Neurobehavioral effects of chronic occupational exposure to organic solvents among Japanese industrial painters.

To investigate the relationship between chronic exposure to organic solvents and changes in central nervous system function, industrial painters were compared with an age- and education-matched referent group of nonexposed workers. Eighty-one male painters completed a symptom questionnaire. Twenty painters underwent both questionnaire and neuropsychological examinations. From the results of pairwise comparisons of the symptoms, dry and scaly skin, being easily depressed without reason, coldness of hands and legs, being easily irritated without reason, loss of appetite, dizziness, and unsteadiness occurred statistically significantly more often among the exposed subjects than among the referents. Performances on the Digit symbol test and vocabulary test scores (synonyms) in exposed subjects were significantly lower than those of controls. In multiple regression models, controlling for age, education, and alcohol intake, a significant relation was found between the duration of the solvent exposure and poor performance in both the Block design and Digit span tests. The relation between toluene exposure and poor performance in both the Santa Ana coordination test and the Benton visual retention test was also significant. The results suggest that a symptom inquiry and some behavioral tests are helpful for detecting the possible effects of exposure to low levels of organic solvents. However, no consistent pattern was observed in regard to the effects of organic solvent exposure on neurobehavioral function, which is coincident with the type I toxic central nervous system disorder as classified by the World Health Organization.