Objectives: This study investigated the relationship between asbestos body identification and the number of sputum specimens obtained from each subject.
Methods: The presence of asbestos bodies in sputum was studied in 142 asbestos workers with former low-exposure levels; the number of specimens collected during 1-3 weeks varied from 2 to more than 4. Furthermore the persistence of asbestos bodies in the sputum of 15 asbestos workers was studied during a long-time follow-up.
Results: Asbestos bodies were present in at least 1 specimen in 44.4% of the 142 subjects. The cumulative percentage of asbestos body presence increased linearly, from 20% to 68%, as the number of specimens increased.
Conclusions: Five specimens did not seem to be sufficient to obtain satisfactory sensitivity in a group with low exposure to asbestos. Neither the type of exposure (to chrysotile only or to chrysotile plus amphibole) nor the presence of an asbestos-related disease clearly influenced the probability of finding asbestos bodies.