论文标题
简单地量化病毒传播的通风的必要性
Necessity of ventilation for mitigating virus transmission quantified simply
论文作者
论文摘要
为了减轻SARS-COV-2大流行，官员采取了社会疏远和全职措施，对房间通风的关注越来越高。对于通风较差的空间，有效的距离实践可能是无效的，这两者通常都充满湍流的空气。这对于使用混合通风的室内空间是典型的。虽然湍流最初会降低病毒源源附近的感染风险，但最终会增加空间中所有乘员无通气的风险。为了补充旨在精确度的详细模型，简约的框架对于促进通风提供了安全量的数量级估计很有用，尤其是在情况需要有限选择的实际决策时。采用运输和扩散的基本原理，我们估计注射到湍流空气房间的病毒体的时间尺度感染了乘员，区分低初始病毒体质量负荷与脱离病毒率的隔离墙的情况与较低的病毒率相比。我们将打开窗口的效果视为通风的代理。当气流以各向同性湍流为主时，确保安全所需的最小面积仅取决于总病毒载荷与感染阈值负荷的比率。极简主义的估计在这里仅表达，在教室和工作场所中，相当于通风的相当于通风，从而显着提高了安全性。
To mitigate the SARS-CoV-2 pandemic, officials have employed social distancing and stay-at-home measures, with increased attention to room ventilation emerging only more recently. Effective distancing practices for open spaces can be ineffective for poorly ventilated spaces, both of which are commonly filled with turbulent air. This is typical for indoor spaces that use mixing ventilation. While turbulence initially reduces the risk of infection near a virion-source, it eventually increases the exposure risk for all occupants in a space without ventilation. To complement detailed models aimed at precision, minimalist frameworks are useful to facilitate order of magnitude estimates for how much ventilation provides safety, particularly when circumstances require practical decisions with limited options. Applying basic principles of transport and diffusion, we estimate the time-scale for virions injected into a room of turbulent air to infect an occupant, distinguishing cases of low vs. high initial virion mass loads and virion-destroying vs. virion-reflecting walls. We consider the effect of an open window as a proxy for ventilation. When the airflow is dominated by isotropic turbulence, the minimum area needed to ensure safety depends only on the ratio of total viral load to threshold load for infection. The minimalist estimates here convey simply that the equivalent of ventilation by modest sized open window in classrooms and workplaces significantly improves safety.
