Cao J J, Lee S C, Chow J C, Cheng Y, Ho K F, Fung K, Liu S X, Watson J G
Research Center for Environmental Technology and Management, Department of Civil and Structural Engineering, The Hong Kong Polytechnic University, Hong Kong, China.
Indoor Air. 2005 Jun;15(3):197-204. doi: 10.1111/j.1600-0668.2005.00336.x.
Six residences were selected (two roadside, two urban, and two rural) to evaluate the indoor-outdoor characteristics of PM(2.5) (aerodynamic diameter <2.5 microm) carbonaceous species in Hong Kong during March and April 2004. Twenty-minute-averaged indoor and outdoor PM(2.5) concentrations were recorded by DustTrak samplers simultaneously at each site for 3 days to examine diurnal variability of PM(2.5) mass concentrations and their indoor-to-outdoor (I/O) ratios. Daily (24-h average) indoor/outdoor PM(2.5) samples were collected on pre-fired quartz-fiber filters with battery-powered portable mini-volume samplers and analyzed for organic and elemental carbon (OC, EC) by thermal/optical reflectance (TOR) following the Interagency Monitoring of Protected Visual Environments (IMPROVE) protocol. The average indoor and outdoor concentrations of 24 h PM(2.5) were 56.7 and 43.8 microg/m(3), respectively. The short-term PM(2.5) profiles indicated that the penetration of outdoor particles was an important contributor to indoor PM(2.5), and a household survey indicated that daily activities were also sources of episodic peaks in indoor PM(2.5). The average indoor OC and EC concentrations of 17.1 and 2.8 microg/m(3), respectively, accounted for an average of 29.5 and 5.2%, respectively, of indoor PM(2.5) mass. The average indoor OC/EC ratios were 5.8, 9.1, and 5.0 in roadside, urban, and rural areas, respectively; while average outdoor OC/EC ratios were 4.0, 4.3, and 4.0, respectively. The average I/O ratios of 24 h PM(2.5), OC, and EC were 1.4, 1.8, and 1.2, respectively. High indoor-outdoor correlations (r(2)) were found for PM(2.5) EC (0.96) and mass (0.81), and low correlations were found for OC (0.55), indicative of different organic carbon sources indoors. A simple model implied that about two-thirds of carbonaceous particles in indoor air are originated from outdoor sources.
Indoor particulate pollution has received more attentions in Asia. This study presents a case study regarding the fine particulate matter and its carbonaceous compositions at six residential homes in Hong Kong. The characteristics and relationship of atmospheric organic and elemental carbon were discussed indoors and outdoors. The distribution of eight carbon fractions was first reported in indoor samples to interpret potential sources of indoor carbonaceous particles. The data set can provide significant scientific basis for indoor air quality and epidemiology study in Hong Kong and China.
2004年3月至4月期间，在香港选取了六个住宅（两个路边住宅、两个城市住宅和两个乡村住宅）来评估细颗粒物（PM₂.₅，空气动力学直径<2.5微米）含碳物质的室内外特征。在每个采样点，使用DustTrak采样器同时记录20分钟平均的室内和室外PM₂.₅浓度，为期3天，以研究PM₂.₅质量浓度的日变化及其室内外（I/O）比值。使用电池供电的便携式微型大容量采样器，在预先烧制的石英纤维滤膜上采集每日（24小时平均）室内/室外PM₂.₅样本，并按照保护视觉环境跨部门监测（IMPROVE）协议，通过热/光反射（TOR）法分析有机碳和元素碳（OC、EC）。24小时PM₂.₅的室内和室外平均浓度分别为56.7和43.8微克/立方米。短期PM₂.₅分布表明，室外颗粒物的渗透是室内PM₂.₅的一个重要来源，一项住户调查表明，日常活动也是室内PM₂.₅出现偶发峰值的来源。室内OC和EC的平均浓度分别为17.1和2.8微克/立方米，分别占室内PM₂.₅质量的29.5%和5.2%。路边、城市和农村地区的室内OC/EC平均比值分别为5.8、9.1和5.0；而室外OC/EC平均比值分别为4.0、4.3和4.0。24小时PM₂.₅、OC和EC的平均I/O比值分别为1.4、1.8和1.2。发现PM₂.₅、EC（0.96）和质量（0.81）的室内外相关性较高，而OC的相关性较低（0.55），这表明室内有机碳来源不同。一个简单模型表明，室内空气中约三分之二的含碳颗粒物源自室外。
室内颗粒物污染在亚洲受到了更多关注。本研究展示了香港六个住宅中细颗粒物及其含碳成分的案例研究。讨论了室内外大气有机碳和元素碳的特征及关系。首次报道了室内样本中八种碳组分的分布，以解释室内含碳颗粒物的潜在来源。该数据集可为香港和中国的室内空气质量及流行病学研究提供重要的科学依据。
