Chrysotile, tremolite, and malignant mesothelioma in man

Journal Article · Tue Mar 01 04:00:00 EST 1988 · Chest; (United States)

DOI:https://doi.org/10.1378/chest.93.3.621· OSTI ID:5194820

Churg, A

The question of whether chrysotile asbestos ever causes mesothelioma in man has become a major public and occupational health issue. Review of the literature suggests that only 53 acceptable cases of chrysotile-induced mesothelioma have ever been reported; of these, 41 cases have occurred in individuals exposed to chrysotile mine dust, all of it naturally contaminated with tremolite. Ten cases have occurred in secondary industry workers, but here the suspicion of amosite or crocidolite contamination is high. Analysis of lung asbestos content indicates that induction of mesothelioma by chrysotile requires, on average, as great a lung fiber burden as induction of asbestosis by chrysotile, whereas amphibole (amosite or crocidolite)-induced mesotheliomas appear at a several hundred-fold smaller lung burden. Tremolite alone has definitely produced mesothelioma in man, particularly when exposure has been to long, high aspect ratio, fibers. Analysis of tremolite:chrysotile fiber ratios in human lung suggests that some, but not all tremolite is removed in milling chrysotile ores. The low incidence of mesothelioma in secondary chrysotile users may reflect the small amount of tremolite left in the product. These observations indicate that although chrysotile asbestos can produce mesothelioma in man, the total number of such cases is small and the required doses extremely large. The data are consistent with the idea that mesotheliomas seen in chrysotile miners and some secondary industry workers are produced by the tremolite contained in the chrysotile ore, but that the short length and low aspect ratio of the tremolite make its carcinogenicity quite low. However, these data are very indirect, and a role for the chrysotile fiber itself is still possible.41 references.

• Research Organization: Univ. of British Columbia, Vancouver (Canada)
• OSTI ID: 5194820
• Journal Information: Chest; (United States), Journal Name: Chest; (United States) Vol. 93:3; ISSN CHETB
• Country of Publication: United States
• Language: English

Related Subjects

560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ASBESTOS
BODY
CARCINOGENESIS
CHALCOGENIDES
DISEASES
DOSE-RESPONSE RELATIONSHIPS
HYDROGEN COMPOUNDS
INDUSTRY
INORGANIC ACIDS
LUNGS
MINERALS
MINING
NEOPLASMS
OCCUPATIONAL DISEASES
OCCUPATIONAL EXPOSURE
ORGANS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PARTICLE SIZE
PATHOGENESIS
RESPIRATORY SYSTEM
SILICA
SILICIC ACID
SILICON COMPOUNDS
SILICON OXIDES
SIZE
TEXTILE INDUSTRY