Mercury

Definition of mercury: Mercury is a chemical element with the symbol Hg and atomic number 80. It is a liquid (at room temperature and atmospheric pressure) heavy metal. This is the common definition for mercury, other definitions can be discussed in the article

Notes

Natural mercury derives from the weathering of mercury-bearing rocks, volcano's and hydrothermal vents. It's industrial use includes electronics, light bulbs and thermometers. Within these products, mercury doesn't pose a health problem. However when vaporised into the air by factories producing these products, it can be deposited in soils, and be flushed through rivers towards the ocean. Once deposited in anoxic soils, mercury is transformed by bacteria to methylmercury. Methylmercury has the tendency to bioaccumulte into animals and to biomagnify through the food chain.

In the Northern hemisphere anthropogenic sources have largely been eliminated since the 1980's. Mercury is the only contaminant (apart from pathogens) that certainly has been responsible for human deaths.. In humans mercury can cause:

• Disruption of the nervous system
• Damage to brain functions
• DNA damage and chromosomal damage
• Allergic reactions, resulting in skin rashes, tiredness and headaches
• Negative reproductive effects, such as sperm damage, birth defects and miscarriages

See also

Mercury pollution Methyl mercury Minamata disease