A Chronic Inhalation Toxicology Study In Monkeys And Rats Exposed To Fibrous Glass.
Mitchell-RI; Reif-RB; Mosberg-AT; Thake-DC; Connell-MM; Donofrio-DJ; Harroff-HH; Roese-AJ
NIOSH 1982 Oct:296 pages
Long term inhalation studies were conducted with rats and monkeys exposed to fibrous glass. Fisher-344-rats and male Cynomologous- monkeys were exposed to concentrations of 0 to 15.62 and 0 to 14.94 milligrams per cubic meter of fibrous glass for 7 hours per day, 5 days a week for 21 and 18 months, respectively. Control groups were exposed to clean air. Body weights were taken weekly and biweekly, and clinical signs and mortality were observed daily. Blood samples were collected twice before treatment and at 16, 32, 48, and 64 weeks during exposure (monkeys) and just prior to sacrifice in both species. Rats were held for 3 additional months after last exposure. Respiratory functions were tested in the monkeys and histopathology was performed on all tissues from both species. There were no compound related deaths; 187 rats died spontaneously and two monkeys died of other causes. There were no postexposure ophthalmologic lesions attributable to fibrous glass exposure nor were there any chemical related clinical symptoms recorded for both species during the study. Body weights were not affected and mean values for hematology and clinical chemistry parameters were within the range of control values in both species. Pulmonary physiology measurements showed small but insignificant deviations from controls in monkeys. There was no restrictive or lung impairment observed. Fibrous glass inhalation induced macrophage aggregates with phagocitized fibrous glass in the lungs and tracheobronchial lymph nodes in monkeys. Macrophage aggregates and granulomas were found in rats. These lesions were dose related as to severity in rats but not in monkeys. The pattern of lesions were similar in both species. Mononuclear cell leukemia was statistically significant and may be exposure related. The authors conclude that inhaled fibrous glass does not cause pulmonary or mesothelial carcinogenesis.
NIOSH-Contract; Respiratory-gas-analysis; Pulmonary-function-tests; Dust-sampling; Physiological-testing; Air-quality-control; Animal-studies; Lung-irritants; Safety-research; Respiratory-irritants; Contract-210-78-0037;
NTIS Accession No.
NIOSH, U.S. Department of Health and Human Services, Cincinnati, Ohio, NTIS PB83-258-111