Danger Metal Mercury (Mercury or Hydrargyrum)

Chemical Properties of Metal Mercury (Mercury or Hydrargyrum) in Nature

Mercury occurs naturally in nature and occur in various forms. In pure form known as "metallic" mercury (Hg (O) or HgO). Mercury is rarely found in nature in pure form, in the form of molten metal, but in inorganic compounds and salts. Mercury can be bonded as a monovalent or divalent (also expressed as Hg (I) and Hg (II)). Many inorganic and organic compounds can be formed from Hg (II).
Several forms of mercury occur naturally, most often found are metallic mercury, mercury sulfide, mercury chloride and methyl mercury. Some micro-organisms in nature can change the nature of the mercury in the form of compounds to form other compounds.

Mercury as mercury sulfide (cinnabar ore). History mentions piles of cinnabar become the main source of mercury mining ore in the commercial. Metallic mercury is obtained by heating the ore at temperatures above 540 ºC. Ore of mercury will evaporate, and the vapors are then captured and cooled to form the liquid metal mercury.

The physical properties of mercury is a shiny, silvery white, are liquid at room temperature. Often used as a liquid in a thermometer and active power. If left in an open container, at room temperature metallic mercury will evaporate. Mercury vapor is white and odorless. The higher the temperature, the more vapors released from liquid mercury metal. Elements of mercury in the atmosphere can undergo transformation in the form of inorganic mercury compounds, allows the formation of deposits of mercury.

Among inorganic mercury compounds in mercury sulfide, HgS, mercury oxide (HgO) and mercury chloride (HgCl2). These mercury compounds are also called mercury salts. Physical manifestation in the form of crystals and white powder, except mercury sulfide, which is blackish red after exposure to light. Some mercury salts (such as HgCl2) are sufficiently volatile (volatile) found in the atmosphere.

When mercury is bound with carbon, which formed compounds called mercury "organic" or compounds organomercury such as methyl mercury, dimethyl mercury, phenyl mercury and ethyl mercury, but by far the most common as complex organic mercury is methyl mercury. Inorganic compounds of mercury compounds, both methylmercury and phenyl mercury in the form of "salt" (eg, methyl mercury chloride or phenyl mercury acetate). In a pure state, most of the compounds are white crystalline solid, except dimethyl mercury in liquid form.

Complex organic mercury is most commonly found in nature and can be processed by microorganisms into forms other compound is methyl mercury. Methyl mercury can accumulate through the food chain: freshwater fish, saltwater fish and marine mammals. The higher the position in the food chain, it also increase the concentration of methyl mercury.

As an element, mercury is important in life and also can be very dangerous chemicals. Mercury has been separated from mineral ores or from fossil fuels and minerals hidden in the earth and waste released into the environment, can very quickly spread among the Earth's surface and atmosphere. On the surface of the soil, water and sediments under a source of zinc mercury biosferic formation.

Mercury Source, Use and Emissions

The mercury released from volcanoes, evaporation from the soil and surface water, through mineral deposits and forest fires. However, it should be noted that emissions from soil and surface water from the sediment mercury existing in nature.

Mercury is also found in coal. Coal-fired fossil fuel used for electricity generation, emissions of mercury into the air in the world.

In addition, mercury available on the world market from several sources:

(1) The main Mine mercury (extracted from ores) are still available in some locations, especially in Algeria, Kyrgyzstan, and China, and the latest (2003) in Spain. Some of them are state-owned. There were also reports of small-scale mining of mercury in China, Russia (Siberia), Outer Mongolia, Peru and Mexico mainly serve local demand.

(2) Mercury occurs as a chemical determinant of mining other metals (such as zinc, gold, silver) or minerals, and natural gas processing.

(3) Reprocessing of tailings (waste disposal) Secondary derived from previous mining. Tailing is possible containing mercury.

(4) Recycling of mercury removed again from the products and waste from industrial processes.

* Organic industry support material as used in the chlor-alkali industry and other industries.

Examples of the use of mercury in our daily lives as metals, among others:

The extraction of gold and silver; as a cathode in a mercury cell chlor-alkali production process; electronic active electronic materials; essential ingredients in fluorescent lamps; eg light streetlights and some car headlights; thermometer; thermostat; manometers for measuring and controlling the pressure (sphygmomanometers); barometers and in amalgam for dental care

Metallic mercury is highly toxic, causing damage to the nervous system albeit at relatively low levels of exposure. It is especially dangerous to the developing fetus. Mercury accumulates in human and animal bodies and can be concentrated through the food chain, especially in certain types of fish. The Commission Directorate General for Health and Consumer Protection recommends that pregnant and nursing mothers should limit their consumption of large carnivorous fish (which prey on small fish) such as swordfish, shark, marlin, pike and tuna.

