Sometime we failed to understand the real face of the people until time reveals it or we have do some research. Mercury is the perfect example.
Yes, once celebrated as Hero (medicinal and many industrial uses) but now it was prohibited in many industries (Villain) and also poses risk towards environmental emissions and health.
On periodic table, it has the symbol of Hg and its atomic number is 80. It exists in several forms
1) Elemental mercury
2) Inorganic mercury component
3) Methylmercury and other organic component
Elemental mercury
Shiny, silvery-white metal and liquid at room temperature. Exposed elemental mercury can evaporate to became an invisible, odourless toxic vapour, if heated it is colourless, odourless gas at room temperature.
Elemental mercury is an element that has not reacted with another substance. When mercury react with another substance, it becomes a compound such as inorganic mercury component or organic mercury component.
It is used in older thermometers, fluorescent light bulbs and some electrical switches.
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| Thermometer |
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| Tilt switch working |
Inorganic mercury component
Occurs abundantly in the environment as minerals cinnabar and metacinnabar.
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| Cinnabar |
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| Metacinnabar |
It will readily combine with chlorine, sulfur and other elements to form inorganic salts. Although the use of mercury salts in consumer products such as medicinal products discontinued (mercurous chloride in laxatives, worming medicines and toothing powders). Still widely used in skin lightening products (soaps & creams). Mercury chloride - Hg2Cl2 is used in photography, topical antiseptic, disinfectant, wood preservative and fungicide.
Human exposure to inorganic mercury salts can occur both in occupational and environmental settings.
Methylmercury
Inorganic mercury salts can attached to airborne particles and then rain and snow deposit on the particles, then to land and redeposit. series of cycles between mercury, water and land with various chemical and physical transformation with the help of micro-organism, mercury will be converted into organic mercury. Methylmercury is the predominant organic component found on the environment and it is highly toxic.
Impact to the environment
Mercury becomes a problem for the environment when it is released from rock and ends up in water & atmosphere. Volcanoes and forest fire are the responsible for natural emission in to atmosphere.
Human activities are more burning fuel that contains mercury on power production, burning mercury containing wastes like electronics, results in higher emission.
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Methylmercury formation - Organic way
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People exposure to Mercury
People are exposed to mercury by consuming fish and shellfish that have high levels of methylmercury(high toxic form of mercury). Not all the fish contains methylmercury, when people eating high mercury level fish it is advised to diversify their foods and periodic consumption is recommended (say 2 weeks once) and as long as we can limit the mercury level on the body no major impact. Eating these fish food's during women's pregnancy time and feeding to young child is not advisable since it poses major health risk.
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| Mercury level in various fish |
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