The Study of Using SMPS to Measurement Size Distribution of Coughing Droplet
Date Issued
2005
Date
2005
Author(s)
Chen, Wei-Yen
DOI
zh-TW
Abstract
Droplet exhaled from human may carry microorganisms capable of transmitting disease. As a result of the size be smaller than micron scale had been proven to occupy the great part of size distribution . The goal of this study was to establish the nano scale size of droplet exhaled by healthy individuals, and to compare the sexual differences of the coughing velocity and droplet concentration. Using sample bag to collect droplet. The droplets from human subjects performing coughing were measured by scanning mobility particle sizer (SMPS) system, and establish the droplet size distribution. Furthermore, these data were treated with statistical analysis, comparing the difference of different ages and sexual classification. Then computing the evaporation time, falling distances, horizontal traveling distances with some assumptions.
The data of SMPS system showed the respiratory droplets ranged from 0.019 to 0.35 mm and 80% of droplets were between 0.03 and 0.2 mm. Most droplets were more than 0.03 mm. The droplets size were not remarkably difference in age and sexual classification, except for group 2 in sexual classification. The data of wind meter showed the velocity ranged from 0.13 to 1.88 m/s. In this study we found the droplet concentration will increase with coughing velocity. In the data of coughing velocity and droplet concentration, male’s is larger than female’s.
In the environment of 20℃ and 50% relative humidity, it took only 7.07×10-5 seconds for 0.2 mm droplet to evaporate, and the falling distance was less than 4.40×10-9 cm, the horizontal traveling distance was about 8.58×10-5 cm. It showed the range of droplets produced by coughing was near the source, and evaporating to form droplet nuclei quickly. If droplet nuclei transmit in the environment, there will be the possibility of infection of diseases. Many infectious diseases belong to nano scale size such as SARS. Therefore this study could be understood its distribution in the smaller scale of droplet size.
Subjects
飛沫粒徑
傳染病控制
嚴重急性呼吸道症候群
droplet diameter
infection control
SARS
SDGs
Type
thesis
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