細懸浮微粒(PM2.5)由於顆粒小可隨著呼吸氣流直達人體肺泡，微粒中挾帶之危害性成分易被血液吸收造成人體健康的影響。多環芳香烴為環境中常見的污染物，且其中多是已知或潛在的致癌物質，廣受國際重視。因為多環芳香烴與細懸浮微粒有共通性的產生來源，因此兩者很容易相互結合對人體產生加成性危害。國內對於大氣細懸浮微粒基質部分，目前多僅止於質量濃度調查，至於細懸浮微粒所含有多環芳香烴則受限於分析方法偵測極限，需要大量樣品的採集，導致採樣時程大幅延長與濃縮過濾程序高耗人力，整體分析難度較其他環境基質為高，至今仍未建立完整之環境背景資料，亟待更精良之分析技術藉以突破採樣瓶頸，利於進行全面性空氣品質調查與人體健康危害評估。本研究以熱脫附技術將收集於濾紙上之多環芳香烴直接導入分析儀器，再結合高解析氣相層析質譜儀，得以大幅減少前處理步驟與降低方法偵測極限。本研究27種PAHs之方法偵測極限為0.340-23.2 pg/m3，可有效檢測大氣中微量但毒性較高之多環芳香烴化合物，提供更精確之檢測數據做為健康風險評估之依據。以此檢測技術調查台灣北部、中部及花東三大空品區大氣PM2.5中多環芳香烴濃度範圍介於0.130-6.63 ng/m3，平均濃度為2.23 ng/m3。冬季濃度高於夏季，單位質量PM2.5所含濃度則為0.071-0.280 ng/µg，平均濃度為0.133 ng/µg。本技術因偵測極限低可縮短採樣時間，對於大氣污染研究可提供較小時間尺度之污染變化探討的有效工具，未來可將此技術導入國內空氣細懸浮微粒中持久性有機污染物之調查分析。;PM2.5, known as respirable aerosol contains heavy metals and organic pollutants. PM2.5 may such as PAHs and Dioxins reach human alveoli when inhaled. The soluble contaminants in the particles are easily absorbed by the blood and endanger human health. Polycyclic aromatic hydrocarbons (PAHs) are common pollutants in the environment. Because many of them are definite or potential carcinogens, they have received great attention by the international community such as the World Health Organization (WHO). PAHs and PM2.5 have a common source such as combustion and vehicle exhaust. Therefore, they are easily combined and cause synergistic effect on human health. In the past, investigations on the airborne fine aerosol matrix mostly concentrated on the mass concentration of PM2.5. Studies on the pollutants such as PAHs existing on PM2.5 are limited due to low the detection limit of the analytical method (MDL) and the requirement of a large amount of sample acquisition, leading to prolonged sampling time and complicate pretreatment processes. Due to the difficulty compared to other environmental matrices, investigations on the PAHs in PM2.5 are limited. It is imperative to develop analytical techniques with lower MDL to overcome the sampling bottlenecks such that comprehensive air quality survey can be conducted for the assessment of human health hazards. In this study, thermal desorption technology is applied to directly introduce the PAHs in the PM2.5 into GC/HRMS for the analysis to significantly reduce the pretreatment processes steps and lower MDL, thereby reducing analysis loss and sampling time. The MDLs of the 27 PAHs in this study are in the range of 0.34 to 23.2 pg/m3, which can effectively detect highly toxic PAHs in the atmosphere, providing more accurate data for risk assessment. Pneliminary results indicate that the concentrations of solid-phase PAHs in ambient air of northern, central and eastern Taiwan are in the range of 0.13-6.63 ng/m3 and the average concentration is 2.23 ng/m3. The PAH concentration measured in winter is higher than that in summer, and the concentration per unit mass of PM2.5 range from 0.071 to 0.280 ng/μg and the average concentration is 0.133 ng/μg. In the future, this technology can be applied for the investigation of persistent organic pollutants (POPs) on fine particles.
