DNA damage induced by exposure to pesticides in children of rural areas in Paraguay

BACKGROUND & OBJECTIVES: Chronic exposure to pesticides can damage DNA and lead to cancer, diabetes, respiratory diseases and neurodegenerative and neurodevelopment disorders. The objective of this study was to determine the frequency of DNA damage through the comet assay and micronucleus (MN) test in two groups of children, under 10 yr of age living in rural Paraguay and in relation to pesticide exposure. METHODS: Two groups of 5 to 10 yr old children were formed; the exposed group (group A, n=43), born and currently living in a community dedicated to family agriculture and surrounded by transgenic soybean crops, and the control group (group B, n=41), born and living in a community dedicated to family agriculture with biological control of pests. For each child, 2000 cells were studied for the MN test and 200 cells for the comet assay. RESULTS: The comparison between exposed and control children revealed significant differences in biomarkers studied for the measurement of genetic damage (cell death and DNA damage). The median of MN was higher in the exposed group (6 vs. 1) (P<0.001). Binucleated cells (2.9 vs. 0.5, P<0.001); broken eggs (5.5 vs. 1.0, P<0.001); karyorrhexis (6.7 vs. 0.5, P<0.001); kariolysis (14.0 vs. 1.0, P<0.001); pyknosis (7.4 vs. 1.2, P<0.001) and condensed chromatin (25.5 vs. 7.0, P<0.001) were significantly higher in the exposed group. The values of tail length (59.1 vs 37.2 μm); tail moment (TM) (32.8 vs. 14.4 μm); TM olive (15.5 vs. 6); % DNA tail (45.2 vs. 27.6) and % DNA head (54.8 vs. 72.4), were significantly different between the two groups. INTERPRETATIONS & CONCLUSIONS: In children exposed to pesticides, a greater genotoxic and cytotoxic effect was observed compared to non-exposed children. Our findings suggest that monitoring of genetic toxicity in population exposed to pesticides and agrochemicals should be done.