Biomonitoramento e avaliação da atividade antioxidante e níveis de acetilcolinesterase no sistema nervoso central de animais expostos à poluição atmosférica da cidade de Pelotas - RS.

Abstract

Pelotas, located in southern Brazil, the economic growth in the last decades (increase of industrial production and vehicle fleet) brought a series of impacts on the human health and environment. Some substances in particles found in the atmosphere may be responsible for the increase of the oxidative stress and inflammatory conditions in some target organs. The present study aimed to monitor the environmental levels of nitrogen dioxide (NO2) during the seasons and material in particles (PM2.5) in 8 locations in the city of Pelotas distributed according to location: southern part, east region, central zone, western, in the southwest, in the north, in southeast and northeast, as well as studying the biochemical changes in rats exposed to air pollution. The NO2 sample was performed using the atmospheric NO2 diffusion principle in cellulose filters impregnated with a specific absorbent solution for reaction with this gas. The equipment DustTrak was used for analysis of the material in particles 2,5 μm. The average percentage in all stations PM2.5 the 8 points analyzed 6 points exceeded the limits recommended by the World Health Organization (WHO) (25 mg/m3). The south point exceeded 95%, point to the east 25.16%, the central zone 58.24%, point west 12.21% exceeded, southeast point exceeded 19.16% and northern 25.6%. Site located in the southwest and northeast region did not exceed the limits of WHO. Regarding the environmental monitoring of NO2 (μg/m3) the average percentage of points did not exceed the values recommended by WHO (40 μg/m3). In order to verify the effect of acute exposure to particulate matter in environmental levels in the winter and summer seasons Wistar adult male rats for periods of 20 hours (4h/day) during 5 days. This procedure was done in two separate locations relative to the dispersion and concentration of pollutants. The analysis of the levels of acetylcholinesterase (AChE) and antioxidant enzymes catalase, dismutase and glutathione peroxidase, superoxide production of thiols and free radicals through the dichlorofluorescein assay in 3 structures of the central nervous system were analyzed: prefrontal cortex, hypothalamus and hippocampus. The levels of AChE were greater in winter of the cortex and the hypothalamus corroborating the high levels of PM2.5 in both local. Concerning oxidative stress can suggest an adaptation from the levels of antioxidant enzymes since we observed in winter and summer production of thiols. The effect of exposure to air pollution in Pelotas influenced local and as well as on the season.