A Study of Worker Exposure from a Hand-Held Contaminant Source in a Simulated Spray Booth Operation

Tracer gas concentrations generated from a hand-held source are measured in the breathing zone of a mannequin, and for an elliptical cylinder positioned in a wind tunnel. Effects on breathing zone concentration due to worker position relative to the direction of airflow and a workpiece are examined. Flow visualization by the smoke wire technique is performed. Worker position was found to be statistically significant in breathing zone concentration. Positioning the worker with the air flow from the side results in a drop of roughly two to three orders of magnitude compared to positioning the worker with the airflow from the back. Interaction was noted between worker position and airflow rate. Tracer gas concentrations were lower in the breathing zone of the mannequin than for the cylinder. The placement of an object downstream of the worker when airflow is from the back resulted in a roughly two-fold increase in breathing zone tracer gas concentration when compared to predicted values with a worker only. Positioning a worker sideways to the airflow appears to result in a substantial decrease in contaminant exposure. Applications and limitations of the results are discussed.Master of Science in Public Healt