咳嗽飛沫粒徑分佈之研究

The study of size distribution of coughing droplet

陳政旻(Cheng-Min Chen)

指導教授 ： 李慧梅

國立臺灣大學/工學院/環境工程學研究所/碩士(2004年)

https://doi.org/10.6342/NTU.2004.00420

摘要

由人體所排出之飛沫會挾帶著能傳播疾病之微生物可能造成近距離和遠距離的傳染，而飛沫粒徑之大小為主要決定這些含致病菌飛沫之傳播途徑。本研究目的為建立健康個體所呼出飛沫與飛沫核之粒徑分佈，利用採樣袋及管柱來收集，分別以氣動微粒分徑器（Aerodynamic Particle Sizer, APS）及微粒電移動度掃瞄分徑器（Scanning Mobility Particle Sizer, SMPS）系統量測受測者咳嗽所產生之飛沫，以建立完整之飛沫粒徑分佈，及利用一些基本假設，計算其於空氣中之蒸發時間、沈降距離及水平距離，並將各受測者實驗資料進行統計分析，以比較不同年齡和性別之差異。
以APS系統實驗結果顯示，飛沫粒徑範圍為0.5∼20mm，約有90∼95％的咳嗽飛沫粒徑在2 mm∼10 mm之間，眾數介於5∼7 mm，大多數之飛沫其粒徑小於10 mm，飛沫核粒徑分佈範圍從0.5至5 mm之間，絕大部分在0.6∼2 mm；年齡層和性別對於飛沫之粒徑並無顯著差異。而以SMPS系統實驗結果證實咳嗽所產生的飛沫，有部分飛沫其粒徑介於0.02∼0.5 mm間。飛沫傳輸方面，於20℃、相對濕度（RH）50%之環境下，粒徑為5 mm之飛沫蒸發時間只需約0.04秒，而在蒸發前之沈降距離還不到0.002公分，而水平傳播距離約為0.008公分，顯示咳嗽所產生之飛沫，其運動範圍只侷限於產生源附近，且很快地蒸發成飛沫核，飛沫核可長時間於空氣中懸浮，可以隨著氣流傳播，使得病菌可藉由空氣傳播。而飛沫或是飛沫核若沈降於物體表面，亦可能接觸此受污染之物體而受感染。

關鍵字

傳染病控制 ； 嚴重急性呼吸道症候群 ； 飛沫粒徑 ； 生物氣膠

並列摘要

Droplet exhaled from human may carry microorganisms capable of transmitting disease in short and long distances. The size of droplet will mainly influence the transmission mode of such infectious droplet. The aim of this study was to establish the size distribution of droplet and droplet nuclei exhaled by healthy individuals, and using sample bag and column to collect them. The droplets from human subjects performing coughing were measured by aerodynamic particle sizer (APS) and scanning mobility particle sizer (SMPS) system, and establish the droplet size distribution. Computing the evaporation time, falling distances, horizontal traveling distances with some assumptions. Furthermore, the data was treated with statistical analysis, comparing the difference of different ages and sexual classification.
The data of APS monitoring showed the respiratory droplets ranged from 0.5 to 20 mm and 90~95% of droplets were between 2 and 10 mm. The mode of droplet size distribution is between 5 and 7 mm. Most droplets were less than 10 mm. The diameter of droplet nuclei was found to range in diameter from 0.5 to 5 mm, and the most amount was between 0.6 to 2 mm. The droplets size were not significantly difference in age and sexual classification. The SMPS confirmed the existence of droplets ranged from 0.02 to 0.5 mm. In the environment of 20℃ and 50% relative humidity, it took only 0.04 seconds for 5 mm droplet to evaporate, and the falling distance was less than 0.002 cm, the horizontal traveling distance was about 0.008 cm. It showed the range of droplets produced by coughing was near the source, and evaporating to form droplet nuclei quickly. Droplet nuclei could suspend in the environment for a long time, and transport with air current. The microorganisms may transmit disease by air. Besides, if droplet or droplet nuclei fall on the surface of objects, one may be infected by toughing the infectious objects.

並列關鍵字

bioaerosol ； SARS ； droplet diameter ； infection control

參考文獻

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40. 台灣行政院衛生署疾病管制局.（2003）SARS防疫專刊。

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