Analysis of Targeted, Suspect, and Non-target Polycyclic Aromatic Hydrocarbons in the Atmosphere of Pohang, Korea using GC×GC-TOFMS

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are recognized as carcinogenic and potentially toxic. However, only the 16 PAHs designated by the United States Environmental Protection Agency (US EPA) are consistently monitored. This is a concern because non-target screening is essential to understand the pollution characteristics of PAH species and assess the overall toxicity of total PAHs. In this study, non-target screening of the ambient air was conducted using the GC×GC-TOFMS analysis of samples taken from passive air samplers deployed for 84 days (June to September) in Pohang, a major industrial city in Korea. The dominance of PAH derivatives in Pohang was attributed to industrial and petrogenic sources. The chemical groups significantly contributing to harbor samples included PAH derivatives, arenes, and thiophene. Emissions from the processing of coal as a raw material and particulate matter from POSCO’s Pohang steel plant also influenced the formation of PAH derivatives and thiophene. The benzo[a]pyrene toxic equivalent quantity (BaP-TEQ) of total PAHs, including both targeted parent PAHs and PAH derivatives, was 2.5 times higher than the targeted parent PAHs alone. The results of this study can serve as a basis for future non-target screening studies by providing insights into the estimation of the overall toxicity of PAHs and the spatial distribution of various compounds.