The importance of blood trace elements in the biomonitoring of agrochemicals exposure and effects on DNA and epigenetic alterations

Background

Pesticides and trace element exposure can cause serious health outcomes. Brazil is a leading agrochemical user(kg/ha). This study aimed to assess DNA damage and epigenetic alterations due to agrochemical exposure in farmers from southern Brazil.

Methods

One hundred and twelve farmers (male and female) with different exposure to agrochemicals were studied: group 1, farmers who handled agrochemicals extensively during the month of sample collection (n=44), and group 2 (n=68), who did not. Lifestyle and occupational information questionnaires were applied. Biomonitoring was performed by evaluating cholinesterase activity, trace element levels in blood, buccal micronucleus cytome assay (BMCyt) in buccal cells, telomere lenght and epigenetic alterations.

Results

Cholinesterase activity showed no significant difference between groups. Blood trace elements such as As, Cr, Ni and V were above reference values, indicating excessive exposure. Strong correlations between trace elements suggested a common source of exposure. Group 1 had higher frequencies of micronuclei, nuclear buds, binucleated, and cell alterations, biomerkers for DNA damage and cytotoxicity. Global DNA methylation was higher in group 1 and correlated with Cr, Ni and Be. Telomere length was negatively correlated with age, Cr and Ni.

Conclusions

Farmers exhibited mutagenicity, telomere lenght and epigenetic alteration associeated with exposure to toxic trace elements, including important carcinogens. Moreover, the results demonstrated the importance of quantified trace elements as exposure biomarkers and the BMCyt assay, as a biomonitoring tool to evaluate agrochemical exposure. Limitations included the characterization of groups obtained through self-reporting and the absence of a non-exposed group.