Mercury is a natural element that occurs throughout our solar system. It can be found in small concentrations in many rocks and is the main component of the mineral cinnabar. Natural background levels can be detected in soils, air, and water around the world.

Historically, mercury has been used by many cultures for a variety of symbolic purposes, such as in good luck charms and to ward off evil. Mercury played a predominant role in alchemy, and was thought to have medicinal uses such as curing syphilis in the 19th century. While the majority of these practices are no longer followed, mercury may still be used in certain regions of the world in artisanal jewelry and trinkets for tourist sales, in small-scale gold mining processes, and can be a significant source of pollution in areas surrounding active and inactive mercury mines.

Although humans have extracted and utilized mercury for centuries, mining and industrial applications for the metal have increased significantly since the industrial revolution. In Canada, mercury releases can typically be attributed to waste incineration, coal combustion, base metal smelting, and the chlor-alkali industry. Despite mercury's toxic nature, humans have taken advantage of its unique properties to produce various consumer products, such as fluorescent lights and dental amalgam. Consequently, the amount of mercury mobilized and released due to human activities has greatly increased, leading to elevated concentrations in air, water, soil, sediments, and living organisms.