Source Apportionment of PM2.5 with Continuous Speciation Monitoring Data and Time-integrated Measurements of Organic Markers

Yi-Hsien Liu, Chun-Sheng Huang, Wei-Cheng Tsai, Ho-Tang Liao, Chia-Yang Chen, CHANG-FU WU, National Taiwan University

     Abstract Number: 309
     Working Group: Source Apportionment

Abstract
Exposure to air pollutants such as fine particulate matter (PM_2.5) causes both acute and chronic adverse health effects. However, PM_2.5 can be contributed by various air pollution sources. In order to develop effective air quality management plans, identifying major sources of air pollutants is essential. This can be achieved by using receptor models, such as Positive Matrix Factorization (PMF), for source apportionment. In this study, hourly PM_2.5 measurements of inorganic ions, elements, organic carbon, and elemental carbon were obtained in an urban area in Taiwan for 14 days in winter. Additional 12-h integrated filter samples were collected simultaneously and analyzed for eight organic compounds such as 2-methylerythritol and arabitol by ultra performance liquid chromatography-tandem mass spectrometer (UPLC-MS/MS). The speciation data were analyzed with (Model 2) and without (Model 1) organic species, respectively, by multiple-time-resolution PMF. Through constraining Model 2 using the traffic-related profile generated from Model 1, the biogenic source (estimated contribution=15%) was identified additionally. The other factors were identified as the ones in Model 1: Traffic-related, Road dust, Sea salt, Oil combustion, and Coal burning/Industry. Backward trajectory modeling indicates that the biogenic source was from the mountains areas. The study results suggest that applying organic species could fill the gap in predicted and observed PM_2.5 concentrations, which is mostly biogenic source in the study area.