TLV-TWA 0.05 mg/m3 for Hg vapor, and
0.10 mg/m3, as Hg for alkyl mercury
and inorganic compounds (ACGIH); ceiling
0.1 mg/m3 (OSHA); IDLH 28 mg/m3
(NIOSH).
介电常数:
1.0(148℃)
物理描述:
Mercury appears as an odorless, silvery metallic liquid. Insoluble in water. Toxic by ingestion, absorption and inhalation of the fumes. Corrosive to aluminum. Used as a catalyst in instruments, boilers, mirror coatings.
颜色/状态:
Silver-white, heavy, mobile, liquid metal; solid mercury is tin-white
The high mobility and tendency to dispersion exhibited by mercury, and the ease with which it forms alloys (amalga) with many laboratory and electrical contact metals, can cause severe corrosion problems in laboratories.
... ONE OF THE ... PATHWAYS, IF NOT THE ONLY PATHWAY, BY WHICH ELEMENTAL MERCURY (HG(0+)) IS ABSORBED ... /& CONVERTED IN VIVO/ IS BY ITS OXIDATION /IN ERYTHROCYTES/ TO HG(2+). ... STUDIES WITH ACATALASEMIC RED BLOOD CELLS (RBCS) /SHOW/ THAT CATALASE-HYDROGEN PEROXIDE SYSTEM PLAYS A DETERMINANT ROLE IN MERCURY UPTAKE THROUGH THIS CATALYTIC OXIDATION SYSTEM; HUMAN ACATALASEMIC RBCS HAD ONLY 1/100 TO 6/100 THE UPTAKE OF MERCURY VAPOR FOUND IN NORMAL RBCS WITH HYDROGEN PEROXIDE.
The oxidation of metallic mercury vapor to divalent ionic mercury ... takes place very soon after absorption, but some elemental mercury remains dissolved in the blood long enough (a few min) for it to be carried to the blood-brain barrier and the placenta ... Recent in vitro studies on the oxidation of mercury by the blood ... indicate that because of the short transit time from the lung to the brain almost all the mercury vapor (97%) arrives at the brain unoxidized. Its lipid solubility and high diffusibility allow rapid transit across these barriers. Oxidation of the mercury vapor in brain and fetal tissues converts it to the ionic form, which is much less likely to cross the blood-brain and placental barriers.
IDENTIFICATION: In its elemental form, mercury is a heavy silvery liquid at room temperature and has a very high vapour pressure. Mercury vapor is more soluble in plasma, whole blood, and hemoglobin than in distilled water, where it dissolves only slightly. The major natural sources of mercury are degassing of the earth's crust, emissions from volcanoes, and evaporation from natural bodies of water. (The world-wide mining of mercury is estimated to yield about 10,000 tons per year. The activities lead to some losses of mercury and direct discharges to the atmosphere). Other important sources are fossil fuel combustion, metal sulfide ore smelting, gold refining, cement production, refuse incineration, and industrial applications of metals. A major use of mercury is as a cathode in the electrolysis of sodium chloride. Mercury is used in the electrical industry, in control instruments in the home and industry, and in laboratory and medical instruments. A very large amount of mercury is used for the extraction of gold. Dental silver amalgam for tooth filling contains large amounts of mercury. Use of skin-lightening soap and creams can give rise to substantial mercury exposure. Occupational exposure to inorganic mercury has been investigated in chloralkali plants, mercury mines, thermometer factories, refineries, and in dental clinics. High mercury levels have been reported for all these occupational exposure situations, although levels vary according to work environment conditions. HUMAN EXPOSURE: The general population is primarily exposed to mercury through the diet and dental amalgam. Acute inhalation exposure to mercury vapor may be followed by chest pains, dyspnea, coughing, hemoptysis, and sometimes interstitial pneumonitis leading to death. (The ingestion of mercuric compounds, in particular mercuric chloride, has caused ulcerative gastroenteritis and acute tubular necrosis causing death from anuria where dialysis was not available). The central nervous system is the critical organ for mercury vapor exposure. Subacute exposure has given rise to psychotic reactions characterized by delerium, hallucinations, and suicidal tendency. Occupational exposure has resulted in erethism as the principal feature of a broad ranging functional disturbance. The kidney is the critical organ following the ingestion of inorganic