Abstract: Atmospheric aerosols, also called Particulate Matter (PM), arouse great interest in studies on climate and air quality, being important indicators of environmental pollution. The objective of this study is to characterize the PM(2,5) as the concentration, chemical composition, black Carbon content and morphology of particulate matter during the transition between the summer and winter period in Pará State (November and December 2022). In the Amazon, this type of study is neglectful, especially during the transition period between the seasons. Minivol, manufactured by Airmetrics, was used to collect the particulate material, and polycarbonate filters with 47mm diameter and pores of 0.4μm with filter change every 24 hours. 22 measurements were performed in locations with different land uses: an urbanized area in Belém-Pa; a coastal mangrove area located in Bragança-Pa, an area close to the sea located in Salinópolis-Pa and a pasture area, affected by mining, in Barcarena-Pa. These sampling sites are strategic to assess the influence of local and regional PM emitting sources as well as long-distance aerosol transport. The concentration was determined by gravimetric method. Scanning electron microscopy (MeV) was used to determine the morphology of PM. The chemical composition of PM and the black Carbon (BC) content will be determined using X-ray fluorescence (XRF) and reflectance, respectively. The analyzes have been carried out in collaboration with several partner laboratories, such as the Mineral Characterization Laboratory of the Geosciences Institute of UFPA (LCM), Laboratory of Atmospheric Process Analysis, at the Astronomy Institute, Geophysics and Atmospheric Sciences at USP (LAPAt) and School of Molecular Sciences, Arizona State University SMS (ASU). The average concentrations of PM2.5 were: Belém (2.81μg/m3)- urban area; Barcarena (1.95 μg/m3)-industrial area; Bragança (1.71 μg/m3)-coastal area of mangrove and Salinópolis (1.21 μg/m3) – area near the sea. The result (MeV) revealed spherical particles, small agglomerates, pointed particles, overlapping particles of layers and biogenic particles, some of them similar to those already reported in the literature. After determining the chemical composition of the PM, it will be possible to finalize the characterization of the PM and determine the contribution of the main sources in the respective municipalities of Amazonia paraense.

Keywords: Air quality, Atmospheric chemistry, Fine Particulate Matter, Amazon, Northeastern Pará.