Record levels of mercury released in Arctic: study

Thawing permafrost in the Canadian Arctic as a result of climate change is releasing unprecedented levels of toxic mercury into the country’s waterways, according to research by three University of Alberta graduate students.

The study focused on eight different thaw slumps in the Northwest Territories measuring samples both up and downstream to determine the amount of mercury in the water, co-lead researcher Kyra St. Pierre said from Denmark Tuesday morning.

Results found mercury concentrations of 1,200 nanograms per litre, drastically higher than the last known Canadian record of 18 nanograms per litre measured in 2016.

“Earlier this year there was a study that came out showing permafrost regions around the world contained more mercury than anywhere else on the planet,” St. Pierre said. “The concentrations themselves are concerning just with how high they are.”

The team’s findings were recently accepted by the Environmental Science & Technology journal and will be published in a future issue, but St. Pierre said their work doesn’t end there.

With most of the mercury found in particle-bound form, St. Pierre said the big question that remains is how this affects organisms because it is unknown if the contaminant can be consumed in this form.

“Looking at whether the mercury attached to these particles is available to eat and consume,” St. Pierre said are the next steps.

If it can be consumed in this solid form, large quantities can be toxic to humans and animals because it has the ability to accumulate in organisms and food webs, she said.

“Climate change is changing the way that these freshwater ecosystems are functioning. We never used to see these slumps really developing to the same scale in the past. Mercury previously stored in soils is now being reactivated into our modern chemical cycles and into modern ecology,” St. Pierre said.