Welp G, Brümmer G W
Institute of Soil Science, University of Bonn, Germany.
Ecotoxicol Environ Saf. 1997 Dec;38(3):200-4. doi: 10.1006/eesa.1997.1577.
Microbial toxicity tests with Cd and Hg and up to 18 soil samples were combined with sorption and solubility measurements. The data ought to indicate to what extent toxic effects of the metals are influenced by sorption and the other factors that may alter their biocidal action. The microbial reduction of Fe(III) oxides to Fe2+ ions was used as a parameter of microbial activity to calculate the total amounts of Cd and Hg that cause 10, 50, and 90% inhibition [effective doses (ED)10, ED50, ED90]. The corresponding solution concentrations [effective concentrations: (EC)10, EC50, EC90] were derived from Freundlich adsorption isotherms. The very large variability in ED values in different soils (ED10: Cd, 5-95 mg/kg; Hg, 0.125-125 mg/kg) can be related to the sorption and solubility behavior of the metals. Nevertheless, the EC values of both metals also indicate a considerable variation (EC10: Cd, 0.01-1.13 mg/liter; Hg, < 0.001-0.041 mg/liter). The influence of soluble soilborne substances on metal speciation is the main reason for their varying toxic potential in different soil solutions. The strong and complex influence of soil properties on the toxicity of heavy metals in soils indicates that both chemical and biological methods of soil analysis are needed to assess the risks of soil contamination adequately.
将镉和汞的微生物毒性测试与多达18个土壤样本相结合，并进行吸附和溶解度测量。这些数据应能表明金属的毒性效应在多大程度上受到吸附以及其他可能改变其杀菌作用的因素的影响。将三价铁氧化物微生物还原为亚铁离子用作微生物活性参数，以计算导致10%、50%和90%抑制率[有效剂量(ED)10、ED50、ED90]的镉和汞的总量。相应的溶液浓度[有效浓度：(EC)10、EC50、EC90]由弗罗因德利希吸附等温线得出。不同土壤中ED值的巨大变异性(ED10：镉，5 - 95毫克/千克；汞，0.125 - 125毫克/千克)可能与金属的吸附和溶解度行为有关。然而，两种金属的EC值也显示出相当大的变化(EC10：镉，0.01 - 1.13毫克/升；汞，< 0.001 - 0.041毫克/升)。土壤中可溶性物质对金属形态的影响是它们在不同土壤溶液中具有不同毒性潜力的主要原因。土壤性质对土壤中重金属毒性的强烈而复杂的影响表明，需要化学和生物学两种土壤分析方法来充分评估土壤污染风险。
