论文标题
由于说话而产生的沉积和蒸发液滴引起的病毒空气负荷
Viral air load due to sedimenting and evaporating droplets produced by speaking
论文作者
论文摘要
蒸发对液滴沉积时间的影响对于估计含有病毒的空气液液滴感染的风险至关重要。对于100 nm <r <60μm的液滴半径，可以在停滞流量近似中描述蒸发，并受到扩散限制。液滴蒸发速率，时间依赖性的液滴大小和沉降时间（包括蒸发冷却的显着效果）提出了分析方程。蒸发使大小液滴的沉积物更长，从而显着增加病毒空气负荷。在说话时，使用最新的痰液和液滴生产率中的SARS-COV-2浓度的估计，一个不断说话而无需口腔盖的单一感染者会产生超过10^4个病毒体的总空气负载。在中型关闭房间中，这导致病毒吸入频率至少为每分钟2.5。低相对湿度，正如冬季和客机中遇到的建筑物所遇到的那样，速度会蒸发，因此最初使悬挂在空气中的较大液滴。
The effect of evaporation on droplet sedimentation times is crucial for estimating the risk of infection from virus-containing airborne droplets. For droplet radii in the range 100 nm < R < 60 μm, evaporation can be described in the stagnant-flow approximation and is diffusion limited. Analytical equations are presented for the droplet evaporation rate, the time-dependent droplet size and the sedimentation time, including the significant effect of evaporation cooling. Evaporation makes the time for large droplets to sediment much longer and thus significantly increases the viral air load. Using recent estimates for SARS-CoV-2 concentrations in sputum and droplet production rates while speaking, a single infected person that constantly speaks without a mouth cover produces a total air load of more than 10^4 virions. In a mid-size closed room, this leads to a viral inhalation frequency of at least 2.5 per minute. Low relative humidity, as encountered inside buildings in winter and in airliners, speeds evaporation and thus keeps initially larger droplets suspended in air.
