940 resultados para 770701 Air quality


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The recent tendency to utilize parking lots for other purposes has demonstrated that more time has been spent by visitors, mainly in great cities. Therefore, this paper investigates the thermal comfort and the air quality indoors in areas specifically used as parking lots by analyzing the direct relation between such environments and vehicular pollution. The thermal comfort and the quality of air indoors in parking lots with different architectonic typology (ground-floor and underground) are also studied, aiming to contribute to the proposition of suitable new areas designated to human usage. Field research was done, in two distinct periods within different weather conditions (January and July) in, two naturally cooled, parking lots located in Natal - RN. The internal environment agents were measured by using tools for air temperature, humidity, speed and direction; interviews with employees and visitors and chemical analysis through appropriate tools to analyze specific material, carbon monoxide and ozone. The results showed that chemical agents densely concentrate mostly in the closed parking space, aggravated by weather conditions, which dissatisfied the visitors. Still, it was shown that architectonic typology, alongside topographical aspects compromise internal environmental conditions, which increases the retention of pollution, leading to dissatisfactory thermal comfort levels and becoming less suitable for usage by visitors considering air and thermal comfort aspects. Consequently, they are not suitable for human stay due to the poor quality of the indoor air

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Most major cities in the eastern United States have air quality deemed unhealthy by the EPA under a set of regulations known as the National Ambient Air Quality Standards (NAAQS). The worst air quality in Maryland is measured in Edgewood, MD, a small community located along the Chesapeake Bay and generally downwind of Baltimore during hot, summertime days. Direct measurements and numerical simulations were used to investigate how meteorology and chemistry conspire to create adverse levels of photochemical smog especially at this coastal location. Ozone (O3) and oxidized reactive nitrogen (NOy), a family of ozone precursors, were measured over the Chesapeake Bay during a ten day experiment in July 2011 to better understand the formation of ozone over the Bay and its impact on coastal communities such as Edgewood. Ozone over the Bay during the afternoon was 10% to 20% higher than the closest upwind ground sites. A combination of complex boundary layer dynamics, deposition rates, and unaccounted marine emissions play an integral role in the regional maximum of ozone over the Bay. The CAMx regional air quality model was assessed and enhanced through comparison with data from NASA’s 2011 DISCOVER-AQ field campaign. Comparisons show a model overestimate of NOy by +86.2% and a model underestimate of formaldehyde (HCHO) by –28.3%. I present a revised model framework that better captures these observations and the response of ozone to reductions of precursor emissions. Incremental controls on electricity generating stations will produce greater benefits for surface ozone while additional controls on mobile sources may yield less benefit because cars emit less pollution than expected. Model results also indicate that as ozone concentrations improve with decreasing anthropogenic emissions, the photochemical lifetime of tropospheric ozone increases. The lifetime of ozone lengthens because the two primary gas-phase sinks for odd oxygen (Ox ≈ NO2 + O3) – attack by hydroperoxyl radicals (HO2) on ozone and formation of nitrate – weaken with decreasing pollutant emissions. This unintended consequence of air quality regulation causes pollutants to persist longer in the atmosphere, and indicates that pollutant transport between states and countries will likely play a greater role in the future.

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A crescente urbanização global tem como consequência o aumento dos níveis de poluentes na atmosfera e a respetiva deterioração da qualidade do ar. O controlo da poluição atmosférica e monitorização da qualidade do ar são passos fundamentais para implementar estratégias de redução e estimular a consciência ambiental dos cidadãos. Com este intuito, existem várias técnicas e tecnologias que podem ser usadas para monitorizar a qualidade do ar. A utilização de microsensores surge como uma ferramenta inovadora para a monitorização da qualidade do ar. E, apesar dos desempenhos dos microsensores permitirem uma nova estratégia, resultando em respostas rápidas, baixos custos operacionais e eficiências elevadas, que não podem ser alcançados apenas com abordagens convencionais, ainda é necessário aprofundar o conhecimento a fim de integrar estas novas tecnologias, particularmente quanto à verificação do desempenho dos sensores comparativamente aos métodos de referência em campanhas experimentais. Esta dissertação, desenvolvida no Instituto do Ambidente e Desenvolvimento em forma de estágio, teve como objetivo a avaliação do desempenho de sensores de baixo custo comparativamente com os métodos de referência, tendo como base uma campanha de monitorização da qualidade do ar realizada no centro de Aveiro durante 2 semanas de outubro de 2014. De forma mais específica pretende-se perceber até que ponto se podem utilizar sensores de baixo custo que cumpram os requisitos especificados na legislação e as especificidades das normas, estabelecendo assim um protocolo de avaliação de microsensores. O trabalho realizado passou ainda pela caracterização da qualidade do ar no centro de Aveiro para o período da campanha de monitorização. A aplicação de microsensores eletroquímicos, MOS e OPC em paralelo com equipamento de referência neste estudo de campo permitiu avaliar a fiabilidade e a incerteza destas novas tecnologias de monitorização. Com este trabalho verificou-se que os microsensores eletroquímicos são mais precisos comparativamente aos microsensores baseados em óxidos metálicos, apresentando correlações fortes com os métodos de referência para diversos poluentes. Por sua vez, os resultados obtidos pelos contadores óticos de partículas foram satisfatórios, contudo poderiam ser melhorados quer pelo modo de amostragem, quer pelo método de tratamento de dados aplicado. Idealmente, os microsensores deveriam apresentar fortes correlações com o método de referência e elevada eficiência de recolha de dados. No entanto, foram identificados alguns problemas na eficiência de recolha de dados dos sensores que podem estar relacionados com a humidade relativa e temperaturas elevadas durante a campanha, falhas de comunicação intermitentes e, também, a instabilidade e reatividade causada por gases interferentes. Quando as limitações das tecnologias de sensores forem superadas e os procedimentos adequados de garantia e controlo de qualidade possam ser cumpridos, os sensores de baixo custo têm um grande potencial para permitir a monitorização da qualidade do ar com uma elevada cobertura espacial, sendo principalmente benéfico em áreas urbanas.

