Avaliação da qualidade do ar no Parque Estadual do Itacolomi (PEI- MG) utilizando Spondias dulcis Forst F. (Anacardiaceae) como organismo bioindicador

• Autor(a) principal: Santos, Eliza Louback Coelho dos
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2553
• topic: Alteraçoes anatomicas; Quimica da atmosfera; Quimica de agua da chuva; Estresse enzimatico; Biomonitoramento ativo; Anatomical changes; Chemistry of the atmosphere; Chemistry of rainwater; Enzymatic stress; Active biomonitoring; CNPQ::CIENCIAS BIOLOGICAS::BOTANICA

Of all air pollutants, fluoride has the most fitotoxicity. Nearby Itacolomi State Park (PEI-MG), located in the city of Ouro Preto, MG, there's an aluminum plant which might be releasing fluoride in that region. It's important to verify the air quality at the PEI, as the air might conduct the fluoride released by the factory onto the site. Spondias dulcis Forst F. (Anacardiaceae), commonly known as cajá-mirim, was selected as a bio-indicator of fluoride for showing a high level of sensitivity in response to that pollutant. This research had the intent to evaluate the fluoride effects of the Ouro Preto plant, with an active bio-monitor utilizing S. dulcis as the bio- indicator organism. For such study, the plants were exposed in four areas of the park (Portaria, Capela, Início da Trilha and Lagoa Seca) and at Universidade Federal de Viçosa, as a reference point (Casa de Vegetação). The emerging of visual symptoms was evaluated daily during the exposure, as well as environmental changes such as wind speed, temperature, humidity and altitude. There were installed rain water collectors and oxidant gathering filters on the exposition shelves during the trial period. By the end of the exposure, there were collected leaflats with and without visual symptoms for anatomic studies in light microscopy, scanning electron microscopy, histochemistry and x-ray microanalysis. The activities of the antioxidant enzymes, lipids peroxidation and quantification of phenolic compounds were analyzed on the healthy leaflats. The fluoride quantification on the dry leaf matter was also analyzed. Fluoride was existent in all PEI areas, meaning that the wind might be spreading the pollutant to the nearby land. The front desk area was considered the most polluted by the rain water analysis, x-ray microanalysis and fluoride quantification on the dry leaf matter. However, the plants at the Lagoa Seca area were the ones with the most visual symptoms, probably due to strong winds at that location, breaking the leaves and enabling the pollutant to enter the plants. The trail start area was considered a clean spot, with few visual symptoms, plants showing as much pollution as the ones at the reference point Greenhouse. It was noticed two types of xisymptoms on the leaflats: a darkening at the adaxial face and a wide brownish necrosis. The anatomic analysis showed three damage patterns: superficial necrosis, reaching just the palisade and spongy parenchyma, deep necrosis, reaching the entire mesophyll and a punctual necrosis perceived only at the central veins. With scanning electron microscopy it was detected a turgor loss and a flattening of the cell's external periclinal wall. In the areas where the damage was more noticeable, there was an erosion of the epicuticular wax that lead to delayering, resulting on the epidermis rupture and internal tissue exposure. At PEI's most polluted areas there ware increases of enzyme activity, synthesis and accumulation of phenolic compounds, that lead to peroxidation of structural lipids due to the massive production of reactive oxygen species caused by the pollutants. By atmospheric data, the pollutants generated by the aluminum plant are reaching PEI. Spondias dulcis was an important bio-indicator species, because in a few days it showed visual symptoms and accumulation of fluoride in their leaf tissues. The anatomy and vegetal physiology were important biomarkers for detecting changes caused by pollutants.