RAPID: Coronavirus: Understanding aerosol transmission and potential control measures in indoor environments

COVID-19是由冠状病毒SARS-CoV 2引起的全球性大流行病。据报道，COVID-19通过直接表面暴露和短距离内的密切个人接触传播。最近的研究表明，该病毒可以在空气中的小颗粒（小于5微米）中存活数小时，并在室内积累。这一结果表明，COVID-19在有人居住的空间中通过空气传播的可能性很大。然而，目前缺乏关于携带病毒的颗粒如何在室内环境中分散的科学信息。该RAPID提案响应了更好地了解室内环境中的空气传播和潜在SARS-CoV 2控制措施的迫切需要。该项目的目标是研究病毒颗粒在人体周围的运输机制，并揭示病毒颗粒的浓度如何受到人体咳嗽和呼吸以及通风率和室内气流模式的影响。这些信息将用于评估控制措施的有效性，如通风，过滤和区域划分对密集居住环境中的气溶胶传输。研究结果将用于帮助保护临床环境和老年生活设施中的弱势群体。这项研究的成功完成将更广泛地为医疗卫生专业人员、科学家、工程师和政策制定者提供信息，以制定有关可用于防止室内气溶胶传播的通风策略和个人防护设备类型的决策。COVID-19大流行是全球规模的卫生紧急情况。新兴科学表明，空气传播SARS-CoV 2（导致COVID-19的病毒）作为一种重要的暴露途径的可能性很高。然而，在我们的理解中存在重大差距，这阻碍了室内环境控制策略的有效使用。本研究项目的总体目标是通过以下方式解决这一知识缺口：（1）对室内环境中由于咳嗽、说话、正常呼吸和在不同通风率和空气混合条件下戴面罩呼吸而引起的SARS-CoV 2气溶胶传输的机理进行理解;（2）假设空气条件稳定、混合良好，通过吸入从感染者释放的SARS-CoV 2气溶胶来评估空气传播感染风险;以及（3）评估通风、过滤和区域划分在密集居住环境中控制气溶胶传播的有效性。这将通过使用数学感染风险模型结合气溶胶传输的计算流体动力学模拟来实现，以提供对我们理解室内环境中病毒气溶胶传输和相关空气传播感染风险至关重要的新信息。该分析将填补我们对人类呼吸区传染性气溶胶传输机制的理解中的关键信息空白。评估的主要参数包括感染者的排放模式（即咳嗽、说话、呼吸）;感染性气溶胶质量和直径;通风策略和室内空气混合率。感染控制措施有效性的参数分析将为建筑系统设计和操作提供指导，以保护人类健康。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

COVID-19 is a worldwide pandemic caused by the Coronovirus SARS-CoV2. COVID-19 is reported to be transmitted through direct surface exposure and through close personal contact within a short distance. Recent studies demonstrate that the virus can survive in small airborne particles (less than 5 micrometers) for hours and accumulate indoors. This result suggests a strong possibility for airborne transmission of COVID-19 in occupied spaces. However, there is a present lack of science-based information on how the virus-laden particles disperse in indoor environments. This RAPID proposal responds to the urgent need to better understand the airborne transmission and potential SARS-CoV2 control measures in indoor environments. The goal of this project is to investigate the transport mechanisms of the virus particle transport around the human body and reveal how the concentrations of virus particles are affected by human coughing and breathing, as well as ventilation rates and indoor airflow patterns. This information will be used to evaluate the effectiveness of control measures such as ventilation, filtration, and zone partitioning on aerosol transmission in densely occupied environments. Results will be used to help protect vulnerable population groups in clinical settings and senior living facilities. Successful completion of this research will more broadly inform medical health professionals, scientists, engineers, and policymakers to make decisions regarding the types of ventilation strategies and personal protective equipment that can be used to prevent aerosol transmission indoors.The COVID-19 pandemic is a health emergency of global scale. Emerging science suggests a high potential for airborne exposure to SARS-CoV2 (the virus responsible for COVID-19) as a significant exposure pathway. However, there are major gaps in our understanding that prevent efficient use of control strategies for indoor environments. The overall objectives of this research project are to address this knowledge gap by: (1) developing a mechanistic understanding of SARS-CoV2 aerosol transport in indoor environments due to coughing, talking, normal breathing, and breathing with a mask under various ventilation rates and air mixing conditions; (2) assessing airborne infection risk using inhalation intake of SARS-CoV2 aerosols released from an infector assuming steady-state, well-mixed air conditions; and (3) evaluating the effectiveness of ventilation, filtration, and zone partitioning for controlling aerosol transmission in densely occupied environments. This will be achieved using a mathematical infection risk model coupled with computational fluid dynamics simulations of aerosol transport to provide new information critical to our understanding of virus aerosol transport and associated airborne infection risk in indoor environments. The analysis will fill a critical information gap in our understanding of the transport mechanisms of infectious aerosols in the human breathing zone. Key parameters to be assessed include the emission mode of the infector (i.e. coughing, talking, breathing); the infectious aerosol mass and diameter; and the ventilation strategy and indoor air mixing rate. Parametric analysis of the effectiveness of infection control measures will inform guidelines for building system design and operations for the protection of human health.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.