MONTREAL -- Arsenic levels in some parts of Montreal’s east end were above the provincial standard last year—but the levels are still good news overall, says the city’s public health department.

That's because they've dropped from two years ago, when the problem was first flagged.

A new report says recent air sampling shows that measures put in place at the CCR copper refinery have worked, said Dr. David Kaiser of Montreal Public Health.

The company was asked to reduce arsenic emissions after an earlier report in 2018 showed they exceeded provincial air standards because of the refinery’s operations.

At the time, residents were told not to worry because even though the levels were above the norms, they were still very low and not a risk to human health.

In high enough concentrations, exposure to manmade arsenic can cause a variety of health problems, including cancer.

After the 2018 report, three sampling stations were installed in the east end, and they recorded declining arsenic emissions through 2019, though at two of the three they’re still not below the standard.

The new cause for worry is whether arsenic emissions are also coming from elsewhere in the east end and not just the refinery. The City of Montreal has launched an investigation to investigate where else they could be coming from. 

Still, the city maintains that there’s no health risk.

Watch the video above to see Dr. David Kaiser’s full interview.