Lead And The Environment :: essays research papers

Lead and The EnvironmentSome materials are so commonplace that we take them for granted. One ofthose materials is a grayish coat that has been with us for thousands of years.That metal is whiz, still one of the worlds most useful substances, and onethat never ceases to find a role in human society.Lead has the atomic symbol of Pb (for plumbum, lead in Latin). Theatomic number for lead is 82 and the atomic mass is 207.19 AMU. It melts atabout 327.502 oC and boils at 1740 oC. Lead is a heavy, ductile, soft, graysolid. It is soluble in nitric acid and insoluble in water. It is assemble in North,Central and South America, Australia, Africa and Europe. In modern time, leadhas found a wide range of uses, and world demand for lead and its products hassteadily increased. Leads usefulness stems from the metals many desirableproperties softness, high density, low melting point, ability to wadradiation, resistance to corrosion, readiness to form alloys and chemicalcompounds, and ease of recycling. Its versatility, as well as its physical andchemical properties, accounted for its extensive use. Lead can be turn over intosheets which can be made into rods and pipes. It can also be molded intocontainers and mixed with other metallic elements.Lead was used in ancient times for making coinage, art objects and waterpipes. One of the first known toxic substances, lead was used by the Romans forlining aqueducts and in glazes on containers used for solid food and wine storage andit is suspected to have resulted in widespread lead poisoning. Members of thefamous Franklin Expedition to the Northwest Passage in the mid-1840s met asimilar fate, world poisoned from lead in solder, widely used at the time toseal tins used to store foods. Until recently, one of the most significant useswas an anti-knock additive in gasoline. In the 1970s and 1980s, steps were takento reduce the use of leaded gas. By 1990, these actions had virtually eliminatedthe use of lead in gasoline. Lead is also one of the outdo and earliest examplesof recycling about 55 percent of the lead used in Canada comes from recycledmaterial.One particular category of toxic tort is injury caused by exposure tolead-based paint. The hazards of lead-based paint have been known since theearly 1900s, when the use of lead in the manufacture of paint was banned inAustralia. The lead mining and lead pigment industries in the United States wereable, however, to forestall the banning the use of lead in the manufacture of