Supporting data for "The rapid natural viral inactivation in an evaporating droplet"

Droplet infection transmission has again become one of the most heated topics due to the SARS-CoV-2 pandemic in 2019. While the viability decay of infectious droplets due to environmental exposure has been studied for nearly a century, the mechanisms of viability decay in respiratory droplets is still unclear, and it lacks a model to evaluate short-range (i.e., conversational distance) droplet viability decay. Recent experimental setup, specifically the droplet levitation device, only allowed capturing droplets after 5 seconds of environmental exposure. Unfortunately, experiment showed the infectivity decay of a large droplet (>50 micrometers in diameter) occurred before 5 seconds, and a new setup was needed to investigate this rapid decay.In this study, we proposed a new setup to capture and analyze droplets after 0.1 to ~9 seconds from initial droplet generation. The droplet drying dynamic was simulated to explain the viability decay measured by the droplet experiment. The simulation results of the droplet composition throughout the evaporation process under various humidity levels are shown here.

2019年新型冠状病毒（SARS-CoV-2）大流行使得飞沫传播再次成为备受关注的热点议题之一。尽管针对环境暴露导致的感染性飞沫存活衰减现象的研究已开展近百年，但呼吸道飞沫的存活衰减机制仍未阐明，且目前缺乏可用于评估短距离（即日常交谈距离）内飞沫存活衰减的模型。现有实验装置，尤其是飞沫悬浮装置，仅能在环境暴露5秒后捕获飞沫。但实验结果显示，直径大于50微米的大飞沫的感染性衰减发生在5秒以内，因此亟需开发新的实验装置以探究这一快速衰减过程。本研究提出了一种新型实验装置，可在飞沫初始生成后的0.1秒至约9秒范围内捕获并分析飞沫。我们通过模拟飞沫干燥动力学过程，解释了飞沫实验中测得的存活衰减现象。本文展示了不同湿度条件下，蒸发全过程中飞沫组分的模拟结果。