Shocked by study, residents want more info on how to stay safe from arsenic released by wildfires

When Morgan Tsetta learned about the arsenic released from wildfires around Yellowknife, she says she was shocked. 

Already concerned about air pollution from inhaling smoke, she said learning that particles of arsenic were in the air gave her more reason to worry. 

A recent study published in Environmental Research Letters found fires near Yellowknife in 2023 released between 69 and 183 tonnes of arsenic into the air and water. 

Tsetta says it shows the continued impact of Yellowknife's Giant Mine. 

"All of the trees, the soil, the land has been contaminated by arsenic — and when that burns, it's a big concern for anybody impacted by abandoned mine sites," she said. 

John B. Zoe, a Tłı̨chǫ citizen and chairperson with Hotıı̀ ts'eeda, an N.W.T.-based research centre supporting culturally competent healthcare, agrees.

"The destruction that we've experienced in mining here for a very long time, it's still continuing," he said. 

The study's lead author, Owen Sutton, said that most of the arsenic released is "naturally occurring" from the soil and bedrock. He said the study is a kind of alarm to say that the amount of arsenic would only become more dangerous the closer the fire burned to the mine site.

Environmental toxicologist Jules Blais agreed there is arsenic around Yellowknife but said the arsenic released from the 2023 wildfires came from arsenic trioxide released from Giant before it faced pollution controls in 1951.

Sutton says his team's research leaves a lot of outstanding questions, including where the arsenic went after it was released.  

Bobby Drygeese, a member of Yellowknives Dene First Nation, said he's worried about how that could impact the food chain. 

"[If] it goes into the berries and the plants, the animals eat the berries  and then we eat the animals and we eat the berries too," Drygeese said. "Plus, if it goes into water, everybody's drinking water, everybody needs water to survive."

Zoe and Tsetta say there should be more information for how people can protect themselves from arsenic poisoning. 

Zoe said it would help to know if there are areas with high concentrations of arsenic that could be in the animals or plants that harvesters should avoid.