NEUROBEHAVIORAL EFFECTS OF OCCUPATIONAL EXPOSURE TO LOW-LEVEL ORGANIC-SOLVENTS AMONG TAIWANESE WORKERS IN PAINT FACTORIES

At six paint factories in northern Taiwan, 325 workers participated in a detailed evaluation that included medical and occupational question naires, blood sampling, neurobehavioral tests, vibratory perception th reshold tests, and thermal perception threshold tests. Because of cult ural differences, a Chinese test battery was modified from the Neurobe havioral Evaluation System 2. Eleven tests were performed: finger tapp ing, continuous performance, associated learning, symbol-digit, patter n comparison, pattern memory, visual digit span, switch attention, ass ociated delayed recognition, mood scales, and vocabulary. Air concentr ations of organic solvents were measured by passive personal samplers and analyzed by gas chromatography. Results showed that major solvents to which the workers were exposed were toluene, xylene, n-hexane, met hyl iso-butyl ketone, and n-butyl acetate. The exposure index (EI) was classified by different exposure patterns and different air concentra tions in the breathing zone as follows: EI 0, nonexposure; EI 1, low e xposure; and EI 2, high exposure (the medians of 8-hr hygienic effects were 0, 0.03, and 0.25, respectively). Because of their diverse socio economic status and demographic characteristics, the workers were divi ded into two groups for additional analysis: one group comprised white -collar workers, including technicians and administrative staff, and t he other comprised blue-collar workers. By using multiple linear regre ssion analysis controls for age, sex, education, and alcohol intake, s ignificant associations were found between increased exposure to solve nt mixtures and performance on some neuropsychologic tests. In the blu e-collar group, significantly prolonged response latencies were observ ed in the tests of continuous performance, pattern comparison, and pat tern memory. Among white-collar workers, significant impairment was ob served in the continuous performance test. All three tests involved vi sual attention and perceptual (speed and memory) functions. It was con cluded that these may be the earliest neurotoxic signs of occupational exposure to low-level organic solvents in paint manufacturing workers . (C) 1997 Academic Press.