Department of Environmental Sciences and Engineering, Gillings School of Global Public Health , The University of North Carolina at Chapel Hill , Chapel Hill , North Carolina 27599 , United States.
Department of Environmental Sciences, School of Environmental and Biological Sciences , Rutgers, The State University of New Jersey , New Brunswick , New Jersey 08901 , United States.
Environ Sci Technol. 2019 Feb 19;53(4):1812-1821. doi: 10.1021/acs.est.8b05852. Epub 2019 Jan 31.
Water-soluble organic gas (WSOG) concentrations are elevated in homes. However, WSOG sources, sinks, and concentration dynamics are poorly understood. We observed substantial variations in 23 residential indoor WSOG concentrations measured in real time in a North Carolina, U.S., home over several days with a high-resolution time-of-flight chemical ionization mass spectrometer equipped with iodide reagent ion chemistry (I-HR-ToF-CIMS). Concentrations of acetic, formic, and lactic acids ranged from 30-130, 15-53, and 2.5-360 μg m, respectively. Concentrations of several WSOGs, including acetic and formic acids, decreased considerably (∼30-50%) when the air conditioner (AC) cycled on, suggesting that the AC system is an important sink for indoor WSOGs. In contrast to nonpolar organic gases, indoor WSOG loss rate coefficients were substantial for compounds with high oxygen-to-carbon (O/C) ratios (e.g., 1.6-2.2 h for compounds with O/C > 0.75 when the AC system was off). Loss rate coefficients in the AC system were more uncertain but were estimated to be 1.5 h. Elevated concentrations of lactic acid coincided with increased human occupancy and cooking. We report several WSOGs emitted from cooking and cleaning as well as transported in from outdoors. In addition to indoor air chemistry, these results have implications to exposure and human health.
水溶性有机气体（WSOG）在家庭中的浓度较高。然而，WSOG 的来源、汇和浓度动态仍不清楚。我们使用配备有碘试剂离子化学（I-HR-ToF-CIMS）的高分辨率飞行时间化学电离质谱仪，实时测量了美国北卡罗来纳州一栋住宅内 23 种室内 WSOG 浓度，发现其在数天内存在显著变化。醋酸、甲酸和乳酸的浓度范围分别为 30-130、15-53 和 2.5-360μg/m。当空调（AC）循环开启时，包括醋酸和甲酸在内的几种 WSOG 浓度明显下降（约 30-50%），表明空调系统是室内 WSOG 的重要汇。与非极性有机气体相比，当空调系统关闭时，具有高氧碳比（O/C）的化合物（例如，O/C>0.75 的化合物的 O/C 比为 1.6-2.2h）的室内 WSOG 损失率系数较大。在空调系统中的损失率系数更不确定，但估计为 1.5h。乳酸浓度升高与人员入住率增加和烹饪活动增加有关。我们报告了一些来自烹饪和清洁过程以及从室外传入的 WSOG。除了室内空气化学之外，这些结果对暴露和人类健康也有影响。
