دانلود رایگان مقاله انگلیسی نشانگرهای سمیت ژنی و استرس اکسیداتیو در کشاورزان در معرض آفت کش ها - نشریه الزویر

ABSTRACT

The effects of chronic exposure to pesticides can lead to the development of several diseases, including different types of cancer, since the genotoxic and mutagenic capacity of these substances can be observed. The objective of this study is to investigate the relation between the occupational exposure to various pesticides and the presence of DNA damage and oxidative stress. Blood samples from 50 rural workers (41 men and 9 women) exposed to pesticides, 46 controls (20 men and 26 women) from the same city (Antônio Carlos, Santa Catarina state, Brazil) and 29 controls (15 men and 14 women) from another city (Florianópolis, Santa Catarina state, Brazil), were evaluated using the comet assay and the cytokinesis-block micronucleus (CBMN) technique for genetic damage, and the test of thiobarbituric acid reactive substances (TBARS) and catalase (CAT) activity for the oxidative stress. Cholinesterase activities were also determined, but there was no statistical difference among exposed workers and controls. Significant differences were found in DNA damage among groups. The comet assay performed on peripheral blood lymphocytes of these individuals had a significantly higher DNA damage index in the exposed group comparing to controls (p < 0.0001). MNi (p < 0.001), NBUDs (p < 0.005) and NPBs (p < 0.0001) were also found to be significantly higher in the exposed group. The TBARS values were significantly higher comparing to the Florianopolis control group (p < 0.0001). Even though CAT values were higher than controls, there was no statistical difference. Thus, it is concluded that the exposed individuals, participants of this study, are more subject to suffer genetic damage and, consequently, more susceptible to diseases resulting from such damages.

4. Conclusion

Farmers exposed to pesticides showed a significant increase in the frequency of MNi, NBUDs and NPBs. The damage index assessed by the comet assay was also significantly higher in these individuals. Therefore, it can be stated that the exposed group is suffering damage from recent exposure that can be repaired, however, they suffer mutations as well. These mutations may be caused by the direct exposure of the DNA to pesticides or by the oxidative stress generated from the exposure, since the markers of oxidative stress are also altered. Thus, it is concluded that individuals exposed to pesticides, participants in this study, are more subject to genetic damage and, consequently, more susceptible to diseases resulting from these damages. The authors emphasize the importance of carry out a second control group of an urban area of a city that does not have a significant role in agricultural production, since in cities with strong agricultural activity, the inhabitants of urban areas are also exposed to pesticides.