ASBESTOS BODIES IN BRONCHOALVEOLAR LAVAGE FLUID IN RELATION TO OCCUPATIONAL HISTORY

Concentrations of asbestos bodies (AB) were assessed by optical microscopy of 10 ml iron-stained samples and compared with the exposure history acquired by personal interview for 156 patients. Concentrations equalling or exceeding 1 AB/ml were found in 85% of patients who had been heavily exposed to asbestos and only 7% of those who were unlikely to have been exposed. Elevated AB concentrations were observed among primary asbestos, shipyard and construction workers. Smoking was not found to affect the AB concentrations. The use of Papanicolaou-stained cytological Millipore preparations during routine screening was a less sensitive method for the assessment of AB concentrations than that involving 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 history was greater than in earlier studies on workers exposed to chrysotile. Concentrations exceeding 1 AB/ml were indicative of a nontrivial exposure to asbestos. Despite the observed correlation between AB concentration and exposure history, the individual variability of AB counts, methodological differences and laboratory-bound reference values are important in the interpretation of AB concentrations in bronchoalveolar lavage (BAL) fluid at individual level. (C) 1994 Wiley-Liss, Inc.