The researchers at umeå University claim that the drug, which is commonly used to treat anxiety in humans and gets into waterways via waste water, showed a decrease in mortality in fish.
According to Swedish scientists, the existing standard ecotoxicological tests mainly focused on the harmful effects of water contaminants and ignore other potential impacts. But the pharmaceutical drug may give some benefit to aquatic organisms that will change the balance of species in the environment and cause serious, cascading ecological effects.
Jonatan Klaminder says: "Ecotoxicological tests were designed with traditional toxic contaminants, e.g. heavy metals and dioxins, which have historically been a major threat to aquatic organisms in surface waters. Pharmaceuticals, designed to improve health, and this new group of contaminants does not fit the traditional point of view".
The researchers tested the effects of high and low concentrations of oxazepam on a population of Eurasian perch in lakes of Sweden. It turned out, the drug is prescribed to treat anxiety and insomnia in people getting into reservoirs, can increase the activity and boldness of Eurasian perch. The biologists noted that the low concentration of oxazepam in the experiments was lower than in treated wastewater in Europe. Other tests showed that the mortality rate of perch, at different concentrations of the drug were much lower compared to the control group without access to the medication.
Scientists believe that "a therapeutic effect leading to increased survival of one species may result in cascading ecological consequences... substance can improve the health of aquatic organism and make suffering from pollution, more competitive."
Co-author Tomas Brodin observation: "Our study focused on only one pharmaceutical impurities. It is not excluded that similar effects can be caused by the influence of a number of drugs that find their way into surface waters, such as antibiotics, painkillers, anti-inflammatory drugs, hormones and antidepressants."
Source: nauka24news.ru/