School of Geography and Ocean Science, Nanjing University, Nanjing, 210023, China; Key Laboratory of Coastal Zone Exploitation and Protection, Ministry of Natural Resources, Nanjing, 210024, China.
School of Geography and Ocean Science, Nanjing University, Nanjing, 210023, China; Key Laboratory of Coastal Zone Exploitation and Protection, Ministry of Natural Resources, Nanjing, 210024, China.
Environ Pollut. 2021 Jul 1;280:116965. doi: 10.1016/j.envpol.2021.116965. Epub 2021 Mar 17.
Cd accumulation in paddy soils and its subsequent transfer to the food chain are widespread environmental issues, which has been extensively investigated in China. However, most studies focused on regional scales and these results may not be applicable to present the Cd contamination status in soil-rice ecosystems at a national scale. Therefore, based on collected data from China's rice cultivation dominated regions, this study provides the Cd pollution level of paddy soils and rice grains in China. Results indicates that the Yangtze River basin, especially Hunan, required more attention due to the elevated Cd concentrations in soil-rice ecosystems. Moreover, this review summarizes the significant natural and anthropogenic sources, transport and accumulation mechanism as well as the influencing factors of Cd in soil-rice ecosystems. The wide occurrence of Cd contamination in paddy soils derived primarily from mining activities, intensive application of phosphates fertilizers and e-waste. Physicochemical characteristics of soil, soil microorganisms, temperature as well as the physiological features of rice plants all contribute to Cd accumulation in rice grains, which can be controlled to mitigate Cd accumulation in rice grains. This review will provide a scientific reference for Cd pollution control and management with respect to paddy field ecosystems in China and other countries.
镉在稻田土壤中的积累及其随后向食物链的转移是广泛存在的环境问题，在中国已经进行了广泛的研究。然而，大多数研究集中在区域尺度上，这些结果可能不适用于描述全国范围内土壤-水稻生态系统中的镉污染状况。因此，本研究基于从中国水稻种植主导地区收集的数据，提供了中国稻田土壤和稻米中镉的污染水平。结果表明，由于土壤-水稻生态系统中镉浓度升高，长江流域特别是湖南地区需要更多关注。此外，本综述总结了镉在土壤-水稻生态系统中的重要自然和人为来源、迁移和积累机制以及影响因素。稻田土壤中镉的广泛污染主要来源于采矿活动、磷肥的大量施用和电子废物。土壤的物理化学特性、土壤微生物、温度以及水稻植株的生理特征都有助于镉在水稻籽粒中的积累，可以通过控制这些因素来减轻水稻籽粒中镉的积累。本综述将为中国和其他国家的稻田生态系统中镉污染的控制和管理提供科学参考。
