Exposure concentration versus environmental concentration: a field survey in organic solvent workplaces.

The relationship was investigated between the environmental concentrations in workplaces and the concentrations in the breath zones of the workers therein. The former was measured in 47 organic solvent workplaces of various types taking both the grid-sampling strategy (Measurement A) and a spot-air sampling to detect possible maximum exposure (Measurement B), while the latter was determined by the application of personal samplers to 328 workers. Although a low yet significant correlation was observed between the results of Measurement A (i.e., the combination of the geometric mean and the geometric standard deviation of the environmental concentration) and the exposure concentration, excess exposure (i.e., over occupational exposure limit exposure) would occur in some workplaces when the occupational exposure limit itself be used as the limit value for the setting of criterion for environmental concentration. The analyses of the experiences suggest no excess exposure would be expected if half the occupational exposure limit be employed as the limit value.