摘要目的 研究N95过滤式防尘口罩的防护效果与使用者对口罩主观评价的关系.方法 选取市场上销售的2个品牌共4种防尘口罩(A1、A2、B1、B2),测试其过滤效率和吸气阻力.根据国人头面二元分栏选取50名测试者,采用核凝计数器法进行4种口罩的密合性测试,并问卷调查测试者佩戴口罩时的主观感受.结果 4种防尘口罩材质的过滤效率和吸气阻力均符合国家标准GB 2626-2006中关于N95防尘口罩的相关规定.4种口罩适合因数的几何均值(GMFF)分别为20.9、14.6、74.0和49.1,两两比较的差异有统计学意义(P＜0.05),密合测试的通过率分别为4％、4％、42％和20％,密合性能均较差,A1和A2两种口罩通过率不到10％.佩戴者对实验口罩呼吸阻力主观感受的差异无统计学意义(P＞0.05).B类口罩与面部吻合程度优于A类口罩,折叠状口罩舒适性高于杯状口罩,差异均有统计学意义(P＜0.05).佩戴者对实验口罩漏气情况的主观评价与客观检测结果的一致性不好,kappa值为0.067(95％CI:-0.029～0.163,P=0.18),一致率为50.00％.结论 国内市场上N95过滤式防尘口罩普遍存在密合性较差的问题,应根据国人头面特征进行改进.同时,接尘工人在选择防尘口罩时应依据密合性测试结果而非个人主观判断.

abstractsObjective To evaluate the protective performance of N95 filtering-facepiece respirators (FFRs) used widely in China and to investigate participants' subjective evaluation about them.Methods Four models (A 1,A2,B 1,B2) of N95 FFRs from two manufactures were chosen to measure the filter penetration and inhalation resistance.Inward leakage was measured by Condensation Nuclei Counting method (CNC) in 50 participants selected using the Chinese respirator fit test panel.Each participant was asked subjective feelings after wearing a respirator by questionnaire survey.Results The filter penetration and inhalation resistance of four FFRs complied with national standards (GB 2626-2006).The geometric mean fit factors (GMFFs) for four models were 20.9,14.6,74.0,49.1 and there passing rates were 4％,4％,42％,10％.All of four models had bad seal performance,especially the passing rate of A1 and A2 were lower than 10％.The self-feelings about the resistance for FFRs had no significant difference (P＞0.05).The results indicated that B (B1 and B2) has a better fit than A (A1 and A2) according to participants' subject evaluation (P＜0.05).The folding style respirator (B2) was significant more comfortable than the cup style respirator (B 1).The subjective feeling of respirators leakage by participant was poor consistent with objective inward leakage test.The kappa index was 0.067 (95％CI:-0.029～0.163,P=0.18) and the consistent rate was 50％.Conclusion The poor seal performance was the biggest problem of N95 FFRs in Chinese market.Respirators should be resigned or improved rely on Chinese facial features.Dust workers should choice a fit respirator according to the result of objective leakage test rather than subjective feeling of leakage.