Abstract

BACKGROUND: Metal co-exposure of human subjects is an important matter of public health concern. It has been shown that Acetylcholinesterase activity is a suitable biomarker for the neurological risk assessment of some metals. A few studies have reported neurotoxicity risk among humans in co-exposure to chromium and nickel. OBJECTIVE: In this study, AChE activity was assessed in occupational exposure to chromium (VI) and co-exposure to nickel (II) and chromium (VI). METHODS: Air sampling was done in chromium electroplating workshops with the NIOSH 7600 and OSHA ID-121 methods for chromium and nickel assessment. Thirty-two workers from hard chromium plating and 30 from decorative chromium plating were evaluated, while AChE activity was measured by the Elman method. RESULTS: Personal exposure to chromium in 20 of the studied people exceeded the TWA set by ACGIH. Occupational exposure to nickel in 47 of the DCP subjects was found to be higher than TWA. Cholinergic inhibition in plating workers was marked by a decrease in AChE compared to controls. Subjects with chromium (VI) exposure contained significantly higher inhibition of AChE activity (p < 0.001) than workers with co-exposure to nickel (II) and chromium (VI). CONCLUSIONS: The chromium-matched electroplaters have no significant difference in AChE activity. It can be concluded that cholinergic inhibition with chromium (VI) is higher than nickel (II) exposure.