A team of scientists from the College of Arts and Sciences at the University of Buffalo (USA) has discovered human antidepressants accumulating in the brains of various fish common in the Great Lakes region. Specifically, the researchers detected high concentrations of these drugs and their metabolized remains in the brain tissue of 10 species of fish found in the Niagara River, a vital conduit that connects two of the Great Lakes of America, Lake Erie and the Lake Ontario, through the famous Niagara Falls.
The discovery of antidepressants in the aquatic life of this river (with a basin of 56 kilometers in length) raises serious environmental concerns, says Diana Aga, leader of the work to the journal Environmental Science and Technology.
“These active ingredients of antidepressants, which are coming out of sewage treatment plants, are accumulating in the brains of fish. It is a threat to biodiversity, and we should be very concerned, ” clarifies Aga.
“These drugs could affect fish behavior. Other research teams have shown that antidepressants can affect fish feeding behavior or survival instincts,” says Aga.
“If changes like these occur in nature, where fish would not detect the presence of predators because of the effect of antidepressants, for example, they have the potential to disrupt the delicate balance between species that helps keep the ecosystem stable. , comments Randolph Singh, co-author of the work.
While it is true that the levels of antidepressants present in the fish analyzed do not represent a danger to humans who eat fish, the risk that these drugs pose to biodiversity cannot be ignored. According to scientists, the alarm must be sounded because we can barely understand what the consequences could be.
A dangerous antidepressant cocktail in water
The percentage of Americans taking antidepressants has increased 65% between 1999-2002 and 2011-14, according to the National Center for Health Statistics. Wastewater treatment facilities have not been able to keep up with this growth, so they are released into the environment.
The researchers found a wide variety of pharmaceutical and personal care chemicals in the organs and muscles of 10 species of fish such as el, walleye, rudd, white perch, yellow perch, rudd, amia bald or rainbow trout. Of all, antidepressants represented the most important problem: these drugs or their metabolites were found in the brain of 100% of all fish species studied by scientists (in some fish around 400 nanograms of norsertraline, a metabolite of sertraline, the active ingredient in Zoloft, per gram of brain tissue).
Apart from sertraline, citalopram (Celexa), and norfluoxetine (Prozac and Sarafem) were also found.
More than half of the fish brain samples had sertraline levels of 100 nanograms per gram or more.
Evidence that antidepressants can change fish behavior generally comes from laboratory studies exposing animals to higher concentrations of drugs than those found in rivers, but the new study’s findings remain concerning: antidepressants that Aga’s team detected in fish brains had accumulated over time, often reaching concentrations that were several times higher than levels in the river. Even up to 20 times more.
Referencia: Prapha Arnnok et al. Selective Uptake and Bioaccumulation of Antidepressants in Fish from Effluent-Impacted Niagara River, Environmental Science & Technology (2017). DOI: 10.1021/acs.est.7b02912
