Mesothelioma in relation to asbestos, terminal progress report.
NIOSH 1971 Jan; :1-21
The carcinogenicity of asbestos (1332214) was examined in LVGLAK- hamsters. Hamsters were given a single injection of 0.5 milliliter of a suspension of 1 of 23 preparations of asbestos or other minerals into the right pleural cavity. Animals were followed for 650 to 700 days after injection or until death. Necropsies were performed. Thoracic contents were examined microscopically and histologically. Presence or absence of pleural adhesions and their character, plaques, thrombi, or other pathologies were noted. Mesotheliomas were found after injection of soft chrysotile (12001295), harsh chrysotile, amosite (12172735), diatomaceous earth, crocidolite (12001284), anthophyllite (16829439), nickel (7440020) powder, and microquartz fibers. Tumors appeared more quickly with harsh chrysotile than with the soft variety. Fibrogenic and carcinogenic responses to chrysotile, amosite, and crocidolite were reduced with reductions in dose. At a dose of 1 milligram, tumors were found only in response to crocidolite. Reduction of fiber length of chrysotile reduced fibrogenic responses and eliminated carcinogenic responses. Electron micrography showed phagocytosis of asbestos fibers by macrophages and by epithelial cells after chrysotile injection.
NIOSH-Grant; Animal-studies; Dust-exposure; Toxic-effects; Laboratory-testing; Clinical-techniques; Testing-equipment; Carcinogens
1332-21-4; 12001-29-5; 12172-73-5; 12001-28-4; 16829-43-9; 7440-02-0
Final Grant Report
NTIS Accession No.
NIOSH, U.S. Department of Health, Education, and Welfare, Cincinnati, Ohio
Fairleigh Dickinson University