Mercury is toxic to human health, posing a particular threat to the development of the child in utero and early in life. Mercury exists in various forms: elemental (or metallic); inorganic (e.g. mercuric chloride); and organic (e.g., methyl- and ethylmercury), which all have different toxic effects, including on the nervous, digestive and immune systems, and on lungs, kidneys, skin and eyes.
It has been estimated that among selected subsistence fishing populations, between 1.5/1000 and 17/1000 children showed cognitive impacts caused by the consumption of fish containing mercury. Mercury releases in the environment result mainly from human activity, particularly from coal-fired power stations, residential heating systems, waste incinerators and as a result of mining for mercury, gold and other metals. Once in the environment, elemental mercury is naturally transformed into methylmercury that bioaccumulates in fish and shellfish.
Human exposure occurs mainly through inhalation of elemental mercury vapors during industrial processes and through consumption of contaminated fish and shellfish. Interventions to prevent environmental releases and human exposure include:
- eliminating mercury production and use in mining and industry;
- promoting use of clean energy sources that do not rely on burning of coal;
- switching to non-mercury thermometers and sphygmomanometers in health care; and
- implementing safe handling, use and disposal of mercury-containing products and waste.
Short information documents for decision makers
- World Health Assembly Resolution (May 2014) - Public health impacts of exposure to mercury and mercury compounds: the role of WHO and ministries of public health in the implementation of the Minamata Convention (English)
- Mercury Exposure and Health Impacts among Individuals in the Artisanal and Small-Scale Gold Mining Community: A Comprehensive Review
Mercury Exposure and Health Impacts among Individuals in the Artisanal and Small-Scale Gold Mining (ASGM) Community (English)
Tools for action
- 2015 Step-by-step guidance on phasing out mercury thermometers and sphygmomanometers
‒ 2011 Technical guidance on replacement of mercury thermometers and sphygmomanometers
Norms and guidance values
- Chemical hazards in drinking-water: Inorganic mercury
- Air Quality Guidelines: Inorganic mercury, pp157-161 (pdf)
- Dietary intake of methylmercury. Evaluation of certain food additives and contaminants (pdf)
Dietary intake of inorganic mercury. Evaluation of certain food additives and contaminants (pdf)
WHO Burden of disease estimates
- Mercury - Assessing the environmental burden of disease at national and local levels (pdf)
- Mercurio - Evaluación de la carga de morbilidad ambiental a nivel nacional y local