TY - JOUR
T1 - Evaluation of short-distance airborne infection risk using a cough generator
AU - Ling, Wei
AU - Ichikawa, Maho
AU - Hashimoto, Kaho
AU - Ogata, Masayuki
AU - Tsutsumi, Hitomi
AU - Morimoto, Shoichi
AU - Shin-Ichi, Tanabe
AU - Hori, Satoshi
N1 - Funding Information:
In this report, we report the outline and results of experiments aimed at experimentally grasping the relation between the concentration of cough and droplet nuclei and the relative humidity at short range. In addition, we evaluated the risk of droplet nuclei infection based on the experimental results and compared the risk assessment of splash nuclear infection risk in near and far distances. From the results of this experiment, we considered as follows. 1) Since the evaporation rate of droplets varies depending on the relative humidity, it is suggested that it affects the temporal change of droplet nuclei concentration. If it is within 1.6 m from the coughing position, possibility of short distance high concentration exposure by droplet nuclei is considered. 2) For the droplet nuclei concentration, the distance condition was more influential than the relative humidity condition. It was found that the risk of droplet nuclear infection due to short distance exposure changes more than the relative humidity depending on the positional relationship between the infected person and the uninfected person. 3) It was confirmed that the risk of droplet nuclear infection due to long-distance exposure varies greatly depending on the number of ventilation times than the relative humidity condition. Since short-range exposure and long-term exposure have different factors influencing the risk of infection, it can be said that it is necessary to implement effective infection control for each. For future work on this topic, I would suggest including a series of very low humidity tests (2%-10%) which is a typical relative humidity value met inside commercial aircraft cabins. This research is based on the collaborative research group by Waseda University and Juntendo University. Part of this research was funded by the Young Researcher Support Project (Early Bird Program), Institute of Science and Engineering, Waseda University.
Funding Information:
This research is based on the collaborative research group by Waseda University and Juntendo University. Part of this research was funded by the Young Researcher Support Project (Early Bird Program), Institute of Science and Engineering, Waseda University.
Publisher Copyright:
© The Authors, published by EDP Sciences. This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0
PY - 2019/8/13
Y1 - 2019/8/13
N2 - Short-distance airborne infections are often thought to occur by large droplets or direct contact. Recent studies have investigated the phenomenon of short-range airborne infection. In this study, the effect of relative humidity and short-distance exposure to cough droplet nuclei were evaluated. The evaluation model for infection risk was designed based on experimental data and previous studies and included sampling efficiency and virus survival rate. As observed in the comparison between short-range exposure and long-range exposure, the short-range exposure to the droplet nuclei by one cough was equivalent to a long-range exposure of several seconds to, depending on the number of ventilations, even for a momentary high-concentration exposure. This suggests the possibility of an infection risk corresponding to the receiving condition. Since short-range exposure and long-range exposure have different factors affecting the risk of infection, it is suggested that effective infection control should be selected for each condition. The risk of infection due to long-range exposure is considered to be sufficiently reduced to that of a single cough if the building meets the necessary number of ventilations. It was suggested that the influence of relative humidity on infection risks is smaller than other factors such as ventilation.
AB - Short-distance airborne infections are often thought to occur by large droplets or direct contact. Recent studies have investigated the phenomenon of short-range airborne infection. In this study, the effect of relative humidity and short-distance exposure to cough droplet nuclei were evaluated. The evaluation model for infection risk was designed based on experimental data and previous studies and included sampling efficiency and virus survival rate. As observed in the comparison between short-range exposure and long-range exposure, the short-range exposure to the droplet nuclei by one cough was equivalent to a long-range exposure of several seconds to, depending on the number of ventilations, even for a momentary high-concentration exposure. This suggests the possibility of an infection risk corresponding to the receiving condition. Since short-range exposure and long-range exposure have different factors affecting the risk of infection, it is suggested that effective infection control should be selected for each condition. The risk of infection due to long-range exposure is considered to be sufficiently reduced to that of a single cough if the building meets the necessary number of ventilations. It was suggested that the influence of relative humidity on infection risks is smaller than other factors such as ventilation.
UR - http://www.scopus.com/inward/record.url?scp=85071835007&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85071835007&partnerID=8YFLogxK
U2 - 10.1051/e3sconf/201911102028
DO - 10.1051/e3sconf/201911102028
M3 - Conference article
AN - SCOPUS:85071835007
SN - 2555-0403
VL - 111
JO - E3S Web of Conferences
JF - E3S Web of Conferences
M1 - 02028
T2 - 13th REHVA World Congress, CLIMA 2019
Y2 - 26 May 2019 through 29 May 2019
ER -