都市行道樹對空氣懸浮微粒濃度影響之實證研究

Effects of Street Trees on Atmospheric Particulate Matters Concentration

陳起鳳(Chi-Feng Chen) ； 楊荏凱(Ren-Kai Yang) ； 郭盈妤(Yin-Yu Kuo)

《華岡農科學報》 34期 (2014/12) Pp. 1-11

摘要

空氣懸浮微粒（PM）對人體健康有害，是空氣污染管制的重點項目。懸浮微粒的來源複雜，含直接排放及衍生物質，同時又受到境外傳輸影響。都市區內，機動車輛是已確知的懸浮微粒主要來源。由於行道樹具有攔截懸浮微粒以及吸收部分氣狀空氣污染物功能，有助改善都市空氣品質，因此本研究為實際測量都市內行道路對空氣懸浮微粒的改善效果。本研究在台北市區內尋找兩處實測點，分別作為有無行道樹的代表路口，實際測量懸浮微粒濃度，並同時觀測道路車輛數量。總共量測平日10次與假日2次，每次量測時間從早上9點至下午5點，每小時記錄。結果發現有行道樹路口的PM_(2.5)濃度較低，兩處PM_(2.5)的平日平均濃度為48.2與46.5μg/m^3。但PM_(10)濃度沒有差異，兩處PM_(10)的平日平均濃度為136.5與137.0μg/m^3。一天的小時變化，實測的兩地點都在10點以後有較低的PM濃度，而下午1點開始上升，濃度最高發生在早上九點與下午五點。對應PM_(2.5)濃度與當時的車輛數量，發現兩者相關性極低。本研究觀測臺北市PM濃度變化，證實有行道樹道路的PM_(2.5)濃度較低，但對PM_(10)濃度沒有影響。

關鍵字

懸浮微粒（PM） ； 行道樹 ； 空氣污染

並列摘要

Atmospheric particulate matters (PM) are harmful for human health and is legislated as an air pollution pollutant. The PM emission sources are complex, including direct sources and secondary sources; simultaneously, PM might be transported from regional sources. In urban area, automobiles emission is a certain PM source. Street trees are able to intercept PM and adsorb some gaseous pollutants to reduce secondary PM generations. The objective of this study is to evaluate the effects of street trees on PM reduction. Two road junctions in Taipei city was chosen to measure the PM concentration. One was the roads with street trees and the other was without street trees. Besides the PM concentration, the transported cars are accounted as well. Total of 10 events was collected in weekdays and two in weekends. Hourly observations from 9 am to 5 pm were measured. The results showed that the average PM concentrations on road with street trees were lower than that without street trees. The average PM2.5 concentration in weekdays on the two test locations was 48.2 and 46.5 μg/m^3. The average PM10 concentration in weekdays was no different and they were 136.5 and 137.0μg/m^3. For the hourly trend, the low PM concentration in weekdays happened between 10 am to 1 pm, and the high PM concentration was at 9 am and 5 pm. The correlation between PM concentration and car numbers was very low. This study confirmed that street trees are helpful for reduce fine PM, such as PM2.5, but not affect coarse PM, like PM10.

並列關鍵字

suspended particulate matter (PM) ； street trees ； air pollution