Abstract

Salvini, M., Binaschi, S., and Riva, M. (1971).Brit. J. industr. Med.,28, 286-292. Evaluation of the psychophysiological functions in humans exposed to the `Threshold Limit Value' of 1,1,1-trichloroethane. The effects on the psychophysiological functions in human beings of exposure to 1,1,1-trichloroethane (methylchloroform; MC) were evaluated by exposing six male university students to an average vapour concentration of 450 p.p.m. for two periods of 4 hours, separated by a 1½-hour interval.

Each subject was examined on two different days, one day undertaking a set of tests in an atmosphere containing MC vapour and on the other day in a `control' atmosphere which did not contain MC. On each of the two days a series of tests was performed at 8.30 a.m. and repeated at 6 p.m. They comprised a perception test with tachistoscopic presentation, Wechsler Memory Scale, a complex reaction time test, and a manual dexterity test. A crossed scheme analysis was used.

After the two exposures no disturbances in motor function, coordination, equilibrium or behaviour patterns were observed in any of the subjects; there were some complaints about eye irritation at the peak exposure periods.

The following conclusion may be drawn from the results. In humans exposed to a vapour concentration of MC of 450 p.p.m. the psychophysiological functions studied were not decreased. The low percentage reduction in performance which was observed is not statistically significant. In the perception test an interaction between exposure to MC and mental fatigue was observed.