With study after study revealing disturbing statistics, it is now difficult to ignore that our drinking water is laced with traces of pharmaceutical drug residues. Comprising of hormones, anti-depressants, pain killers, antibiotics and what not, the brew that we might be gulping with every sip of water is indeed something to worry about.
Though the amount being reported is microscopic, the very presence of pharmaceutical drugs and their by-products have raised a valid question. Do these chemicals found in our drinking water really present serious, measurable health risks over long-term?
One reason for the detection of these distressing chemicals and their metabolites in the water cycle is clearly the advances being made in the analytical technology that helps to precisely trace these chemicals and drugs even at very low concentrations. Another alarming but irrefutable fact is that we have started to rely on too many medications – whether prescription or over the counter. We are taking drugs to treat a range of conditions ranging from headaches to depression, acid reflux to heart failure and high blood pressure to hormonal imbalances.
While regulatory agencies, including the World Health Organization (WHO), claim that the traces are too small to be causing any threat to human health, non-profit environmental watch groups and other scientists are expressing concern. The truth is: these findings are recent and how this potent cocktail of drugs present in our water supply can harm us in the long term is still an unknown, unexplored variable.
How do the drugs get into the water?
When you take a medication, only a fraction of it is absorbed by the body. The remaining gets discharged as body waste, and is flushed down the toilet. In addition, people tend to flush unused medications down the toilet too. And careless discharge of drugs by healthcare facilities further compound the situation.
While the waste water is treated before being cleared into reservoirs and other water sources, the reality is our sewage treatment plants are simply not equipped to deal with these kinds of contaminants. No wonder, research shows traces of all sorts of pharmaceutical drugs in the water consumed by 40 million Americans. America is not alone. Water contamination by drugs is a problem of a global scale.
Emma Rosi-Marshall, the lead author of a 2013 study that examined the effects of common pharmaceutical compounds on the health of aquatic life and water quality, said, “Pharmaceutical pollution is now detected in waters throughout the world. Causes include aging infrastructure, sewage overflows, and agricultural runoff. Even when waste water makes it to sewage treatment facilities, they aren’t equipped to remove pharmaceuticals. As a result, our streams and rivers are exposed to a cocktail of synthetic compounds, from stimulants and antibiotics to analgesics and antihistamines.” 
What studies and investigations around the world are showing us?
The U.S. Geological Survey, scientific agency for natural sciences, has been investigating this trend from as early as the 1990’s. The scientists from various organizations have raised grave concerns over the potential effects of pharmaceuticals in the water supplies on plant life, animals and naturally occurring bacteria, not to mention the consequences on human health.
An article in the Harvard Health highlights that a study conducted by the USGS in 1999 and 2000 found “measurable amounts of one or more medications in 80% of the water samples drawn from a network of 139 streams in 30 (US) states. The drugs identified included a witches’ brew of antibiotics, antidepressants, blood thinners, heart medications (ACE inhibitors, calcium-channel blockers, digoxin), hormones (estrogen, progesterone, testosterone), and painkillers”.
A recent study by USGS show that a range of pharmaceuticals are widespread in small streams in the South-eastern United States; most common including drugs used to treat Type II diabetes, pain, and seizures and used as an anti-histamine.  
An investigation conducted by the Associated Press in 2008 revealed a “vast array of pharmaceuticals including antibiotics, anti-convulsants, mood stabilizers and sex hormones in the drinking water supplies of at least 41 million Americans.” 
The writers further explain that, “more than 100 different pharmaceuticals have been detected in lakes, rivers, reservoirs and streams throughout the world. Studies have detected pharmaceuticals in waters throughout Asia, Australia, Canada and Europe even in Swiss lakes and the North Sea. For example, in Canada, a study of 20 Ontario drinking water treatment plants by a national research institute found nine different drugs in water samples. Japanese health officials in December (of that year) called for human health impact studies after detecting prescription drugs in drinking water at seven different sites.”
In 2013, results from the study conducted by U.S Environmental Protection Agency, attested to the seriousness of the situation. The scientists examined the samples from 50 wastewater plants across the nation for 56 drugs including high-blood pressure medications, and over-the-counter drugs like Tylenol and ibuprofen. The results were shocking; more than half of the samples tested were found positive for 25 of such drugs – common ones including opioids, acid reflux and congestive heart failure drugs, and also Tylenol and ibuprofen . Notably, the scientists were also surprised to find that high blood pressure medications were present in the largest concentration.
