School of Engineering, Cardiff University, Cardiff, UK.
School of Engineering, Cardiff University, Cardiff, UK.
Sci Total Environ. 2022 Sep 10;838(Pt 4):156518. doi: 10.1016/j.scitotenv.2022.156518. Epub 2022 Jun 7.
The literature includes many studies which individually assess the efficacy of protective measures against the spread of the SARS-CoV-2 virus. This study considers the high infection risk in public buildings and models the quality of the indoor environment, related safety measures, and their efficacy in preventing the spread of the SARS-CoV-2 virus.
Simulations are created that consider protective factors such as hand hygiene, face covering and engagement with Covid-19 vaccination programs in reducing the risk of infection in a university foyer. Furthermore, a computational fluid dynamics model is developed to simulate and analyse the university foyer under three ventilation regimes. The probability of transmission was measured across different scenarios.
Estimates suggest that the Delta variant requires the air change rate to be increased >1000 times compared to the original strain, which is practically not feasible. Consequently, appropriate hygiene practices, such as wearing masks, are essential to reducing secondary infections. A comparison of different protective factors in simulations found the overall burden of infections resulting from indoor contact depends on (i) face mask adherence, (ii) quality of the ventilation system, and (iii) other hygiene practices.
Relying on ventilation, whether natural, mechanical, or mixed, is not sufficient alone to mitigate the risk of aerosol infections. This is due to the internal configuration of the indoor space in terms of (i) size and number of windows, their location and opening frequency, as well as the position of the air extraction and supply inlets, which often induce hotspots with stagnating air, (ii) the excessive required air change rate. Hence, strict reliance on proper hygiene practices, namely adherence to face coverings and hand sanitising, are essential. Consequently, face mask adherence should be emphasized and promoted by policymakers for public health applications. Similar research may need to be conducted using a similar approach on the Omicron (B.1.1.529) variant.
文献中包含许多单独评估针对 SARS-CoV-2 病毒传播的保护措施的功效的研究。本研究考虑到公共建筑中的高感染风险，并对室内环境质量、相关安全措施及其在预防 SARS-CoV-2 病毒传播方面的功效进行建模。
模拟考虑了保护因素，例如手部卫生、戴口罩以及参与新冠疫苗接种计划，以降低大学门厅内感染的风险。此外，还开发了计算流体动力学模型，以模拟和分析三种通风模式下的大学门厅。在不同场景下测量了传染的概率。
估计表明，与原始毒株相比，Delta 变体需要将空气交换率增加>1000 倍，这在实际中是不可行的。因此，适当的卫生措施，如戴口罩，对于减少二次感染至关重要。在模拟中比较不同保护因素时发现，室内接触导致的感染总负担取决于（i）口罩佩戴率，（ii）通风系统的质量，以及（iii）其他卫生措施。
仅依靠通风，无论是自然、机械还是混合通风，都不足以降低气溶胶感染的风险。这是由于室内空间的内部配置，包括（i）窗户的大小和数量、位置和开启频率，以及空气抽出和供应入口的位置，这些往往会导致空气停滞的热点，（ii）过高的所需空气交换率。因此，严格依赖适当的卫生措施，即遵守口罩佩戴和手部卫生，是至关重要的。因此，政策制定者应该强调并促进口罩佩戴率，以用于公共卫生应用。可能需要使用类似的方法对奥密克戎（B.1.1.529）变体进行类似的研究。
