冠狀病毒事件對臺灣大都會區空氣品質變化趨勢之研究

我國衛生福利部疾病管制署於2020年1月20日成立「嚴重特殊傳染性肺炎中央流行疫情指揮中心」。2021年5月19日，由於社區傳播及本土個案人數持續擴大，指揮中心宣布全國提升疫情警戒至第三級。歷經兩個多月，指揮中心宣布全國三級警戒於7月27日起，將三級警戒調降至二級警戒。而配合政策三級警戒期間我國許多企業陸續宣布居家辦公，或分流彈性上班在家辦公等政策，導致多數人皆留在家中，影響正常商業活動運行進而減少交通需求。本研究針對大都會區（臺北市、新北市、桃園市、臺中市、臺南市、高雄市）污染型態變化進行疫情前後分析比較，研究2017年至2021年5-9月之間（疫情警戒期間）細懸浮微粒(PM2.5)、二氧化氮(NO2)之相關性分析，研究結果顯示，在疫情警戒期間，細懸浮微粒（PM2.5）的下降幅度為：臺北市約下降了36%至44%、新北市約下降了26%至45%、桃園市約下降了33%至43%、臺中市約下降了18%至40%、臺南市約下降了25%至32%、高雄市約下降了12%至30%；而二氧化氮（NO2）的下降幅度為：臺北市約下降了28%至49%、新北市約下降了38%至61%、桃園市約下降了37%至55%、臺中市約下降了31%至51%、臺南市約下降了39%至54%、高雄市約下降了25%至67%。研究顯示，由於交通和工業活動的減少，以及其他人為活動的限制，空氣污染物的排放減少，這導致了細懸浮微粒(PM2.5)、二氧化氮(NO2)濃度的下降。而不同都會區間的下降幅度有所差異，這也可能受到城市規模、交通密度、工業結構等因素的影響。本研究針對距離大都會區各測站最近及合適之交流道進行車流量與污染型態變化分析比較，研究2017年至2021年5月（疫情警戒期間）車流量與細懸浮微粒(PM2.5)及二氧化氮(NO2)之相關性分析，研究結果顯示，在疫情警戒期間，細懸浮微粒（PM2.5）下降幅度為：大同測站鄰近圓山交流道（約1.62公里）下降幅度約為 59%至76%、三重測站鄰近三重交流道（約0.3公里）下降幅度約為54%至69%、平鎮測站鄰近中壢交流道（約0.64公里）下降幅度約為51%至77%、西屯測站鄰近南屯交流道（約2.04公里）下降幅度約為50%至61%、新營測站鄰近新營交流道（約2.72公里）下降幅度約為33%至53%、仁武測站鄰近鼎金系統交流道（約1.58公里）下降幅度約為36%至55%；二氧化氮（NO2）下降幅度：大同測站鄰近圓山交流道（約1.62公里）下降幅度約為58%至65%、三重測站鄰近三重交流道（約0.3公里）下降幅度約為64%至74%、平鎮測站鄰近中壢交流道（約0.64公里）下降幅度約為55%至60%、西屯測站鄰近南屯交流道（約2.04公里）下降幅度約為37%至69%、新營測站鄰近新營交流道（約2.72公里）下降幅度約為63%至69%、仁武測站鄰近鼎金系統交流道（約1.58公里）下降幅度約為53%至71%。研究顯示，交通流量與空氣污染之間的密切關聯性，特別是對細懸浮微粒(PM2.5)、二氧化氮(NO2)這兩種主要的空氣污染物，而交通是城市空氣污染的主要來源之一，因此當交通流量減少時，空氣品質往往會有所改善，並且相對應地，細懸浮微粒(PM2.5)、二氧化氮(NO2)的濃度也有所下降。本研究結果顯示，封鎖措施導致交通量減少、工業活動減少以及其他人為活動的限制，進而減少了空氣污染物的排放，疫情警戒期間各大都會區中的臺北市、新北市、桃園市、臺中市、臺南市、高雄市的細懸浮微粒(PM2.5)濃度平均下降幅度在36%至44%之間，二氧化氮(NO2)濃度平均下降幅度在28%至67%之間。此外，研究還針對距離大都會區各測站最近及合適之交流道進行車流量與污染型態變化分析比較，結果如下：(1)車流量下降：疫情警戒期間，大都會區測站附近的交流道平均車流量普遍下降，下降幅度在57%到92%之間。週二至週四、週六和週日這些特定時間段，車流量減少得最為明顯，這是因為疫情封鎖期間限制了人們的活動，包括通勤和社交等，導致交通流量明顯減少。(2)細懸浮微粒（PM2.5）下降：隨著車流量的減少，細懸浮微粒（PM2.5）的濃度也有所下降，不同測站附近交流道對應的PM2.5下降幅度在59%至76%之間。這顯示交通排放是PM2.5的重要來源之一，限制交通流量對改善空氣品質起到了積極的影響。(3)二氧化氮（NO2）下降：與PM2.5類似，二氧化氮（NO2）的濃度在測站附近交流道警戒期間也有所下降，下降幅度在37%至74%之間。NO2主要來自汽車、柴油車等交通工具的排放，因此減少車流量對降低NO2濃度產生了明顯影響。整體顯示，因為疫情，研究發現交通源之污染對空氣品質的影響，研究成果可提供作為對移動污染源管制之參考資料。

