Monday, March 1, 2010
Les pharmaceutiques dans les rivières
L'état du Maine est chanceux: des pharmaceutiques jetés dans les poubelles aboutissent dans les dépotoirs dont les jus de lixiviation sont amassés, traités dans des usines de traitement des eaux usées pour être ensuite être rejetés dans les rivières. Le Maine est chanceux parce que la plupart des habitants de cet état ne s'alimente pas en eau potable de ces rivières qui recoivent les eaux usées traitées.
Mais le Richelieu n'a pas cette chance. Il a des dépotoirs dans son bassin versant, et il reçoit les rejets de plusieurs usines de traitement des eaux usées. Et dans son bassin versant se trouve des hôpitaux, des CLSC, des CHSLD et des résidences pour personnes autonomes et semi-autonomes.
Autrement dit, il se consomme beaucoup de médicaments. Et même si les médicaments qui ne sont pas consommés sont jetés aux poubelles, il se pourrait très bien qu'une partie de ceux-ci aboutissent dans les rivières quand même! Et si l'eau potable est puisée d'une source d'eau de surface comme une rivière, on en boit aussi, même sans ordonnance!
"Even if you're careful, drugs can end up in water
PORTLAND, Maine — The federal government advises throwing most unused or expired medications into the trash instead of down the drain, but they can end up in the water anyway, a study from Maine suggests. Tiny amounts of discarded drugs have been found in water at three landfills in the state, confirming suspicions that pharmaceuticals thrown into household trash are ending up in water that drains through waste, according to a survey by the state's environmental agency that's one of only a handful to have looked at the presence of drugs in landfills.
That landfill water - known as leachate - eventually ends up in rivers. Most of Maine doesn't draw its drinking water from rivers where the leachate ends up, but in other states that do, water supplies that come from rivers could potentially be contaminated. The results of the survey are being made known as lawmakers in Maine consider a bill, among the first of its kind in the nation, that would require drug manufacturers to develop and pay for a program to collect unused prescription and over-the-counter drugs from residents and dispose of them.
Scientists and environmentalists have long known of the common presence of minute concentrations of pharmaceuticals in drinking water, either through human excretion flushed into sewers or leftover medicine thrown down the drain. Research shows that pharmaceuticals sometimes harm fish and other aquatic species, and that human cells can fail to grow normally in the laboratory when exposed to trace concentrations of certain drugs. The Maine Department of Environmental Protection found tiny amounts - measured in parts per trillion - of medications ranging from antidepressants and birth control pills to blood pressure and cholesterol prescriptions. The most prevalent drugs were over-the-counter pain relievers, including ibuprofen and acetaminophen.
Leachate at Maine landfills typically is piped or trucked to municipal wastewater treatment plants. Those plants are not equipped to remove drugs from the water before it is discharged into rivers and the ocean. The pharmaceuticals found in the landfills don't pose a direct threat to drinking water, Hyland said. The landfills are lined to protect groundwater supplies, and in Maine there aren't any wastewater plants that treat leachate and discharge into rivers that ultimately supply drinking water. But the leachate - in high enough concentrations - can pose a threat to fish and shellfish. Research suggests that hormonal drugs, such as birth control pills, tend to feminize fish. If the trend continues, Hyland said, there could be too few male fish to continue reproduction.
"Many larger states have big rivers that are used for both waste disposal and drinking water supplies, places like Ohio and Pennsylvania," Tolman said. "The same river gets used a number of times, and they're very concerned about treatment of sewage and leachate."
Excerpts from article written by Clarke Canfield of the Associated Press here: http://seattletimes.nwsource.com/html/businesstechnology/2011008317_apuspharmawaterlandfills.html