BIC-ESAT and SKL-ESPC, College of Environmental Sciences and Engineering, Peking University, Beijing, China.
Department of Environmental Science, Policy, and Management, University of California, Berkeley, California.
Indoor Air. 2019 Jul;29(4):630-644. doi: 10.1111/ina.12562. Epub 2019 May 17.
We investigate source characteristics and emission dynamics of volatile organic compounds (VOCs) in a single-family house in California utilizing time- and space-resolved measurements. About 200 VOC signals, corresponding to more than 200 species, were measured during 8 weeks in summer and five in winter. Spatially resolved measurements, along with tracer data, reveal that VOCs in the living space were mainly emitted directly into that space, with minor contributions from the crawlspace, attic, or outdoors. Time-resolved measurements in the living space exhibited baseline levels far above outdoor levels for most VOCs; many compounds also displayed patterns of intermittent short-term enhancements (spikes) well above the indoor baseline. Compounds were categorized as "high-baseline" or "spike-dominated" based on indoor-to-outdoor concentration ratio and indoor mean-to-median ratio. Short-term spikes were associated with occupants and their activities, especially cooking. High-baseline compounds indicate continuous indoor emissions from building materials and furnishings. Indoor emission rates for high-baseline species, quantified with 2-hour resolution, exhibited strong temperature dependence and were affected by air-change rates. Decomposition of wooden building materials is suggested as a major source for acetic acid, formic acid, and methanol, which together accounted for ~75% of the total continuous indoor emissions of high-baseline species.
我们利用时间和空间分辨测量技术，研究了加利福尼亚州一栋单层住宅中挥发性有机化合物（VOC）的源特征和排放动态。在夏季进行了 8 周、冬季进行了 5 周的测量，共检测到约 200 个 VOC 信号，对应于 200 多种物质。空间分辨测量结果结合示踪剂数据表明，居住空间中的 VOC 主要是直接排放到该空间，只有少量来自地下室、阁楼或室外。居住空间中的时间分辨测量结果显示，对于大多数 VOC，其基线水平远高于室外水平；许多化合物也表现出间歇性短期增强（峰值）的模式，明显高于室内基线。根据室内与室外浓度比和室内平均值与中值比，将化合物分为“高基线”或“峰值主导”。短期峰值与居住者及其活动有关，尤其是烹饪。高基线化合物表明建筑材料和家具持续释放室内空气污染物。使用 2 小时分辨率定量计算出的高基线物种的室内排放率，强烈依赖于温度，并且受空气交换率的影响。木质建筑材料的分解被认为是乙酸、甲酸和甲醇的主要来源，它们共同占高基线物种总连续室内排放量的约 75%。
