Wind velocity and dispersion/advection–diffusion of artificial droplets and droplet nuclei in a domed all-weather multi-purpose stadium
Abstract To evaluate the COVID-19 infection risk and the effectiveness of countermeasures at mass-gathering events, we measured the dispersion and advective diffusion of artificial droplets and artificial droplet nuclei at the Tokyo Dome, Japan (capacity 55,000 people). We also measured and evaluate...
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Nature Portfolio
2024-11-01
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| Series: | Scientific Reports |
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| Online Access: | https://doi.org/10.1038/s41598-024-76806-y |
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| author | Naohide Shinohara Noboru Kurihara Wataru Naito Aya Iwai Tetsuo Yasutaka Toshihiro Morioka Toshiyuki Takatsuji Masayuki Ogata Koichi Tatsu |
| author_facet | Naohide Shinohara Noboru Kurihara Wataru Naito Aya Iwai Tetsuo Yasutaka Toshihiro Morioka Toshiyuki Takatsuji Masayuki Ogata Koichi Tatsu |
| author_sort | Naohide Shinohara |
| collection | DOAJ |
| description | Abstract To evaluate the COVID-19 infection risk and the effectiveness of countermeasures at mass-gathering events, we measured the dispersion and advective diffusion of artificial droplets and artificial droplet nuclei at the Tokyo Dome, Japan (capacity 55,000 people). We also measured and evaluated the effectiveness of wearing masks and increasing the space between seating areas. If people were seated facing forward, artificial droplets did not reach the mouths of surrounding people, suggesting low risk of droplet transmission. For an artificially generated cough or sneeze, the volume of droplets deposited on the hair, back of the neck, and back of the human in front, and the backs of the seats in front, decreased by two to three orders of magnitude when a mask was worn, regardless of the type of mask. However, when the mask was worn with the nose out, the amount deposited on the back of the seat in front was reduced by only 17%. Even in seats with the highest particle concentration in the vicinity of the source, only 0.097%–0.24% of the generated droplet nuclei (1.0–3.0 μm) from the source were inhaled. Our results suggest that the infection risk at the Tokyo Dome via droplet and airborne transmission was low. |
| format | Article |
| id | doaj-art-22f3cfb38b5c46f1af788fc2a72e29c8 |
| institution | OA Journals |
| issn | 2045-2322 |
| language | English |
| publishDate | 2024-11-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj-art-22f3cfb38b5c46f1af788fc2a72e29c82025-08-20T02:13:27ZengNature PortfolioScientific Reports2045-23222024-11-0114111410.1038/s41598-024-76806-yWind velocity and dispersion/advection–diffusion of artificial droplets and droplet nuclei in a domed all-weather multi-purpose stadiumNaohide Shinohara0Noboru Kurihara1Wataru Naito2Aya Iwai3Tetsuo Yasutaka4Toshihiro Morioka5Toshiyuki Takatsuji6Masayuki Ogata7Koichi Tatsu8National Institute of Advanced Industrial Science and Technology (AIST), Research Institute of Science for Safety and Sustainability (RISS)National Institute of Advanced Industrial Science and Technology (AIST), National Metrology Institute of Japan (NMIJ)National Institute of Advanced Industrial Science and Technology (AIST), Research Institute of Science for Safety and Sustainability (RISS)National Institute of Advanced Industrial Science and Technology (AIST), National Metrology Institute of Japan (NMIJ)National Institute of Advanced Industrial Science and Technology (AIST), Geological survey of JapanNational Institute of Advanced Industrial Science and Technology (AIST), National Metrology Institute of Japan (NMIJ)National Institute of Advanced Industrial Science and Technology (AIST), National Metrology Institute of Japan (NMIJ)Tokyo Metropolitan UniversityNational Institute of Advanced Industrial Science and Technology (AIST), Research Institute of Science for Safety and Sustainability (RISS)Abstract To evaluate the COVID-19 infection risk and the effectiveness of countermeasures at mass-gathering events, we measured the dispersion and advective diffusion of artificial droplets and artificial droplet nuclei at the Tokyo Dome, Japan (capacity 55,000 people). We also measured and evaluated the effectiveness of wearing masks and increasing the space between seating areas. If people were seated facing forward, artificial droplets did not reach the mouths of surrounding people, suggesting low risk of droplet transmission. For an artificially generated cough or sneeze, the volume of droplets deposited on the hair, back of the neck, and back of the human in front, and the backs of the seats in front, decreased by two to three orders of magnitude when a mask was worn, regardless of the type of mask. However, when the mask was worn with the nose out, the amount deposited on the back of the seat in front was reduced by only 17%. Even in seats with the highest particle concentration in the vicinity of the source, only 0.097%–0.24% of the generated droplet nuclei (1.0–3.0 μm) from the source were inhaled. Our results suggest that the infection risk at the Tokyo Dome via droplet and airborne transmission was low.https://doi.org/10.1038/s41598-024-76806-yCoronavirus infection 2019 (COVID-19)Mass-gathering events (MGEs)Transmission riskInfection riskCough simulatorFace mask |
| spellingShingle | Naohide Shinohara Noboru Kurihara Wataru Naito Aya Iwai Tetsuo Yasutaka Toshihiro Morioka Toshiyuki Takatsuji Masayuki Ogata Koichi Tatsu Wind velocity and dispersion/advection–diffusion of artificial droplets and droplet nuclei in a domed all-weather multi-purpose stadium Scientific Reports Coronavirus infection 2019 (COVID-19) Mass-gathering events (MGEs) Transmission risk Infection risk Cough simulator Face mask |
| title | Wind velocity and dispersion/advection–diffusion of artificial droplets and droplet nuclei in a domed all-weather multi-purpose stadium |
| title_full | Wind velocity and dispersion/advection–diffusion of artificial droplets and droplet nuclei in a domed all-weather multi-purpose stadium |
| title_fullStr | Wind velocity and dispersion/advection–diffusion of artificial droplets and droplet nuclei in a domed all-weather multi-purpose stadium |
| title_full_unstemmed | Wind velocity and dispersion/advection–diffusion of artificial droplets and droplet nuclei in a domed all-weather multi-purpose stadium |
| title_short | Wind velocity and dispersion/advection–diffusion of artificial droplets and droplet nuclei in a domed all-weather multi-purpose stadium |
| title_sort | wind velocity and dispersion advection diffusion of artificial droplets and droplet nuclei in a domed all weather multi purpose stadium |
| topic | Coronavirus infection 2019 (COVID-19) Mass-gathering events (MGEs) Transmission risk Infection risk Cough simulator Face mask |
| url | https://doi.org/10.1038/s41598-024-76806-y |
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