Personal air samplers were applied to workers dealing with trichloroethylene as washing solvent in an automobile workshop and exposure levels of the vapour were measured. At the same time, urinary metabolites (trichloroethanol, trichloroacetic acid, and total trichlorinated compounds) of the workers were measured at each excretion period. On the other hand, the levels of solvent vapours in the working yard were measured both by a room air sampler as time-weighted average concentrations and by Kitagawa detection tubes as spot-sampled concentrations at 30 minutes' intervals during the work time.
The time-weighted average concentrations of trichloroethylene vapour in the morning work time (3 hours) and in the whole working time (7 hours) measured by personal air samplers correlated well to the levels of trichloroethanol in the urine excreted 8 hours after the beginning of the work. This means that the measurement of the levels of trichloroethanol in the urine, collected at the end of the ordinary working time, is a reliable means to estimate the severity of personal exposure to trichloroethylene vapour. And the levels of the solvent vapour in the working yard measured as the time-weighted average concentrations were not always equal to those as the spot-sampled concentrations. The results suggested that it was necessary to measure both by the room air sampler (as the time-weighted average concentrations which are prescribed in the principles of the threshold limited values) and by the detection tubes (as monitors of ceiling values) for the environmental assessment of trichloroethylene vapour in the working yard.