Long-term exposure to jet fuel. II. A cross-sectional epidemiologic investigation on occupationally exposed industrial workers with special reference to the nervous system.

No abstract

ABSTRACr Sixteen men were studied in an exposure chamber to assess the effect of four hours' exposure to toluene (3.25 mmol/m3), xylene (2-84 mmol/m3), a mixture of toluene and xylene (2-20 + 0*94 mmol/m3), and a control condition. With the aid of microcomputers, subjects performed tests of simple reaction time, short term memory, and choice reaction time immediately after entering the chamber, after two, and after four hours' exposure. The results indicate that the performance on the tests was unaffected by exposure. In the light of this result the risk of an acute effect on central nervous functions after exposure for four hours at concentrations that do not exceed the Swedish threshold limit values was considered to be minimal.

Exposure to trichloroethylene: III. Psychological functions. Scand. j. work environ. & health 4 (1976) 220-224. The effect of exposure to the solvent trichloroethylene (TRI) on the performance of tests of numerical ability, reaction time (simple and choice), and short-term memory was studied in 15 healthy male subjects. The subjects were tested individually on three different occasions during exposure to 540 and 1,080 mg/m3 of TRI in inspiratory air and under control conditions, respectively. At predetermined times during the three 70-min exposure periods, samples were taken of the subjects' alveolar air. Neither the reaction time tests nor the short-term memory test showed any signs of performance decrement during exposure to TRI as compared to those administered under control conditions. However, a statistically significant decrement in performance was obtained on the test of numerical ability during exposure to TRI. The results as a whole indicate that there should not be any risk of an acute effect on central nervous functions at concentrations which do not considerably exceed the Swedish threshold limit value for the solvent (160 mg/m3).

A longitudinal study was performed to investigate the behavioral changes associated with occupational exposure to organic solvents. An initial simple reaction time (SRT) test was performed on a group of steel workers who were exposed to vapor concentrations of solvents clearly exceeding threshold limit values (TLVs). A second SRT measurement was made six months following the completion of major improvements in the hygiene quality of the work environment which resulted in a reduction of exposure levels to 20% of the TLVs valid at the time. Approximately fifteen months after this measurement, a final SRT test was performed. The workers' performance on the SRT test improved over the three measurements. At the first measurement occasion SRT was found to be related to the degree of exposure, while no such relation could be observed on the following measurement occasions. The results indicate that the workers' central nervous functioning had been negatively affected by solvent exposure and that this effect was at least partially reversible in nature; they thus confirm the importance of changes which enhance the hygienic quality of the work environment.