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Details

Asbestos Dust: A Study on the Pathogenetic Mechanism.

PB90129396

Publication Date	1972
Personal Author	Gross, P.; Harley, R. A.
Page Count	26
Abstract	Samples of crocidolite (12001284), amosite (12172735), and Canadian chrysotile (12001295) were prepared by five different methods for intratracheal injection to rats. A fairly high mortality was noted in the first 6 months, generally from pneumonia. Of the 1537 rats injected intratracheally one to four times, only 727 rats survived 6 months. The total dosage ranged from 1.75 to 21 milligrams. The results of the study indicated that the intratracheal injection of the three most important asbestos (1332214) dusts into rats caused no induction of cancer. It made no difference to the outcome whether these dusts were natural or had been modified by the addition or subtraction of trace metals, or whether the dusts had been heated. A significant lessening of the fibrogenicity of asbestos dust was caused by heating the dusts. These findings suggested that the theory that trace metals assist in the pathogenic potential of asbestos dust must be abandoned. The failure of lung cancers to develop in the study as they had in previous studies could not be explained. The report concluded that the pathogenicity of chrysotile asbestos may not be attributable to its fibrous shaped particles, its magnesium-silicate molecule, or to its crystalline character.
Keywords	Asbestos Serpentine Rats Respiratory neoplasms Dust particles Tables(Data) Crocidolite Amosite Dose-response relationships
Source Agency	National Institute for Occupational Safety and Health
NTIS Subject Category	57Y - Toxicology 57E - Clinical Medicine 68A - Air Pollution & Control
Corporate Authors	Industrial Health Foundation, Inc., Pittsburgh, PA.; Medical Univ. of South Carolina, Charleston.; National Inst. for Occupational Safety and Health, Cincinnati, OH.
Supplemental Notes	Prepared in cooperation with Medical Univ. of South Carolina, Charleston. Sponsored by National Inst. for Occupational Safety and Health, Cincinnati, OH.
Document Type	Technical Report
Title Note	Technical rept. (Final).
NTIS Issue Number	199005

Asbestos Dust: A Study on the Pathogenetic Mechanism.

Asbestos Dust: A Study on the Pathogenetic Mechanism.
PB90129396

Publication Date	1972
Personal Author	Gross, P.; Harley, R. A.
Page Count	26
Abstract	Samples of crocidolite (12001284), amosite (12172735), and Canadian chrysotile (12001295) were prepared by five different methods for intratracheal injection to rats. A fairly high mortality was noted in the first 6 months, generally from pneumonia. Of the 1537 rats injected intratracheally one to four times, only 727 rats survived 6 months. The total dosage ranged from 1.75 to 21 milligrams. The results of the study indicated that the intratracheal injection of the three most important asbestos (1332214) dusts into rats caused no induction of cancer. It made no difference to the outcome whether these dusts were natural or had been modified by the addition or subtraction of trace metals, or whether the dusts had been heated. A significant lessening of the fibrogenicity of asbestos dust was caused by heating the dusts. These findings suggested that the theory that trace metals assist in the pathogenic potential of asbestos dust must be abandoned. The failure of lung cancers to develop in the study as they had in previous studies could not be explained. The report concluded that the pathogenicity of chrysotile asbestos may not be attributable to its fibrous shaped particles, its magnesium-silicate molecule, or to its crystalline character.
Keywords	Asbestos Serpentine Rats Respiratory neoplasms Dust particles Tables(Data) Crocidolite Amosite Dose-response relationships
Source Agency	National Institute for Occupational Safety and Health
NTIS Subject Category	57Y - Toxicology 57E - Clinical Medicine 68A - Air Pollution & Control
Corporate Authors	Industrial Health Foundation, Inc., Pittsburgh, PA.; Medical Univ. of South Carolina, Charleston.; National Inst. for Occupational Safety and Health, Cincinnati, OH.
Supplemental Notes	Prepared in cooperation with Medical Univ. of South Carolina, Charleston. Sponsored by National Inst. for Occupational Safety and Health, Cincinnati, OH.
Document Type	Technical Report
Title Note	Technical rept. (Final).
NTIS Issue Number	199005