Fish are being affected by a significant amount of anti-depressants in the waterways a new study in Canada has found.
Researchers at the University of Montreal's chemistry department found that there was a significant amount of anti-depressant medicine in the waste water of Montreal’s sewage system and that these are affecting fish tissue and brain activity. They also surmise that this effect is likely to be seen in cities around the world.
The researcher’s exposed Brook trout to varying amounts of effluent Montreal water over a three-month period. They found that there was a significant reduction in brain synapse activity in fish exposed to waste water.
Dr. Sébastien Sauvé, who works in the university's chemistry department, told the Canadian Press: "We have data that does show that antidepressant drugs do accumulate in fish tissues — there's significantly more in the liver than in the muscle, but there's also more in the brain tissues. is a bit more of a cause for concern because we have a molecule that's known and used for brain alteration functions in humans, so if we do have an accumulation in fish brain, it raises a question of what the impact is on the fish."
Even though some work is being done on ozone treatment of waste water, the structure of the medication makes it difficult to completely remove all traces.
Sauve was at pains to point out that the risk to humans eating the fish was minimal as the fish muscle is not really affected and that there was little risk to drinking treated water:
"The amount of antidepressants being released into our river works out to roughly the equivalent of a grain of salt in an Olympic-size swimming pool," Sauvé said.
"If we do a comparison with the exposure to humans from the traces of those compounds that remain in drinking water, the risk is really minimal. If someone was to drink two litres of tap water a day, every day for 70 years, they would have had the equivalent of...a small fraction of a pill."
This study ties in with another that PFK reported on last year, which found that residues of Prozac results in sexual dysfunction in fish.