【摘要】 大气颗粒物污染严重影响人群健康。佩戴口罩是较为普遍的个体日常防护措施,其实际防护效果受到诸多环境因素和人为因素的影响。通过模拟人体呼吸实境,研究了锥形静电棉层口罩（A）和折叠型纱布口罩（B）在实际大气环境中的颗粒物过滤效率,分析了颗粒物粒径、大气环境PM2.5质量浓度、呼气相对湿度等因素对口罩过滤效率的影响。结果表明,对于0.3、0.5、1.0、2.5、5.0和10μm的颗粒物,A类口罩的过滤效率均值分别为73.4%、80.9%、83.5%、84.6%、86.5%和87.7%,B类口罩的过滤效率均值分别为70.3%、77.1%、79.9%、82.0%、85.2%和85.9%。颗粒物粒径对A、B两类口罩的过滤效率具有极为显著的影响(A:χ²=223.543,P=2.588×10^-46;B:χ²=214.396,P=2.356×10^-44)。在该研究粒径范围（0.3-10μm）内,口罩的颗粒物过滤效率呈现随颗粒物粒径增大而升高的趋势。A、B两类口罩对0.3μm颗粒物的过滤效率均与环境PM_2.5质量浓度呈显著负相关(A:r=-8.710×10^-1,P=2.320×10^-5;B:r=-9.110×10^-1,P=2.400×10^-6),且B类口罩的降幅高于A类口罩。A、B两类口罩对6个粒径颗粒物的过滤效率与人体呼气相对湿度之间均不存在显著的相关关系。实验结果突显了在实际环境下针对口罩防护效果进行实验的必要性和重要性,可为后续健康风险评估等相关研究提供科学参考。更多还原

【Abstract】 Particulate matter pollution poses a serious threat to population health. Wearing facepiece respirators is a common individual protective measure. However, in reality, the actual efficiencies of facepiece respirators would be affected by many environmental and human factors. This study simulated the breathing process of a human in a real-world environment to evaluate the efficiencies of a conical electrostatic cotton mask（A） and a folded gauze mask（B）. It analyzed the effects of four potential factors,namely particle size, facepiece respirator type, ambient particle pollution level, and relative humidity of exhaled breath, on the respirators’ efficiencies. The results showed that for particulate matter of size 0.3, 0.5, 1.0, 2.5, 5.0 and 10 μm, the average removal efficiencies of respirator A were 73.4%, 80.9%, 83.5%, 84.6%, 86.5%, and 87.7% respectively, and those of respirator B were 70.3%, 77.1%, 79.9%, 82.0%, 85.2%, and 85.9% respectively. Particle size had a statistically significant impact on the removal efficiencies of both respirators(A: χ²=223.543, P=2.588×10^-46; B: χ²=214.396, P=2.356×10^-44). For the particle size range investigated in this study（0.3-10 μm）, the removal efficiency showed a tendency to increase with the particle size. The removal efficiencies of respirators A and B for 0.3 μm-sized particles were significantly negatively correlated with the mass concentration of ambient PM_2.5(A: r=-8.710×10^-1, P=2.320×10^-5; B: r=-9.110×10^-1, P=2.400×10^-6), and the reduction for respirator B was higher than that for respirator A. There was no significant correlation between the removal efficiency and relative humidity of exhaled breath for both respirators. The results of this study thus highlight the necessity and importance of taking potential factors into account when evaluating the efficiencies of facepiece respirators in a real environment. This study provides valuable information for future work on human health risk assessment.更多还原