The Lead Smelting Industry

The superior environmental performance derives essentially fiom the totally enclosed furnace operating under negative pressure and fiom the sealing of all ports via specially designed devices. When processing secondary lead materials, the post combustion of process gases at temperatures in excess of 1300°C results in levels of dioxins and fiirans that are well below the statutory levels. These unique features are particularly well suited to the requirements of the lead smelting industry. 

But, although in this respect the responsibility is being shifted back to the employer, there remain subtle ways in which the lead smelting industry continues to hold workers responsible for the problem. This is facilitated by the way in which lead contamination is measured. There are two common types of measurement lead-in-blood and lead-in-air. Lead-in-blood measurements are clearly more relevant from a medical point of view. But lead-in-blood measurements leave the way open to holding the victim responsible in a manner which is not possible with lead-in-air measurements. The point is that a focus on lead-in-air leads to a policy of containing lead emissions at their source, clearly a management responsibility. A focus on lead-in-blood throws up the additional possibility of encouraging workers to wear personal protective equipment—... 

This part of the text covers the general structure of the lead smelting industry, including its scope, its history and details of raw material supplies used for the recovery of lead metal. 

Several heavy metals, particularly lead, are known to cause major adverse effects to the mammalian kidney, resulting in kidney function impairment. Adverse effects to the mammalian kidney caused by lead include lesions on the proximal tubule and Henle s loop, and the presence of lead inclusion bodies. The metal also is known to cause aminoaciduria, phosphaturia, glycosuria, and renal tubular acidosis. Workers associated with lead-smelting industries also have shown kidney cancer. 

The secondary lead industry now represents almost 70 per cent of total lead supply and hence exceeds the scale of the primary smelting industry. 

Kaldo) appear much less likely to achieve widespread commercial acceptance in the primary lead smelting industry. 

The lead-bearing components ate released from the case and other nordead-containing parts, followed by the smelting of the battery plates, and refinement to pure lead or specification alloys. The trend toward battery grid alloys having Httle or no antimony, increases the abiHty of a recovery process to produce soft lead (refined). As requited in the production of primary lead, each step in the secondary operations must meet the environmental standards for lead concentration in ait (see Air pollution Lead compounds, industrial toxicology). 

Centuries after man had started to use iron oxides as colouring agents, he discovered how to smelt them. The first iron was produced between 4000 and 2000 BC. Since then, this product of iron oxides has been used in weapons, utensils, tools, implements and construction. The extensive English iron ore deposits contributed to the lead England acquired in the Industrial Revolution. 

Humans have been exposed more and more to metallic contaminants in the environment, mostly from the products of industry. There are three main sources of metals in the environment. The most obvious are the processes of extraction and purification mining, smelting, and refining. Another is the release of metals from fossil fuels (e.g., coal, oil), when these are burned. Cadmium, lead, mercury, nickel, vanadium, chromium, and copper are all present in these fuels, and considerable amounts enter the air or are deposited in ash. The third and most diverse source is the production and use of industrial products containing metals, which is increasing as new applications are found. The modem chemical industry, for example, uses many metals or metal compounds as catalysts metal compounds are used as stabilizers in the production of many plastics, and metals are added to lubricants, which then find their way into the environment.21... 

MacMillan Smoke Wars, pp. 243—245 Quivik, Smoke and Tailings, pp. 434— 438. The Anaconda smelter produced 14,000 tons of arsenic in 1933 (it is unclear whether this is expressed as As or as As203) T. LeCain, The Limits of Eco-efficiency Arsenic Pollution and the Cottrell Electrical Precipitator in the U.S. Copper Smelting Industry, Environmental History, vol. 5, pp. 336—351 (2000). Arsenic usage for pesticides in the United States in 1934 can be calculated from P. A. Neal et al., A Study of the Effect of Lead Arsenate Exposure on Orchardists and Consumers of Sprayed Fruit, Public Health Service Bulletin 267, 1941, p. 12, as approximately 21,000 tons (as As). In this calculation, the average arsenic content of lead arsenate is assumed to be 20% and the annual consumption of Paris green is assumed to be 4.5 million pounds. 

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