Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Department of Environmental Sciences, International Islamic University, Islamabad 44000, Pakistan.
Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
Ecotoxicol Environ Saf. 2014 May;103:101-7. doi: 10.1016/j.ecoenv.2013.10.016. Epub 2014 Jan 10.
Food chain contamination by cadmium (Cd) is globally a serious health concern resulting in chronic abnormalities. Rice is a major staple food of the majority world population, therefore, it is imperative to understand the relationship between the bioavailability of Cd in soils and its accumulation in rice grain. Objectives of this study were to establish environment quality standards for seven different textured soils based on human dietary toxicity, total Cd content in soils and bioavailable portion of Cd in soil. Cadmium concentrations in polished rice grain were best related to total Cd content in Mollisols and Udic Ferrisols with threshold levels of 0.77 and 0.32mgkg(-1), respectively. Contrastingly, Mehlich-3-extractable Cd thresholds were more suitable for Calcaric Regosols, Stagnic Anthrosols, Ustic Cambosols, Typic Haplustalfs and Periudic Argosols with thresholds values of 0.36, 0.22, 0.17, 0.08 and 0.03mgkg(-1), respectively. Stepwise multiple regression analysis indicated that phytoavailability of Cd to rice grain was strongly correlated with Mehlich-3-extractable Cd and soil pH. The empirical model developed in this study explains the combined effects of soil properties and extractable soil Cd content on the phytoavailability of Cd to polished rice grain. This study indicates that accumulation of Cd in rice is influenced greatly by soil type, which should be considered in assessment of soil safety for Cd contamination in rice. This investigation concluded that the selection of proper soil type for food crop production can help us to avoid the toxicity of Cd in our daily diet.
食物链中镉（Cd）的污染是一个全球性的严重健康问题，会导致慢性异常。大米是大多数世界人口的主要主食，因此，了解土壤中 Cd 的生物可利用性与其在大米中的积累之间的关系至关重要。本研究的目的是根据人类饮食毒性、土壤中总 Cd 含量和土壤中可利用的 Cd 部分，为 7 种不同质地的土壤建立环境质量标准。抛光大米中 Cd 浓度与 Mollisols 和 Udic Ferrisols 中的总 Cd 含量关系最为密切，阈值分别为 0.77 和 0.32mgkg(-1)。相比之下，Mehlich-3 可提取 Cd 阈值更适合 Calcaric Regosols、Stagnic Anthrosols、Ustic Cambosols、Typic Haplustalfs 和 Periudic Argosols，阈值分别为 0.36、0.22、0.17、0.08 和 0.03mgkg(-1)。逐步多元回归分析表明，Cd 对水稻籽粒的植物可利用性与 Mehlich-3 可提取 Cd 和土壤 pH 值密切相关。本研究中建立的经验模型解释了土壤性质和可提取土壤 Cd 含量对抛光大米籽粒中 Cd 植物可利用性的综合影响。本研究表明，土壤类型对大米中 Cd 的积累有很大影响，在评估土壤中 Cd 污染对大米的安全性时应考虑这一点。本研究得出的结论是，选择适当的土壤类型进行粮食作物生产有助于避免我们日常饮食中 Cd 的毒性。
