Neurological risk assessment of co-exposure to heavy metals (chromium and nickel) in chromium-electroplating workers

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.