Ecosystem Monitoring

Thompson

The International Nickel Company Ltd. (Inco) established a mining and smelting facility at Thompson, Manitoba that began operation in 1961. The facility produces primarily nickel, with lesser amounts of copper and cobalt. Atmospheric emissions of concern associated with the Inco operation include nickel, copper, and sulphur dioxide.

Vegetation dynamics, snow, and soil are monitored periodically at several permanent sites near Thompson in order to assess the long-term effects of atmospheric emissions on tree growth, plant species composition and diversity, and snow and soil chemistry in the boreal forest ecosystem.

Long-term monitoring indicates that there has been a gradual accumulation of nickel and copper in forest soils in the vicinity of Thompson. These findings raised concerns that concentrations of copper, nickel and other elements might also be elevated in surface soils within the city. A joint survey was undertaken by Manitoba Conservation and Inco to determine the concentration of nickel and other elements in the surface soils across the community. The survey concluded that although nickel was elevated at some of the sites sampled, the risk of human health effects from exposure to surface soils was considered to be extremely low.