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A crescente urbanização global tem como consequência o aumento dos níveis de poluentes na atmosfera e a respetiva deterioração da qualidade do ar. O controlo da poluição atmosférica e monitorização da qualidade do ar são passos fundamentais para implementar estratégias de redução e estimular a consciência ambiental dos cidadãos. Com este intuito, existem várias técnicas e tecnologias que podem ser usadas para monitorizar a qualidade do ar. A utilização de microsensores surge como uma ferramenta inovadora para a monitorização da qualidade do ar. E, apesar dos desempenhos dos microsensores permitirem uma nova estratégia, resultando em respostas rápidas, baixos custos operacionais e eficiências elevadas, que não podem ser alcançados apenas com abordagens convencionais, ainda é necessário aprofundar o conhecimento a fim de integrar estas novas tecnologias, particularmente quanto à verificação do desempenho dos sensores comparativamente aos métodos de referência em campanhas experimentais. Esta dissertação, desenvolvida no Instituto do Ambidente e Desenvolvimento em forma de estágio, teve como objetivo a avaliação do desempenho de sensores de baixo custo comparativamente com os métodos de referência, tendo como base uma campanha de monitorização da qualidade do ar realizada no centro de Aveiro durante 2 semanas de outubro de 2014. De forma mais específica pretende-se perceber até que ponto se podem utilizar sensores de baixo custo que cumpram os requisitos especificados na legislação e as especificidades das normas, estabelecendo assim um protocolo de avaliação de microsensores. O trabalho realizado passou ainda pela caracterização da qualidade do ar no centro de Aveiro para o período da campanha de monitorização. A aplicação de microsensores eletroquímicos, MOS e OPC em paralelo com equipamento de referência neste estudo de campo permitiu avaliar a fiabilidade e a incerteza destas novas tecnologias de monitorização. Com este trabalho verificou-se que os microsensores eletroquímicos são mais precisos comparativamente aos microsensores baseados em óxidos metálicos, apresentando correlações fortes com os métodos de referência para diversos poluentes. Por sua vez, os resultados obtidos pelos contadores óticos de partículas foram satisfatórios, contudo poderiam ser melhorados quer pelo modo de amostragem, quer pelo método de tratamento de dados aplicado. Idealmente, os microsensores deveriam apresentar fortes correlações com o método de referência e elevada eficiência de recolha de dados. No entanto, foram identificados alguns problemas na eficiência de recolha de dados dos sensores que podem estar relacionados com a humidade relativa e temperaturas elevadas durante a campanha, falhas de comunicação intermitentes e, também, a instabilidade e reatividade causada por gases interferentes. Quando as limitações das tecnologias de sensores forem superadas e os procedimentos adequados de garantia e controlo de qualidade possam ser cumpridos, os sensores de baixo custo têm um grande potencial para permitir a monitorização da qualidade do ar com uma elevada cobertura espacial, sendo principalmente benéfico em áreas urbanas.

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There is increasing evidence of a causal link between airborne particles and ill health and this study monitored the exposure to both airborne particles and the gas phase contaminants of environmental tobacco smoke (ETS) in a nightclub. The present study followed a number of pilot studies in which the human exposure to airborne particles in a nightclub was assessed and the spatio-temporal distribution of gas phase pollutants was evaluated in restaurants and pubs. The work reported here re-examined the nightclub environment and utilized concurrent and continuous monitoring using optical scattering samplers to measure particulates (PM10) together with multi-gas analysers. The analysis illustrated the highly episodic nature of both gaseous and particulate concentrations in both the dance floor and in the bar area but levels were well below the maximum recommended exposure levels. Short-term exposure to high concentrations may however be relevant when considering the possible toxic effects on biological systems. The results give an indication of the problems associated with achieving acceptable indoor air quality (IAQ) in a complex space and identified some of the problems inherent in the design and operation of ventilation systems for such spaces.

