Experimental and numerical studies on the impact of work practices used to control exposures occurring in booth-type hoods.
The observation that the between-worker variance component of exposure is significant for those performing the same tasks suggests that work practices are an important determinant of exposure. Decisions to implement engineering controls may be less than optimal if these work practices are not carefully identified. This study examines the position of the worker with respect to an object and the airflow direction in a large booth-type hood, and its implications for control of exposure. Experiments are conducted in a wind-tunnel using a mannequin and tracer gas techniques to measure exposures in the various positions at different air velocities. Smoke-wire, flow-visualization techniques are employed to correlate the exposures with the airflow patterns. Numerical predictions of these flow patterns and exposures compare favorably with experimental data, despite limitations. Further work is underway to examine more realistic situations such as spray-painting applications.