title: Fibrogenicity and carcinogenic potential of smelter slags used as abrasive blasting substitutes.
abstract: This study was designed to examine the fibrogenic and carcinogenic potentials of three smelter slags (primary copper slag, secondary copper slag, and nickel slag) that have been used for a number of years as substitutes for sand in abrasive blasting operations. Seven groups of 85 male Fischer 344 rats (approximately 180 g) were used. Each group was given a single 20-mg dose of one of the following test materials via intratracheal instillation: primary copper slag, secondary copper slag, nickel slag, feldspar, Min-U-Sil, novaculite, or vehicle control. Chemical, particle size, and surface area analyses were performed for each test dust. Animals were weighed monthly, and ten animals per group were necropsied at the 6-, 12-, and 18-mo interim sacrifices. The terminal sacrifice was conducted at 22 mo. Hematoxylin and eosin stained histologic sections were prepared from designated formalin-fixed tissues collected at necropsy and examined microscopically. The pulmonary fibrogenic and carcinogenic potentials of the three smelter slags were compared histopathologically with feldspar, novaculite, Min-U-Sil, and vehicle controls. Only minimal to slight alveolar wall fibrosis was seen in the two copper slag groups, while the response seen with nickel slag was consistent with a foreign body reaction with minimal fibrosis seen in only an occasional animal. The major reaction seen in both the feldspar- and the novaculite-treated rats was a granulomatous inflammation with varying degrees of fibrosis associated with the granulomas. Significant numbers of primary lung tumors, principally adenocarcinomas and adenomas, were seen in the copper slag (p = 0.005 and p = 0.022 for the primary and secondary slags, respectively), in the feldspar (p = 0.007), in the novaculite (p less than 0.001), and in the Min-U-Sil (p less than 0.001) groups when compared to the vehicle control group. In addition, the Min-U-Sil and novaculite groups had significantly elevated pulmonary tumor proportions relative to the other treatments (p less than or equal to 0.002), with the Min-U-Sil being higher than the novaculite (p = 0.012). On the basis of the tumor incidence data, one must conclude that both copper slags tested in this study are carcinogenic to rats.
authors: Division of Biomedical and Behavioral Science, National Institute for Occupational Safety and Health, Cincinnati, Ohio 45226.
authors: L E
authors: LE
authors: Stettler
authors: J E
authors: JE
authors: Proctor
authors: S F
authors: SF
authors: Platek
authors: R J
authors: RJ
authors: Carolan
authors: R J
authors: RJ
authors: Smith
authors: H M
authors: HM
authors: Donaldson
mesh_terms: D000395:Air Pollutants, Occupational / Q000633:toxicity*; D000818:Animals; D003300:Copper / Q000633:toxicity*; D004391:Dust; D004781:Environmental Exposure; D006099:Granuloma / Q000139:chemically induced / Q000473:pathology; D008175:Lung Neoplasms / Q000139:chemically induced* / Q000473:pathology; D009532:Nickel / Q000633:toxicity*; D010316:Particle Size; D011658:Pulmonary Fibrosis / Q000139:chemically induced* / Q000473:pathology; D051381:Rats; D011916:Rats, Inbred F344; D013194:Staining and Labeling; D013499:Surface Properties
chemical_list: D000395:Air Pollutants, Occupational; D004391:Dust; D003300:Copper; D009532:Nickel