Neuropsychological function in retired workers with previous long term occupational exposure to solvents

Objectives-It is plausible that neurodegenerative processes of aging might have a contributing role in the development of chronic effects of exposure to organic solvents. This study evaluated the risk for neuropsychological d eficits among retired workers, relative to their histories of exposure to o ccupational solvents. Methods-This cross sectional evaluated retired male workers, 62-74 years of age, including 89 people with previous long term occupational exposure to solvents (67 retired painters and 22 retired aerospace manufacturing worker s), and 126 retired carpenters with relatively minimal previous exposure to solvents. Subjects completed a standardised neuropsychological evaluation and psychiatric interview, structured interviews for histories of occupatio nal exposure and alcohol consumption, and questionnaires assessing neurolog ical and depressive symptoms. Results-By comparison with the carpenters, the painters on average reported greater cumulative alcohol consumption and had lower scores on the WAIS-R vocabulary subtest, usually presumed to reflect premorbid intellectual func tioning. These findings, however, were not sufficient to account for the ot her study findings. Controlling for age, education, vocabulary score, and a lcohol use, the painters had lower mean scores on test measures of motor, m emory, and reasoning ability; and a subgroup of aerospace workers with mode rate to high cumulative exposure to solvents (n=8) had lower mean scores on measures of visuomotor speed, and motor, attention, memory, and reasoning ability. Subjects were more likely to have an increased number of relativel y abnormal test scores (three or more outlier scores on 17 test measures) a mong both the painter group (odds ratio (OR), 3.1; 95% confidence interval (95% CI) 1.5 to 6.2) and the subgroup of aerospace workers with higher cumu lative exposure (OR 5.6; 95% CI 1.0 to 38). The painters, but not the aeros pace workers, reported significantly more neurological and depressive sympt oms. Conclusions-The findings are consistent with residual central nervous syste m dysfunction from long term exposure to organic solvents, persisting years after the end of exposure.