[Mineralogical study of non-fibrous particles in bronchoalveolar lavage fluid]

A chemical and mineral analysis of non-fibrous particles was performed using transmission electron microscopic analysis in 77 broncho-alveolar lavages (BAL) requested as an aid to diagnosis. A qualitative mineral analysis of the BAL defined the ubiquitous elements (iron, silicates, silica) or frequent (titanium, aluminium, nickel, chromium, calcium) for which a semi-quantitative analysis of the BAL was shown to be necessary in the interpretation of the results. On the other hand a qualitative analysis was generally sufficient for rare particles, their presence being evidence of occupational or environmental exposure. A study of the correlation between the doctors' assessments and the qualitative results of the BAL shows that, with the exception of silica, exposure to ubiquitous or common particles is poorly estimated. Better orientated mineralogical studies will occur with requests for BAL by the medical staff. Greater knowledge of the background exposure in control non-exposed subjects will enable better utilisation of the results of this technique.