PM2.5 and BC Characteristics in the Sao Paulo Megacity, Southeastern Brazil
CAROLINE FERNANDA HEI WIKUATS, Rafaela Squizzato, Thiago Nogueira, Edmilson Dias de Freitas, Maria de Fatima Andrade,
University of São Paulo Abstract Number: 161
Working Group: Biomass Combustion: Outdoor/Indoor Transport and Indoor Air Quality
AbstractPM
2.5 concentrations are still above the Air Quality Standards in the Metropolitan Area of São Paulo (MASP), the fourth-largest urban agglomeration in the world with 21.6 million inhabitants and the most developed and industrialized region in South America. Many studies have been performed in São Paulo but without evaluating the toxicity of PM
2.5 associated with its sources. Therefore, we intend to determine the chemical composition, emission sources, and toxicity of PM
2.5 with measurements in an urban site close to vehicular emissions. PM
2.5 and BC samplings in the Faculty of Medicine of the University of São Paulo (FMUSP) occurred from May 10 to October 31, 2021. Average concentrations of PM
2.5 in PTFE filters and the TEOM monitor were 16.3±9.6 and 14.7±8.9 µg.m
-3, respectively. For BC evaluated with the Aethalometer, the result was 1.6±1.5 µg.m
-3. August 23 to 25, 2021, presented the highest daily concentrations related to biomass burning in a state park at MASP, as northwesterly winds transported the smoke plume to FMUSP. PM
2.5 values ranged from 38.9 to 42.2 µg.m
-3 in PTFE filters, 38.7 to 43.3 µg.m
-3 in the TEOM monitor, and 3.5 to 5.0 µg.m
-3 for BC. Wildfires are a significant event in some Brazilian regions in winter, mostly between August and September. In August 2021, 2,277 fire outbreaks followed in the state of São Paulo, an increase of 282% compared to July. During the analyzed period, the major elements observed in PM
2.5 samples were sulfur, sodium, potassium, iron, silicon, zinc, and aluminum, with values ranging from 946.0 to 127.7 ng.m
-3. These elements are mainly related to vehicular emission, brake and tire wear, and soil resuspension, which are characteristics of the sampling site since FMUSP is close to high-traffic roads. Sources quantification will be assessed by applying the Positive Matrix Factorization (PMF).