ASBESTOS BODIES IN BRONCHOALVEOLAR LAVAGE FLUID IN RELATION TO OCCUPATIONAL HISTORY

Concentrations of asbestos bodies (AB) were assessed by optical micros copy of 10 ml iron-stained samples and compared with the exposure hist ory acquired by personal interview for 156 patients. Concentrations eq ualling or exceeding 1 AB/ml were found in 85% of patients who had bee n heavily exposed to asbestos and only 7% of those who were unlikely t o have been exposed. Elevated AB concentrations were observed among pr imary asbestos, shipyard and construction workers. Smoking was not fou nd to affect the AB concentrations. The use of Papanicolaou-stained cy tological Millipore preparations during routine screening was a less s ensitive method for the assessment of AB concentrations than that invo lving iron-stained preparations. The expression of AB concentration as AB/ml or AB/million cells were found to be equally useful indicators of exposure. The correlation between AB concentration and exposure his tory was greater than in earlier studies on workers exposed to chrysot ile. Concentrations exceeding 1 AB/ml were indicative of a nontrivial exposure to asbestos. Despite the observed correlation between AB conc entration and exposure history, the individual variability of AB count s, methodological differences and laboratory-bound reference values ar e important in the interpretation of AB concentrations in bronchoalveo lar lavage (BAL) fluid at individual level. (C) 1994 Wiley-Liss, Inc.