This metal has a melting point of - 39 ° C and boiling point and 357 ° C. It is the only liquid metal at 25 ° C and 1 atm.
The vapor of the metal, when inhaled, and its compounds, when ingested, can be easily absorbed by the body, being highly toxic.
At room temperature, the metal is slowly evaporated, poisoning plants and animals which are infected or via the food chain through breathing, particularly in the vicinity of large amounts of metallic mercury.
The diagnosis of contamination, very difficult to do in the early stages, it becomes clearer with the increase of its contents in the body. The dramatic symptoms include headache, drowsiness vision, depression, loss of motor cotrole and finally, muscle paralysis, and failure of kidney function. Mental deterioration and sensitive behavior or changes are also common as a result of poisoning.
During the nineteenth century it was common to use mercury compounds used in the processing of felt to make hats. Thus, the character Mad Hatter, the book Alice in Wonderland, Lewis Carroll, based, in fact, a common type of poisoning suffered by hatters of the time, whose manifestations include symptoms that are mixed with madness.
Fluorescent bulbs have mercury in its interior, the equivalent of one drop of liquid mercury in the gaseous state. Both of them, and thermometers containing the metal inspire care when eventually broken. About 3 ml of liquid mercury is sufficient, when evaporated to leave the atmosphere fourth poorly ventilated with mercury vapor levels above what is acceptable.
The disposal of industrial effluents where this metal is present a serious threat to the environment.
What is the purpose of using mercury in the mines?
The response is related to a unique ability of this liquid metal. He is capable of dissolving gold, forming an amalgam (a solution of metal - in this case, gold - mercury).
When in the mining are not nuggets size such that it can separate them by hand, mercury is added to the slurry containing gold in powder form. Form a mixture of gold, which does not mix the slurry. The amalgam is then removed and heated with a propane torch until complete evaporation of the mercury, leaving the gold.
During this process, the miner is considerably contaminated by inhaling toxic vapors.The mud is dirty mercury dropped into the river, where he will also almost all of the released vapor, which condenses after cooling.
There, in the rivers, bacteria that transform mercury into methylmercury cations, and also in dimethylene. Both contaminate plankton, which feed small fish. Then the mercury spreads throughout the food chain, ending up in the bodies of larger fish, the people and other animals.
This is how the mercury content in each organism increases along the food chain, a process that is called biomagnification, offering serious risks to the environment and human health.
Have been reported cases of newborns with mental and neurological motivated by mercury contamination of mothers during pregnancy.