Caracterization of organic compounds on aerosols colected in São Paulo during dry season (2019)

• Grant number: 21/12442-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2021
• End date: October 31, 2022
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Meteorology
• Principal Investigator: Pérola de Castro Vasconcellos
• Grantee: Thayná da Silva Santos
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 16/18438-0 - São Paulo Metropolitan Area, jointly tracking climate change and air quality - METROCLIMA-MASP, AP.PFPMCG.TEM

Abstract

The chemical characterization of the particulate material is of great importance, as it allows an assessment of the emission sources that affect a given site and the study of air quality enables public policy measures. Vehicle sources are the most important in the Metropolitan Region of São Paulo (MRSP). Another important issue for air quality on the region is the contribution of biomass burning, especially that which occurs due to the transport of aerosols from agricultural and forest fires. Polycyclic aromatic hydrocarbons (PAHs) are well studied due to their carcinogenic properties and are formed in combustion processes (fossil fuels and biomass). Oxygenated and nitraded derivatives of PAHs (oxi and nitro-PAH) may be more toxic than their precursors. The purpose of this scientific initiation project is to obtain the chemical characterization of the particulate matter, with the determination of polycyclic aromatic hydrocarbons in environmental samples collected in São Paulo. The intensive sampling campaign was carried out in the dry season of 2019 (winter), with the collection of 99 samples of particulate matter in quartz fiber filters (PM2.5 during 24h). In the laboratory of the Study Group on Atmospheric Chemistry of the Institute of Chemistry (IQ-USP), organic extracts will be fractionated into classes of compounds and the determination of PAH and derivatives will be performed with the use of gas chromatography (GC-MS). After quantification of concentrations, the toxicity of the samples (benzo(a)pyrene equivalent) and the emission sources will be evaluated, using diagnostic reasons of isomers.Within the contexts of Metroclima and SOPRO (Chemical and toxicological SOurce PROfiling of particulate matter in urban air) projects, the results will be used for studies of emission sources, with the use of positive matrix factoring. The projects mentioned involve the proposal of measures to improve air quality in São Paulo, attending the air quality standards and approaching the guidelines of the World Health Organization. (AU)