Hydroelectric dams put indigenous people at risk, study says
The Muskrat Falls project will cause a spike in toxic methylmercury in wild food sources that are crucial to Labrador communities, says a new Harvard University study of hydro dam effects on indigenous people.
“Methylmercury concentrations in locally caught fish, birds and seals — which nearby Inuit populations use as a source of food — likely will increase up to tenfold” in the dammed lower Churchill River, it says of Muskrat Falls.
“After flooding, expected mean methylmercury concentrations in lake trout, seal, tern eggs, brook trout and char liver are all projected to be at or above the Canadian retail limit for methylmercury.”
Average exposure to the neurotoxin for local Inuit “is forecasted to double following flooding, and over half of the women of childbearing age and young children in the most northern community (Rigolet) are projected to exceed the U.S. Environmental Protection Agency’s” guidelines, says the study.
The peer-reviewed paper was published Wednesday in the journal Environmental Science & Technology.
Methylmercury, formed when mercury blends with bacteria as vegetation rots under water, is a neurotoxin linked to cardiovascular and immune problems and hyperactivity in children. Health risks depend on who eats tainted foods, and how often.
When pregnant women, nursing mothers and young children eat too much contaminated seafood, there’s an increased risk of nervous system problems in the developing child.
Study co-author Ryan Calder said methylmercury risks could be lessened with more clearing of the reservoir area.
“The evidence suggests that removal of organic carbon — especially soil organic carbon from the flooded area — will reduce the extent to which methylmercury is produced after flooding,” he said in an interview.
The study forecasts equal or greater methylmercury concentrations for 11 other planned or proceeding hydroelectric projects across Canada.
That’s because indigenous populations in those regions typically consume even more country foods, it says.
All the developments assessed are within 100 kilometres of aboriginal communities. They include the Romaine Complex under construction in Quebec and the proposed Gull Island dam and power house in Labrador.
“We have to respect that local foods are a cornerstone of indigenous health,” Calder said. “It should be a priority in the development of these projects to preserve that.”
About 2,000 Inuit and other settlers living downstream from Muskrat Falls on traditional hunting grounds near Lake Melville have for years raised alarms about potential contamination.
The study projected methylmercury spikes using data from nine sites across three ecosystems, including soil samples from the Muskrat Falls reservoir site.
Satellite data to assess the organic carbon content of soil at other planned or imminent reservoirs helped researchers extrapolate results across Canada.