Source identification and seasonal variation of polycyclic aromatic hydrocarbons associated with atmospheric fine and coarse particles in the Metropolitan Area of Porto Alegre, RS, Brazil

• Published in: Atmospheric research 2012-11, Vol.118, p.390-403
• Main Authors: Teixeira, Elba Calesso, Agudelo-Castañeda, Dayana M., Fachel, Jandyra Maria Guimarães, Leal, Karen Alam, Garcia, Karine de Oliveira, Wiegand, Flavio
• Format: Article
• Language: English
• Subjects: Air. Soil. Water. Waste. Feeding; Applied sciences; Atmospheric pollution; Atmospherics; Biological and medical sciences; Brazil; Carcinogens; Diagnostic systems; Diesel emission; Environment. Living conditions; Exact sciences and technology; Gasoline emission; GC-MS; Medical sciences; Metropolitan areas; Mobile sources; Pollutants physicochemistry study: properties, effects, reactions, transport and distribution; Pollution; Polyallylamine hydrochloride; Polycyclic aromatic hydrocarbons; Public health. Hygiene; Public health. Hygiene-occupational medicine; Seasonal variations; Toxicity equivalent factor
• ISSN: 0169-8095; 1873-2895
• DOI: 10.1016/j.atmosres.2012.07.004

The purpose of the present study was to evaluate the polycyclic aromatic hydrocarbons (PAHs) in fine (PM2.5) and coarse particles (PM2.5–10) in an urban and industrial area in the Metropolitan Area of Porto Alegre (MAPA), Brazil. Sixteen U.S. Environmental Protection Agency (EPA) priority polycyclic aromatic hydrocarbons (PAHs) were measured. Filters containing ambient air particulate were extracted with dichloromethane using Soxhlet. Extracts were later analyzed, for determining PAH concentrations, using a gaseous chromatograph coupled with a mass spectrometer (GC-MS). The polycyclic aromatic hydrocarbons (PAHs) were more concentrated in PM2.5 with an average of 70% of total PAHs in the MAPA. The target PAH apportionment among the main emission sources was carried out by diagnostic PAH concentration ratios, and principal component analysis (PCA). PAHs with higher molecular weight showed higher percentages in the fine particles in the MAPA. Based on the diagnostic ratios and PCA analysis, it may be concluded that the major contribution of PAHs was from vehicular sources (diesel and gasoline), especially in the PM2.5 fraction, as well as coal and wood burning. The winter/summer ratio in the PM2.5 and PM2.5–10 fractions in the MAPA was 3.1 and 1.8, respectively, revealing the seasonal variation of PAHs in the two fractions. The estimated toxicity equivalent factor (TEF), used to assess the contribution of the carcinogenic potency, confirms a significant presence of the moderately active carcinogenic PAHs BaP and DahA in the samples collected in the MAPA. ► Evaluation of PAHs emission profiles in PM2.5 and PM2.5–10 in urban/industrial area. ► The distribution of sources was assessed by diagnostic PAH ratios and by PCA. ► The seasonal variation was evaluated and confirmed by winter/summer PAH ratios. ► The results were used to estimate the TEF contribution of the highly carcinogenic BaP.