關鍵字

冠狀病毒（ COVID-19）；細懸浮微粒(PM2.5) ；二氧化氮(NO2)

並列摘要

On January 20, 2020, the Center for Disease Control and Prevention of the Ministry of Health and Welfare of Taiwan country established the "Central Epidemic Command Center for Severe Special Infectious Pneumonia". On May 19, 2021, due to the continuous expansion of community transmission and the number of local cases, the command center announced that the national epidemic alert has been raised to the third level. After more than two months, the command center announced that the national alert level 3 will be lowered to alert level 2 starting from July 27. During the three-level alert period of the policy, many companies in my country have successively announced policies such as working from home, or diverting flexible work to work from home. As a result, most people stay at home, which affects the operation of normal business activities and reduces transportation demand. This study analyzes and compares the changes in pollution patterns in metropolitan areas (Taipei City, New Taipei City, Taoyuan City, Taichung City, Tainan City, and Kaohsiung City) before and after the epidemic. Period) fine suspended particulates (PM2.5) and nitrogen dioxide (NO2) correlation analysis, the research results show that during the epidemic alert period, fine suspended particulates (PM2.5) decreased as follows: Taipei City decreased by about 36 % to 44%, New Taipei City dropped by about 26% to 45%, Taoyuan City dropped by about 33% to 43%, Taichung City dropped by about 18% to 40%, Tainan City dropped by about 25% to 32%, and Kaohsiung City dropped by about 25% to 32%. The city has dropped by about 12% to 30%; while the decline in nitrogen dioxide (NO2) is as follows: Taipei City has dropped by about 28% to 49%, New Taipei City has dropped by about 38% to 61%, and Taoyuan City has dropped by about 37%. % to 55%, Taichung City dropped by about 31% to 51%, Tainan City dropped by about 39% to 54%, and Kaohsiung City dropped by about 25% to 67%. Studies have shown that emissions of air pollutants have decreased due to reductions in traffic and industrial activities, as well as other human-induced restrictions, which have led to a decrease in concentrations of fine aerosols(PM2.5), nitrogen dioxide (NO2). The rate of decline in different metropolitan areas varies, which may also be affected by factors such as city size, traffic density, and industrial structure. The results of this study show that the blockade measures lead to reduced traffic volume, reduced industrial activities, and restrictions on other human activities, thereby reducing the emission of air pollutants. Taipei City, New Taipei City, Taoyuan City, Taichung City City, Tainan City, and Kaohsiung City, the average decrease in the concentration of fine suspended particulates (PM2.5) was between 36% and 44%, and the average decrease in the concentration of nitrogen dioxide (NO2) was between 28% and 67%.In addition, the study also analyzed and compared the changes in traffic flow and pollution patterns for the nearest and most suitable interchanges from the metropolitan area. The results are as follows: (1) The traffic flow decreased: The average traffic volume of interchanges generally decreased, ranging from 57% to 92%. The reduction in traffic flow was most pronounced during specific time periods from Tuesday to Thursday, Saturday and Sunday, as restrictions on people's activities, including commuting and socializing, during the epidemic lockdown resulted in a significant reduction in traffic flow. (2) Decrease in fine suspended particles (PM2.5): With the reduction of traffic flow, the concentration of fine suspended particles (PM2.5) also decreased, and the PM2.5 corresponding to the interchanges near different stations decreased by 59% to 76%. This shows that traffic emissions are one of the important sources of PM2.5, and restricting traffic flow has a positive impact on improving air quality. (3) Decrease in nitrogen dioxide (NO2): Similar to PM2.5, the concentration of nitrogen dioxide (NO2) also decreased during the warning period of the traffic road near the station, and the decrease range was between 37% and 74%. NO2 mainly comes from the emissions of automobiles, diesel vehicles and other vehicles, so reducing traffic flow has a significant impact on reducing NO2 concentration. On the whole, due to the epidemic, research has found the impact of traffic source pollution on air quality, and the research results can be used as reference materials for the control of mobile pollution sources.