A radiographic survey of public school building maintenance and custodial employees.

Analyses of radiographs from a cohort of 457 school maintenance and custodial workers (90 had no employment other than at a school) demonstrated an increased prevalence of abnormalities consistent with asbestos-caused disease. Pleural abnormalities predominated (24 of 29). The abnormalities could not be explained by occupational asbestos exposures which may have occurred prior to school employment. Abnormality prevalence ranged from 1.7% among those with less than 10 years to 37% among those with 30 or more years of public school employment. Laborers and skilled tradesmen with more than 20 years of school employment had a higher prevalence of abnormality (40 and 28%) than the building engineers (14%). In order to ensure that future asbestos exposure and disease risk is minimized in buildings constructed with asbestos-containing materials (ACM), implementation of asbestos hazard identification and abatement must include a rigorous operations and maintenance program. Control of asbestos exposure from in-place ACM is a public health priority.

Mesothelioma among employees with likely contact with in-place asbestos-containing building materials.

The occurrence of mesothelioma is a sentinel event in occupational and environmental disease. A mesothelioma surveillance system was established utilizing existing computerized Wisconsin vital statistics data maintained since 1959 and a Cancer Reporting System (CRS) established in 1978. Review of the death certificate listing of usual occupation and industry from 487 mesothelioma deaths in Wisconsin from 1959 to 1989 led to the investigation of 41 persons with likely exposure to inplace asbestos-containing building materials (ACBM): 12 school teachers, 10 school maintenance employees, 7 public building maintenance workers, 5 private building maintenance workers, and 7 commercial and factory workers performing maintenance activities. For 10 (34%) of the 29 maintenance workers the only source of asbestos exposure identified was their maintenance work. For five (17%) histories indicated some prior employment in occupations and industries with probable asbestos exposures. Opportunities for indirect occupational exposure were identified for ten who had been employed in the residential construction industry. One maintenance worker was exposed to asbestos in the household and another had neighborhood exposure. For 9 (75%) of the school teachers, the only identifiable potential source of asbestos exposure was derived from in-place ACBM in schools. One teacher had spent a season in the merchant marine aboard an iron ore-hauling ship and 2 had worked in the residential construction industry. Two of the teachers were sisters, and in two instances, two teachers had taught in the same school facility. We conclude that individuals occupationally exposed to in-place ACBM are at risk for the subsequent development of mesothelioma.