Cancer from arsenic exposure in Rouyn-Noranda 'unacceptable' risk: Quebec public health director

Quebec’s top public health officer says “it is unacceptable” for the Horne copper smelter in Rouyn-Noranda to continue emitting toxic arsenic and cadmium at the levels it now does, given the increased cancer risk to people who live nearby.

Horne copper smelter belched 30 times more arsenic last year than Environment Ministry deems safe

A man sitting at a table during a news conference.
Quebec's public health director, Dr. Luc Boileau, was in Rouyn-Noranda Wednesday to present the INSPQ's findings into the cancer risk of emissions from the Horne copper smelter. (Annie-Claude Luneau/Radio-Canada)

Quebec's top public health officer says "it is unacceptable" for the Horne copper smelter in Rouyn-Noranda to continue emitting toxic arsenic and cadmium at the levels it now does, given the increased cancer risk to people who live nearby.

Dr. Luc Boileau weighed in on the debate over toxic emissions from Canada's only copper smelter in the wake of a new study by Quebec's public health institute, the INSPQ. 

That study found the 23,000 people living in the core of the city in the Abitibi-Témiscamingue region have a significantly higher risk of developing lung cancer than people who are not exposed to arsenic or cadmium emissions.

If exposure to the toxic emissions stays the same as it has been for the past 30 years, the region would see an additional one to 14 cases of lung cancer per population of 23,000 over a 70-year period, the study concluded.

"These are numbers that, when we look at them, can appear, for many, small," said Boileau.

However, when scaled up to determine the risk to a population of one million, that would represent 13 to 554 additional cases of lung cancer over the same time frame, Boileau explained.

"We largely surpass the risks that are normally acceptable," he said. Quebec health authorities consider the risk to be negligible when there is only one additional case of cancer per million people, Boileau said.

The Horne smelter, which has been operating since 1925, is the main emitter of arsenic and cadmium in the city, located 630 kilometres northwest of Montreal.

A residential street with a smelter at the end of the street.
The 97-year-old Horne smelter, the only copper smelter in Canada, is located in the residential neighbourhood of Notre-Dame, in Rouyn-Noranda, Que. (Jean-Michel Cotnoir/Radio-Canada)

Search on for ways to cut emissions

Just last year, the smelter reported an average annual concentration of arsenic of 87 nanograms per cubic metre (ng/m3) — nearly 30 times more than the 3 ng/m3 that the Quebec Environment Ministry considers safe.

Boileau's comments Wednesday come just as Glencore Canada, the company that operates the smelter, is renegotiating a certificate with the province that would allow the Horne smelter to continue to exceed the government's recommended emissions threshold.

Until now, the province has allowed the aging smelter to emit up to 33 times more arsenic than the provincial limit, with the understanding that Glencore will find ways to gradually reduce emissions.

Claude Bélanger, the general manager of the smelter, said the company should have acted sooner to reduce emissions. He also recognizes the need to improve communication with citizens.

"We take full accountability for reducing our emissions. We know that we can do a better job in that regard," he said.

A man talking to a Radio-Canada reporter
The Horne smelter's general manager, Claude Bélanger, said his company should have acted sooner to reduce its emissions. (Radio-Canada)

Bélanger said the smelter has many concrete plans to reduce emissions to the "lowest levels" it can, but he did not specify what quantity that is or whether the company would be able to reach the threshold considered safe by the government.

He said reducing emissions is a project that will cost hundreds of millions of dollars and will require financial help from the Quebec government.

He said for now, some of the solutions include buying more of the properties around the smelter to create a large buffer zone.

The smelter is also working on a pilot project that would use new technology to cut emissions by 10 to 40 per cent.

But even if its emissions were to be reduced to the threshold considered "safe" by the Quebec Environment Ministry, the lung cancer risk to the surrounding population would still not be zero, according to the INSPQ.

'All options are on the table': Premier Legault

Boileau said he understands that the situation is worrisome. He said his job is not to make decisions on what the Horne smelter should do, but to provide people with facts.

He said the risk analysis continues, although he does not think the risk is so great that it would warrant closing the smelter, which employs more than 620 people in the region.

At a news conference Tuesday, Quebec Premier François Legault said he would be willing to go as far as to close the Horne smelter if it fails to come up with a way to reduce arsenic emissions to a level that is considered safe.

"All options are on the table," Legault said. "What is very important is to make sure that the health of citizens [is] secure."

Quebec's environment minister, Benoit Charette, said his government is negotiating an emission target with the smelter that would reduce the public health risks as much as possible.

"If the company tells us 'technologically it's not possible' but that public health tells us, 'There's a danger for the population,' that's where a closure could be considered,'' he said.

Actions needed now

For Maude Letendre, what's important is to act now.

"We know that the risk is already there, so why wait?" she asked. "They should have moved before. Some decisions should have been made a long time ago, and nothing was done."

A couple embracing in their home.
Maude Letendre and her partner Daniel Tardif, pictured here when they still lived in Rouyn-Noranda, moved to the Gaspé Peninsula because they were worried about the risk arsenic emissions posed to their children's health. (Jean-Marc Belzile/Radio-Canada)

The mother of two used to live in Rouyn-Noranda, but she and her partner decided to move away after a 2019 public health report showed that children in the city had 3.7 times more arsenic in their bodies than children elsewhere in the province.

"We were too scared for our children," she said. "I actually do not live in Rouyn-Noranda because of the arsenic emissions — it's only for that."

Although she's now living in the Gaspé, Letendre is still actively involved in a citizens' group called Comité Arrêt des Rejets et Émissions Toxiques de Rouyn-Noranda, which lobbies to end the toxic emissions.

She said the committee understands the economic importance of the smelter and is not necessarily advocating for a permanent shutdown, but she said it wants the smelter to reach the safe threshold of 3 ng/m3 if it is to continue operating.

Last Sunday, a group of about 50 doctors and public health officials signed an open letter urging Legault to crack down on the emissions.


Émilie Warren

Regional reporter

Émilie Warren covers regional stories across the province of Quebec for CBC news in Quebec City. She has also worked as an intern reporter for the CBC in Vancouver and the Health Unit, and as an intern producer for World Report. You can reach her at

With files from Radio-Canada's Annie-Claude Luneau


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