INTERNAL LOAD OF ALUMINUM AND THE CENTRAL-NERVOUS-SYSTEM FUNCTION OF ALUMINUM WELDERS

OBJECTIVES - Because the brain is the recognized target organ for alum inum toxicity, internal aluminum load and central nervous system funct ions were investigated among aluminum welders in a shipyard. METHODS - Seventeen male welders with a mean age of 37 (range 24-48) years and a history of about four years of metal inert-gas welding on aluminum w ere the subjects. Aluminum in serum (S-A1) and urine (U-A1) was analyz ed with graphite-furnace atomic absorption spectrophotometry. Central nervous system functions were examined with neuropsychological tests, symptom and mood questionnaires, quantitative electroencephalo,oraphy (QEEG), and P300 evoked responses. RESULTS - The mean S-A1 concentrati on was 0.21 (range 0.03-0.64) mu mol . l(-1) and the mean U-A1 was 2.8 (range 0.9-6.1) mu mol . l(-1). Although the welders performed normal ly on the neuropsychological tests, there was a negative association b etween all four memory tests and U-A1 and a positive association betwe en the variability of visual reaction times and S-A1. In the QEEG, the amount of delta and theta activity in the frontal region correlated p ositively and the amount of alpha activity in the frontal region corre lated negatively with S-A1. CONCLUSIONS - The S-A1 and U-A1 measuremen ts indicated increased internal loads of aluminum in most of the welde rs. This finding is compatible with slowly eliminated aluminum from ti ssues. The neuropsychological assessment suggested disturbing effects of aluminum on short-term memory, learning, and attention. In the QEEG , a corresponding exposure-effect relationship was found for activity in the frontal region. Further studies are needed on the possibility t hat exposure to aluminum welding fumes causes harm to human health.