Zimmerman John H, Williams Alan, Schumacher Brian, Lutes Christopher, Warrier Rohit, Cosky Brian, Thompson Ben, Holton Chase W, Bronstein Kate
Office of Research and Development, U.S. Environmental Protection Agency, 109 TW Alexander Dr., P.O. Box 12055, Research Triangle Park, Durham, NC 27711, USA.
Office of Research and Development, U.S. Environmental Protection Agency, 960 College Station Road, Athens, GA 30605, USA.
Atmosphere (Basel). 2025 Apr;16(4):378. doi: 10.3390/atmos16040378. Epub 2025 Mar 27.
Subsurface contamination can migrate upward into overlying buildings, exposing the buildings' inhabitants to contaminants that can cause detrimental health effects. This phenomenon is known as vapor intrusion (VI). When evaluating a building for VI, one must understand that seasonal and short-term variability are significant factors in determining the reasonable maximum exposure (RME) to the occupants. RME is a semi-quantitative term that refers to the lower portion of the high end of the exposure distribution-conceptually, above the 90th percentile exposure but less than the 98th percentile exposure. Samples were collected between December 2020 and April 2022 at six non-residential commercial buildings in Fairbanks, Alaska. The types of samples collected included indoor air (IA); outdoor air; subslab soil gas; soil gas; indoor radon; differential pressure; indoor and outdoor temperature; heating, ventilation, and air conditioning (HVAC) parameters; and other environmental factors. The buildings in close proximity to the volatile organic compound (VOC) source/release points presented less variability in indoor air concentrations of trichloroethylene (TCE) and tetrachloroethylene (PCE) compared to the buildings farther down gradient in the contaminated groundwater plume. The VOC data pattern for the source area buildings shows an outdoor air temperature-dominated behavior for indoor air concentrations in the summer season. HVAC system operations had less influence on long-term indoor air concentration trends than environmental factors, which is supported by similar indoor air concentration patterns independent of location within the plume. The use of soil temperature and indoor/outdoor temperatures as indicators and tracers (I&Ts) across the plume as predictors of the sampling period could produce a good estimation of the RME for the building occupants. These results, which show the use of soil temperature and indoor/outdoor temperatures as I&Ts, will help advance investigative methods for evaluation of VI in similar settings and thereby improve the protection of human health in indoor environments.
地下污染可能向上迁移至上方的建筑物，使建筑物内的居民接触到可能对健康产生有害影响的污染物。这种现象被称为蒸气侵入（VI）。在评估建筑物的蒸气侵入情况时，必须明白季节性和短期变化是确定居住者合理最大暴露量（RME）的重要因素。RME是一个半定量术语，指的是暴露分布高端的较低部分——从概念上讲，高于第90百分位数暴露但低于第98百分位数暴露。2020年12月至2022年4月期间，在阿拉斯加费尔班克斯的六座非住宅商业建筑中采集了样本。采集的样本类型包括室内空气（IA）；室外空气；楼板下土壤气体；土壤气体；室内氡；压差；室内和室外温度；供暖、通风和空调（HVAC）参数；以及其他环境因素。与受污染地下水羽流中梯度较低的建筑物相比，靠近挥发性有机化合物（VOC）源/释放点的建筑物中三氯乙烯（TCE）和四氯乙烯（PCE）的室内空气浓度变化较小。源区建筑物的VOC数据模式显示，夏季室内空气浓度受室外气温主导。与环境因素相比，HVAC系统运行对长期室内空气浓度趋势的影响较小，这一点得到了羽流内不同位置相似的室内空气浓度模式的支持。将土壤温度和室内/室外温度用作整个羽流的指标和示踪剂（I&T），作为采样期的预测指标，可以很好地估算建筑物居住者的RME。这些结果表明将土壤温度和室内/室外温度用作I&T，将有助于改进类似环境中蒸气侵入评估的调查方法，从而加强室内环境中对人类健康的保护。
