The systematic epidemiological monitoring of populations exposed to chemical agents, is one type of sanitary control that allows early detection of health problems. Human biomonitoring may be conducted with various cytogenetic tests, which evaluate genotoxic effects by detecting DNA damage. One validated and accepted test is the Micronucleus Assay, applied to the buccal epithelial cells. Workers, who were occupationally exposed, participated in our survey: 60 sugar cane cutters, 30 gasoline attendants, and 30 pesticide-sprayer pilots of small airplanes. Comparing the three groups, sugar cane cutters revealed higher fold increase (FI) of abnormalities: pyknotic nuclei (FI=31.4), chromatin condensation (FI=18.8) and binucleated cells (FI=15.0); gasoline attendants exhibited chromatin condensation (FI=14.5) and micronucleus (FI=3.6), and pilots showed severe nuclear abnormalities, counted as binucleated cells (FI=269.5), pyknotic nuclei (FI=54.2) and cells with chromatin condensation (FI=45.2). The biomonitoring of the side effects derived of exposure to genotoxic substances, in the workplace, such as the one we have done for this research, is fundamental for the design of corrective and preventive strategies that assure the health of the worker and biosecure working conditions. Detection of these biomarkers in exposed people indicates genotoxicity events and increased risk of disease development.

Keywords: Occupational Exposure; Nuclear Biomarkers; Cytotoxicity;