Water-soluble organic carbon (WSOC) makes up a large mass fraction of the organic carbon in the aerosol and can influence important cloud processes in the atmosphere. The capacity of WSOC to form metallic complexes with transition metals is well known; however, its influence on the aerosol of urban areas in the Amazon region is not very well known. In this study, we investigated the relationship between WSOC, black carbon (BC), levoglucosan (LEV) and transition metals (Fe, Cu and Mn) present in the PM2.5 (particles with a diameter smaller than 2.5 µm) of an urban environment during the dry season in the central Amazon. Oxalic acid (C2) was used to identify the influence of transition metals on WSOC. The mean mass concentration value of the PM2.5 was 14.72 μg m-3 (2.11-31.68 μg m-3). The WSOC made up 58.34% of the PM2.5 mass, followed by BC (20.28%), and LEV (2.62%). The WSOC showed significant correlation with the transition metals analyzed (> 0.56), especially Mn with C2 (linear coefficient (R2) = 0.74). A multiple linear regression with WSOC, BC and LEV showed a strong linear correlation between them (R2 = 0.86), indicating the influence of biomass burning and vehicle traffic on the organic aerosol.

Classrooms are microenvironments in which children and teenagers may be exposed to fine particulate matter (PM2.5). Iranduba is a rural city in the Amazon region close to many brick kilns and road with high traffic levels. In this study, indoor and outdoor PM2.5 levels were measured in a classroom in Iranduba, and the PM2.5 exposure effects on student’s health were calculated. High indoor PM2.5 concentrations and high indoor-to-outdoor ratio values indicated particle accumulation within the classroom. The high percentage of black carbon (10%) in the dry season revealed the influence of burning processes on PM2.5 composition. Se, S, and Pb had an enrichment factor > 5, indicating that there is an important source for these elements in the city. The positive matrix factorization (PMF) model indicated soil resuspension, burning processes and vehicular emissions as the main PM2.5 sources. The excess risk shows that our classroom occupants are expected to be 30% more likely to develop lung-cancer than a group exposed to a background level of PM2.5. Therefore, it is important to have an effective ventilation system in order to reduce the accumulation of pollutants within the classroom and also to control/decrease the emission of pollutants in the city.

É apresentado um modelo para quantificação de fontes e deposição de espécies nutrientes que contribuem com a formação e concentração do aerossol atmosférico. Para este procedimento foram utilizadas ferramentas estatísticas como: a análise de componentes principais (PCA) e análise de regressão linear múltipla (MLRA) associadas a modelos de deposição de partículas segregadas por tamanho. Em região rural do sudeste do Brasil, a queima de biomassa, produtos de reações secundárias, e re-suspensão de poeira do solo possibilitaram explicar 43%, 31% e 21% da massa do MP2.5, respectivamente. A re-suspensão de poeira e a queima de biomassa contribuíram com 22% e 19%, respectivamente, da massa do MP10. A re-suspensão possibilitou explicar cerca da metade da massa das partículas grossas. Cerca de 40% de NO3--N, 20% de fósforo e 55% de potássio depositados tem origem nas emissões relacionadas com a agricultura. Atualmente a deposição sobre a floresta tropical é aumentada pelos fatores de 12.2 (N), 6.2 (P) e 2.6 (K) com relação a aqueles que existiam nas condições naturais do passado.

A procedure is presented for quantification of sources contributing to atmospheric aerosol chemical nutrient concentrations and dry deposition fluxes. Source apportionment using principal component analysis (PCA) and multiple linear regression analysis (MLRA) was followed by application of a size-segregated particle dry deposition model. In a rural region of southeast Brazil, biomass burning, products of secondary reactions, and soil dust re-suspension explained 43%, 31% and 21% of PM2.5 mass, respectively. Re-suspension and biomass burning contributed 22% and 19%, respectively, to PM10 mass, and re-suspension accounted for approximately half of the mass of coarse particles. At least 40% of NO3--N, 20% of phosphorus and 55% of potassium deposited originated from agriculture-related emissions. Deposition to tropical forest is currently higher than the minimum under natural conditions by factors of 12.2 (N), 6.2 (P) and 2.6 (K).

Emissões industriais são as fontes principais de poluição atmosférica no parque industrial de Cubatão, no sudeste do Brasil, onde a dispersão é limitada pela extensa faixa de montanhas na região. O transporte de veículos pesados é uma fonte importante de gases e aerossóis e pode influenciar nas concentrações de poluentes atmosféricos próximos à superfície, dependendo das condições meteorológicas. Este trabalho mostra que as fontes industriais foram predominantes nos fluxos de SO2, enquanto que o transporte veicular foi a principal fonte de NO2 para a atmosfera. A rápida remoção de NO2 e SO2 da atmosfera foi atribuída às reações na fase gasosa e reações heterogêneas, respectivamente. Concentrações médias de MP10 aumentaram cerca de uma ordem de magnitude durante a circulação da brisa do mar. Foi demonstrado que instrumentação de resposta rápida pode fornecer uma alternativa conveniente às medidas obtidas com equipamentos fixos para mapeamento espacial (horizontal e vertical) de poluentes atmosféricos.

Industrial emissions are a notorious source of atmospheric pollution in the Cubatão industrial park of Southern Brazil, where dispersion is restricted by surrounding mountain ranges. It is shown here that road transport is also a large source of gases and aerosols, which can dominate pollutant concentrations at ground level, depending on meteorological conditions. SO2 was released mainly by industry, while road transport was a major source of NOx. Rapid removal of NO2 and SO2 was attributed to fast gas phase and heterogeneous reactions, respectively. Average PM10 concentrations increased by an order of magnitude during sea breeze fumigation, and high particulate pollution events were associated with vehicular activity. It is demonstrated that fast-response portable instrumentation can provide a useful alternative to measurements at fixed network sites for spatial (horizontal and vertical) mapping of atmospheric pollutants.