Airborne Fiber Levels in a Hospital Operations and Maintenance Program

Abstract

Operations and maintenance (O&M) programs for management of asbestos in buildings are being widely implemented; however, little information is available to evaluate the effectiveness of such programs. In this article we present data for airborne asbestos fiber concentrations for 394 samples (191 area and 203 personal) collected during 106 jobs that were part of an O&M program at a hospital. These data were provided to the Health Effects Institute-Asbestos Research by H⁺GCL, Inc., a Boston-based firm which was responsible for development and management of the program over an 18-month period. All samples were analyzed by H⁺GCL using phase contrast microscopy. Analyses of the data show that the average airborne concentration for personal samples was 0.1108 fibers/ml (f/ml) (percentiles: 50th, 0.0599 f/ ml; 90th, 0.2345 f/ml; 95th, 0.4176 f/ml; maximum: 0.8395 f/ml). The average for the area samples was 0.0196 f/ml (percentiles: 50th, 0.0096 f/ml; 90th, 0.0342 f/ml; 95th, 0.0542 f/ml; maximum: 0.4222 f/ml). When the data were used to calculate 8-hour time-weighted average concentrations for occupational exposures, 95 percent were below 0.1 f/ml and 99 percent were below 0.2 f/ml. Jobs associated with asbestos removal had a 2 to 2.5fold higher average fiber concentration than jobs not involving removal. Among the different buildings, the highest mean value for personal samples was found in the building with the oldest, and greatest variety of, asbestos-containing material; such a relationship was less clear-cut for area samples. Sample duration was found to be inversely related to fiber concentrations among personal samples. Based on multivariate analyses, these relationships appeared to be largely independent of one another. Finally, several other variables that were expected to be related to fiber concentrations, including degree of engineering control, type of maintenance work, and type of room, were not found to have a significant effect on the airborne levels found in this study.