Estudo das alterações hematológicas, bioquímicas e genotóxicas induzidas por agrotóxicos em agricultores do estado do Piauí

Abstract

Exposure to pesticides represents a potential risk to human health. In addition to poisoning, these compounds may interact with DNA, causing degenerative diseases, including cancer. The risk assessment for pesticides was conducted in the municipalities of Picos, Piripiri, Barras and José de Freitas with farm workers (exposed group) and 55 administrative officers from Teresina (Capital) as unexposed group. It was as a proposal for the continuation of studies previously performed in other cities of Piauí (Baixa Grande do Ribeiro, Ribeiro Gonçalves and Uruçuí). The purpose of this study was to evaluate the toxicity and genotoxicity/mutagenicity effects of occupational exposure to complex mixtures of pesticides by using hematologic, enzymatic and genotoxic/mutagenic biomarkers. Initially, a questionnaire recommended by the International Commission for Protection Against Environmental Mutagens and Carcinogens-ICPEMC was applied, then biological material was collected for the hematological, biochemical, genotoxic and mutagenic analysis.The population exposed to pesticides (n = 97) had a mean age of 40.37 years and a mean working time of 19.32 years, with a schedule of 41.38 hours per week. 50.5% of the farmers use personal protective equipment (PPE). About their lifestyle, 33% were smokers; 59.8% consume alcohol; 34% use prescription drugs; 54.6% were vaccinated in the last 6 months; 68% do not consume vegetables, and 96.9% eat meat. They use 13 different types of active ingredients, 53.5% are herbicides. As for hematological parameters of the 97 workers exposed, only 39% presented leucopenia, and only 10% presented low red blood cell count. The biochemical variables: urea, total proteins and fractions, Gamma GT, there were no significant changes. However, the dosages of creatinine, AST, ALT and alkaline phosphatase, showed significant changes (p <0.05) compared to the control group. It was also observed that butilcolinesterase inhibition was a non-significant data. Genotoxicity was observed on the exposed farmers (p <0.001), as seen in the damage index (45.85 vs 12.51) and the damage frequency (29.41 vs. 9.98) in exfoliated cells. We found a high damage index (33.27 vs. 10.12) and frequency of damage (21.44 vs. 9.38) in the lymphocytes of the exposed farmers, when assessed by the comet test. The mutagenic evaluation by the increase of micronuclei (MN) in oral mucosa was also statistically significant (p <0.001) in the exposed farmers (4.95 ± 2.81) compared to those not exposed (0.72 ± 1.20), as well as the increase in the frequency of MN (0.24 ± 0.14 vs. 0.03 ± 0.06). Similarly, mutagenicity in the lymphocytes evaluated by the MN test with cytokinesis block was observed (p <0.01) in the farmers (p <0.001) when compared to the unexposed group (9.38 ± 1.05 vs. 5.50 ± 0.84). Significant increase (p <0.001) in the percentage of chromosomal aberrations (CA) in exposed workers compared to the unexposed (3.24 ± 0.44. vs. 0.40 ± 0.07) were observed, with significance (p <0.001) for the types of AC: dicentric chromosomes, rings, tricentrics, acentric ring, terminal deletion and interstitial deletion. Significant evidence (p <0.001) for apoptosis was found in oral mucosa cells and lymphocytes, with cytokinesis blocking. Positive correlations (p <0.01, p <0.05) of DNA damage in oral mucosa cells were found for age, smoking, drinking and working time. However, these correlations were not observed for the micronuclei. In oral mucosa cells, apoptosis and binucleated cells were significantly (p <0.01) correlated with the age of the worker. Regarding the MN in lymphocytes, the percentage of AC and apoptosis, positive correlations with the alcohol consumption (p <0.01) was observed. MN in lymphocytes was also significantly correlated (p <0.05) with the low intake of micronutrients and the use of PPE. The parameters of genotoxicity and mutagenicity were indicative of genetic instability, which may suggest the risk of cancer. Thus, the biomonitoring of these farmers is necessary as a strategy for health surveillance, prevention and promotion of occupational health in the state of Piaui.