Pollutant Information: Mercury 

About Mercury

Category: Heavy metals and base cations

Acute exposure to high levels of elemental mercury vapour can lead to irritation of the lungs as well as causing coughing, chest pain and shortness of breath. High levels can also result in central nervous system (CNS) effects such as tremors and mood changes. Chronic exposure also leads to CNS disorders, with effects such as increased excitability, excessive shyness and irritability.

Emissions have declined by 86% since 1990. The main sources are coal use in public electricity and heat production and industrial combustion, iron and steel production processes, waste incineration and the manufacture of chlorine in mercury cells. Emissions have declined as a result of improved controls on mercury cells and, subsequently, their replacement by diaphragm or membrane cells, and the decline of coal use. The large reduction in between 1993 and 1996 is due to improved abatement at crematoria and because of improved standards at MSW incinerators. The large reduction in waste emissions from 1997 onwards is because sites incinerating MSW were modified so as to generate electricity at this time and so are classified as power stations from then on. However, the emissions from these sites were also significantly reduced at this time through better emission control.

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Time series graph


Notable events

Start year End year Sector Information Impact
1992 1996 Waste Incineration Municipal Solid Waste (MSW) incinerators not meeting the new standards closed in the period leading up to December 1996. Improved abatement at waste incineration plant from 1993 (and requirement to including heat recovery/electricity gen.) Decrease in emissions
1993 1996 Waste Incineration Improved abatement at crematoria. Decrease in emissions
1993 1998 Production Processes Decline in emission due to abatement and declining activity in Chloro Alkali and metal industry Decrease in emissions
1984 1985 Combustion in Energy and Transformation Industry 1984 miners' strike led to a significant decrease in the use of coal for combustion in electricity generation. A noticeable dip in emissions from coal-fired combustion sources in 1984 but increase in use of alternative fuels (e.g. Oil) and resulting emissions of pollutants (Cadmium & Lead). Decrease in emissions
1984 1985 Other stationary combustion 1984 miners' strike led to a significant decrease in the use of coal for combustion in electricity generation. A noticeable dip in emissions from coal-fired combustion sources in 1984 but increase in use of alternative fuels (e.g. Oil) and resulting emissions of pollutants (Cadmium & Lead). Decrease in emissions
1999 2011 Chemical Industry Tightening emission controls for the chemical industry under IPPC enforced by the Environment Agency and Defra. Decrease in emissions
1990 2011 Combustion in Energy and Transformation Industry Deregulation in the use of gas for electricity production. Increased use of Combined Cycle Gas Turbine (CCGT) stations and other gas fired plant rather than coal for electricity generation. Decrease in emissions