Instead of being complacent, we should be looking at ways to treat our drinking water to remove “down the drain” chemicals, says a Trent University professor who has conducted experiments showing that they can affect the reproduction of fish.
Chris Metcalfe warns that such chemicals as estrogens, personal care products and pharmaceuticals often remain unchanged through waste water treatment, then are discharged into rivers and lakes such as Okanagan.
He’s done studies both in-lake and in the lab in Ontario that showed they have impacts on aquatic organisms in very small quantities.
Impacts included doses as small as five parts per trillion, which, when added to a lake in Northern Ontario, affected zooplankton and algae, caused reproductive failure in frogs and fathead minnows and feminized lake trout.
As well, he says they took samples of white perch from the Great Lakes and there was evidence of intersex in the gonads, with egg cells in the testicular tissue.
Although they don’t know the source for certain, it was likely chemicals released in waste water discharged into the lakes, he said.
In fish, such anti-depressants as serotonin control reproduction, while they regulate spawning in bivalves and egg-laying in gastropods, he said.
Estrogenic compounds can come from sewage, surface cleaners, detergents, scents and fragrances, mouthwash and anti-bacterial soaps. As far as pharmaceuticals are concerned, he noted our bodies only use 30 to 50 per cent of the drugs and the rest is peed out and ends up in waste water treatment plants, and then the environment.
Primarily, he said, such treatment plants separate the solids from aqueous and discharge the latter into the environment. They’re designed to remove conventional pollutants, not what he calls “down the drain” chemicals.
He says we should be concerned both about the impact of biosolids that are applied onto agricultural land or into landfills and about releases into surface waters, both because of their uptake by aquatic organisms and because often waste water is recycled back into our bodies as drinking water.
As well, he said such chemicals as bisphenol A, or BPA, which is added to polycarbonate plastics and resins that coat the inside of fruit tins, leach compounds into the liquid which can be harmful.
Last week, under the federal government’s Canadian Environmental Protection Act, BPA was declared toxic and this week, the government banned its use in plastic baby bottles.
Hormones and synthetic hormones, found in thyroid replacement medication, analgesics and anti-inflammatories, antibiotics, antacids, lipid regulators, Beta blockers, anti-depressants, and such illegally-used drugs as cocaine and methamphetamines, are all of concern in waste water discharges, he said, because of their potential environmental impacts.
On human health, there is a concern about creation of antibiotic resistance, he noted.
Recycling of such drugs from waste water into drinking water he called “drugs on tap” although he said most are not in quantities that accumulate to equal even a normal human dose.
However, he said there are concerns about the possible adverse effects of mixtures of chemicals; the impacts on people with drug allergies; and their impacts on infants and pregnant women.
Research is now underway in the Okanagan to learn what unknown compounds are being released from waste water treatment plants into the lake.
In the meantime, Metcalfe suggested we can all make some value decisions to try and reduce the amount of such chemicals that go into the environment. For instance, no pharmaceuticals should be flushed directly down the toilet. There is a provincial disposal program and most pharmacies will take unused medications back.
Such products as anti-bacterial soap aren’t necessary and some chemists recommend people simply don’t use it for everyday cleaning.
We should also be making an effort to move toward better treatment of domestic sewage before discharging it into the environment, he said, and compounds like BPA, which are known to have harmful effects, should be government regulated.
Metcalfe was speaking at the three-day One Watershed—One Water conference in Kelowna this week, put on by the Okanagan Basin Water Board and the Canadian Water Resources Association.