Pharmaceuticals in our drinking water: Is this a cause for alarm?
Government agencies assert that the contamination of the waterways with pharmaceutical chemicals is not alarming; at least not yet. However, independent scientists are finding disturbing clues from aquatic life. Hordes of studies and scientific papers suggest that fish and amphibians are showing different behavior and transformed reproductive systems in response to the long-term, low-dose exposure to hormonally active drugs, antidepressants and other medications found in water.
For example, birth control pills and hormonal therapies tend to discharge estrogen in the water supply. This is having a feminizing effect on the male fish. And there is more, adding weight to the troubling evidence:
- A 2007 study reports that male fishes downstream of some wastewater channels synthesise vitellogenin, a protein synthesized by females when their oocytes mature; and develop early-stage eggs in their testes. It is believed that this feminization is due to the presence of natural or synthetic estrogens (used in birth-control pills) or chemicals that mimic estrogen .
- Another preliminary study conducted by the researchers at the University of Idaho found that fathead minnows, when dunked in water containing anti-depressants and anticonvulsants (which is present in tap water) showed 324 genetic alterations linked to human neurological disorders, including autism . The minnows showed these traits after swimming for just 18 days in the contaminated water.
- A recent 2016 study published in the Environmental Science and Technology suggests that human contraceptive progestin has a negative effect on reproductive behavior of the fathead minnow .
Potential health risks for humans?
As often quoted by regulatory agencies and health officials, the drug residues in water have been found at levels that are considered too low to be of any immediate concern. However, it can’t easily be ignored that there is also a lack of effective long-term studies and models that can envisage the impact of low-dose but chronic exposure of this cocktail on human health. In addition, no formal regulations exist that mandates the monitoring of pharmaceutical chemicals in our drinking water.
Especially considering the reports of hormones leeching into the waterways, the concern seems genuine. It is because hormones typically work at low concentrations in the body, thus even the miniscule amounts being traced can have serious health repercussions. Another important question is whether certain populations are more susceptible to the effects of pharmaceuticals and hormones in drinking water, for example pregnant women, infants and people with disabilities?
Again, there are no concrete studies so far that could prove any kind of adverse effect but then it is a known fact that children are more prone to such exposures. In a WebMD article, titled Drugs in Our Drinking Water? Sarah Janssen, MD, PHD, MPH, a science fellow at the Natural Resources Defense Council, says, “We know that kids, including babies and toddlers, as well as foetuses, are more susceptible to environmental exposures because their bodies are still developing and their exposure on a pound-per-pound basis is higher. And they lack the detoxification system adults have. So it is not unreasonable to expect they would be at higher risk.”
- Cary Institute of Ecosystem Studies. Streams stressed by pharmaceutical pollution. Press Release 2013.
- Bradley et al. Metformin and Other Pharmaceuticals Widespread in Wadeable Streams of the Southeastern United States. Environ. Sci. Technol. Lett., 2016
- Pharmaceuticals Commonly Detected in Small Streams in the Southeastern United States. News Release. USGS. 2016
- Jeff Donn, Martha Mendoza And Justin Pritchard. AN AP INVESTIGATION : Pharmaceuticals Found in Drinking Water. Associated Press.
- Martha Rosenberg. Drugs in the Drinking Water? Don’t Ask and Officials Won’t Tell. Organic Consumers Association. March 8, 2016.
- Kidd KA, Blanchfield PJ, Mills KH, Palace VP, Evans RE, Lazorchak JM, Flick RW. Collapse of a fish population after exposure to a synthetic estrogen. Proc Natl Acad Sci U S A. 2007 May 22;104(21):8897-901. Epub 2007
- Matt Harvey. Your tap water is probably laced with antidepressants. Salon. March 15, 2013.
- Frankel, T.E., Meyer, M.T., Kolpin, D.W., Gillis, A.B., Alvarez, D.A., and Orlando, E.F., 2016, Exposure to the contraceptive progestin, gestodene, alters reproductive behavior, arrests egg deposition, and masculinizes development in the fathead minnow (Pimephales promelas): Environmental Science and Technology, v. 50, no. 11, p. 5991-5999, doi:10.1021/acs.est.6b00799.