Effects of occupational exposure to aluminum on nervous system: clinical and electroencephalographic findings.

OBJECTIVES The aim of the present study was to assess the effects of aluminum (Al) on the nervous system functions in workers chronically exposed to Al. MATERIALS AND METHODS The study covered a selected group of 67 male workers (mean age, 38.7 SD 10.3 years; range 23-55 years) involved in the Al production. Their employment duration ranged between 2 and 34 years (mean, 14.6 SD 8.9 years). Aluminum oxide (Al203) concentrations varied from 0.13 to 1.95 mg/m3 (arithmetic mean, 0.40 mg/3, geometric mean, 0.35 mg/m3 SD 0.29). Urine Al concentrations found in smelters ranged from 8.5 to 93.0 microg/l (mean, 42.9 SD 20.5 microg/l). The control group consisted of 57 men non-occupationally exposed to Al, matched by gender, age and work shifts. RESULTS Clinically, headache (41.8%), increased emotional irritability (56.7%), concentration difficulty (22.4%), insomnia (22.4%) and mood lability (14.9%) predominated among functional disorders of the nervous system in workers chronically exposed to Al. Objective neurological examinations did not reveal organic lesions in the central or peripheral nervous system. In the EEGs classified as abnormal, generalized and paroxysmal changes were most common. CONCLUSIONS The results of this study suggest that exposure to Al203 at concentrations below MAC values induces subclinical effect in the nervous system.