Taking birth control pills? You may be turning local fish into girls, says a scientist.
University of Alberta biologist Greg Goss gave a free talk on pharmaceuticals in the North Saskatchewan River Monday at the Art Gallery of Alberta. About 90 people attended. The talk, organized by the North Saskatchewan Watershed Alliance (NSWA) and the North Saskatchewan Riverkeeper, was one of several events connected to Canada Water Week.
Goss is a world-renowned environmental toxicologist who studies the effects of drugs on fish at the Gold Bar wastewater treatment plant.
He’s found plenty of drugs in Edmonton’s wastewater post-treatment, he says — caffeine, Prozac, triclosan and more. Today’s treatment plants aren’t designed to trap them, so they go right into our rivers.
One drug in particular, ethinylestradiol, is a powerful estrogen-like compound found in birth control pills. When he exposed male fish to that substance at levels found in Edmonton’s treated wastewater, the fish started growing ovaries. “If you take male fish and expose them to [this], you get female fish.”
There are about 3,300 drugs approved for use in Canada, Goss says, many of which last for a long time in water. “Our kidneys are very efficient at getting rid of drugs very quickly,” he says. “Depending on the drug, 70 per cent of the drug is peed out in the first half-hour.”
None of the contaminants Goss found in Edmonton’s wastewater exceeded provincial guidelines. The problem, he explains, is that there are a lot of contaminants: pesticides, herbicides, painkillers, hormones and more, many of which act on the same biological systems.
These drugs aren’t at levels that affect humans, but they do affect fish. “Whether we like it or not, humans and fish are pretty similar when it comes to what they respond to.”
A southern Alberta study found that drugs from Feedlot Alley caused female-male ratios in a nearby river to go from 50-50 to 10 to 1. “You have almost all females in your population.”
An Ontario researcher found that adding synthetic estrogen to a lake at levels found in that province’s wastewater caused the lake’s fish population to collapse. Other drugs found in Edmonton’s wastewater have been known to weaken immune systems and testosterone production in fish. “These drugs will not kill animals,” he says, but they do have an effect.
We have a responsibility to the people downstream of us to keep these drugs out of our wastewater, Goss says. “One person’s outflow is another’s drinking water.”
Treatment plants could catch these drugs with activated charcoal (found in many portable filters), Goss says, but you’d have to burn half the world’s forests to get enough of it. “The cost would be astronomical.”
His team is now testing membranes, UV light and nanomaterials to see if they can stop the drugs without making the problem worse.
We’re not going to stop using drugs, Goss says — indeed, as our population ages, we’ll probably use more — but we can use less of them. “The one that I really rail against is antibacterial soap,” he says, as it contains triclosan, which is an endocrine disruptor that can feminize fish. “Soap by itself is antibacterial. It doesn’t need triclosan in it.”
We can also dispose of our drugs properly. Only about 20 per cent of unused drugs are returned to pharmacies for proper disposal, he notes — the rest get chucked or flushed. “We could drop those [drug] levels substantially if we just said to people … do not flush your drugs down the toilet.”
Alberta is very lucky to have reasonably clean water in its rivers, Goss says. “Let’s keep it that way.”
