Distribuição de tamanho de aerossóis submicrométricos em Diadema, SP
Arquivos
Data
2022-02-11
Autores
Sousa, Helen Cristina de Lima e 
Orientadores
Rizzo, Luciana Varanda
Tipo
Trabalho de conclusão de curso
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Os grandes centros urbanos sofrem com a urbanização desordenada, altas demandas de transporte e atividades industriais, que levam à emissão de poluentes atmosféricos, causando a deterioração da qualidade do ar e impactos na saúde da população. Dentre os poluentes, destacam-se as partículas de aerossol, presente na atmosfera em diversas faixas de tamanho, desde alguns nanômetros até 100 µm. Os aerossóis são classificados a partir de seu diâmetro e divididos em 4 grupos ou modas: moda de nucleação, Aitken, acumulação e moda grossa. Este estudo teve como objetivo analisar medidas de distribuição de tamanho de aerossóis submicrométricos em Diadema, identificando padrões de variabilidade temporal e processos dinâmicos. Foram analisados dados de um experimento realizado no verão 2016/2017 no campus Diadema da UNIFESP, incluindo dados de propriedades físicas e químicas de aerossóis, concentração de gases traço e dados meteorológicos fornecidos pela estação meteorológica do Instituto de Astronomia, Geofísica e Ciências Atmosféricas da Universidade de São Paulo (IAG/USP). Utilizando o software R, foi caracterizada a variabilidade temporal das distribuições de tamanho e a ocorrência e relevância das modas de nucleação, Aitken e de acumulação. Também foi realizada uma análise cluster que permitiu associar a ocorrência de determinados formatos de distribuição de tamanho a condições atmosféricas. A concentração média do número total de partículas foi de 1,22 x 104 cm-3 e o diâmetro geométrico médio foi de 51,5 nm, com predominância da moda de Aitken. Na análise cluster foram obtidos quatro agrupamentos. Os clusters 1 e 3 possuem grande contribuição da moda de nucleação, sugerindo a presença de partículas frescas e pouco processadas. A ocorrência do cluster 2 no período da tarde, sob ventos de leste e alta umidade relativa sugere a influência da brisa marítima. O cluster 4 apresenta características de material mais processado, corroborando com o fato de as distribuições de tamanho possuírem um diâmetro um pouco maior em comparação aos demais clusters. Os resultados também sugerem a influência da deposição úmida de aerossóis durante um período com altas taxas de precipitação. O estudo evidencia a importância de monitorar a concentração de aerossóis ultrafinos para melhor avaliar os riscos à saúde humana decorrentes da exposição ao material particulado.
Large urban centers suffer from disorderly urbanization, great demand for transport and industrial activities, which lead to the emission of atmospheric pollutants, causing the deterioration of air quality and impacts to the human health. Among the pollutants, aerosol particles stand out, present in the atmosphere in various size ranges, from a few nanometers to 100 μm. Aerosols are classified based on their diameter and divided into 4 categories or modes: nucleation mode, Aitken, accumulation, and coarse mode. This study aimed to analyze measurements of the size distribution of submicrometric aerosols in Diadema, identifying patterns of temporal variability and dynamic processes. Data from an experiment carried out in the summer of 2016/2017 at the Diadema campus of UNIFESP were analyzed, including data on physical and chemical properties of aerosols, the concentration of trace gases, and meteorological data provided by the meteorological station of the Astronomy, Geophysics and Atmospheric Sciences Institute of the University of Sao Paulo (IAG/USP). The temporal variability of size distributions and the occurrence and relevance of nucleation, Aitken, and accumulation modes were characterized using the R software. A cluster analysis was also carried out, which allowed associating the occurrence of certain size distribution formats with atmospheric conditions. The mean concentration of the total number of particles was 1.22 x 104 cm-3 and the mean geometric diameter was 51.5 nm, with a predominance of the Aitken mode. In the cluster analysis, four clusters were obtained. Clusters 1 and 3 have a large contribution of the nucleation mode, suggesting the presence of fresh and poorly processed particles. The occurrence of cluster 2 in the afternoon, under easterly winds and high relative humidity, suggests the influence of the sea breeze. Cluster 4 presents characteristics of more processed material, corroborating that the size distributions have a slightly larger diameter than the other clusters. The results also suggest the influence of aerosol wet deposition during a period with high precipitation rates. This study shows the importance of monitoring the concentration of ultrafine aerosols to better assess the risks to human health arising from exposure to particulate matter.
Large urban centers suffer from disorderly urbanization, great demand for transport and industrial activities, which lead to the emission of atmospheric pollutants, causing the deterioration of air quality and impacts to the human health. Among the pollutants, aerosol particles stand out, present in the atmosphere in various size ranges, from a few nanometers to 100 μm. Aerosols are classified based on their diameter and divided into 4 categories or modes: nucleation mode, Aitken, accumulation, and coarse mode. This study aimed to analyze measurements of the size distribution of submicrometric aerosols in Diadema, identifying patterns of temporal variability and dynamic processes. Data from an experiment carried out in the summer of 2016/2017 at the Diadema campus of UNIFESP were analyzed, including data on physical and chemical properties of aerosols, the concentration of trace gases, and meteorological data provided by the meteorological station of the Astronomy, Geophysics and Atmospheric Sciences Institute of the University of Sao Paulo (IAG/USP). The temporal variability of size distributions and the occurrence and relevance of nucleation, Aitken, and accumulation modes were characterized using the R software. A cluster analysis was also carried out, which allowed associating the occurrence of certain size distribution formats with atmospheric conditions. The mean concentration of the total number of particles was 1.22 x 104 cm-3 and the mean geometric diameter was 51.5 nm, with a predominance of the Aitken mode. In the cluster analysis, four clusters were obtained. Clusters 1 and 3 have a large contribution of the nucleation mode, suggesting the presence of fresh and poorly processed particles. The occurrence of cluster 2 in the afternoon, under easterly winds and high relative humidity, suggests the influence of the sea breeze. Cluster 4 presents characteristics of more processed material, corroborating that the size distributions have a slightly larger diameter than the other clusters. The results also suggest the influence of aerosol wet deposition during a period with high precipitation rates. This study shows the importance of monitoring the concentration of ultrafine aerosols to better assess the risks to human health arising from exposure to particulate matter.