Abstract: Although cities are an important source of aerosol particles, aerosol number flux measurements over urban areas are scarce. These measurements are however important as they can allow us to identify the different sources/sinks of aerosol particles and quantify their emission contributions. Therefore, they can help us to understand the aerosol impacts on human health and climate, and to design effective mitigation strategies through the reduction of urban aerosol emissions. In this work we analyze the aerosol number concentrations and fluxes for particles with diameters larger than 2.5 nm measured by eddy covariance technique at an urban area (Granada city, Spain) from November 2016 to April 2018. This is the first study of particle number flux in an urban area in the Iberian Peninsula and is one of the few current studies that report long-term aerosol number flux measurements. The results suggest that, on average, Granada urban area acted as a net source for atmospheric aerosol particles with median particle number flux of 150 × 106 m−2 s−1. Downward negative fluxes were observed in only 12% of the analyzed data, and most of them were observed during high aerosol load conditions. Both aerosol number fluxes and concentrations were maximum in winter and 50% larger than those measured in summer due to the increased emissions from domestic heating, burning of residual agricultural waste in the agricultural area surrounding the site, as well as to the lower aerosol dilution effects during winter. The analysis of the seasonal diurnal variability of the aerosol number concentration revealed the significant impact of traffic emissions on aerosol population over Granada urban area in all seasons. It also shows the impact of domestic heating and agricultural waste burning emissions in winter as well as the influence of new particle formation processes in summer and spring seasons. Closer analysis by wind sector demonstrated that both aerosol concentrations and fluxes from urban sector (where high density of anthropogenic sources is located) were lower than those from rural sector (which includes agricultural area but also the main highway of the city). This evidences the strong impact of aerosol emissions from traffic circulating on the highway on aerosol population over our measurement site.

Palavras-Chave: urban areas; aerosols; concentration ratio; atmospheres; particles; eddy currents; data covariances

CASQUERO-VERA, J.A.; LYAMANI, H.; TITOS, G.; MOREIRA, G. de A.; BENAVENT-OLTRA, J.A.; CONTE, M.; CONTINI, D.; JARVI, L.; OLMO-REYES, F.J.; ALADOS-ARBOLEDAS, L. Aerosol number fluxes and concentrations over a southern European urban area. Atmospheric Environment, v. 269, p. 1-10, 2022. DOI: 10.1016/j.atmosenv.2021.118849. Disponível em: http://repositorio.ipen.br/handle/123456789/32956. Acesso em: $DATA.

Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.

Como referenciar este item

Abstract: Studies on air quality within automotive vehicles are an emerging research area in Brazil, especially in the city of São Paulo, one of the most polluted cities in the world and with the largest fleet of vehicles in the country. Indoor air quality is an indicator of environmental health that takes into account, in addition to thermal comfort, factors that interfere in precarious air conditions, such as the presence of fungi, bacteria and carbon dioxide in indoor air-conditioned environments. The objective of the present study was to analyse the fungal contamination in air-conditioning filters collected from 21 automotive vehicles and the study found 17 fungal genera in all samples collected (100%), including toxigenic fungi such as Penicillium, Fusarim and Aspergillus, indicating that indoor air quality can compromise the health of a portion of the population, such as professional drivers. Among the Aspergillus genus, the results showed the presence of the A. flavus, A. niger, A. fumigatus, A. ochraceus and A. clavatus species, which cause severe allergic and pulmonary respiratory diseases. Air in artificially heated environments should provide comfort to its occupants but it may pose a risk to human health if the car filtration system is contaminated by pathogenic fungi.

Palavras-Chave: fungi; air quality; air pollution; vehicles; automobiles; air filters; air conditioning; pathogens; microorganisms; wastes; indoor air pollution; urban areas

AQUINO, SIMONE; LIMA, JOSE E.A. de; NASCIMENTO, ANA P.B. do; REIS, FABRICIO C. Analysis of fungal contamination in vehicle air filters and their impact as a bioaccumulator on indoor air quality. Air Quality, Atmosphere & Health, v. 11, n. 10, p. 1143-1153, 2018. DOI: 10.1007/s11869-018-0614-0. Disponível em: http://repositorio.ipen.br/handle/123456789/29408. Acesso em: $DATA.

Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.

Como referenciar este item

Abstract: This study employs surface and remote sensing data jointly with deep learning techniques to examine the influence of vehicular traffic in the seasonal patterns of CO, NO2 , PM2.5, and PM10 concentrations in the São Paulo municipality, as the period of physical distancing (March 2020 to December 2021), due to SARS-CoV-2 pandemic and the resumption of activities, made it possible to observe significant variations in the flow of vehicles in the city of São Paulo. Firstly, an analysis of the planetary boundary layer height and ventilation coefficient was performed to identify the seasons’ patterns of pollution dispersion. Then, the variations (from 2018 to 2021) of the seasonal average values of air temperature, relative humidity, precipitation, and thermal inversion occurrence/position were compared to identify possible variations in the patterns of such variables that would justify (or deny) the occurrence of more favorable conditions for pollutants dispersion. However, no significant variations were found. Finally, the seasonal average concentrations of the previously mentioned pollutants were compared from 2018 to 2021, and the daily concentrations observed during the pandemic period were compared with a model based on an artificial neural network. Regarding the concentration of pollutants, the primarily sourced from vehicular traffic (CO and NO2 ) exhibited substantial variations, demonstrating an inverse relationship with the rate of social distancing. In addition, the measured concentrations deviated from the predictive model during periods of significant social isolation. Conversely, pollutants that were not primarily linked to vehicular sources (PM2.5 and PM10) exhibited minimal variation from 2018 to 2021; thus, their measured concentration remained consistent with the prediction model.

