country and found that 85 man-made chemicals, including some medications, were commonly slipping through municipal treatment systems and ending up in our tap water. Another report by the Associated Press found trace amounts of dozens of pharmaceuticals in the drinking water supplies of some 46 million Americans. Remember: We All Live Downstream.
If it can’t be filtered out in water treatment plants, it will end up in municipal water supplies.
Bryan Brooks, a biologist at Baylor University in Texas became intrigued by urban water cycles and subsequently made landmark discoveries of antidepressants in the brains of fish as well as subtle effects on their behavior. Like many researchers in this area, he notes the difficulty of deciphering the effects of the motley mix of drugs and other chemicals in the environment on different animals. “The biggest concern is the stew effect,” says Scott Dye of the Sierra Club’s Water Sentinels program. “Trace amounts of this mixed with trace amounts of that can equal what? We don’t know.”
Researchers have found evidence that even extremely diluted concentrations of drug residues harm fish, frogs and other aquatic species, and have been shown to labs to impair human cell function. Antibiotics in the water supply may increase bacterial resistance to antibiotics.
One of the common culprits is estrogen, much of which is inadvertently released into sewers through the urine of women taking birth control. Studies have shown that estrogen can wreak reproductive havoc on some fish, which spawn infertile offspring sporting a mixture of male and female parts. Researchers at the University of Pittsburgh found that human breast cancer cells grew twice as fast when exposed to estrogen taken from catfish caught near untreated sewage overflows. “There is the potential for an increased risk for those people who are prone to estrogenic cancer,” said Conrad Volz, lead researcher on the study. Do we wonder why people in developed nations have fertility issues?
With water shortages a growing issue around the world, water re-use is likely to become more popular. This makes it more likely drug residues will end up in our food and drinking water.
One solution is to intensify the cleaning process. Switzerland has spent huge sums upgrading its treatment facilities to remove micro-pollutants. Yet many countries cannot afford this strategy.
NSF International, urges individuals to not use their toilets or sinks to dispose of unused medications and to opt for the garbage instead; most modern landfills are lined to keep such contaminants inside.
Professor Klaus Kümmerer at Leuphana University in Lüneburg, Germany, says high-tech treatments can convert pharmaceuticals into biologically active molecules that we know even less about.
Kümmerer began his academic career looking at pollutants in the environment. What he saw forced him to switch his attention to the other end of the pipeline—the creation of new drugs. He advocates “benign by design,” a concept he began promoting more than ten years ago. Under this new creed, drug companies should look at biodegradability as desirable during drug development. Drugs would be designed to break down naturally. This is expensive and it will take some time to get the drug companies on board with one more regulation on their industry.
And drugs aren’t the only problem in our water supplies. Household cleaners, lotions, cosmetics, fragrances, nicotine, caffeine, sunscreen, microplastics and microfibers, etc all end up in our water systems because waste treatment plants do not have the technology to remove all these substances.