PDF(Pubmed)
Abstract：
In order to control the spread of Covid-19, authorities provide various prevention guidelines and recommendations for health workers and the public. Personal protection equipment (PPE) and physical barrier are the most widely applied prevention measures in practice due to their affordability and ease of implementation. This study aims to investigate the effect of PPE and physical barriers on mitigating the short-range airborne transmission between two people in a ventilated environment. Four types of PPE (surgical mask, two types of face shield, and mouth visor), and two different sizes of the physical barrier were tested in a controlled environment with two life-size breathing thermal manikins. The PPE was worn by the source manikin to test the efficiency of source control. The measurement results revealed that the principles of PPE on preventing short-range droplet and airborne transmission are different. Instead of filtering the fine droplet nuclei, they mainly redirect the virus-laden exhalation jet and avoid the exhaled flow entering the target\'s inhalation region. Physical barriers can block the spreading of droplet nuclei and create a good micro environment at short distances between persons. However, special attention should be paid to arranging the physical barrier and operating the ventilation system to avoid the stagnant zone where the contaminant accumulates.
摘要：
为了控制新冠肺炎的传播，当局为卫生工作者和公众提供了各种预防指南和建议。个人防护设备（PPE）和物理屏障由于其可负担性和易于实施而成为实践中应用最广泛的预防措施。这项研究旨在调查PPE和物理屏障对减轻通风环境中两个人之间的短距离空中传播的影响。四种类型的PPE(外科口罩，两种类型的面罩，和嘴部遮阳板)，在受控环境中使用两个真人大小的呼吸热人体模型测试了两种不同尺寸的物理屏障。由源人体模型佩戴PPE以测试源控制的效率。测量结果表明，PPE在防止短距离液滴和空中传播方面的原理是不同的。不是过滤细小的液滴核，它们主要改变携带病毒的呼出射流的方向，避免呼出气流进入目标的吸入区域。物理屏障可以阻挡液滴核的扩散，并在人与人之间的短距离内创造良好的微环境。然而,应特别注意布置物理屏障和操作通风系统，以避免污染物积聚的停滞区。
