MCUT Research

Journal of Hazardous Materials / 2024, Vol. 476, 134977

Insight into the diurnal variations and potential sources of ambient PM_2.5-bound polycyclic aromatic hydrocarbons during spring in Northern Taiwan

Main authors: Yi-Wen Chen, Kuan-Ting Liu, Ho Thi Phuong Thao, Meng-Ying Jian, Yu-Hsiang Cheng / MCUT

In recent decades, polycyclic aromatic hydrocarbons (PAHs), the primary organic pollutants associated with particulate matter (PM), have attracted significant attention due to their carcinogenic and mutagenic potential. However, past studies have lacked exploration into the diurnal variation characteristics of PAHs, primarily due to limited analytical technical capabilities. Therefore, this study aimed to investigate the diurnal variations, possible sources, and potential health risks associated with PM_2.5-bound PAHs in northern Taiwan.. (論文連結)

This study utilized a thermal-desorption device coupled with gas chromatography/mass spectrometry (TD-GC/MS) to identify the levels of PAHs in PM_2.5 during short periods (3-hr). In addition, source apportionment was conducted using the positive matrix factorization (PMF) model, while the potential source contribution function (PSCF) and concentration weighted trajectory (CWT) models were applied to analyze the origins of pollution sources.

The mean concentration of total PAHs in PM_2.5 was 1.22 ± 0.69 ng m⁻³ during the sampling period, with high molecular weight PAHs dominating. PMF results indicated that industrial emissions and traffic emissions (57.7%) were the predominant sources, followed by petroleum volatilization and coal/biomass combustion (42.3%). Diurnal variation analysis showed that industrial and traffic emissions peaked during traffic rush hours, whereas petroleum volatilization and coal/biomass combustion were higher at noon. PSCF and CWT results suggested that industrial and traffic emissions mainly originated from local sources, particularly near the sampling site and the western coastal area of Taiwan. Furthermore, source-attributed excess cancer risk (ECR) revealed that industrial and traffic emissions posed the highest cancer risk during morning rush hours (1.69 ×10⁻⁵), while petroleum volatilization and coal/biomass combustion peaked at noon (4.75 ×10⁻⁶). These findings suggest that reducing emissions from industrial and vehicle sources, especially during morning traffic hours, could effectively mitigate associated health risks.