Genotoxic biomonitoring of tobacco farmers: Biomarkers of exposure, of early biological effects and of susceptibility

► Tobacco farming presents hazards to those who cultivate and harvest the plant. ► The genotoxic and mutagenic effects in tobacco farmers were investigated. ► Genetic susceptibility, oxidative stress and trace elements were determined. ► Results show that farmers are exposed to substances with genotoxic potential. ► This investigation suggests that tobacco farmers are suffering occupational risk. Tobacco farming presents several hazards to those who cultivate and harvest the plant. The genotoxic and mutagenic effects in tobacco farmers were investigated. In order to verify the relationship between genetic susceptibility and biomarkers GSTT1, GSTM1, GSTP1, CYP2A6, PON, OGG1, RAD51, XRCC1, and XRCC4 genes polymorphism were evaluated. Oxidative stress markers and trace elements content were determined. Peripheral blood cells samples were collected from 111 agricultural workers during pesticides application and leaf harvest, and 56 non-exposed subjects. Results show that farmers are exposed to mixture of substances with genotoxic and cytotoxic potential. Only GSTM1 null and CYP2A6*9 showed significant associations with cytokinesis-blocked micronuclei assay results. In pesticide application an increase in trace elements content was observed. The results indicated that exposure to pesticides and nicotine can influence antioxidant enzymes activity. Our study drives the attention once more to the need for occupational training on safe work environment for farm workers.