Road tunnel, roadside, and urban background measurements of aliphatic compounds in size-segregated particulate matter

作者：Alves Celia A^*; Oliveira Cesar; Martins Natercia; Mirante Fatima; Caseiro Alexandre; Pio Casimiro; Matos Manuel; Silva Hugo F; Oliveira Cristina; Camoes Filomena

来源：Atmospheric Research, 2016, 168: 139-148.

DOI：10.1016/j.atmosres.2015.09.007

• Size-segregated particles
• Hopanes
• Alkanes
• Road tunnel
• Roadside
• Urban background

Particulate matter samples were collected in a road tunnel in Lisbon (PM0.5, PM0.5-1, PM1-2.5, and PM2.5-10) and at two urban locations representing roadside and background stations (PM2.5 and PM2.5-10). Samples were analysed for organic and elemental carbon (OC and EC), n-alkanes, n-alkenes, hopanes, some isoprenoid compounds, and steranes. Particulate matter concentrations in the tunnel were 17-31 times higher than at roadside in the vicinity, evidencing an aerosol origin almost exclusively in fresh vehicle emissions. PM0.5 in the tunnel comprised more than 60% and 80% of the total OC and EC mass in PM10, respectively. Concentrations of the different aliphatic groups of compounds in the tunnel were up to 89 times higher than at roadside and 143 times higher than at urban background. Based on the application of hopane-to-OC or hopanes-to-EC ratios obtained in the tunnel, it was found that vehicle emissions are the dominant contributor to carbonaceous particles in the city but do not represent the only source of these triterpenic compounds. Contrary to what has been observed in other studies, the Sigma hopane-to-EC ratios were higher in summer than in winter, suggesting that other factors (e.g. biomass burning,

• 出版日期2016-2-1