北京秋季室内外PM2.5污染水平及其相关性

PM2.5 Concentrations in Indoor and Outdoor Air and Their Relationship in the Fall of Beijing

目的了解北京市住宅室内空气颗粒物的污染状况,研究室外颗粒物以及室内活动对室内颗粒物浓度变化的影响,为制订和修订相应的室内空气质量标准提供基础数据及相应的科学依据。方法于2008年10月27—31日对一社区居民住宅(8户)的室内和室外同步进行PM2.5的采集。采用称重法测得住宅室内外PM2.5的质量浓度,同时结合在线连续观测数据和时间活动模式问卷调查结果,了解各种污染源对室内外颗粒物浓度变化的影响。结果采样期间的室内、室外平均浓度分别为58.5和74.1μg/m3,IO比值(室内与室外颗粒物质量浓度之比)为0.85。室内人为活动(做饭,打扫等)会使室内颗粒物浓度瞬间急剧增大,是室内主要的污染源之一;在夜间,室外颗粒物的渗透作用是影响室内环境的主要因素。结论与国外相比,国内的室内PM2.5浓度仍处于一个较高的污染水平,做饭可能产生高浓度的颗粒物。室内环境应当受到公众的关注。

Objective To investigate indoor particle pollution in the residence of Beijing, and to find out how both outdoor particles and indoor human activities affect the indoor fine particle （PM2.5） levels, which may supply the basic data for setting indoor air quality standards. Methods Eight houses were selected in a residential district during October, 2008 and indoor and outdoor PM2.5 samples were collected. PM2.5 concentration was obtained by weighting the mass of the filter before and after sampling. The detailed information of online PM2.5 data （DustTrak） and time-activity pattern questionnaires explained how human activities affected the variation of indoor and outdoor PM2.5. Results The indoor and outdoor PM2.5 average concentrations were 58.5μg/m^3 and 74.1μg/m^3, respectively. The average IO ratio was 0.85 during the sampling. The indoor activities, especially cooking and sweeping, caused the drastic variation of indoor PM2.5 concentration. The indoor activities were the main indoor pollution sources, while the infiltration of outdoor particles was the most important factor that affected the indoor microenvironment at night. Conclusion In Chinese residences, the PM2.5 concentrations in the indoor air were still in a higher polluted level compared with the developed countries. Cooking activities may make particulate matter of utmost concentration. The indoor microenvironment should be paid more attention by the public.