Solvent-induced chronic toxic encephalopathy.

Chlorinated solvents, especially trichloroethylene, have been extensively used for metal degreasing since the beginning of this century. There have been case reports of cranial nerve damage and symptoms of acute and reversible encephalopathy. However, another issue during the last decade is the possible existence of a syndrome of chronic cerebral dysfunction. Our study deals with the risk of developing a state of psychoorganic syndrome after long-term exposure to solvents, mainly trichloroethylene. In this historical cohort study, 96 metal degreasers participated in a clinical medical and psychological examination. The risk of developing psychoorganic syndrome was proportional to the exposure duration, to increasing age, and to decreasing primary intellectual level. Using logistic regression analysis, there was a significantly increased risk of developing psychoorganic syndrome from solvent exposure. There was an odds ratio of 5.6 (0.93-34.3) for psychoorganic syndrome in the medium-exposed group. In the most highly exposed group, with a mean full-time exposure duration of 11 years, there was a significantly increased risk of psychoorganic syndrome, the adjusted odds ratio was 11.2 (1.9-66.6). None of four other potential confounders (arteriosclerotic disease, neurologic/psychiatric disease, alcohol abuse, and current solvent exposure) had any significant associations to psychoorganic syndrome.