臺北都會區國民小學校園空氣中粒狀污染物之特性

Abstract

本研究觀察及分析臺北都會地區國民小學校園中大氣粒狀污染物（particulate matter）的特性及探討可能的污染來源，並且評估校園環境粒狀污染物質量濃度與鄰近空氣品質監測站量測數據之相關性。本研究在臺北都會區不同交通流量（高、中、低）的地區各選擇兩所國小作為採樣對象，於2006年8月至2007年4月期間以十階微孔均勻沉積衝擊器（Micro-Orifice Uniform Deposit Impactor, MOUDI）進行粒狀物質採樣及重量分析，另外利用環保署所屬之臺北市一般空氣品質監測站對PM10監測的數據作比對。研究結果顯示，六所國小校園採樣點的粒狀污染物平均質量濃度範圍介於58.21∼110.11 μg/m3，皆未超過我國空氣品質標準PM10之24小時標準值125 μg/m3。六所國小校園環境中粒狀污染物的粒徑分布接近於對數正常分布（log-normal distribution），質量中位數粒徑介於0.191∼4.463 μm，且粒狀污染物的粒徑分布輪廓可綜括為雙峰分布型態，主波峰落於細微粒粒徑範圍（＜1.0 μm ），次波峰則是落在粗微粒粒徑範圍，介於3.2∼5.6 μm之間。另將高、中、低不同交通流量與校園環境粒狀污染物進行變異數分析（ANOVA），結果具有統計上顯著意義（p＝0.047），表示粒狀污染物質量濃度與交通流量呈現正相關的關係。依季節性粒狀污染物質量濃度的變化而言，春季、秋季、冬季平均質量濃度分別為84.98±22.20 μg/m3、65.30±22.05 μg/m3、90.66±39.03 μg/m3，冬季之粒狀污染物質量濃度較春季和秋季為高。在各校所測得的粒狀污染物濃度與其鄰近空氣品質監測站PM10監測數據的相關性則呈現不一致的結果。

This study is aimed to characterize the ambient particulate matter at elementary schools in Taipei metropolis and their source, and their correlation to the corresponding data from the nearby air monitoring stations. The two elementary schools located in each light, moderate and heavy traffic area were for selected particulate sampling during August 2006 to April 2007. The samples were collected in campus by using 10-stage micro-orifice uniform deposit impactor（MOUDI）and weighted. In addition, the PM10 data from the nearby air monitoring stations of Taiwan Environmental Protection Administration were also adopted for comparison. The results show that the average mass concentration of the particulate sampling in six elementary schools ranged from 58.21 to 110.11 μg/m3, which all did not exceed the standard of Taiwan EPA, 24h PM10 of 125 μg/m3. The particle size distribution of particulate matter at six elementary schools almost fitted log-normal distribution. The mass medium diameter ranged from 0.191∼4.463 μm. The size distribution of particulate matter can be summed up the bimodal type, and the primary peak occurred in fine particle size range, and second peak was in the ranges from 3.2∼5.6 μm. The analysis of variance（ANOVA）indicates the positive correlation between the mass concentration of particulate matter and traffic density（p＝0.047）. The average mass concentration in spring, autumn and winter were 84.98±22.20 μg/m3, 65.30±22.05 μg/m3, 90.66±39.03 μg/m3, respectively. The particulate matter mass concentration measured at six elementary schools did not consistently correlate with the PM10 data from the nearby air monitoring stations.