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

It is believed that mercury neurotoxicity is due to induction of oxidative stress [as determined by increased concentrations of malondialdehyde (MDA)], but we don’t know if to have higher concentrations of MDA involves to have more neurological disorders. Objective: To establish association between urinary concentrations of MDA and the severity of neurological abnormalities in people exposed to mercury. Materials and methods: A cross-sectional study was done. Inclusion criteria: men between 18 and 60 years with occupational exposure to metallic mercury. The sample was taken from a database of 110 patients exposed to mercury. Information was gathered from medical records with emphasis on neurologic outcome, from the mercury concentration in urine of 24 hours and from urinary MDA analysis. For statistical analysis, nonparametric tests were used for comparisons between concentrations of MDA among those with neurological disorders vs. those without disorders and to evaluate differences in the concentrations of this substance according to the severity of these alterations; it was performed correlation analysis between urinary concentrations of MDA and urinary concentrations of mercury. Results: The concentrations of MDA in patients exposed to mercury with neurological abnormalities were not different from those without abnormalities. MDA concentrations neither were associated with the severity of clinical findings. There was no correlation between MDA and urinary mercury concentrations. Conclusion: It will be necessary to search biological samples other than urine that could reflect what occurs in CNS or look for other pathophysiological causes to explain the presence of clinical findings in these patients.