台北都會區室內外細粒徑氣懸微粒的特性及汽機車污染源之探討

A study of Characteristics and Vehicular Sources of Aerosol in Typical Indoor and Outdoor Environments in Taipei

楊慈定(Tzu-Ting Yang) ； 王秋森(Chiu-Sen Wang)

《台灣公共衛生雜誌》 20卷4期 (2001/08) Pp. 321-330

https://doi.org/10.6288/TJPH2001-20-04-08

摘要

目標：本研究主要在探討台北都會區不同類型建築物在自然通風及無室內污染源狀況下其室內與室外環境中細粒徑氣懸微粒的質量濃度，並利用質量平衡方法，探討微粒的穿透因子、空氣換氣率、及微粒沉積損失率對室內與室外微粒濃度比值的影響；另外，以含碳數C23至C26的正烷類，當作機動車輛排放微粒的追蹤劑，探討室內外氣膠源自機動車輛排氣的百分率。方法：本研究採樣儀器為Model 400 Micro-environment Monitor (MSP Corporation, Minneapolis, MN, USA，以下簡稱MEM)，其50%的切開粒徑是2.5μm。採樣地點及時段分別為：（１）台北市南港區一般典型三樓住家，陽台及客廳；日間時段為8:00am至5:30pm，夜間為7:00pm至次日7:00am；（２）台北縣新店市大豐國小三樓教室，教室走廊及室內；時段為8:00am至3:30pm；（３）台北市徐州路台大公共衛生學院新址一樓辦公室，後方圍牆上和辦公室內；時段為8:00am至5:00pm。除測量微粒質量濃度外，樣本並以300ml二氯甲烷經15分鐘超音波震盪萃取後，以GC/FID分析C23至C26的正烷類含量。結果與結論：台北都會區在日間門窗皆開啟狀下的三種不同類型建築物（住家、教室與辦公室）其(I/O)PM2.5在統計上並無顯著的差異，因在室內無細粒徑微粒污染源情況下，室內PM2.5微粒主要源自外滲入。三種不同類型的室內外環境微粒樣本中C23~C26正烷類濃度總和佔PM2.5的質量分率，其室內外比值大於１。即PM2.5微粒中汽機車排放所貢獻的比率室內高於室外，因為微粒相C23~C26正烷類主要來源為汽機車微粒相排放，其粒徑分佈集中於較小的粒徑區間0.1~1μm，故較不易沈降。另外，根據追蹤劑推估住家、教室與辦公室的室內PM2.5微粒大約有50%源自汽機車排放。

關鍵字

換氣率 ； 微粒沉積損失率 ； 穿透因子 ； 追蹤劑 ； 正烷類

並列摘要

Objectives: The primary objective of this study was to investigate the mass concentrations of outdoor and indoor aerosols in typical Taipei buildings with natural ventilation and no indoor particle sources. Particulate n-alkanes were used as tracers for vehicular emissons to evaluate the contribution of vehicular emissions to the fine particles. Methods: Sampling of fine particles was carried out by two impactors with a cut-off aerodynamic diameter of 2.5μm. The sites selected for sampling included: (1) a third-floor apartment, (2) a third-floor school classroom, and (3) a first-floor office. Sampling was conducted from 8:00 a.m. to 3:30 p.m. in the classroom, from 8:00 a.m. to 5:00 p.m. in the apartment, and in the office from November 1999 to April 2000. After weighing, the samples were extracted with CH2,Cl, and then analyzed for n-alkanes by a gas chromatography/flame ionization detector system Results and Conclusions: The indoor-to-outdoor ratio of PM2.5 concentrations did not differ significant. ly among the three types of buildings during daytime when tile doors and windows were open. These indoor environments had no significant PM2.5sources. Therefore, the fine particles mainly came from outdoors. The regression equation for the mass fractions of C23 to C26 n-alkanes in indoor and outdoor fine particles was y=l.09x+0.02, R2=0.53, where y represented the indoor mass fraction. This implies that the I/O ratio of the mass fractions of C23 to C26 n-alkanes in fine particles was 1.09. The results indicate that particles from vehicular emissions contributed a greater fraction to indoor fine particles than to outdoor fine particles. The results of this study show that vehicular emissions contributed about 50% of indoor aerosols in typical classrooms and residential buildings in Taipei.

並列關鍵字

urban aerosols ； indoor environments ； PM2,5 ； vehicular emissions.