The owner of a western Quebec copper smelter says it will adhere to the government's new requirements and reduce arsenic emissions to five times the provincial norm by 2027.

The smelter in Rouyn-Noranda, Que., is owned by Switzerland-based Glencore and is currently certified to emit 100 nanograms of arsenic per cubic metre of air -- 33 times the provincewide standard.

Glencore's operations in the town more than 600 kilometres northwest of Montreal have been a cause for serious concern in the region after studies have shown that local residents have higher rates of lung cancer than the provincial average.

On Monday, Quebec Environment Minister Benoit Charette said the Horne smelter would have to reduce emissions to 15 nanograms of arsenic per cubic metre of air within five years or close.

The company said Thursday it expects that it will cost $500 million for it to adapt to the new emissions cap and that talks are underway to obtain government aid to fund the required changes.

Claude Belanger of Glencore's North American copper operations told reporters that a company analysis indicates that the air quality across the majority of the town will be at the provincial standard of three nanograms of arsenic per cubic metre by 2027.

- This report by The Canadian Press was first published on Aug. 18, 2022