The Blake High School, Minneapolis, Minnesota, United States of America.
PLoS One. 2021 May 5;16(5):e0250275. doi: 10.1371/journal.pone.0250275. eCollection 2021.
One of the main challenges during the COVID-19 pandemic is the lack of safety measures and guidelines to reduce the risk of viral spread among people during gatherings. This study was conducted to evaluate the distance of oral and nasal droplet spread in a model that simulates coughing and sneezing in a public setting, specifically a school setting, to guide faculty and staff members with safety measures and guidelines to reduce droplet spread. Several models were prepared to observe and visualize the spread of fluid simulating respiratory droplets in places such as the classroom and the cafeteria, in which a student would be more susceptible to contract a virus since individuals cannot wear masks while eating. For all trials, a 2.54 centimeter balloon with 0.3 milliliters of diluted fluorescent paint was placed inside a mannequin head and was exploded outwards from the mannequin's mouth at 5 pounds per square inch (psi). Using a black light, the expelled fluorescent macroscopic droplets were visualized. When applying safety precautions and guidelines such as mandating face masks, the results of the experiments conducted in this study with a surgical mask, were extremely positive. However, without other safety precautions such as face masks and barriers, social distancing proved to be ineffective. In conclusion the most effective way to prevent droplet spread during activities where masks simply cannot be worn, such as eating, is to apply barriers between the individuals. Applying barriers and wearing masks successfully prevented macroscopic droplet spread.
在 COVID-19 大流行期间,主要挑战之一是缺乏安全措施和指南,以减少人们在聚会时病毒传播的风险。这项研究旨在评估模拟在公共场所(特别是学校)咳嗽和打喷嚏的模型中口腔和鼻腔飞沫传播的距离,以便为教职员工提供安全措施和指南,以减少飞沫传播。准备了几个模型来观察和可视化模拟呼吸道飞沫在教室和自助餐厅等场所的传播情况,在这些场所,学生更容易感染病毒,因为个人在进食时无法佩戴口罩。对于所有试验,将 2.54 厘米的气球用 0.3 毫升稀释荧光漆放在人体模型头内,并以每平方英寸 5 磅(psi)的压力从模型口中向外爆炸。使用黑光观察喷出的荧光宏观液滴。当采用安全预防措施和指南(例如强制戴口罩)时,本研究中使用外科口罩进行的实验结果非常积极。但是,如果没有其他安全预防措施(例如口罩和屏障),则社交距离证明是无效的。总之,在无法佩戴口罩的活动中,防止飞沫传播的最有效方法是在个人之间设置屏障。使用屏障和口罩成功地防止了宏观飞沫传播。