Analysis of the core of ferruginous bodies and the relationship between body type and core characteristics

The cores of 164 ferruginous bodies from seven non-primary asbestos workers were analyzed by the carbon planchet method to elucidate the nature of the core mineral and the relationship between ferruginous body type and the core characteristics. One hundred and sixty-two cores, except for two talcs, were all amphibole group asbestos. Amosite and anthophyllite fibers were all finer than 0.9 micron and mainly less than 0.5 micron in diameter and had tendency to form type I asbestos bodies. On the other hand, tremolite and actinolite fibers constituted non-beaded club-like type II or type IV bodies and tended to have a larger diameter than that of amosite or anthophyllite fibers (p less than 0.005). These results suggest that the type of asbestos body depends fundamentally on the core diameter (width) rather than the type of asbestos, although the core diameter was correlated with asbestos type. For the analysis and evaluation of ferruginous body cores, which are completely coated, it is necessary to denude the ferruginous coating. This study suggested the usefulness of the carbon planchet method with Dodson's method.