The World Health Organisation on Mercury
Key facts
- Mercury is a naturally occurring element that is found in air, water and soil.
- Exposure to mercury – even small amounts – may cause serious health problems, and is a threat to the development of the child in utero and early in life.
- Mercury may have toxic effects on the nervous, digestive and immune systems, and on lungs, kidneys, skin and eyes.
- Mercury is considered by WHO as one of the top ten chemicals or groups of chemicals of major public health concern.
- People are mainly exposed to methylmercury, an organic compound, when they eat fish and shellfish that contain the compound.
The WHO recognises that Mercury is one of the top 10 greatest public health concerns. They further recognise that that it may have toxic effects on the nervous, digestive and immune systems, even in small amounts.
Their fact sheet highlighted the events in Minamata, Japan between 1932 and 1968. A factory producing acetic acid poured large amounts of mercury in the water system as a by product of waste. At least 50 000 people were affected to some extent and more than 2000 cases of Minamata disease were certified. Minamata disease peaked in the 1950s, with severe cases suffering brain damage, paralysis, incoherent speech and delirium.
Health effects of mercury exposure
Elemental and methylmercury are toxic to the central and peripheral nervous systems. The inhalation of mercury vapour can produce harmful effects on the nervous, digestive and immune systems, lungs and kidneys, and may be fatal. The inorganic salts of mercury are corrosive to the skin, eyes and gastrointestinal tract, and may induce kidney toxicity if ingested.
Neurological and behavioural disorders may be observed after inhalation, ingestion or dermal exposure of different mercury compounds. Symptoms include tremors, insomnia, memory loss, neuromuscular effects, headaches and cognitive and motor dysfunction. Mild, subclinical signs of central nervous system toxicity can be seen in workers exposed to an elemental mercury level in the air of 20 ?g/m3 or more for several years. Kidney effects have been reported, ranging from increased protein in the urine to kidney failure.
How to reduce human exposure from mercury sources
The WHO go on to make a few recommendations on how to reduce mercury, including the environmental reduction of mercury through industry. They include the following recommendation:
Phase out use of non-essential mercury-containing products and implement safe handling, use and disposal of remaining mercury-containing products.
Mercury is contained in many products, including:
- batteries
- measuring devices, such as thermometers and barometers
- electric switches and relays in equipment
- lamps (including some types of light bulbs)
- dental amalgam (for dental fillings)
- skin-lightening products and other cosmetics
- pharmaceuticals.
To date we have seen an elimination of mercury in batteries, thermometers, switches, lamps, and skin products. What we HAVE NOT seen is any attempt to phase out mercury amalgams and that used in pharmaceuticals. Why might that be? We suspect interest groups with deep pockets are more focused on the bottom line than in public health!!!