Abstract
The fibrogenic potentials of coal and copper slags used as substitutes for silica sand in abrasive blasting operations were assessed in rats. The test animals were given a single pulmonary intralobar instillation of 20 mg of test material and were sacrificed 10 months after dosing. Pulmonary fibrosis was seen in the coal slag-treated rats while no fibrosis was seen in the copper slag-treated animals. Granulomas were seen in the lungs from all treatment groups. The results of the study emphasize the need for bioassay of silica sand replacements for fibrogenic potential in spite of the low free silica contents of these materials.