Try to reduce your exposure to all forms of mercury whenever possible.

The health effects of mercury exposure depend on its chemical form, the route of exposure, and the level of exposure.

What is mercury?

Mercury is a naturally occurring element which is the only metal that is a liquid at room temperature. Mercury was traditionally used in common household items such as thermometers, thermostats and fluorescent light bulbs. Mercury is a heavy silver-white metal which exists in different forms with varying toxicity.

Methylmercury is a common organic form that is more toxic than the elemental form. The largest source of mercury is industry and human sources, while natural sources such as volcano eruptions and soils and rocks contain it as well.

How does mercury accumulate in the body?

Methylmercury has the ability to bioaccumulate in cells and tissues. Bioaccumulation of methylmercury is due to its ability to pass the cell membrane and build up within tissues over time. Additionally, mercury can be taken up by other animals when ingested during predation, resulting in higher food chain predators potentially having higher mercury levels.

What are the health impacts of mercury?

The health effects of mercury (Health Canada) exposure depend on its chemical form (elemental, inorganic or organic), the route of exposure (inhalation, ingestion or skin contact) and the level of exposure. Vapour from liquid elemental mercury and methylmercury are more easily absorbed than inorganic mercury salts and can cause more harm. You should try to reduce your exposure to all forms of mercury whenever possible.

How can I reduce my risk of mercury exposure?

Elemental mercury from dental fillings does not generally pose a health risk. However, Health Canada does suggest that when the fillings need to be repaired, you may want to consider using a product that does not contain mercury. Pregnant women, people allergic to mercury and those with impaired kidney function should avoid mercury fillings. The primary teeth of children should be filled with non-mercury materials.

Follow Health Canada’s fish consumption advice in order to enjoy the health benefits of eating fish while controlling exposure to mercury. Predatory fish such as shark, swordfish, fresh and frozen tuna have higher levels of mercury and should be consumed only occasionally. Certain groups (young children, women who are or may become pregnant) should also limit their consumption of canned albacore (white) tuna.

If you eat sport fish, follow the Ontario sport fishing guide in order to control your exposure to mercury.

Because mercury is toxic, even small mercury spills should be considered hazardous and cleaned up carefully (Environment Canada). Products containing mercury should be disposed of properly.

Some commonly used consumer products contain mercury. To find more information about mercury-containing products and what alternatives exist, visit Environment Canada’s mercury-containing products page. Using fluorescent lamps, which contain small amounts of mercury, can reduce energy consumption and decrease overall mercury emissions, as long as they are recycled properly.

For more information:

If you would like to speak to a public health inspector about mercury, you can submit your question or complaint electronically or call 705.522.9200, ext. 464 (toll-free 1.866.522.9200).

This item was last modified on August 16, 2019