DHI Water, Environment, Health, 2970 Hørsholm, Denmark.
Environ Monit Assess. 2012 Mar;184(3):1231-41. doi: 10.1007/s10661-011-2035-5. Epub 2011 Apr 12.
Chloroform is one of the most frequently found anthropogenic groundwater contaminants. Recent investigations, however, suggested that chloroform in groundwater may also originate from a natural production in soils. As societies response to the occurrence of chloroform in groundwater may depend upon its origin as anthropogenic or naturally produced, test methods are needed to measure the potential of natural soil chloroform production. Field measurements of ambient air and soil air, and field and laboratory incubation studies were evaluated for measurement of relative soil chloroform production at a site with four different vegetation types (spruce forest, beech forest, grassland, and grain field) on comparable geological soil. All test methods showed varying soil production of chloroform with spruce forest soil being most productive and grain field soil being least productive. Field measurements of the ratio of soil air to ambient air chloroform concentrations exhibited the smallest difference between high production and low production areas, whereas laboratory incubation studies showed the largest difference. Thus, laboratory incubation studies are suggested as most efficient for estimating relative chloroform production in soil. The study indicated that soil samples should be tested not more than 14 days after sampling. Furthermore, it was found that potentially limiting compounds, such as chloride or nitrate, are not needed to be added in spike experiments to obtain reliable production results. However, it should be recognized that the processes of soil chloroform production are not known yet in all details. Other factors than those studied here may affect the test methods for soil chloroform production too.
氯仿是最常见的人为地下水污染物之一。然而，最近的调查表明，地下水中的氯仿也可能来源于土壤的自然产生。由于社会对地下水氯仿的处理可能取决于其是人为产生还是自然产生，因此需要测试方法来测量自然土壤氯仿产生的潜力。对具有四种不同植被类型（云杉林、山毛榉林、草原和麦田）的同一地质土壤上的一个地点的环境空气和土壤空气的现场测量、现场和实验室培养研究，评估了相对土壤氯仿产生的测量方法。所有测试方法均显示出不同的土壤氯仿产生，其中云杉林土壤的产生能力最强，麦田土壤的产生能力最弱。土壤空气与环境空气氯仿浓度比值的现场测量显示，高产生区与低产生区之间的差异最小，而实验室培养研究则显示出最大的差异。因此，实验室培养研究被认为是估计土壤中相对氯仿产生的最有效方法。该研究表明，土壤样本应在采样后不超过 14 天进行测试。此外，发现无需在加标实验中添加潜在限制化合物（如氯化物或硝酸盐）即可获得可靠的产生结果。然而，应该认识到，土壤氯仿产生的过程尚未完全了解。除了这里研究的因素外，其他因素也可能会影响土壤氯仿产生的测试方法。
