Assessment of past asbestos exposure in patients: occupational questionnaire versus monitoring in broncho-alveolar lavage.

Two different methods have been tested for assessing retrospectively occupational exposure to asbestos dust in 80 cases with suspected asbestos-related thoracic diseases: 1) Occupational history was recorded by an interviewer using a standardized questionnaire. The patients were divided into three groups: those obviously exposed (E), those obviously not exposed (NE) and those with an inconclusive questionnaire (IQ). 2) Ferruginous bodies were isolated from lung washing fluid and counted under the light microscope. In the questionnaire groups, the proportions positive for ferruginous bodies in lung washing fluid were as follows: E, 29/33; NE, 1/7; IQ, 17/40. In cases positive for ferruginous bodies in lung washing fluid, the median numbers of bodies per ml of fluid were: E, 11.7 (range, 0.05-31,250); NE, 0.06; IQ, 1.1 (range, 0.06-350) Since the data provided by the two methods were in good agreement (P less than 0.001) for the E and NE questionnaire groups, the presence of ferruginous bodies in lung washing fluid is considered to be a good indicator of past exposure. In the IQ group, the monitoring of ferruginous bodies in lung washing fluid demonstrated exposure to asbestos in 43% of cases.