title: The effect of contaminant source momentum on a worker's breathing zone concentration in a uniform freestream.
abstract: Several factors affecting breathing zone concentration were examined in a paint spray booth by using a tracer gas method. The variables in the study include contaminant momentum, the presence of a flat plate downstream of the worker, the distance between the contaminant source and the body, and the worker's motion. A dramatic reduction in breathing zone concentration was observed when the spray gun emitted contaminants with high momentum. Reductions of 30-50% were observed because of the other variables. The source momentum effect was studied, subsequently, in a wind tunnel by measuring the breathing zone concentration of a mannequin with various flows through jets of different diameter, at varying freestream velocities. A functional relationship was determined between nondimensional breathing zone concentration and contaminant source momentum. This relationship is supported by numerical simulations. The effect of contaminant momentum on the near-wake flow field is discussed in conjunction with results from the numerical simulations.
authors: Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill 27599-7400.
authors: T
authors: T
authors: Kim
authors: M R
authors: MR
authors: Flynn
mesh_terms: D000392:Air Movements; D000395:Air Pollutants, Occupational; D006801:Humans; D009038:Motion; D016272:Occupational Health; D010150:Paint; D012119:Respiration
chemical_list: D000395:Air Pollutants, Occupational