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Coal mine contaminants blown onto snowpack in Alberta, B.C.: study

Generic image of snowback in Alberta. (CTV News) Generic image of snowback in Alberta. (CTV News)

Cancer-causing chemicals are being blown downwind from coal mines in southern British Columbia in concentrations that rival those next to oilsand mines, newly published research has concluded.

"Our results reveal, for the first time, clear evidence that coal mining contaminants are spread far downwind from their sources," says the paper, published in the journal Environmental Science and Technology.

The research, conducted by scientists from the Alberta government and the University of Alberta, studied the snowpack around four coal mines in British Columbia's Elk Valley. They sampled 23 sites at varying distances from the mines in 2022 and 2023, melting a surface-to-ground column of snow and analyzing the results.

"In a winter snowpack, you're capturing everything that's being deposited as long as that snowpack is on the ground," said Kira Holland, a University of Alberta postgraduate researcher. "It provides an amazing record for a season."

When analyzed, the melted snow proved high in polycyclic aromatic compounds, a class of chemicals closely associated with fossil fuels. So-called PACs are considered to cause cancer as well as damage the liver and immune system.

Their distribution in the snowpack matched prevailing wind patterns, with samples nearer a mine yielding higher levels, and their composition matched that found in Elk Valley coal.

"We found the snowpack had particularly high PACs," Holland said. "The pattern of deposition looks like very high concentration near these mining sites that decrease with distance."

Alberta's environmental guidelines for PACs in rivers and lakes range between .015 micrograms and 5.8 micrograms per litre of water, depending on the specific chemical.

One site in the study recorded 100 micrograms per litre. Another six sites showed at least 10 micrograms and seven showed at least one microgram.

Those levels are in the same range as those found adjacent to oilsands mines in northern Alberta, Holland said.

"The magnitude of the deposition is similar."

The study also considered how far the chemicals might travel. Using airshed modelling, it suggests the PACs could be travelling more than 100 kilometres east into Alberta, although it doesn't say how high those concentrations might be.

The results should encourage more research on the health and environmental impact of those chemicals, Holland said.

"PACs are not just affecting the environment. They're affecting communities ... who are constantly being exposed to coal dust. There haven't been any community-based health monitoring studies in the Elk Valley."

The study echoes previous findings led by the same scientist, Colin Cooke at Alberta Environment and Protected Areas. In November, Cooke published research that found coal dust had contaminated an alpine lake that is near coal mines but otherwise unconnected.

The new study comes as Alberta's energy regulator prepares for hearings on Northback Holdings' applications for coal exploration at Grassy Mountain in southwest Alberta, near the Elk Valley. The regulator is currently deciding on what level of participation should be granted interveners, based on how directly and adversely affected they are.

One of those interveners awaiting a decision is the Pekisko Group, made up of local ranchers. They have produced a modelling report that also aligns with the new paper, showing coal mining impacts spread far beyond the mine's immediate vicinity and well into grazing lands.

Laura Laing, who ranches in the area but isn't a member of Pekisko, said the increasing body of research suggests the regulator should draw its circle widely.

"The impacts of coal affect all Albertans," she wrote in an email. "An Australian coal company has no right to say we aren’t impacted by their intentions to explore and develop a coal mine on Grassy Mountain."

This report by The Canadian Press was first published June 19, 2024.