Relationship of symptoms to occupational styrene exposure and to the findings of electroencephalographic and psychological examinations.

Abstract

Ninety-eight male laminating workers occupationally exposed to styrene were clinically examined, and their symptoms were clarified with the aid of a questionnaire. The mandelic acid concentration in urine was used as the measure of current exposure. The median mandelic acid concentration (mean of five determinations) of the exposed group was 808 mg/l (Q1 439, Q3 1390). The symptoms of the exposed group were compared with those of unexposed men (n=98) and also correlated to the mandelic acid concentration. Symptoms of fatigue, difficulties in concentration and symptoms of irritation occurred statistiscally significantly more often in the exposed group than in the unexposed one (p < 0.01). During the workday irritation and „prenarcotic” symptoms, e.g., nausea, dizziness and a drunken feeling, were reported significantly more often (p < 0.001) in the exposed group. When the relationship between symptoms, and also symptom scores, and the mandelic acid concentration was examined, no statistically significant correlation was found. Also a comparison of symptoms of the most and least exposed groups revealed no statistically significant difference. Earlier abnormal electroencephalographic (EEG) findings and abnormal psychological functions (lowered psychomotor accuracy and speed) had been found to statistically significantly correlate with urinary mandelic acid concentration. In the present investigation the symptoms and symptom scores of the groups with abnormal EEGs or psychological functions were compared to the group with corresponding normal findings, and no statistically significant difference was found. The clinical examination did not reveal any neurological deficits. In an attempt to determine whether mandelic acid causes uroepithelial atypias, a urinary cytologic examination was made; none of the 35 specimens showed any suspicious cellular changes. The results of the symptom survey indicate that the presence of symptoms can not be used as a predictor of exposure or as a predictor of abnormal findings in psychological and EEG examinations. They might also indicate that the symptoms and the objective findings describe different aspects of the effects of styrene exposure.