台北市通勤者暴露於次微米微粒、細微粒、粗微粒與一氧化碳之研究

Abstract

研究目的：本研究針對通勤者於四種交通工具內：公車、汽車、機車與捷運，進行懸浮微粒(PM)與一氧化碳(CO)暴露評估。另外亦針對機車騎士於設有公車專用道之道路，與未設有公車專用道之道路，進行懸浮微粒(PM)與一氧化碳(CO)暴露評估。 研究方法：評估台北市通勤者PM1.0、PM1.0-2.5、PM2.5-10、PM10與CO於四種交通工具、六條採樣路線上之濃度，採樣時間為週一至週五，上午與下午交通尖峰時間，儀器每分鐘一筆採樣值存於資料記錄器，採樣過程並以攝影機或紀錄表記載通勤所發生的特殊事件，該事件會影響通勤旅程中PM與CO濃度，如公車開門的時間、汽車與機車通勤者遇交通號誌停車的時間、捷運通勤者步行的時間。此外，我們結合車內測得之PM與CO濃度、車輛行駛的時間以及呼吸量來估計通勤者之暴露量。 採樣結果：車內PM1.0、PM1.0-2.5、PM2.5-10與PM10質量濃度值最高為機車，其次為公車、捷運，最低為汽車。車內PM1.0平均濃度分別為機車39.5μg/m3、公車28.5μg/m3、捷運24.9μg/m3、汽車18.3μg/m3。我們發現公車開門後會造成車廂內PM2.5-10與PM10濃度升高；汽車內PM與CO濃度於通勤過程中不會受特殊事件的影響；機車遇交通號誌停車以及通勤於未設有公車專用道之道路時，其PM與CO的濃度較高；捷運通勤者於步行途中，所受到PM與CO的暴露，高於捷運車廂內的濃度。成人於車內PM1.0每年平均暴露量，機車為10.3 mg、公車為7.4 mg、汽車為5.7 mg、捷運為3.9 mg。 結論：台北市機車騎士於通勤過程中，車內PM與CO濃度顯著高於公共運輸工具之公車與捷運，且高於私家車內之濃度。機車騎士停車以及行駛在未設有公車專用道之道路時，PM濃度會顯著較高，此一濃度差異導致成人在機車上的暴露量高於公車、捷運與汽車。

Objective：This study examined in-vehicle concentration and commuter exposures of particulate matter (PM) and carbon monoxide (CO) in four transportations: bus, car, motorcycle, and mass rapid transit(MRT). Methods：Personal exposures to air pollutants (PM1.0, PM1.0-2.5, PM2.5-10, PM10, and CO) were simultaneously measured in four transportations on six routes during the morning and evening rush hours during weekdays in Taipei. The frequency distribution of 1-min data were recorded in data logger. We also used video or documentary to record unusual events, such as bus door open time, stopped duration at traffic light for car and motorcycle commuters, walking period for MRT commuter, which could influence PM and CO concentrations on trips while commuting. We also examined the motorcycle riders’ exposure to PM and CO on the road with buslane and without buslane, separately. We examine commuter exposure to PM and CO by combining in-vehicle concentrations, commuting time and commuter’s ventilation rate. Results：The in-vehicle mass concentration of PM1.0, PM1.0-2.5, PM2.5-10 and PM10 was highest in motorcycle, followed by bus, MRT and car. The in-vehicle concentrations of PM1.0 in motorcycle, bus, MRT and car were 39.5μg/m3, 28.5μg/m3, 24.9μg/m3 and 18.3μg/m3. We found that PM2.5-10 and PM10 in-vehicle concentration for bus would be elevated when the door of bus was opened. For car drivers, the concentrations of PM and CO were rarely varied, even when encountering to unusual events. For motorcycle riders, the concentrations of PM and CO were higher while stopping at the traffic lights than while moving. For MRT commuters, the concentrations of PM and CO were higher while walking than while staying in vehicle. The concentrations of PM and CO for motorcycle riders were higher while commuting on the road without buslane than those with buslane. Adult commuters’ annual PM1.0 exposures were 10.3 mg by motorcycle, 7.4 mg by bus, 3.9 mg by MRT and 5.7 mg by car. Adult commuters’ annual CO exposures were 2.3 g by motorcycle, 1.1 g by bus, 0.1 g by MRT and 5.4 g by car. Conclusion：We concluded that motorcyclists had higher PM and CO exposures than public transportation riders and private car drivers while commuting in Taipei. The vehicle exhausts were main sources of commuter exposure to PM and CO in Taipei.