This is due to mercury at high risk for human health. According to the World Health organization (WHO), arctic south pole, which does not have the sources of mercury contamination, suffered dangerous contamination levels on marine mammals and other species, which is becoming groceries.

As chemical compounds such as the battery; vaccine (as a preservative in etilmercury form in thimerosal); biocide / fungicide in the paper industry, paint and wheat germ; in pharmacy as an antiseptic; reactants laboratory analysis; eg catalysts for vinyl chloride monomer product; pigments and dyes / paints; detergents, soaps and creams is as a bactericide bleach); and explosives.

The use of mercury has been reduced significantly in many industrialized countries, particularly over the last two decades. Although discontinued its use in OECD countries but is still used in other countries. Use of mercury has been banned or severely restricted in some countries because of its effects on humans and the environment.

In the European Union mercury is no longer used in detergents, soaps, paints, biocides, gold (except for French Guiana) and mercury content in the soap banned for export by Annex V of Regulation (EC) No 304/2003 of the European Parliament and the Council of January 28, 2003 concerning the export and import of dangerous chemicals (oJ L 63, 06.03.03, p 1-26).

Mercury into the environment (air, water and soil) mainly through the burning of coal; city ​​and medical waste incinerators; the production of iron and steel; cement production; production of chlor-alkali compounds; krematoria; gold mine; dental amalgams and mercury-containing waste bin; smelting and refinement of metallic ores; and the effects of mercury exposure (consumption in the food chain).

Mercury compounds are highly toxic to human life, ecosystems and wildlife. At high doses can cause death, but also a relatively low doses can have serious effects are adverse neurodevelopmental, and recently discovered the possibility of harmful effects on the cardiovascular, reproductive and immune systems.

To compound alkilmercury source is the intake of food, especially fish and other seafood. This is because methylmercury accumulating (hoarding) biological. In large fish such as tuna, shark, marlin allows the accumulation of methylmercury in their bodies than non-predatory fish. For mercury vapor, the most important source for the general public with regard to dental care is amalgam, for example for nurses in hospitals, for dental nurses, dentists and laboratory workers. For inorganic mercury compounds, diet is the most important source for most people. However, for some people, the use of skin creams and soaps containing mercury and the use of mercury for cultural / destination obedience to rituals or traditional medicine, can also result in a lot of exposure to inorganic mercury compounds.

Organic mercury, in the form of methylmercury is the most toxic when exposed to humans. Neurotoxicant good methylmercury, especially one that may cause adverse effects on brain development. In addition, the complex compounds can enter through the placenta from mother to fetus, and the blood-brain barrier, therefore, during pregnancy is recommended to be careful with exposure or intake of mercury. In addition, some studies have shown that elevated levels of mercury in small quantities cause effects on the cardiovascular system, causing increased mortality. Given that many of cardiovascular disease is found worldwide, these findings, although yet to be confirmed, stating that the intake of methylmercury exposure or require additional attention and follow-up. Moreover, methylmercury compounds suspected to cause cancer to humans (group 2B) according to the International Agency for Research on Cancer (IARC, 1993), based on the overall evaluation.

Fish is the main source of human food. If the fish consumed comes from polluted rivers and the sea would pose a danger to methyl mercury. The most dangerous risk are fetuses, (fetuses), infants and young children. As a result, fish consumption by pregnant women, children, and women raises concerns because of possible mercury exposure. Experts estimate that nearly half (44%) of young people in France who have high levels exceed health standards, are at risk of mercury poisoning.

One of the worst industrial disasters in history caused by waste mercury compounds into Minamata Bay, Japan. The Chisso Corporation, a manufacturer of fertilizer and petrochemical company, was found responsible for the pollution in the bay in 1932-1968. It is estimated that more than 3,000 people-eating fish from lakes suffer from various deformities, which became known as Minamata disease. The Supreme Court held November 2005 the central government and Kumamoto Prefecture assign responsibility for the Minamata disease is obliged to provide compensation of 71.5 million yen in damages to the plaintiffs case of industrial poisoning.

The main route of exposure is inhalation of mercury vapor. Approximately 80% of the inhaled vapor (steam inhalation) will be absorbed by the lung tissue. The steam easily penetrates the blood-brain barrier and cause neurotoxicant. if absorbed by the intestines, mercury can be oxidized in the body to form organic compounds.

Due to inhalation of mercury vapor can cause a disruption in the human neurological system. Specific symptoms observed among tremors, (feet and hands shaking uncontrollably), emotions, insomnia, memory loss, neuromuscular changes, and headaches. In addition, there are effects on the kidney and thyroid. High-dose exposure also lead to death.