US EPA

3097632 

Journal Article 

Alveolar Dust Clearance Capacity as Determinant of Individual Susceptibility to Asbestosis: New Experimental Observations 

Begin, R; Masse, S; Sebastien, P 

1989 

Yes 

Annals of Occupational Hygiene
ISSN: 0003-4878
EISSN: 1475-3162 

NIOSH/00194154 

33 

2 

279-282 

English 

2757326 

10.1093/annhyg/33.2.279 

WOS:A1989AF86000013 

New experimental observations of sheep chronically exposed to chrysotile (12001295) asbestos which suggest alveolar dust clearance capacity may be a major determinant of individual susceptibility to asbestosis were reported in a letter to the editor. Fifteen sheep injected intratracheally with 100 milligrams of chrysotile fibers in saline every 2 weeks for 2 years were sacrificed 60 months after first exposure. Early asbestosis had been well established in ten sheep (group-A) after 24 months, while five sheep (group-B) did not have asbestosis. After 60 months, lung function had significantly worsened in group-A; group-B sheep still had airway disease but no interstitial lung disease. Microscopic analysis of necropsy lung tissue indicated the following geometric mean fiber counts/microgram dried tissue for group-A and group-B, respectively: total fibers, 125 and 90; fibers shorter than 5 micrometers, 46 and 62; and fibers longer than 5 micrometers, 67 and 32. The authors conclude that significantly more fibers, particularly long fibers, were retained in lung tissue of animals developing asbestosis compared to animals not developing interstitial lung disease.