Asbestos-related radiographic abnormalities in public school custodians

A cross-sectional prevalence study of 120 public school custodians was carried out to investigate the prevalence of asbestos-related disease and to determine the proportion with disease attributable to asbestos exposures in school buildings. Medical and occupational histories, flow-volume loops, and posterior-anterior, lateral, and anterior oblique (AO) chest radiographs were obtained. Single breath DLCO was measured and chest auscultation performed. The present report describes radiographic abnormalities and associations with exposure. Mean age of subjects was 57 years and mean duration of work as a custodian, 27 years. Fifty-seven (47.5%) had no known or likely exposure to asbestos outside of their work as a school custodian (NOE). Pleural plaques (PP) occurred in 40 (33%) of the total group and 12 (21%) of the group with NOE. Multivariate analysis revealed significant associations (p less than 0.05) between PP and duration of asbestos exposure. The proportion with PP increased PP detection by a factor of 1.9. Our results reveal PP prevalence in excess of background in the study population and indicate that PP are attributable to asbestos exposure in schools in a subset with NOE. Prudent management of asbestos in buildings is indicated for the prevention of related disease.