Spatio-Temporal Variation of Pm2.5 And Their Associated Health Risk in Taipei City, Taiwan

Abstract

This study contains the chemical characteristics and source apportionment of PM 2.5 during 2019-2020, near the National Taiwan University and city Tunnel at Taipei city (Taiwan). Positive Matrix Factorization (PMF) was used to quantify the potential of polycyclic aromatic hydrocarbons (PAHs) sources. The influences of local pollution (LP), long range transport (LRT) and Power Plant are showed by using Bivariate Polar Plot (BPP), Potential source contribution function (PSCF) and Enrichment Factor (EF) with Positive Matrix Factorization (PMF) Furthermore, the chemical analysis were including PAHs, water soluble ions, organic carbon (OC), elemental carbon (EC) and metal element respectively. The results indicated that coal combustion and vehicles emission were the main sources of PAHs at urban site. Its concentration in the urban site was higher in LP than LRT however, it showed a similar concentration in normal. The ions concentration at urban site during the daytime on weekdays were higher than nighttime on weekends due to the high values of NO 3 - . Additionally, the same phenomena was observed in metal concentration as a result of high values of K associated with coal combustion. According to the simulation of PM 2.5 , the PSCF values was higher (>0.6) in the coastal and continental areas of Mongolia. However, at tunnel site, the PM 2.5 and PAHs emission factors for all types of vehicle were estimated higher in daytime than at nighttime due to high exhaust emissions from the vehicles. The mass ratio of OC/EC showed a high value in daytime than nighttime due to high carbon aerosols emissions. The metal and ion showed a higher concentrations at outlet than inlet due to high traffic emissions. The incremental lifetime cancer risk (ILCR) of Cr 6+ was higher in metal but it not exceeded from its tolerable limits.

Keywords: Positive Matrix Factorization, Bivariate Polar Plot, Elemental carbon, PM2.5, PAHs.