Ferruginous bodies in sputum as an indication of exposure to airborne mineral fibers in the mesothelioma villages of Cappadocia.

The counts of ferruginous bodies (pulmonary-coated mineral fibers) in sputum samples from inhabitants in each of the two agricultural villages of Karain and Tusköy (Cappadocia, central Turkey) increased with subjects' age, whereas 94% of samples collected in the neighboring villages were free of ferruginous body. These findings are consistent with the previous hypothesis that the very high frequency of mesothelioma in Karain and Tusköy was related to exposure to airborne mineral fibers of natural origin.