Absence of Genotoxic Effect of Mercury Vapor in Lymphocytes of Occupationally Exposed Individuals

Abstract

Objective: to evaluate the genotoxic effects caused by exposure to Hg vapor in individuals with occupational exposure in a municipality in northern Brazil. Methods: Blood samples were collected from 70 individuals (38 exposed and 32 unexposed controls) in heparinized tubes. The comet assay and the micronucleus test were used to detect the occurrence of genotoxic effects. The results were statistically analyzed using the Shapiro-Wilk normality test, Student's T test and ANOVA. Non-parametric data were analyzed using the Mann-Whitney and Kruskal-Wallis tests. Spearman's test was used to assess the correlation between dependent variables. Mean, geometric mean and standard deviation (SD) were calculated. Results and Conclusions: The evaluation of genotoxicity revealed no difference in the frequency of DNA damage when the two groups, control and exposed, were compared, even considering confounding variables such as smoking and alcoholism, gender, age, time of exposure. In conclusion, our results indicate that exposure to Hg vapor (elemental form) did not produce detectable genotoxic changes in blood cells in vivo. Research Implications: Although no genotoxic effects were detected in blood cells from individuals exposed to mercury vapor, studies with cells that are in more direct contact with this source of contamination, such as oral and nasal epithelial cells, should be performed to confirm whether elemental form of Hg has no genotoxic effect.