1000 resultados para Segurança Ambiental


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The proposal of this study was to obtain the profile of these metals distribution Al, Co, Cu, Pb, Cr, Ni, Co and Zn in sediments from lakes in the city of Londrina-PR and evaluate the environmental risk resulting from such distribution. The parameters of comparison were the values of geological occurrence of these metals in soil from this region, the concentrations of metals in soil samples in the surroundings of the sediments collection points, the guiding values from CETESB and resulting rate risk from RAC criterion application. The result shows that the numerical scale RAC alone is incomplete to this evaluation.

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The increasing use of nanomaterials in several products in different areas such as electronics, cosmetics, food and drugs has attracted the attention of the scientific community due to unknown properties of these materials, such as the life cycle and the interaction with receptor organisms once they reach the environment. In this context, the present work shows an updated scenario of nanomaterials applications, characterization methods and toxicity evaluation, also addressing important aspects related to the development and application of nanotechnology under the environmental point of view.

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Planet transformations caused by human intervention in the last 200 years are largely due to chemical impact. Therefore, this study aimed to identify and analyze the environmental perception of undergraduate students and lecturers in the Chemistry course of the Federal University of Lavras, accounting for the topics "Environmental Definition" and "Relationship between Chemistry and Environment". Two thematic axes for discussion were proposed using theories of Social Representation and Environmental Complexity, with the aim of stimulating the conservationist reasoning and actions. Such axes were proposed to give support to the education of chemists at the undergraduate level.

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The mineral waste studied was host rock from a chromite mine located in Andorinha/Bahia, extracted and stockpiled in yards without specific application. Host rock was submitted to chemical analysis, XRD, SEM-EDS, IR and TGA and classified according to ABNT standards for solid waste classification. Analyses confirmed that this host rock, classified as ultrabasic, consists mainly of dolomite, calcite and diopside. Hazard assessment results showed this host rock should be classified as class II B - inert waste, important for its potential application in agriculture as a soil acidity correction agent.

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In this work, noise and aromatic hydrocarbons levels of indoor and outdoor karting circuits located in Rio de Janeiro were assessed. The sampling was perfomed using active charcoal cartridges, followed by solvent desorption and analysis by gas chromatography with mass spectrometry detection. This study demonstrated that the karting circuits, venues for entertainment, were a major source of air pollution with the detection of considerable amounts of these compounds (2.0 to 19.7 µg m-3 of benzene; 4.1 to 41.1 µg m-3 of toluene; 2.8 to 36.2 µg m-3 of ethylbenzene; 0.7 to 36.2 µg m-3 of xylenes) and high noise levels.

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A study evaluating Brazilian chemical researchers understanding of the scope of the terms Environmental Sustainability and Sustainable Development, and their assessment of how to deal with environmental fragility and limits, is reported. Results showed a certain degree of acknowledgement of the need for a more sustainable development, but little agreement on the magnitude of the environmental limits. The researchers recognized the limitations of the classical paradigms "of dilution" and "of risk", but showed no agreement on the requirements of the new "ecological paradigm" based on Environmental Sustainability and the 12 principles of Green Chemistry, important to assess the role of Green Chemistry for Sustainability.

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This paper shows the investigation results related to identifying the prospects of addressing environmental issues in the discipline of environmental studies, included in the bachelor degree course in chemistry at nine institutions of higher education in the south and southeast. From the analysis of the interviews we found that environmental issues are part of the initial licensing, but still require a deepening of possible interfaces and convergences between the dimensions of environmental chemistry and green chemistry, as well as a greater approach to and association with the field of environmental education in addressing environmental issues.

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Ecological risk assessment is a process evaluating the likelihood that adverse ecological effects may occur or are occurring as a result of exposure to one or more substances. Relevant information needed to predict risks from pesticides includes their physical chemical properties, mobility in soil, persistence in the environment, and bioaccumulation and toxicity in relevant organisms. Although currently a requirement for pesticide registration in Brazil, this process is not yet fully implemented in the country. This review aims to outline the principles of environmental risk assessment for pesticides, focusing on aquatic organisms, and to discuss the studies and efforts conducted in Brazil in this area.

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Arsenic is considered a semimetal, and its wide distribution in the Earth's crust in different chemical forms, including organic and inorganic species, has a great deal of influence on the mechanisms of toxicity. Exposure to arsenic can be either through occupational practice (use of pesticides) or by the consumption of water and food containing the element. Rice is considered a fundamental constituent of the basic diet of Brazilians and is usually cultivated in flooded conditions. Such a plantation system results in an increased amount of As in the soil and hence a greater accumulation of As in the plant, which is highlighted by the inorganic species' classification as highly toxic. Besides the use of mitigation techniques to reduce the toxicological risk, monitoring the concentration of As and its chemical species in rice and rice products is required through the establishment of legislation in the area. Thus, some world organizations are conducting improved research to determine and establish acceptable concentrations of As and its chemical species in rice, e. g., in 2012, FDA researchers described a chemical speciation methodology for As in rice and rice products. Hence, the application of existing chemical speciation methods and the establishment of parameters for ensuring food security and exposure risk assessment deserve particular consideration.

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Relata-se a experiência da realização de prova prática no concurso para seleção de médicos residentes no Centro Universitário Serra dos Órgãos, Teresópolis (RJ). Houve uma primeira fase com prova teórica (PT) de múltipla escolha e uma segunda fase com prova prática presencial (PP), ambas eliminatórias e classificatórias. As cinco áreas básicas do ensino médico foram avaliadas por meio do exame clínico de dois pacientes - um clínico ou cirúrgico e outro da área materno-infantil, conforme sorteio. A PP objetivou avaliar atitudes, habilidades e conhecimentos. Houve capacitação de dois tipos de bancas: a primeira com docentes das áreas clínica e cirúrgica, dita clínico-cirúrgica (CC), e a segunda com docentes das áreas de pediatria, tocoginecologia e saúde coletiva, chamada materno-infantil e preventiva (MIP). Não houve correlação significativa entre as notas da PT e as da PP. A PP foi determinante para a classificação final em cinco dos seis programas oferecidos. Houve correlação entre as notas das bancas CC e MIP (r = 0,483, p < 0,001). Houve uniformidade das notas intrabanca e interbanca. A PP é exeqüível, segura e importante instrumento para a adequação do ensino de graduação em Medicina às diretrizes curriculares.