Quantcast

Toxic Leftovers From Giant Mine Found in Snowshoe Hares

Animals
Snowshoe hares near the now closed Giant Mine outside of Yellowknife, N.W.T show signs of arsenic contamination. Denali NPS / Flickr / CC BY-SA

By Som Niyogi and Solomon Amuno

Even though it was closed decades ago, the Giant Mine on the outskirts of Yellowknife has left a long environmental legacy.


The gold extraction process, which required roasting ores at extremely high temperatures, created a toxic byproduct called arsenic trioxide. For about 55 years (1948-2004), arsenic and other toxic elements were released into the environment, causing widespread contamination of the terrestrial and aquatic ecosystems around Yellowknife.

About 237,000 tonnes of arsenic trioxide dust is buried underground, and several nearby lakes show arsenic contamination.

Elevated arsenic levels have also been reported in soil, vegetation and fish around Yellowknife, but we knew little about how it has affected the health of the small mammals that live in the area.

Many of these fur-bearing animals are still being trapped for their pelts and for food, so knowing their arsenic levels is also important for human health.

Weak Bones

Small mammals can serve as sentinels for environmental contamination. Snowshoe hares (Lepus americanus) live in a relatively small area and eat soil, so they are likely to accumulate higher levels of arsenic and other trace metals from the environment.

Exposure to elevated levels of arsenic can cause damage to the liver and other organs. And cadmium, a toxic metal and another byproduct of the gold extraction process, can replace calcium in the bones, leading to bone deformities and weakness.

In humans, chronic arsenic exposure (usually from water) can lead to changes in skin colour, skin growths and cancers of the skin, lung and internal organs.

When we measured arsenic and cadmium levels in hares living within two kilometres of the Giant Mine and compared them to hares living about 20 kilometres away from Yellowknife, the results were striking.

The arsenic levels in the guts of snowshoe hares living near the Giant Mine were 20-50 times greater than those living away from it. We also saw higher concentrations of arsenic in the organs and nails of the Giant Mine hares.

Cadmium levels were also higher but the difference wasn't as marked. Hares from both locations had weaker bones and showed signs of osteoporosis, probably due to chronic exposure to cadmium.

Ecological Implications

This chronic exposure to elevated levels of arsenic and cadmium may explain why snowshoe hares living near the Giant Mine are in poor health.

Wildlife living in metal contaminated areas in other parts of the world have also shown problems with reproduction, osteoporosis, neurological damage and chronic metabolic disease. But in Canada, it's the first time we've seen small wild mammals with chronic arsenic poisoning.

The high levels of pollutants could compromise the long-term survival of the snowshoe hare and other small mammals in the Yellowknife area.

The high arsenic and cadmium burden in hares could have consequences for other animals that prey on them, such as foxes, wolves or other carnivorous mammals, and for the people who hunt them.

Reposted with permission from our media associate The Conversation.


EcoWatch Daily Newsletter

The 16-year-old Swede Greta Thunberg speaks during her protest action for more climate protection with a reporter. Steffen Trumpf / picture alliance / Getty Images

By Mark Hertsgaard and Kyle Pope

It's been 30 years since Bill McKibben rang the warning bells about the threat of man-made climate change — first in a piece in The New Yorker, and then in his book, The End of Nature.

Read More Show Less
At the International Motor Show (IAA), climate protestors are calling for a change in transportation politics. © Kevin McElvaney / Greenpeace

Thousands of protestors marched in front of Frankfurt's International Motor Show (IAA) on Saturday to show their disgust with the auto industry's role in the climate crisis. The protestors demanded an end to combustion engines and a shift to more environmentally friendly emissions-free vehicles, as Reuters reported.

Read More Show Less
Sponsored
Setting and testing the line protections for Siemens SF6 gas insulated switchgear in 2007. Xaf / Flickr / CC BY-NC 2.0

Electricity from renewable sources is growing exponentially as the technology allows for cheaper and more efficient energy generation, but there is a dark side that has the industry polluting the most powerful greenhouse gas known to humanity, as the BBC reported.

Read More Show Less
Ella Olsson / Pexels

By Elizabeth Streit, MS, RDN, LD

Sweet and regular potatoes are both tuberous root vegetables, but they differ in appearance and taste.

They come from separate plant families, offer different nutrients, and affect your blood sugar differently.

Read More Show Less
Scientists in Saskatchewan found that consuming small amounts of neonicotinoids led white-crowned sparrows to lose significant amounts of weight and delay migration, threatening their ability to reproduce. Jen Goellnitz / Flickr

By Julia Conley

In addition to devastating effects on bee populations and the pollination needed to feed humans and other species, widely-used pesticides chemically related to nicotine may be deadly to birds and linked to some species' declines, according to a new study.

Read More Show Less
Sponsored

German Chancellor Angela Merkel's government is set to unveil a package of measures on Friday, Sept. 20, to ensure that the country cuts its greenhouse gas emissions 55% by 2030, compared with the 1990 levels.

Read More Show Less
Assorted plastic bottles. mali maeder / Pexels

California ended its 2019 legislative session Saturday without passing two bills that would have led the nation in tackling plastic pollution, The Mercury News reported.

Read More Show Less
People carry children on a flooded street in Almoradi, Spain on Sept. 13. JOSE JORDAN / AFP / Getty Images

Record rainfall and flooding in southeastern Spain killed six people as of Saturday, The New York Times reported.

Read More Show Less