Analysis of production and spread of aerosolized pathogens: toward quantitative distancing, occupancy, and ventilation guidelines for work and public places

包括COVID-19在内的许多传染病都是通过直接接触感染者产生的气溶胶或二次接触受污染的表面而传播的。这些气溶胶是由感染者在呼吸、说话、打喷嚏和咳嗽等呼气过程中进入环境的，它们的产生和传播直接属于流体力学的范畴。持续的COVID-19疫情表明，有效的社交距离指南对于降低随后吸入受污染的雾化颗粒的风险至关重要。然而，它也表明我们对气溶胶疾病传播的理解存在重大差距，缺乏可靠的缓解和遏制战略。例如，目前的社会距离规则是基于对静态环境中产生的受污染气溶胶传播的简单估计。因此，他们低估了在工作场所和公共场所的各种活动中需要保持的安全距离，在这些活动中必须考虑病原体积聚和通风的影响。此外，目前没有关于个人防护装备的适当使用和选择、占用限制的数据驱动的健康和安全准则，也没有关于减轻传染病空气传播风险和在大流行、地方流行病或流行病条件下维持业务活动的适应性准则。拟议的研究将通过系统的定量分析来解决这些缺陷，为室内工作场所制定可靠和适应性的社会距离、占用限制、通风设置和个人防护装备使用指南。结果将通过向加拿大工业提供工作场所健康和安全服务的非营利性项目伙伴网络直接转化为加拿大工业。研究结果将有助于在2019冠状病毒病大流行期间维持经济和社会活动的基本水平，减轻季节性流行病的不利影响，并为加拿大应对不可避免的未来大流行事件做好准备。

Many infectious diseases, including COVID-19, are transmitted through direct contact with aerosols produced by an infected person or secondary contact with contaminated surfaces. Such aerosols are introduced into the environment by an infected person during expiratory events, such as breathing, speaking, sneezing, and coughing, and their production and spread directly fall into the domain of fluid mechanics. The ongoing outbreak of COVID-19 has demonstrated that effective social distancing guidelines are critical to reduce the risk of subsequent inhalation of contaminated aerosolized particles. However, it also demonstrated critical gaps in our understanding of aerosol disease transmission and lack of reliable mitigation and containment strategies. For example, the current social distancing rules are based on simple estimates of the spread of contaminated aerosols produced in a static environment. They therefore underestimate the safe distances that need to be maintained in various activities at workplaces and public areas, where effects of pathogen accumulation and ventilation must be considered. Further, there are currently no data-driven health and safety guidelines available for the appropriate usage and selection of personal protective equipment (PPE), occupancy limits, and the adaptive guidelines for mitigating risks of airborne transmission of infectious diseases and maintaining business activities in pandemic, endemic, or epidemic conditions. The proposed research will address these deficiencies through a methodical quantitative analysis, producing reliable and adaptive social distancing, occupancy limits, ventilation settings, and PPE usage guidelines for indoor workplaces. The results will be translated directly to the Canadian industry through the non-profit project partner network which provides workplace health and safety services to Canadian industry. The outcomes will be instrumental for maintaining the essential levels of economic and social activities during the ongoing COVID-19 pandemic, mitigating the adverse impact of seasonal epidemics, and preparing Canada for inevitable future pandemic events.