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.