Basic knowledge of mercury
What impression do you have of mercury? Do you consider it to be a typical hazardous material that is represented by Minamata disease? Or a substance that is familiar because it is widely used in daily life? Let us now explore some basic facts about mercury.
|Atomic symbol||Hg (derived from hydrargyrum in Latin, i.e. quicksilver in English)|
|Denotation||mercury in English (derived from Mercury)|
Properties of mercury
Mercury is a metal with the following three unique characteristics, and has been familiar and valuable to human beings since before BC.
- The pressure of mercury vapor is rather high and it easily forms amalgams with other metals.
- The melting point of mercury is below freezing point, which makes mercury the only metal that is liquid at room temperature and normal pressure.
- The specific gravity of mercury is so large that iron floats on liquid mercury.
Types of mercury
|Type||Symbol of element||Main use and characteristics||Toxicity|
|Metal mercury||Hg||Alkali industry; fluorescent tube; cold cathode fluorescent lamp (CCFL); blood-pressure meter; thermometer; rectifier; relay contact; gold mining using amalgamation; plating; dental filling material (also contained in petroleum, coal, natural gas, shale gas, etc.)||May cause amalgam poisoning, or mercury poisoning through long-period inhalation of high concentration of mercury|
|Inorganic mercury||Mercury sulfide||HgS||Cinnabar; pigment; paint; vermilion inkpad||Not substantially toxic. Even when it enters a body, it is excreted in short time.|
|Mercury oxide||HgO||Mercury cell; germicide, preservative, medicine for conjunctivitis|
|Mercuric (i) chloride||Hg2Cl2||Purgative; diuretic|
|Mercuric (ii) chloride||HgCl2||Vinyl chloride manufacture; disinfectant||Highly toxic|
|Organic mercury||Alkyl mercury||The general term of organic mercury compounds that are composed of mercury bound with the alkyl group (CnH2n+1-) such as the methyl group (CH3-) and the ethyl group (C2H5-).|
|(1) Methyl mercury||CH3HgX||Seed disinfectant, catalyst for acetylene derivatives.
(There are compounds such as methyl mercury chloride, methyl mercury bromide, methyl mercury hydroxide, methyl mercuric acetate, and methyl mercury nitrate.)
A toxin that is soluble in oil and is susceptible to biological accumulation. The main cause of Minamata disease.
|High toxicity that affects the nerve center|
|(2) Dimethyl mercury||C2H6Hg||Toxicology test
Flammable liquid that is transparent and has slightly sweet odor
|One of most toxic neurotoxins|
|(3) Sodium ethylmercurithiosalicylate||C9H9HgNaO2S||Preservative for vaccines.
Suspected as one of causes of autism.
|(4) Diethyl mercury||C4H10Hg||Toxicology test
Colorless combustible liquid having slightly sweet odor.
One of causes of Minamata disease.
|Extremely high neurotoxicity.|
|Phenylmercuric acetate||CH3COOHgC6H5||Germicide for agricultural chemicals.
Currently agricultural use prohibited
|Highly toxic. Causes kidney disorder when taken into human body.|
- YAMAMOTO, Yoshihiro. “Harukanaru Suigin no Tabi (Long Journey of Mercury)”, Sanbunsha
- “Suigin (Mercury)”, The Chemical Society of Japan (ed.), Maruzen
- IKUSHIMA, Kenji. “Suigin-shorigijyutsu ga Nihon no Enerugi-kiki o Sukuu (Mercury Treatment Technology Saves the Energy Crisis in Japan)”, CMC Publishing Co. Ltd.