Source Apportionment of Volatile Organic Compounds with Continuous Speciation Monitoring Data and Time-integrated measurements of Organic Markers

Volatile Organic Compounds (VOCs) could contribute to the formation of secondary organic aerosols and ozone, both of which are detrimental to human health and the environment. There has been growing interest in developing more precise methods for analyzing VOC sources, and Positive Matrix Factorization (PMF) is widely used. However, overlapping chemical compositions of the retrieved factor profiles often pose challenges in accurately distinguishing sources, even with high-resolution VOC data. While the role of organic compounds (OC) in enhancing PMF-based source apportionment of PM_2.5 has been well-documented, studies integrating VOCs with organic molecular tracers remain limited. This study aims to integrate VOCs and organic molecular tracers into PMF analysis to improve the accuracy of source identification and quantification.

Hourly VOC monitoring and 12-hour integrated filter sampling were conducted during a 21-day period in summer at an industrial complex in southern Taiwan. A two-stage PMF modeling approach was applied, with the first stage focusing on VOC analysis and the second stage incorporating both VOC and OC markers. In Stage 1, seven factors were identified, with the three highest contributors attributed to Vehicle Gasoline Combustion (18%), Industrial Emissions (17%), and Synthetic Resin and Paints (16%). In Stage 2, after incorporating OC data, additional sources were identified, including biogenic emissions, cooking sources and  biomass burning, offering a more comprehensive source apportionment. These findings demonstrate that incorporating organic species can bridge gaps in VOC source apportionment, enhancing the resolution and accuracy of pollution source identification.