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There is increasing evidence of a causal link between airborne particles and ill health and this study examined the exposure to both airborne particles and the gas phase contaminants of environmental tobacco smoke (ETS) in a bar. The work reported here utilized concurrent and continuous monitoring using real-time optical scattering personal samplers to record particulate (PM10) concentrations at two internal locations. Very high episodes were observed in seating areas compared with the bar area. A photo-acoustic multi-gas analyser was used to record the gas phases (CO and CO2) at eight different locations throughout the bar and showed little spatial variation. This gave a clear indication of the problems associated with achieving acceptable Indoor Air Quality in a public space and identified a fundamental problem with the simplistic design approach taken to ventilate the space. Both gaseous and particulate concentrations within the bar were below maximum recommended levels although the time-series analysis illustrated the highly episodic nature of this exposure.

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Indoor and outdoor concentrations of various pollutants were measured in a naturally ventilated building in the West End of Edinburgh during and after the period of the Commonwealth Heads of Government Meeting (CHOGM) to assess the effect upon indoor pollution levels of the closure of some streets in the city. The relationships between indoor and outdoor air qualities in respect of traffic-generated pollutants were studied and the building’s relative attenuation of external pollution levels investigated. The peak concentrations of some of the external pollutants were attenuated by the building and the internal concentrations showed a reduction of up to 30% in some periods. During periods of reduced traffic, the early analyses indicate that the daily mean concentrations of the pollutants were not significantly different from those measured at other times.

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An integrated method for the prediction of the spatial pollution distribution within a street canyon directly from a microscopic traffic simulation model is outlined. The traffic simulation package Paramics is used to model the flow of vehicles in realistic traffic conditions on a real road network. This produces details of the amount of pollutant produced by each vehicle at any given time. The authors calculate the dispersion of the pollutant using a particle tracking diffusion method which is superimposed on a known velocity and turbulence field. This paper shows how these individual components may be integrated to provide a practical street canyon pollution model. The resulting street canyon pollution model provides isoconcentrations of pollutant within the road topography.

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This study aimed to determine the concentration and inorganic chemical composition of samples from airborne particulate matter inhaled in fine and coarse fractions. Aerosol samples were collected in 2013 and 2014, from sites located in the cities of Londrina and Maringa, in the state of Paraná, Brazil. The samples were collected daily (24h) in two campaigns: winter and summer. For the collection, was used a dichotomous sampler with quartz fiber filter with 47 mm in size and 2 µm porosity, 97% efficiency, retaining particles of up to 0.3 µm. Quantification of the airborne particulate matter mass was performed by gravimetry method. The results from Londrina to PM2.5 and MP2,5-10 represent, respectively, 29.2% and 70.8% of airborne particulate matter in the winter campaign (2013), 30.9% (PM2.5) and 69.1 % (MP2,5-10) in the summer campaign (2013), and 35.9% (PM2.5) and 64.1% (MP2,5-10) in the winter 2014 campaign. In the city of Maringa, the results presented the percentage of 42.0% (PM2.5) and 58.0% (MP2,5-10) for the winter season (2014), and 28.8% (PM2.5) and 71.2 % (MP2,5-10) for the summer season (2014). The PM2.5/PM10 ratio was on average 0.3, demonstrating that both cities are developing urban areas. Analysis of the major soluble inorganic species in water (NO3-, SO42- and Cl-) associated with MP2,5-10 were quantified by ion chromatography at the LACA Laboratory in the State University of Londrina, with the largest contribution found in all campaigns was to NO3-. The NO3-/SO42- ratios above 1.0 indicate the local traffic contribution. The analysis of metals associated with PM2.5 was carried out by mass spectrometry with inductively coupled plasma (ICP-MS) in the Federal University of Santa Catarina. The Zn, Pb, Cu and Mn concentrations found in all campaigns indicate the contribution of mobile sources to PM2.5. The concentration of BCe in PM2.5 was determined by reflectance, with higher BCe concentrations being found in winter campaigns. In general, Londrina presented the highest concentrations from the species analyzed when compared to Maringá. In addition, the analysis of the air mass trajectories indicated the transportation of pollutants coming mainly from fires in the southeastern region of the country.

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The “Compass E-Newsletter” is published quarterly by the South Carolina Department of Health and Environmental Control and is compiled by the Office of Solid Waste Reduction and Recycling to provide environmental information from the agency.

