Evaluation for compensation of asbestos-exposed individuals. I. Detection and quantification of asbestos-related nonmalignant impairment.

An objective method for measuring nonmalignant respiratory impairment caused by inhaled asbestos has been devised. Three standard physiologic tests (the forced vital capacity [FVC], the forced expiratory volume in 1 s [FEV1], the single-breath diffusing capacity for carbon monoxide [DCO]) and the posteroanterior chest roentgenogram are utilized. The age-, height-, and sex-specific normal ranges of the FVC%, the DCO%, and the FEV1/FVC% have been used in the method. The theory and rationale are described. The resulting algorithm can be presented using a nomogram. Data on 586 asbestos-exposed subjects were analyzed by the proposed method. Empirical evaluation showed the sensitivity to be greater than 90% in definitive diagnosis of asbestosis without airflow obstruction, and the specificity to be greater than 80% for those cases judged eligible for nomographic evaluation. Exceptions were found in 15 cases diagnosed clinically as asbestosis, none of whom had any evidence of pulmonary fibrosis. In addition, 50 cases diagnosed as "no asbestosis" did have evidence of pulmonary fibrosis and would have qualified for some compensation by the proposed method. In summary, this approach has been shown to yield a reliable final asbestos-related lung impairment index that, when taken together with individual societal data, can provide a reliable basis for determining compensation.