A new report by an environmental advocacy group has found pesticide residues in drinking water in more than 30 Quebec municipalities, including a widely used chemical compound considered among the most impactful on the environment and human health. The report, which is the second of its kind by Vigilance OGM, highlights that although Quebec and Canadian standards have not been exceeded, concentrations of a pesticide metabolite, metolachlor ESA, did exceed European standards in Montreal, Longueuil, and five other cities in the province. In a recent interview, Thibault Rehn, the executive director of Vigilance OGM, explained that Quebec standards are based on assessments conducted by Health Canada, which establishes what the group describes as a toxicological standard, while standards in Europe are based on the precautionary principle. “[The concentrations] is still legal because the Quebec government bases their standard or evaluations in general on Health Canada and the concern with Health Canada is that they have standards based on the studies from the [agriculture] industry,” Rehn said. “And the problem with studies by the industry is that they are not transparent, not peer-reviewed, and we can’t base our standard through a science that is not transparent for us.” He added that the precautionary principle in Europe is a science-based framework used to protect populations and ecosystems when there are gaps in scientific knowledge regarding how a mixture of pollutants affects public health and nature. “We say that it’s impossible to evaluate the impact of all pesticides that you drink, that you have in your diet. So let’s try to put the bar very low. In Quebec, we put it very high because we base our standard through Health Canada, and for us, it’s not science-based because this science is not transparent.” Rehn said agricultural activity around Montreal can help explain why metolachlor ESA was detected at levels exceeding European standards in Montreal and Longueuil. “In Quebec, more than 70 per cent of the drinking water comes from rivers. In Quebec, we take water from the St. Lawrence River. Since the majority of agriculture is around Montreal, all the rivers go, at the end, into the St. Lawrence. And if we take this water from the St. Lawrence, for sure we will have a certain amount of pesticides,” Rehn said. The report also found that drinking water in Saint-Césaire, Que., had the highest total pesticide concentration, reaching 2,103 ng/L, more than four times the European limit. Rehn noted that it was very difficult to link the pesticide concentrations found in drinking water to specific disease diagnoses. He said, however, that many independent studies have shown a link between high levels of pesticide exposure and chronic illnesses such as Parkinson’s disease and certain forms of cancer, particularly blood cancers. According to the executive director, the Quebec government officially recognized Parkinson’s disease as an occupational illness related to agricultural pesticide use in 2019. The group is now calling on the next Quebec government to reduce the province’s “excessive use” of pesticides. “Secondly, we want a monitoring of the pesticide. You know the CAQ government has cut monitoring of water quality, and we want it back,” he said. “And third, we want a science-based evaluation for the standard. And it has to be on peer review, transparent, independent science, and independent from the industry; otherwise, is not considered as science for us.” With files from CTV News’ Max Harrold
