Air

Mercury

Mercury is a toxic element that enters the environment from natural processes (such as volcanic eruptions, vapor from oceans and the weathering of soils and rocks) and human activities (such as metal smelting, coal combustion, incineration of municipal waste).

After entering soil or precipitation, mercury compounds can be converted by bacteria or chemical action to a more toxic, organic form (methylmercury) and deposited in lakes, rivers and streams. This accumulates in fish tissue and becomes more concentrated as it moves up the food chain.

Human exposure to methylmercury occurs through eating contaminated fish. In sufficient doses, mercury can cause neurological and developmental damage to humans and wildlife. In northern areas, First Nations communities have reduced their consumption of fish because of perceived or actual risks of mercury contamination.

As the risks of mercury become more apparent, governments are working with industry to develop different policies and regulations to lower man-made mercury emissions.

Mercury has been identified as a toxic substance under the Canadian Environmental Protection Act. Federal, provincial and territorial governments are now developing a Canada-wide standard to limit mercury emissions from industrial, municipal and other emission sources.

Because some mercury emissions can be carried long distances by winds, federal and provincial governments in Canada are working with their counterparts in the U.S. on ways to manage cross-border mercury emissions.