College of Resource & Environment, Hunan Agricultural University, Changsha, 410128, People's Republic of China.
Hunan Province Irrigation Water Quality Purification Engineering Center, Changsha, 410128, People's Republic of China.
Environ Sci Pollut Res Int. 2020 Dec;27(35):44249-44256. doi: 10.1007/s11356-020-10282-5. Epub 2020 Aug 6.
In order to unravel the cadmium (Cd) enrichment patterns in rice (Oryza sativa L.) grown under different exogenous exposure pathways, the pot experiment was conducted in a greenhouse. Cd was added to the soil-rice system via mixing soil with Cd-containing solution, irrigating the pots with Cd-containing water and leaf-spraying with Cd solution to simulate soil pollution (SPS), irrigation water pollution (IPS), and atmospheric deposit pollution sources (APS), respectively. No significant (p > 0.05) differences in plant height and rice grain yield were observed among all treatments including three different Cd pollution sources and control. The contents of Cd in rice plants significantly (p < 0.05) increased with increase in Cd concentrations in three pollution sources. The distribution pattern of Cd in the rice plant organs treated with SPS and IPS followed the order: roots > stems > leaves > husk > brown rice, while it was leaves > roots > stems > husk > brown rice treated with APS. At the same level of treatment, the highest concentration of Cd was observed in rice organs (except for middle and high concentrations treatment roots) grown under APS, followed by IPS and SPS, suggesting that the Cd bioavailability from different pollution sources followed the order of APS > IPS > SPS. It is concluded that the atmospheric pollution contributed more enrichment of rice with Cd. Therefore, in field environment, air deposits should also be analyzed for toxic metals during assessment of food chain contamination and health risk.
为了揭示不同外源暴露途径下水稻（Oryza sativa L.）中镉（Cd）的富集模式，在温室中进行了盆栽实验。通过将含 Cd 溶液与土壤混合、用含 Cd 水灌溉盆和叶面喷洒 Cd 溶液来模拟土壤污染（SPS）、灌溉水污染（IPS）和大气沉积污染源（APS），将 Cd 添加到土壤-水稻系统中。在包括三种不同 Cd 污染源和对照在内的所有处理中，水稻的株高和稻谷产量均无显著差异（p＞0.05）。随着三种污染源中 Cd 浓度的增加，水稻植株中 Cd 的含量显著增加（p＜0.05）。SPS 和 IPS 处理的水稻植株器官中 Cd 的分布模式为：根＞茎＞叶＞壳＞糙米，而 APS 处理的则为叶＞根＞茎＞壳＞糙米。在相同处理水平下，APS 处理下的水稻器官（中高浓度处理的根除外）中 Cd 浓度最高，其次是 IPS 和 SPS，表明不同污染源的 Cd 生物有效性顺序为 APS＞IPS＞SPS。研究结论表明大气污染对水稻中 Cd 的富集贡献更大。因此，在野外环境中，在评估食物链污染和健康风险时，也应分析空气中的沉积有毒金属。
