Association between Concentrations of Malondialdehyde (MDA) and Neurological Abnormalities in People Occupationally Exposed to Mercury

Abstract

It is believed that mercury neurotoxicity is due to induction of oxidative stress [as determinedby increased concentrations of malondialdehyde (MDA)], but we don’t know if to have higherconcentrations of MDA involves to have more neurological disorders. Objective: To establish associationbetween urinary concentrations of MDA and the severity of neurological abnormalitiesin people exposed to mercury. Materials and methods: A cross-sectional study was done. Inclusioncriteria: men between 18 and 60 years with occupational exposure to metallic mercury. Thesample was taken from a database of 110 patients exposed to mercury. Information was gatheredfrom medical records with emphasis on neurologic outcome, from the mercury concentration inurine of 24 hours and from urinary MDA analysis. For statistical analysis, nonparametric testswere used for comparisons between concentrations of MDA among those with neurologicaldisorders vs. those without disorders and to evaluate differences in the concentrations of thissubstance according to the severity of these alterations; it was performed correlation analysisbetween urinary concentrations of MDA and urinary concentrations of mercury. Results: Theconcentrations of MDA in patients exposed to mercury with neurological abnormalities were notdifferent from those without abnormalities. MDA concentrations neither were associated withthe severity of clinical findings. There was no correlation between MDA and urinary mercuryconcentrations. Conclusion: It will be necessary to search biological samples other than urinethat could reflect what occurs in CNS or look for other pathophysiological causes to explain thepresence of clinical findings in these patients.

Keywords

• malondialdehyde
• MDA
• mercury
• neurotoxicity
• mining
• free radicals.