Chemical characteristics of size-segregated particles from a brazilian coastal megacity

Particulate matter (PM) size distribution samples were collected using a Micro-Orifice Uniform Deposit Impactor (MOUDI) in Rio de Janeiro between July and September 2016 during the Olympic and Paralympic periods, when there was an increase in tourist flow, changes in the local economy, modifications in traffic and pollution emission patterns. The samples were analyzed for elemental composition using inductively coupled plasma mass spectrometry (ICP-MS), for organic and inorganic ions using ion chromatography, and for polycyclic aromatic hydrocarbons (PAHs) using gas chromatography-mass spectrometry (GC/MS). The data were processed, interpreted, and discussed through statistical analyses performed in R Language, including boxplots and Pearson correlation methodology. Results were categorized according to particle size: coarse, fine, ultrafine, and nano. Chloride dominated the coarse particulate matter (PMC; 18–3.2 µm), NO₂⁻ the fine fraction (PMF; 1.8–0.56 µm), and HCOO⁻ the ultrafine fraction (PMN; 320–56 nm). Ni, Pb, Sb, and V were enriched in PMN. Four- and five-ring PAHs were predominant across all particle size groups. The species present in the coarse fraction come from natural sources, while those in the fine fraction are of anthropogenic origin, mainly from the combustion of diesel and gasoline by vehicle engines.