Estimation of airborne viral emission: Quanta emission rate of SARS-CoV-2 for infection risk assessment
Estimation of airborne viral emission: Quanta emission rate of SARS-CoV-2 for infection risk assessment
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DOI：
10.1016/j.envint.2020.105794
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发表时间：
2020-08-01
影响因子：
11.8
通讯作者：
Morawska, L.
中科院分区：
文献类型：
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作者：
Buonanno, G.;Stabile, L.;Morawska, L.
空气传播是一种传染途径，尽管科学文献中有证据表明它在流行病中可以发挥作用，但仍未对其进行充分调查。医学研究领域致力于寻找治疗和补救措施来抵消病毒的影响，而工程领域则通过模拟病毒在流行期间的空气传播来参与室内环境的风险评估。为此，需要病毒空气排放数据。不幸的是，基于特定的逆向工程案例，此信息通常仅在爆发之后可用。在这项工作中，提出了一种基于口腔病毒载量、呼吸活动类型（如呼吸、说话、耳语）、呼吸生理参数（如吸入速率）和活动水平（如休息、站立、轻度运动）来估计传染性受试者释放的病毒载量的新方法。结果表明，无症状传染性SARS-CoV-2受试者在轻度活动（如缓慢行走）时发声可达到高量子发射率（100量子h(-1)），而有症状的SARS-CoV-2受试者在静息条件下大多具有低量子发射率（< 1量子h(-1)）。然后，通过评估意大利室内微环境中无症状SARS-CoV-2受试者在引入病毒控制措施前后感染的人数，将量子排放率的研究结果纳入感染风险模型，以证明其应用价值。模拟结果清楚地表明，在室内环境中，适当的通风对病毒的控制起着关键作用。
Airborne transmission is a pathway of contagion that is still not sufficiently investigated despite the evidence in the scientific literature of the role it can play in the context of an epidemic. While the medical research area dedicates efforts to find cures and remedies to counteract the effects of a virus, the engineering area is involved in providing risk assessments in indoor environments by simulating the airborne transmission of the virus during an epidemic. To this end, virus air emission data are needed. Unfortunately, this information is usually available only after the outbreak, based on specific reverse engineering cases. In this work, a novel approach to estimate the viral load emitted by a contagious subject on the basis of the viral load in the mouth, the type of respiratory activity (e.g. breathing, speaking, whispering), respiratory physiological parameters (e.g. inhalation rate), and activity level (e.g. resting, standing, light exercise) is proposed. The results showed that high quanta emission rates ( 100 quanta h(-1) ) can be reached by an asymptomatic infectious SARS-CoV-2 subject performing vocalization during light activities (i.e. walking slowly) whereas a symptomatic SARS-CoV-2 subject in resting conditions mostly has a low quanta emission rate (< 1 quantum h(-1) ). The findings in terms of quanta emission rates were then adopted in infection risk models to demonstrate its application by evaluating the number of people infected by an asymptomatic SARS-CoV-2 subject in Italian indoor microenvironments before and after the introduction of virus containment measures. The results obtained from the simulations clearly highlight that a key role is played by proper ventilation in containment of the virus in indoor environments.