According to a recent study by public health authorities, the company’s Horne Smelter located in Rouyn-Noranda, Canada, has been emitting 165 nanograms of arsenic per cubic metre of air on-site.
This emission is 55 times more than the standard safe level of three nanograms.
Boileau said the emission level must be brought down to 15 nanograms immediately, citing evidence that the toxic spill poses the risk of cancer and other health issues.
The official added: “At a threshold of 15 nanograms, the protection objectives will be achieved. It reduces the risk of lung cancer for the general population.”
In response, Glencore spokesperson Alexis Segal said: “We take note of the recommendation issued today by the National Director of Public Health regarding air quality in Rouyn-Noranda, and are sensitive to the concerns expressed about the well-being of the community.
“We are more determined than ever to minimise our environmental footprint and offer our full cooperation to reduce our emissions to a minimum.
The mining company will prepare an action plan in this regard ‘in the coming days’.
While Quebec’s Environment Ministry has been keeping tabs on Glencore’s plan to reduce emissions, Quebec Premier Francois Legault has said the plant will be shuttered if the company fails to act.
The Horne Smelter has been operational in the region since 1926.
According to Glencore, the plant adds $389.54m (C$500m) to Quebec’s gross domestic product, and generates more than 650 direct and 1,850 indirect jobs.
The company plans to invest $1.2bn (C$1.5bn) in the plant over the next decade to bring down arsenic and greenhouse gas emissions.