Silica dust exposures during selected construction activities.
Flanagan ME; Seixas N; Majar M; Camp J; Morgan M
Am Ind Hyg Assoc J 2003 May/Jun; 64(3):319-328
This study characterized exposure for dust-producing construction tasks. Eight common construction tasks were evaluated for quartz and respirable dust exposure by collecting 113 personal task period samples for cleanup; demolition with handheld tools; concrete cutting; concrete mixing; tuck-point grinding; surface grinding; sacking and patching concrete; and concrete floor sanding using both time-integrating filter samples and direct-reading respirable dust monitors. The geometric mean quartz concentration was 0.10 mg/m(3) (geometric standard deviation [GSD]=4.88) for all run time samples, with 71% exceeding the threshold limit value. Activities with the highest exposures were surface grinding, tuck-point grinding, and concrete demolition (GM[GSD] of 0.63[4.12], 0.22[1.94], and 0.10[2.60], respectively). Factors recorded each minute were task, tool, work area, respiratory protection and controls used, estimated cross draft, and whether anyone nearby was making dust. Factors important to exposure included tool used, work area configuration, controls employed, cross draft, and in some cases nearby dust. More protective respirators were employed as quartz concentration increased, although respiratory protection was found to be inadequate for 42% of exposures. Controls were employed for only 12% of samples. Exposures were reduced with three controls: box fan for surface grinding and floor sanding, and vacuum/shroud for surface grinding, with reductions of 57, 50, and 71%, respectively. Exposures were higher for sweeping compound, box fan for cleanup, ducted fan dilution, and wetted substrate. Construction masons and laborers are frequently overexposed to silica. The usual protection method, respirators, was not always adequate, and engineering control use was infrequent and often ineffective.
Silica-dusts; Silicates; Dusts; Dust-exposure; Construction; Construction-industry; Construction-workers; Occupational-exposure; Quartz-dust; Respirable-dust; Sampling; Sampling-methods; Dust-sampling; Respirators; Respiratory-protective-equipment; Exposure-levels; Exposure-assessment
University of Washington, Department of Environmental Health SC-34, Field Research and Consultant Group, 4225 Roosevelt Way NE, Suite 100, Seattle, WA 98115, USA
Research Tools and Approaches: Intervention Effectiveness Research
American Industrial Hygiene Association Journal
University of Washington, Seattle, Washington