The effects of exposure to aluminium on neurobehavioural function and dopaminergic metabolism

Abstract

A study was conducted to evaluate the effects of exposure to aluminium (Al) on neurobehavioural function and dopaminergic metabolism among 33 exposed workers compared to 40 controls. The parameters measured included concentrations of Al in air, serum Al and urine Al. WHO Neurobehavioural Core Test Battery was used to measure the neurobehavioural functions. Homovanillic acid (HVA) and vanillymandellic acid (VMA), two end products of catecholamine metabolism were measured using high-pressure liquid chromatography (HPLC). Determinations of Al in serum and urine were carried out using precolumn lumogallion reaction HPLC technique. The geometric mean of the airborne concentration of inhalable Al dust was 1.90 mg/m3 (range 0.62-8.24 mg/m3). The mean concentration of Al in urine was significantly higher in the exposed workers than the controls (12.25 ± 6.04 vs 5.78 ± 3.10 ug/l), but no statistical difference was observed for serum Al (1.68 ± 0.63 vs 1.31 ± 0.40 mug/l); suggesting that urinary Al is a better biomarker for Al exposure. The neurobehavioural evaluation showed that there were significant differences for Santa Ana tests, digit symbol and Benton test, implying that the manual dexterity, eye-hand coordination and memory were poorer in the Al-exposed workers. The data also showed that both of the catecholamine metabolites were higher in the exposed group, especially urinary VMA (p < 0.01). These data reflect that exposure to Al could interfere with the dopaminergic metabolism and neurocognitive function.