Assessment of DNA damages in lymphocytes of agricultural workers exposed to pesticides by comet assay in a cross-sectional study

Purpose: To assess the predictive power of the comet assay in the context of occupational exposure to pesticides. Materials and methods: The recruited subjects completed a structured questionnaire and gave a blood sample. Exposure to pesticides was measured by means of an algorithm based on Dosemeci’s work (Agricultural Health Study). Approximately 50 images were analyzed for each sample via fluores- cence microscopy. The extent of DNA damage was estimated by tail moment (TM) and is the product of tail DNA (%) and tail Length. Results: Crude significant risks (odds ratios, ORs) for values higher than the 75th percentile of TM were observed among the exposed subjects (score>1). The frequency of some confounding factors (sex, age and smoking) was significantly higher among the exposed workers. A significant dose–effect relationship was observed between TM and exposure score. Significant high-risk estimates (ORs), adjusted by the studied confounding factors, among exposure to pesticides and TM, % tail DNA and tail length were confirmed using unconditional logistic regression models. Conclusions: The adjusted associations (ORs) between the comet parameters and exposure to pesti- cides were significant. The sensitivity of the comet test was low (41%), the specificity (89%) and the predictive positive value (0.77) were found acceptable.