Palavras-Chave: urban areas; air pollution; air quality; machine learning; vehicles; coronaviruses

MOREIRA, GREGORI de A.; CACHEFFO, ALEXANDRE; ANDRADE, IZABEL da S.; LOPES, FABIO JULIANO da S.; GOMES, ANTONIO A.; LANDULFO, EDUARDO. Analyzing the influence of vehicular traffic on the concentration of pollutants in the city of São Paulo: an approach based on pandemic SARS-CoV-2 data and deep learning. Atmosphere, v. 14, n. 10, p. 1-16, 2023. DOI: 10.3390/atmos14101578. Disponível em: http://repositorio.ipen.br/handle/123456789/34210. Acesso em: $DATA.

Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.

Como referenciar este item

Abstract: This work presents the use of two elastic lidar systems to assess the horizontal variation of the PBL height (PBLH) and aerosol layer aloft in the São Paulo Megacity. These two lidars performed simultaneous measurements 10.7 km apart in a highly urbanized and relatively flat area of São Paulo for two winter months of 2019. The results showed that the PBLH differences display diurnal variation that depends on the PBL during daytime growth phases. Cloud and sea breeze effects control most of PBLH variation. In the absence of cloud and sea breeze, the maximum difference (~300 m) occurs in the rapid development stage and is due to topographic effects. When the PBL approaches its maximum daily value, it tends to level off with respect to the topography. In addition, it was presented a method that combines elastic lidar (to detect an aerosol layer) and satellite data (to classify such a layer from Aerosol Optical Depth (AOD) and Aerosol Index (AI) information) for the detection of biomass burning events. This methodology demonstrated that the variations caused by Biomass Burning in AOD and AI enable both the detection of aerosol plumes originating from biomass burning and the identification of their origin.

Palavras-Chave: boundary layers; earth atmosphere; biomass; burns; urban areas; optical radar

MOREIRA, GREGORI de A.; OLIVEIRA, AMAURI P. de; CODATO, GEORGIA; SANCHEZ, MACIEL P.; TITO, JANET V.; SILVA, LEONARDO A.H. e; SILVEIRA, LUCAS C. da; SILVA, JONATAN J. da; LOPES, FABIO J. da S.; LANDULFO, EDUARDO. Assessing spatial variation of PBL height and aerosol layer aloft in São Paulo Megacity using simultaneously two lidar during winter 2019. Atmosphere, v. 13, n. 4, p. 1-16, 2022. DOI: 10.3390/atmos13040611. Disponível em: http://repositorio.ipen.br/handle/123456789/33156. Acesso em: $DATA.

Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.

Como referenciar este item

Abstract: Vehicular emissions comprise a main source of air pollutants, especially particulate matter (PM), which contains toxic compounds. Brazil has been restricting vehicular emissions for more than 30 years to minimize the impacts of fleet vehicles, but despite the restrictive legislation, several Brazilian cities still suffer from the effects of atmospheric pollution. The adoption of nature-based solutions (NbS) is being hailed as a sound alternative for improving urban air quality. In this sense, trees are a true reflection of the NbS concept since they can directly decrease PM levels by intercepting and resuspending particles, as well as altering pollution dispersion patterns. We wanted to understand the practical outcome of urban forest fragments as an NbS. Therefore, using litterfall in urban forest fragments, this study reported the role of green areas in reducing air pollution concentrations in 4 urban parks in Sao Paulo Megacity, Brazil. Air contaminants (Cd, Cu and Pb) varied from the edge to the core of urban forests. Multivariate analysis revealed that areas with different vehicle fleets influenced the input of air pollutants into these forest fragments. Our study further showed that trees serve as a natural barrier against PM. It can be concluded that this low-cost NbS alternative can reduce air pollution and has a potential to improve human health and well-being, and should be incorporated into municipal policies and programs, especially in critical locations of high human density. and poorly managed green areas.

Palavras-Chave: urban areas; forests; environmental policy; planning

RAMON, MAURO; RIBEIRO, ANDREZA P.; THEOPHILO, CAROLINA Y.S.; MOREIRA, EDSON G.; CAMARGO, PLINIO B. de; PEREIRA, CARLOS A. de B.; SARAIVA, ERLANDSON F.; TAVARES, ARMANDO dos R.; DIAS, ANTONIO G.; NOWAK, DAVID; FERREIRA, MAURICIO L. Assessment of four urban forest as environmental indicator of air quality: a study in a brazilian megacity. Urban Ecosystems, v. 26, n. 1, p. 197-207, 2023. DOI: 10.1007/s11252-022-01296-7. Disponível em: http://repositorio.ipen.br/handle/123456789/34009. Acesso em: $DATA.

Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.

Como referenciar este item