divalent mercury salts. Occupational exposure to metallic mercury has long been associated with the development of proteinuria. Both metallic mercury vapor and mercury compounds have given rise to contact dermatitis. Mercurial pharmaceuticals have been responsible for Pink disease (acrodynia) in children, and mercury vapor exposure may be a cause of "Kawasaki" disease. Results of both human and animal studies indicate that about 80% of inhaled metallic mercury vapour is retained by the body, whereas liquid metallic mercury is poorly absorbed via the gastrointestinal tract. ANIMAL STUDIES: Evidence of damage to brain, kidney, heart, and lungs have been reported in rabbits exposed acutely to metallic mercury vapor at certain concentrations. Both reversible and irreversible toxic effects may be caused by mercury and its compounds. In two studies, tremor and behavioural effects were observed in rabbits and rats after several weeks of exposure to metallic mercury vapour. Depending upon the animal strain tested, either auto-immunity or immunosuppression is observed. The most sensitive adverse effect caused by mercuric mercury is the formation of mercuric-mercury-induced auto-immune glomerulonephritis. Mercuric chloride was found to induce gene mutations in mouse lymphoma cells and DNA damage in rat and mouse fibroblasts. The World Health Organization reported no evidence that inorganic mercury is carcinogenic. The neurotoxic effect seen after exposure to metallic mercury vapour is attributable to the divalent mercury ion formed through oxidation in the brain tissue. Significantly more mercury is transported to the brain of mice and monkeys after the inhalation of elemental mercury than after the intravenous injection of equivalent doses of the mercuric form.
来源:Hazardous Substances Data Bank (HSDB)
毒理性
致癌性证据
癌症分类:D组 不可归入人类致癌性类别
Cancer Classification: Group D Not Classifiable as to Human Carcinogenicity
CLASSIFICATION: D; not classifiable as to human carcinogenicity. BASIS FOR CLASSIFICATION: Based on inadequate human and animal data. Epidemiologic studies failed to show a correlation between exposure to elemental mercury vapor and carcinogenicity; the findings in these studies were confounded by possible or known concurrent exposures to other chemicals, including human carcinogens, as well as lifestyle factors (e.g., smoking). Findings from genotoxicity tests are severely limited and provide equivocal evidence that mercury adversely affects the number or structure of chromosomes in human somatic cells. HUMAN CARCINOGENICITY DATA: Inadequate. ANIMAL CARCINOGENICITY DATA: Inadequate.
Evaluation: There is inadequate evidence in humans for the carcinogenicity of mercury and mercury compounds. There is inadequate evidence in experimental animals for the carcinogenicity of metallic mercury. There is limited evidence in experimental animals for the carcinogenicity of mercuric chloride. There is sufficient evidence in experimental animals for the carcinogenicity of methylmercury chloride. In making the overall evaluation, the Working Group took into account evidence that methylmercury compounds are similar with regard to absorption, distribution, metabolism, excretion, genotoxicity and other forms of toxicity. Overall evaluation: Methylmercury compounds are possibly carcinogenic to humans (Group 2B). Metallic mercury and inorganic mercury compounds are not classifiable as to their carcinogenicity to humans. (Group 3). /Mercury and mercury compounds/
Several studies have correlated the number of dental amalgam fillings or amalgam surfaces with the mercury content in brain and kidney tissue from human autopsy. Subjects with no dental amalgam had a mean mercury level of 6.7 ng/g (2.4-12.2) in the occipital cortex; whereas, subjects with amalgams had a mean level of 12.3 ng/g (4.8-28.7) ... Amalgam-free subjects had a mean mercury level in kidneys of 49 ng/g (21-105), whereas subjects with amalgam fillings had a corresponding level of 433 ng/g (48-810). /Mercury alloy/
1.周国泰,化学危险品安全技术全书,化学工业出版社,1997 2.国家环保局有毒化学品管理办公室、北京化工研究院合编,化学品毒性法规环境数据手册,中国环境科学出版社.1992 3.Canadian Centre for Occupational Health and Safety,CHEMINFO Database.1998 4.Canadian Centre for Occupational Health and Safety, RTECS Database, 1989