Researchers at the University of Buffalo have discovered that human antidepressants and their breakdown products are building up in the brains of fish in the Niagra River that flows between Lake Erie and Lake Ontario. Researchers at two universities in Thailand have confirmed these results.
The researchers started out by looking for a variety of chemicals that are in human medications and personal care products. They checked the organs and muscles of 10 species of fish, and antidepressants stood out as the major problem. All 10 species they checked had detectable levels of these drugs.
How is this happening?
The drugs they found: Zoloft, Celexa, Prozac and Sarafem, are widely used in both US and Canada. Usage increased by 65% between 1999 and 2014, according to the US National Center for Health Statistics. The drugs people take do not magically disappear – a significant amount passes out of the body through the urine, sometimes intact and sometimes changed to a slightly different form that may be more or less active than the original drug. Water treatment systems do not remove these drugs, allowing them to flow into lakes and rivers where the fish live, along with treated waste water.
Worse, levels of antidepressants found in fish brains were several times higher than the concentration in the water, suggesting that the drugs are accumulating in fish over time. When fish are exposed to a drug but cannot break it down or clear it from their bodies, this can result in gradually increasing amounts being stored…in this case, in the fish’s brains.
The species tested were smallmouth bass, largemouth bass, rudd, rock bass, white bass, white perch, walleye, bowfin, steelhead and yellow perch. The rock bass had the highest concentrations of antidepressants, but several fish had a variety of drugs in their bodies and all 10 species tested were found to have some level of antidepressants.
What about humans?
The good news (if you can call it that…) is that we don’t eat fish brains, so this is unlikely to affect humans. But what about the fish? It is not yet known how these drugs might affect their health and behaviour, but other studies suggest they can affect feeding behaviour or survival instincts (for example, not noticing predators as readily).
However, if your drinking water originally comes from a lake or river, chances are you’re being exposed to a low-level cocktail of drugs, too. Many experts have felt that the drug levels in drinking water, being much lower than a person would take as treatment, could not have a significant effect. However, no one really knows whether a mixture of many active drugs, consumed at low levels over a lifetime, is a risk to people’s health.
A group of researchers found drug levels high enough to be “of environmental concern” in the Great Lakes and Minnesota River that included traces of acetaminophen (Tylenol), codeine, antibiotics, hormones, steroids, anti-epileptic drugs and dozens of other chemicals.
Health Canada reportedly found traces of drugs in samples of drinking water that came from lakes and rivers across Canada. Their report has not yet been published but was described in an article on cbc.ca website.
Some experts particularly worry about effects on the hormone and immune systems. Researchers have discussed a possible link between hormones from birth control pills that end up in the environment and increased risk of prostate cancer. Other compounds with estrogen-like activity, such as certain pesticides likely add to this risk.Scientists have already proven that these chemicals are creating “intersex” fish – male fish who have developed eggs in their testicles – putting the survival of certain species at risk in some waterways.
What can we do about it?
Wastewater treatment plants focus on killing disease-causing bacteria and removing solid matter, nitrogen, phosphorus and dissolved organic carbons. However, they pay little or no attention to drugs, hormones and chemicals that might be in human urine. Fish, especially those who live near sewage outlets, are being exposed to a cocktail of drugs 24 hours a day and it is not known whether humans exposed to a low level mixture of active drugs could be affected…
Its time to upgrade our sewage treatment systems and find ways to remove these chemicals from waste water, preventing their release into the environment. Treatment of waste water needs to be improved! Make your voice heard - ask for improvements to the waste treatment systems in your area.
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