Aplicação de bioindicadores e avaliação clínica em trabalhadores rurais expostos aos praguicidas organofosforados visando subsidiar a implantação de uma rede de atenção primária à saúde

Abstract

The use of pesticides in Brazil has been growing recently, leading to an increase in the intoxication cases caused by the exposure, especially of farm workers, to these substances. Among all the pesticides, the organophosphates (OF) are one of the most used groups, although they present high toxicity, which is risky for population. Thus, the aim of this study was to evaluate the exposure of farm workers to organophosphates pesticides through the determination of clinical evaluation associated biomarkers, providing information for the implementation of a primary health care system by the Government. It was a cross-sectional and population-based evaluation study approved by the Ethics Committees in Research of UNIFENAS and UNIFAL-MG (Document numbers 415856 and 149718), allowing the use of a 1,027 rural workers sample from Alfenas-MG health regional, considering epidemiological, clinical and occupational risk variables. Two forms were applied, one for collection of rural workers epidemiological and clinical data, and the Primary Care Assessment Tool (PCATool), as well as the determination of plasma, erythrocyte and total cholinesterase, and the evidences of liver and kidney function. Subsequently, from this population, two groups were selected: the occupationally exposed to the complex mixture of pesticides with OF (n = 94), and the occupationally exposed to the complex mixture of pesticides without OF (n = 94). Both groups were evaluated through urinary dialkyl phosphates biomarkers, genotoxicity assays (cytome and comet), and polymorphism of CYP2C9, comparing these results with those obtained in a group of individuals not occupationally exposed to pesticides, urban residents (n = 50). From the PCATool responses (n = 1027), it was noticed that despite high coverage, the occupational risk and its consequences have not been detected by the family health services, referring to a non-oriented primary care. When compared to other study groups, the clinical evaluated data showed significant changes in the central nervous, respiratory and auditory systems in workers exposed to the mixture containing OF. In the biological monitoring of the occupationally exposed group, the plasma, erythrocyte, and total cholinesterase activities changed in 63.8%, 12.8% and 14.8%, respectively, with 92.6% of dialkyl phosphates detection in urine. Moreover, in this group it was a significant change in all the test parameters cytome when compared with the group not exposed occupationally. The comet assay showed DNA damage through significant difference between exposed and unexposed groups by Tail moment. CYP2C9 polymorphism presented a higher frequency of allele * 1 / * 2 and * 1 / * 3 in the exposed population in relation to the unexposed group. However, there was no significant correlation between this test and cholinesterase activities, nor with dialkyl phosphates concentration in urine and genotoxicity tests. The results obtained in this ascertained study, with a Brazilian rural population, suggested that these workers are exposed to pesticides in a risky way. In addition to this fact, low education levels and precarious primary care actions increase the probability of intoxication events, indicating the importance of health teams training for promoting, preventing and treating this population. The combination of internal dose, effect, genotoxicity and susceptibility biomarkers can be an important tool to assess the exposure of rural population, decreasing the emergence of diseases resulting from occupational exposure to pesticides.