College of Urban and Environmental Sciences, Laboratory for Earth Surface Processes, Sino-French Institute for Earth System Science, Peking University, Beijing 100871, China; School of Civil & Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
College of Urban and Environmental Sciences, Laboratory for Earth Surface Processes, Sino-French Institute for Earth System Science, Peking University, Beijing 100871, China.
Environ Int. 2021 Jan;146:106026. doi: 10.1016/j.envint.2020.106026. Epub 2020 Oct 28.
Because of the severe air pollution in northern China, facemasks have gained popularity in this area in recent years. Although the results of previous studies have shown the effectiveness of wearing facemasks for intercepting particles, the individual differences and the overall health benefits of wearing facemasks have not been comprehensively documented. In this study, using both model and personal tests under various conditions, we test eight major brands of facemasks for their removal efficiencies (REs) of particulate matter (PM) in six size ranges (from 0.3 μm to >10 μm). The results are used to assess the overall exposure reduction at the individual and population levels in Beijing. We find significant differences in REs among PM sizes, facemask brands, pollution levels, and genders. Combining the information on the usage of various brands, facemask wearing rates, and PM concentrations in the ambient and indoor air in this area, we evaluate the overall effect of facemask wearing on PM exposure reduction. It is quantitatively demonstrated that because people spend most time indoors, facemask protection is limited. For facemask wearers, the overall exposure can be reduced by less than 20%, whereas the reduction rate is as low as 2.4 ± 1.6% for the entire adult populations even in the year with the highest level of pollution with an annual mean PM concentration of 102 ± 98 μg∙m. As a strategy of self-protection from long-term exposure to particulate matter, wearing facemasks outdoors is inferior to the installation of indoor air purifiers.
由于中国北方地区严重的空气污染，近年来，口罩在该地区广受欢迎。尽管之前的研究结果表明佩戴口罩拦截颗粒物的有效性，但口罩佩戴的个体差异和整体健康益处尚未得到全面记录。在这项研究中，我们使用模型和个人在各种条件下的测试，测试了八种主要品牌的口罩对六种粒径范围（从 0.3μm 到 >10μm）的颗粒物的去除效率（RE）。结果用于评估在北京的个体和人群水平的整体暴露降低程度。我们发现，RE 在 PM 粒径、口罩品牌、污染水平和性别之间存在显著差异。结合该地区各种品牌的使用信息、口罩佩戴率以及环境和室内空气中的 PM 浓度，我们评估了口罩佩戴对 PM 暴露降低的整体效果。定量表明，由于人们大部分时间都在室内，口罩的防护作用有限。对于口罩佩戴者来说，整体暴露量的减少不到 20%，而即使在污染最严重的一年，即 PM 浓度年平均值为 102±98μg·m 时，整个成年人群的减少率也低至 2.4±1.6%。作为一种长期暴露于颗粒物的自我保护策略，佩戴户外口罩不如安装室内空气净化器。
