| Chemical Speciation of Lead Dust Associated with Primary Lead Smelting Terry M. Spear,1 Wayne Svee,1 James H. Vincent,2 and Nick Stanisich3 1School of Mines, Montana Tech of The University of Montana, Butte, MT 59701-8997 USA
2Division of Environmental and Occupational Health, School of Public Health, University of Minnesota, Minneapolis, MN 55455 USA
3Portage Environmental Inc., Idaho Falls, ID 83404 USA Abstract
The research presented in this article assessed geochemical factors relating to dust produced during primary lead smelting. Bulk dust samples and size-selective airborne dust samples were collected from four areas of a primary lead smelter and analyzed by X-ray diffraction and sequential chemical extraction. X-ray diffraction showed that the smelter dusts were composed primarily of sulfides, oxides, sulfates, and silicates of metal ores, with galena being the primary dust component. Sequential extraction revealed the solubility of lead compounds at less than 7% in the exchangeable and mildly acidic steps for the bulk dusts collected from four smelter areas. The later steps of the extraction procedure were more effective in dissolving the lead compounds associated with the bulk dust samples, with 43%, 26%, and 8% of the total lead, in the ore storage, sinter, and blast/dross smelter areas, respectively, being extracted in the residual step. Sequential extraction of coarse airborne dust samples from the ore storage and sinter plant showed that 1.2% and 4.1% of the total lead, respectively, was exchangeable. The finer particle size fractions from these areas of the smelter showed higher percentages of exchangeable lead. Of the course airborne dust from the blast/dross furnace processes, 65% of the total lead was exchangeable. However, the largest percentage of lead from these areas was associated with the finer particle-size fractions. If lead bioavailability is related to its solubility as determined through sequential extraction, the health hazards associated with lead exposure may be appreciably enhanced in the blast and dross furnace processes. Key words: bioavailability, lead dust, lead speciation, sequential extraction. Environ Health Perspect 106:565-571 (1998) . [Online 11 August 1998] http://ehpnet1.niehs.nih.gov/docs/1998/106p565-571spear/ abstract.html Address correspondence to T.M. Spear, School of Mines, Montana Tech of The University of Montana, 1300 W. Park Street, Butte, MT 59701-8997 USA. We thank the management and workers at the primary lead smelter where this research was carried out. Received 3 March 1998 ; accepted 29 April 1998.
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