Lock K, Janssen C R
Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent University, Gent, Belgium.
Environ Sci Technol. 2001 Nov 1;35(21):4295-300. doi: 10.1021/es0100219.
Metal bioavailability is influenced by soil characteristics and aging period. In the present study, both factors were modeled by comparing metal bioavailability in spiked artificial soil and historically contaminated field soils. The chronic toxicity of zinc to Folsomia candida in spiked artificial soils could be predicted with a model based on pH, cation exchange capacity, and total zinc concentration. However, this model could not adequately predict chronic zinc toxicity in contaminated field soils. Porewater concentration and water- and calcium chloride-extracted zinc fractions of the contaminated field soils were lower than those predicted using models developed for spiked artificial soils, indicating that the effect of aging on metal bioavailability should be taken into account. The reproduction of F. candida in contaminated field soils was lower than predicted with models developed using zinc concentration in the porewater and the water- and calcium chloride-extracted fractions in spiked artificial soils. This suggests that these fractions are not the only bioavailable zinc fractions and that dietary metal exposure might also be an important route of uptake under environmentally relevant conditions. Aging and dietary uptake should be studied urgently in order to be able to perform effect-based risk assessments of metal contaminated soils.
金属生物有效性受土壤特性和老化时间的影响。在本研究中，通过比较添加金属的人工土壤和历史污染农田土壤中的金属生物有效性对这两个因素进行了建模。基于pH值、阳离子交换容量和总锌浓度的模型可以预测添加金属的人工土壤中锌对食菌跳虫的慢性毒性。然而，该模型无法充分预测污染农田土壤中锌的慢性毒性。污染农田土壤的孔隙水浓度以及水和氯化钙提取的锌组分低于使用添加金属的人工土壤开发的模型所预测的值，这表明应考虑老化对金属生物有效性的影响。污染农田土壤中食菌跳虫的繁殖率低于使用孔隙水中锌浓度以及添加金属的人工土壤中水和氯化钙提取组分开发的模型所预测的值。这表明这些组分并非唯一具有生物有效性的锌组分，并且在与环境相关的条件下，通过饮食摄入金属可能也是一个重要的吸收途径。迫切需要对老化和通过饮食摄入进行研究，以便能够对金属污染土壤进行基于效应的风险评估。
