Short-term leaf responses of Nicotiana tabacum Bel-W3 to ozone under the environmental conditions of São Paulo, SE - Brazil

The present study aimed to study if the intensity and precocity of short-term leaf responses of Nicotiana tabacum 'Bel-W3' depended on the daily atmospheric levels of ozone and/or daily meteorological conditions in a State Park located in the city of São Paulo, SE Brazil. From 16 September to 14 October 2002, three lots of six potted plants were exposed for fourteen days. Leaf necrosis, atmospheric ozone concentrations and meteorological parameters were daily measured. The average percentage of leaf necrosis ranged from 5 percent to 20 percent. A 4th degree polynomial model was proposed to explain daily progress of leaf necrosis on plants. The average ozone levels were increased from morning (1.3-39.2 ppbv) to the midday (1.6-52.0 ppbv) and decreased in the evening (0.5-39.9 ppbv). Daily pattern of accumulated percentage of leaf necrosis was not strictly related to ozone, but was influenced by the meteorological conditions and stage of development of leaves.

O estudo objetivou verificar se a intensidade e precocidade de respostas foliares de curto prazo de Nicotiana tabacum 'Bel-W3' dependem dos níveis atmosféricos de ozônio e/ou das condições meteorológicas diárias em um Parque Estadual localizado na cidade de São Paulo, SE-Brasil. Entre 16 de setembro e 14 de outubro de 2002, três lotes contendo seis plantas envasadas foram expostos no ambiente por quinze dias. Necroses foliares, concentrações atmosféricas de ozônio e parâmetros meteorológicos foram medidos diariamente. A porcentagem média de área foliar com necroses variou de 5 por cento a 20 por cento. Um modelo polinomial de quarto grau foi proposto para explicar o progresso diário das necroses foliares nas plantas. Os níveis médios de ozônio aumentaram a partir da manhã (1.3-39.2 ppbv) até o meio dia (1.6-52.0 ppbv), diminuindo a tarde (0.5-39.9 ppbv). O padrão diário de aumento de área foliar com necroses não foi relacionado estritamente com ozônio, mas foi influenciado pelas condições meteorológicas e pelo estágio de desenvolvimento das folhas.

In situ monitoring of mutagenicity of air pollutants in Säo Paulo City using Tradescantia-SHM bioassay

The Tradescantia stamen hair mutation assay (Trad-SHM) was employed for assessing the environmental mutagenesis in two areas of Säo Paulo City. The study sites were defined as follows: 1) Celso Garcia Avenue, an industrial area on the outskirts of the urban center (Belém neighborhood), with an average daily traffic volume of 8,750 vehicles; 2) Doutor Arnaldo Avenue, in downtown area (Pinheiros neighborhood), with a mostly residential and business offices occupation, with an average daily traffic volume of 46,125 vehicles. The negative control (background) site is located in the city of Jaguariúna, 138 km from Säo Paulo, in an area of low atmospheric pollution. The mutation frequency observed for Belém was similar to the background for clone 4430, whereas plants exposed in Pinheiros showed significant increases in mutation rate. Positive correlation was observed between mutation frequency and the levels of particulate matter in the atmosphere. This indicated a relationship between mutation frequency and the amount of atmospheric pollution present at the exposure sites in Säo Paulo City, with special reference to vehicular emissions

Air pollution impact on the Atlantic forest in the Cubatäo region, SP, Brazil

The rain forest covering the slopes of the Serra do Mar mountains, in the vicinity of Cubatão, SP, has been damaged by a variety of air pollutants emitted by the industrial complex established in the region. In a study by the Instituto de Botânica (São Paulo) and the Universities of Essen and Kassel (Germany) sensitive and cumulative indicator plants were explosed to the environment in an active biomonitoring program, in order to get information on the current air pollution situation and on the spatial and temporal distribution of air pollutants in the region, draw conclusions on the causes of vegetation damage, and facilitate risk prognosis. Native plant species, indigenous to the ecosystem were also studied (passive biomonitoring), in order to evaluate the present state of the vegetation, the effects of air pollution on plant vitality and detect mechanisms of pollution resistance. Both kinds of biomonitoring were performed in four sites: Pilões river valley, Caminho do Mar, Mogi river valley and Paranapiacaba, which are located at different altitudes, at various distances from pollution sources and consequently receive different kinds and loads of air pollution. Based on our results, fluorides, sulfur and metals are considered the main causes of the forest decline at the Mogi valley, whereas ozone. PAN and sulfur are implicated at Caminho do Mar. Native tree species show several chemical and biochemical alterations caused by the air pollution impact, that give information on their resistance or sensitivity to air pollution.