Biomonitoramento genético de indivíduos expostos ocupacionalmente a pesticidas no povoado Vila Bessa, município de Conceição do Jacuípe, Bahia

Abstract

The high consumption of pesticides in Brazil and all over the world have lead researches to relate this exposition to possible genetic and health damages in rural workers. Studies reveal that cancer is considered a genetic disease, once it results of the mutation accrual in genes involved with control of proliferation and cellular differentiation or mutations in genes involved with the DNA repair. The aim of this study was realize a genetic biomonitoring in individuals occupationally exposed to pesticides evaluating the occurrence of chromosomal damages, by the Micronucleus assay in exfoliated cells of buccal mucosa, Comet assay and Chromosome Aberration assay in peripheral blood lymphocytes. Hematologic and hepatic alterations were also evaluated. The studied population included 32 agriculturists living in the village of Vila Bessa, Conceição do Jacuípe, Bahia, occupationally exposed to pesticides, and 30 control individuals, with no history of pesticides exposition. For the micronucleus assay, the material was collected by scaling buccal mucosa with a cytobrush, the smear was made and then fixed in methanol/acetic acid solution (3:1) and colored by Feülgen/Fast Green Method, slides were analyzed in blind test by optic microscopy in a minimum of 1000 cells/individual. To realize the assay of Comet and Aberration, Chromosomal and hematologic and hepatic alterations, were collected 10 mL of peripheral blood. Comet test was made according the methodology described by Singh et al. (1988), were counted 100 comet by slides and classified, by visual analyses, into five categories of damages (0, 1, 2, 3 e 4), and then calculated the index and frequency of damage. Chromosome Aberration test was realized with a lymphocytes culture and obtaining of metaphases by interrupting the cells cytokinesis. The hemogram and the transaminases TGO, TGP and GGT were analyzed; those were processed by the biochemical analyses laboratory of Escola Bahiana de Medicina e Saúde Pública. That wasn´t statistical difference in the occurrence of micronucleus among the evaluated groups (p = 0.163), but nuclear alterations, indicative of apoptosis and necrosis, were significantly found in the pesticide exposed group (p = 0.001), indicating a major cellular injury than a simple answer to epithelium´s differentiation and maturation. Numeric Chromosome Aberrations (3.3%) were significantly found in the exposed group (p = 0.001), were found DNA damages evaluated by the Comet assay in score 1 (p<0.001) in the exposed group; as also index of chromosomal damage with media ± SEM 4.032 ± 0.3336 to the control group and media ± 41.05 ± 3.227 to the pesticide exposed group (p<0.0001); and frequency of damage: media ± SEM control group 4.081 ± 0.3667 and media ± SEM pesticide exposed group 38.44 ± 2.664, with significant differences in the exposed group (p<0.0001). The studied individuals are exposed to glifosate and methyl parathion, both toxic to the human organism, and were anemics (p=0.004) and with leukopenia (p<0.001), however with no alterations in hepatic evaluations. We conclude that these individuals are exposed to potentially genotoxic agents, besides present hematologic alterations, and that the persistence of this contact with the pesticides can trigger to phenomenon’s involved with cancer initiation and promotion.