Whole blood lead

Lead (Plumbum, Pb), atomic weight 207.19, silver-gray soft metal. Specific gravity 11.35 (20 ° C), melting point 327.4 ° C, boiling point 1620 ° C. Valences 2 and 4. Insoluble in water, dilute hydrochloric acid and sulfuric acid. Soluble in nitric acid, acetic acid and lye. When heated to 400 ~ 500 ℃, a large amount of steam is generated. Lead vapor is rapidly oxidized into lead oxide (Pb2O) in the air. Common inorganic lead compounds are lead monoxide (PbO, Mito monk), lead dioxide, lead trioxide (Pb2O3, camphor), lead trioxide (Pb3O4, lead Dan), lead chloride, lead sulfide (PbS , Black lead dan, black tin dan), lead sulfate, lead nitrate, lead acetate and basic lead carbonate [2Pb [O2 & middot; Pb (OH) 2], lead white] and so on. In daily life, the excessive absorption of lead from the digestive tract (with leaded containers, food, drugs) and respiratory tracts such as automobile exhaust gas> 0.5mg / d can cause lead poisoning, cause harm to health, and mainly damage the nervous system and blood system.