About one in four Montrealers consume some form of antidepressant (!?) And these drugs, transported by water pipes, have an effect on fish in the St. Lawrence, a Canadian study published in the journal Chemosphere.
Previous studies have shown that fish accumulate residues of antidepressants in their livers and muscles. This study shows that these residues also accumulate in the tissues of the brain as to affect some activities. Sébastien Sauvé and Andre Lajeunesse, University of Montreal (Quebec) conducted an experiment in tanks equipped with water purification plant of the City of Montreal, which compared the tissue of trout exposed for three months to wastewater effluent from the city of Montreal to those trout that receive discharges treated with ozone and trout kept in tanks without effluent.
Traces of six antidepressants - Prozac, Effexor Praxil and, in particular - have been found. Concentrations were lower in fish exposed to water after the ozone treatment. But this process generates new molecules for which the effects are ignored, says Professor Sauvé.
A biomarker involved in regulating the neurotransmitter serotonin - which plays a role in mood, depression, anxiety and pain - showed that brain activity was altered fish.
The impact of these drugs on the fish and the ecosystem of the St. Lawrence River is unknown.
Montreal has a very rudimentary sewer system, he says. Virtually only the solids are removed and the water is not subject to any disinfection. But anyway, the chemical structure of the antidepressants makes them very difficult to remove from sewage, even using the most sophisticated systems, "he said.
The study was funded by the Plan of chemicals management at Health Canada, the Plan of Action Saint-Laurent and the Canadian Foundation for Innovation.
Last September, a study by the University of Ottawa, published in the journal Aquatic Toxicology, found that the antidepressant Prozac (fluoxetine) blocked the sexual attraction and hampering reproduction in goldfish. Facilities wastewater treatment current, indicated by Professor Vance Trudeau, an author, are not designed to eliminate the traces of the drug. But some countries like Germany, he said, have adopted an approach of zero tolerance vis-à-vis the environmental pollution by pharmaceuticals. Their treatment plants invest in costly equipment needed to filter drugs.