Short, fine and WHO asbestos fibers in the lungs of quebec workers with an asbestos-related disease.

BACKGROUND The possible role of short asbestos fibers in the development of asbestos-related diseases and availability of lung fiber burden data prompted this study on the relationships between fiber characteristics and asbestos-related diseases among compensated workers. METHODS Data collected between 1988 and 2007 for compensation purposes were used; lung asbestos fibers content of 123 Quebec workers are described according to socio-demographic characteristics, job histories and diseases (asbestosis, mesothelioma, lung cancer). RESULTS Most workers (85%) presented chrysotile fibers in their lungs, and respectively 76%, 64%, and 43% had tremolite, amosite, and crocidolite. Half of the total fibers were short, 30% were thin fibers and 20% corresponded to the World Health Organization definition of fibers (length ≥ 5 μm, diameter ≥ 0.2 and <3 μm). Chrysotile fibers were still observed in the lungs of workers 30 years or more after last exposure. CONCLUSION Our findings stress the relevance of considering several dimensional criteria to characterize health risks associated with asbestos inhalation.