Typical ferruginous bodies considered as asbestos bodies (AB) were collected from the lungs of 19 asbestos-exposed and 25 non-exposed urban subjects. Of the 319 body cores analysed by energy dispersive spectrometry (EDS), 315 were asbestos. The non-asbestos cores were talc and crystalline silica. 89.2% of the asbestos cores were commercial amphiboles (amosite/crocidolite), 7% were chrysotile and 3.8% were non-commercial amphiboles (anthophyllite/tremolite). The commercial amphibole bodies were found in exposed and non-exposed subjects and chrysotile bodies mostly in exposed subjects. The non-commercial amphibole bodies were detected in non-exposed patients with low lung AB levels; this background contamination would be more difficult to detect in lungs containing large amounts of bodies due to occupational exposure. Chrysotile bodies and tremolite/anthophyllite bodies were not observed together. We suggest that in Belgium the source of non-commercial amphiboles exposure is not contamination by chrysotile.