London News & Search
Anti-depressants are building up in the brains of fish in a North American river and could affect their behaviour, researchers have found.
The drugs enter the water cycle through human urine, but water treatment works in the Niagara River, which forms part of the border between Canada and the US, are failing to strip them out.
As a consequence, a concentration of drugs has been building up in fish brains, according to scientists at University at Buffalo and two Thai universities, Ramkhamhaeng University and Khon Kaen University.
Remnants of commonly-used anti-depressants such as Prozac, Celexa (citalopram) and Zoloft (sertraline) were found in ten different fish species.
Dr Diana Aga, professor of chemistry at the University at Buffalo said the finds were worrying.
In a statement, she said: “It is a threat to biodiversity, and we should be very concerned.”
“These drugs could affect fish behaviour. We didn’t look at behaviour in our study, but other research teams have shown that antidepressants can affect the feeding behaviour of fish or their survival instincts. Some fish won’t acknowledge the presence of predators as much.”
The research, published in the journal Environmental Science & Technology, found levels of anti-depressants in fish brains were several times higher than levels in the river itself, meaning the chemicals are building up over time.
The fish in the River Niagra have already suffered from contamination after a massive accidental sewage leak earlier this month meant river was temporarily blackened by wastewater.
Water treatment works are inadequate when it comes to removing human drugs passed through urine because they focus on solid matter and disease-causing bacteria, Dr Aga said.
“These plants are focused on removing nitrogen, phosphorus, and dissolved organic carbon but there are so many other chemicals that are not prioritised that impact our environment,” she said.
“As a result, wildlife is exposed to all of these chemicals. Fish are receiving this cocktail of drugs 24 hours a day, and we are now finding these drugs in their brains.”
The rock bass fish had the highest concentrations of antidepressants, but several other species including the largemouth bass, rudd and bowfin had a build-up of drugs in their brains.
One in six Americans ((16.7 per cent) take a psychiatric drug, with anti-depressants the most common kind, according to the Journal of the American Medical Association.
The chemicals are not believed to be a threat to humans as fish brains are generally not eaten.
London News & Search