北京市冬季采暖期家用空气净化器净化效果评价

Evaluation of purification effects of household air purifiers during winter heating period in Beijing

[目的]了解北京市采暖期住宅室内外颗粒物浓度,并评估家用净化器对室内颗粒物的净化效果。[方法]2015年11月—2016年1月间,选择北京市某区15户住宅,采用粉尘仪实时监测每户在开启家用型高效颗粒物空气(HEPA)净化器前后各24 h室内外PM_(2.5)和PM_(10)质量浓度,并在净化器开启后采用多通道仪监测室内PM_(2.5)、PM_(10)及其他多种粒径颗粒物浓度;采用室内外颗粒物浓度比值(I/O值)描述室内颗粒物相对室外的污染水平,并用配对样本的Wilcoxon符号秩检验比较净化前后I/O值差异;采用颗粒物清除率评价短时净化效率,并采用Friedman M检验和Wilcoxon符号秩检验进行比较。[结果]各户净化器运行前后的日均PM_(2.5)浓度的I/O值中位数及四分位数间距分别为1.79(2.63)和0.46(0.49),PM_(10)的I/O值中位数及四分位数间距分别为1.44(1.65)和0.40(0.46)。PM_(2.5)和PM_(10)净化前后的I/O值差异均有统计学意义(P<0.05)。净化器开始运行到室内颗粒物浓度达稳定水平的时间约为3 h,对空气动力学直径≤0.3μm的颗粒物平均清除率为59.03%;>0.3~0.5μm的颗粒物为63.08%;>0.5~1μm的颗粒物为67.00%;PM_(2.5)为63.60%;PM_(10)为71.91%。不同粒径颗粒物的清除率差异具有统计学意义(P<0.05)。[结论]家用型HEPA净化器可降低室内PM_(10)、PM_(2.5)及更小粒径颗粒物浓度,在3 h内降低不同粒径颗粒物浓度60%以上,其对不同粒径颗粒物的去除效果有所不同。

[ Objective ] To measure the concentrations of residential indoor and outdoor particulate matters （PM） during winter heating period in Beijing, and evaluate the effectiveness of household air purifiers on reducing indoor PM. [ Methods ] From November 2015 to January 2016, fifteen residential houses were recruited from a district in Beijing and monitored for indoor and outdoor concentrations of PM2.5 and PM10 for 24h before and after operating selected purifiers using high- efficiency particulate air （HEPA） technique. Multi-channel particle monitor was used to monitor indoor PM2.5, PM10, and other smaller size-fractionated PM levels. Indoor/outdoor （I/O） PM ratios were used to indicate relative levels of indoor PM compared with outdoor PM levels, and Wilcoxon signed rank test for paired samples was applied to compare the I/O ratios with and without air purifiers operating. Purification rates of different PM fractions were used to evaluate the short-term effectiveness of air purifiers, and Friedman Mtest and Wilcoxon rank test were used to compare their difference. [ Results ] The median and interquartile range of I/O ratios of PM2.5 daily averages without and with air purifiers operating were 1.79 （2.63） and 0.46 （0.49）, respectively, and those of PM10 without and with air purifiers operating were 1.44 （1.65） and 0.40 （0.46）,