Exposição ao glifosato e incidência de câncer em agricultores familiares do Município de Cerro Largo - RS

Abstract

The present research made use of interviews with family farmers in the municipality of Cerro Largo, RS and the collection of oral mucosa cells from these farmers for the analysis of micronuclei, with the objective of analyzing possible evidence that shows the relationship between glyphosate herbicide exposure and the incidence of neoplasias in farmers in this municipality. The research was composed of two stages, the first one being the application of a semi-structured questionnaire, where 6 communities were randomly selected and 20 farmers from each community were interviewed, totaling 120 farmers. The second stage was the collection of buccal mucosa from 10 farmers for the control case and 10 for the test. The data obtained from the application of the questionnaire were analyzed by the Chi-Square test, using a 95% confidence interval. The results of the micronuclei and variable frequencies were analyzed using the Kruskal-Wallis statistical test with a significance level of 5%. As the results indicate, the interviewees are of high age, 74 individuals are 51 years old or more and only 21 are in the age group between 20-40 years old. Regarding the level of education, 60% have only primary education. In relation to the use of glyphosate, 62.5% reported using it, mainly in the soybean and corn crops, and 26.66% used it between 5-10 years. 37.33% of the farmers are exposed between 30 minutes to one hour each application. Regarding the cases of cancer in the family, 62 farmers (51.66%) reported that they have had or have cases of cancer in their families. The association between age and use of glyphosate was not significant (p = 0.12), as well as the association between age and cancer cases was not significant (p = 0.06), between the cases of cancer and the use of glyphosate (p = 0.51) and the association between the cancer cases and the time of use of glyphosate (p = 0.56). Based on the interview data, it was found that farmers are at constant risk to their health, because they showed inadequacy of the rules of safe use of glyphosate herbicide, besides to the lack of knowledge about the dangerous nature of this pesticide by farmers. The micronucleus test has been widely used to evaluate the mutagenicity caused by agrochemicals. In this study the test was used to determine the genotoxic effects caused by glyphosate, demonstrating that exposure to the glyphosate herbicide increased the Micronucleus frequency in the test group (p = 0.0002), as well as highly significative increased frequency of cellular changes such as broken egg (p = 0.001), binucleation (p = 0.0001), caryolysis (p = 0.0004), there was only no significant difference in the cellular alteration of the karyorrhexis (p = 0.131). This study contributed to the recognition of the existence of risk factors associated with the use of glyphosate on the health of the rural workers of this municipality, that is, the use of the glyphosate herbicide may be capable of causing damage to the oral mucosa epithelium, adaptive via cellular modifications.