Hu Ruifang, Seyfferth Angelia L
Department of Plant and Soil Sciences, University of Delaware, Newark, Delaware 19716, United States.
ACS Omega. 2021 Jul 23;6(30):19876-19882. doi: 10.1021/acsomega.1c02741. eCollection 2021 Aug 3.
Cadmium (Cd) is a toxic trace element that can be transported from soil into rice grain, posing health threats to rice consumers. Among the global studies on rice grain Cd, only one market survey reported grain Cd levels from Cambodia, an important rice-growing country in Southeast Asia. Here, we collected paired rice and soil samples in the wet and dry seasons from major rice-growing regions across five provinces in Cambodia and report the relationships between plant Cd and soil Cd parameters. Both DTPA-extractable and nitric acid digestible soil Cd are significant predictors for Cd levels in rice straw and grain. Rice grain Cd concentrations ranged 3 orders of magnitude from 0.002 to 1.066 mg kg with the median and mean concentrations of 0.024 and 0.091 mg kg, respectively; these values have an upper range that is higher than previously reported. The highest grain Cd levels were found in rice grown in the dry season from two provinces located southeast of Phnom Penh along the Lower Mekong River, and their corresponding soil Cd levels were relatively higher than those collected during the wet season and around the Tonle Sap. While the source of higher Cd may be geogenic or due to anthropogenic activities, our data demonstrate that geographical and perhaps seasonal differences in grain Cd exist even within a small country that might not be reflected in market surveys.
镉（Cd）是一种有毒微量元素，可从土壤转移至稻谷中，对食用大米的人群构成健康威胁。在全球关于稻谷镉含量的研究中，仅有一项市场调查报道了东南亚重要水稻种植国柬埔寨的稻谷镉含量水平。在此，我们在柬埔寨五个省份的主要水稻种植区，于雨季和旱季采集了成对的水稻和土壤样本，并报告了植物镉与土壤镉参数之间的关系。二乙三胺五乙酸（DTPA）可提取态和硝酸可消化态土壤镉都是稻草和稻谷中镉含量的重要预测指标。稻谷镉浓度范围为0.002至1.066毫克/千克，相差3个数量级，中位数和平均浓度分别为0.024和0.091毫克/千克；这些数值的上限高于先前报道。在湄公河下游金边东南部两个省份旱季种植的水稻中，发现了最高的稻谷镉含量水平，其相应的土壤镉含量也相对高于雨季以及洞里萨湖周边采集的样本。虽然较高镉含量的来源可能是地质成因或人为活动，但我们的数据表明，即使在一个小国之内，稻谷镉含量也存在地理差异，甚至可能存在季节差异，而这些差异可能在市场调查中未得到体现。
