[Neurologic and neurophysiologic examinations of workers occupationally exposed to aluminium]

Studies conducted to assess aluminum (Al)-induced toxicity to humans and environment. It has been implicated that Al is involved in the etiology of Alzheimer's disease and other neurodegenerative disorders, though this is controversial. The aim of the present study was to assess Al effects on the nervous system functions in workers chronically exposed to this metal.

The study covered a selected group of 67 male workers (mean age, 38.7 +/- 10.3 years; range 23-55 years) involved in aluminum production. Their employment duration ranged between 2 and 34 years (mean, 14.6 +/- 8.9 years). Aluminum oxide (Al2O3) concentrations varied from 0.2 to 1.95 mg/m3 (arithmetic mean, 0.40 mg/m3, geometric mean, 0.35 mg/m3, SD = 0.29). Urine aluminum concentrations found in smelters ranged from 8.5 to 93.0microg/l (mean, 42.9 +/- 20.5 microg/l). The control group consisted of 57 men non-occupationally exposed to Al matched by gender, age and work shifts.

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. The objective neurological examinations did not reveal organic lesions in the central or peripheral nervous system. In EEG classified as abnormal, generalized and paroxysmal changes were most common. Examinations of visual evoked potentials (VEP) revealed abnormalities, primarily in the latency of the response evoked.

The results of this study suggest that exposure to Al2O3 at concentrations within MAC values induces subclinical effect in the nervous system.