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Air pollution can threat the environment and public health, and is assess by pollutant ́s concentration measurements in order to verify whether the limits set by environmental agencies are being respected. However, these measures do not indicate immediately the impacts to living beings. To faced this problem, plants are been investigated as potential bioindicators of air pollution and, among them, stand out bromeliads Tillandsia genus which colonize various substrates,. obtaining water and nutrients from the atmosphere directly. In this context, this research assessed the potential of epiphytic bromeliad Tillandsia recurvata (L.) L. found in urbanized areas of the city of Curitiba - PR as a bioindicator of urban air pollution. According to vehicle traffic, five sample points were selected and classified. Points P1 and P2 were classified as high-traffic vehicle due presenting trucks and urban transport; point P3 was classified as moderate traffic due the predominance of private vehicles and urban transport; and points P4 and P5 were classified as low-traffic, presenting circulation of private vehicles only. There were analyzed the abundance of T. recurvata, morphophysiological parameters (leaf area, leaf specific area, sclerophylly index, percentage dry weight / fresh weight, chlorophyll (a + b), analysis of structural mesophyll organization) and the heavy metals accumulation (Fe, Cd, Cr, Cu, Pb and Zn). The abundance analysis and the results obtained for metals analysis were correlated with the intensity of vehicular traffic, directing the sampling points P1 > P2 = P3 > P4 = P5. This result demonstrate that the abundance of T. recurvata is greater in urban air pollution impacted areas, thus indicating that T. recurvata absorbs and accumulates metals and can be used in biomonitoring of urban air pollution in areas impacted by vehicular traffic. Morphophysiological parameters analyzed shows that the internal plant ́s structure is not significantly impacted by urban air pollution due plant ́s adptations. The presence of absorbing scales, the CAM metabolism pathway and it ́s store water ability, among other features, demonstrate their potential as bio-indicator in urban areas, especially regarding heavy metals accumulation .

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Children spend a large part of their time at schools, which might be reflected as chronic exposure. Ultrafine particles (UFP) are generally associated with a more severe toxicity compared to fine and coarse particles, due to their ability to penetrate cell membranes. In addition, children tend to be more susceptible to UFP-mediated toxicity compared to adults, due to various factors including undeveloped immune and respiratory systems and inhalation rates. Thus, the purpose of this study was to determine indoor UFP number concentrations in Portuguese primary schools. Ultrafine particles were sampled between January and March 2014 in 10 public primary schools (35 classrooms) located in Porto, Portugal. Overall, the average indoor UFP number concentrations were not significantly different from outdoor concentrations (8.69 × 10(3) vs. 9.25 × 10(3) pt/cm(3), respectively; considering 6.5 h of indoor occupancy). Classrooms with distinct characteristics showed different trends of indoor UFP concentrations. The levels of carbon dioxide were negatively correlated with indoor UFP concentrations. Occupational density was significantly and positively correlated with UFP concentrations. Although the obtained results need to be interpreted with caution since there are no guidelines for UFP levels, special attention needs to be given to source control strategies in order to reduce major particle emissions and ensure good indoor air quality.

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O presente estudo analisa a associação entre partículas inaláveis (PM10) à superfície e determinadas situações meteorológicas, com base em dados (1999-2003) de concentração de partículas finas e grosseiras de estações de qualidade do ar da região de Lisboa e observações meteorológicas. Associaram-se os episódios de poluição a situações sinópticas, com base em cartas de superfície do modelo do Centro Europeu de previsão a médio prazo (ECMWF). Os episódios que ocorrem com maior frequência no Inverno estão associados a um anticiclone. Depressões de origem térmica e vales que se estendem do Norte de África ocorrem poucas vezes, mas a probabilidade de se verificar um episódio com essas situações é elevada. Para cinco destes episódios analisaram-se campos do modelo ECMWF (escala sinóptica) e do modelo ALADIN (mesoscala). As elevadas concentrações de partículas associadas aos episódios estudados resultaram de uma forte influência do nível850 hPa, corroborados pelo modelo de retro-trajectórias do KNMI. ABSTRACT; The present study analyses the relationship between particles (PM10) and specific meteorological patterns based on fine and coarse particles concentration data (1999 to 2003) from the Lisbon area air quality network and meteorological observations. Associations were established between PM10 events and synoptic patterns based on surface fields from European Centre for Medium-Range Weather Forecast (ECMWF) Model. Winter events occur mainly under high pressure conditions. Thermal lows and troughs over North Africa affecting the lberian Península occur less frequently; however, the probability of a PM event with this synoptic pattern is high. Meteorological fields from the ECMWF model (synoptic scale) and the ALADIN model (mesoscale) were analyzed for five of these episodes. The 850 hPa level is quite relevant for determining high PM10 concentrations at the surface, as confirmed by KNMI trajectory model.

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Indoor Air 2016 - The 14th International Conference of Indoor Air Quality and Climate