Duncan Candice M, Brusseau Mark L
Soil, Water and Environmental Science Department, School of Earth and Environmental Sciences, University of Arizona, Tucson, AZ 85721, United States.
Soil, Water and Environmental Science Department, School of Earth and Environmental Sciences, University of Arizona, Tucson, AZ 85721, United States; Hydrology and Atmospheric Sciences Department, School of Earth and Environmental Sciences, University of Arizona, Tucson, AZ 85721, United States.
Sci Total Environ. 2018 Mar;616-617:875-880. doi: 10.1016/j.scitotenv.2017.10.235. Epub 2017 Oct 31.
The majority of prior phytoscreening applications have employed the method as a tool to qualitatively determine the presence of contamination in the subsurface. Although qualitative data is quite useful, this study explores the potential for using phytoscreening quantitatively. The existence of site-specific and non-site-specific (master) correlations between VOC concentrations in tree tissue and groundwater is investigated using data collected from several phytoscreening studies. The aggregated data comprise 100 measurements collected from 12 sites that span a wide range of site conditions. Significant site-specific correlations are observed between tetrachloroethene (PCE) and trichloroethene (TCE) concentrations measured for tree tissue and those measured in groundwater for three sites. A moderately significant correlation (r=0.56) exists for the entire aggregate data set. Parsing the data by groundwater depth produced a highly significant correlation (r=0.88) for sites with shallow (<4m) groundwater. Such a significant correlation for data collected by different investigators from multiple sites with a wide range of tree species and subsurface conditions indicates that groundwater concentration is the predominant factor mediating tree-tissue concentrations for these sites. This may be a result of trees likely directly tapping groundwater for these shallow groundwater conditions. This master correlation may provide reasonable order-of-magnitude estimates of VOC concentrations in groundwater for such sites, thereby allowing the use of phytoscreening in a more quantitative mode.
先前的大多数植物筛选应用都将该方法用作定性确定地下污染存在情况的工具。尽管定性数据非常有用，但本研究探讨了定量使用植物筛选的潜力。利用从多项植物筛选研究中收集的数据，研究了树木组织中的挥发性有机化合物（VOC）浓度与地下水之间特定地点和非特定地点（总体）相关性的存在情况。汇总数据包括从12个地点收集的100次测量值，这些地点涵盖了广泛的场地条件。在三个地点，观察到树木组织中测得的四氯乙烯（PCE）和三氯乙烯（TCE）浓度与地下水中测得的浓度之间存在显著的特定地点相关性。对于整个汇总数据集，存在中等显著的相关性（r = 0.56）。按地下水深度对数据进行分析后，对于地下水浅（<4米）的地点，相关性非常显著（r = 0.88）。不同研究者从多个地点收集的数据，涵盖了广泛的树种和地下条件，却存在如此显著的相关性，这表明对于这些地点，地下水浓度是调节树木组织浓度的主要因素。这可能是由于在这些浅地下水条件下，树木可能直接汲取地下水所致。这种总体相关性可为这些地点的地下水中VOC浓度提供合理的数量级估计，从而使植物筛选能够以更定量的方式使用。
