Bioaccumulation of Selenium, Heavy Metals and Rare Earth Elements with Different Rice Cultivars Grown on Seleniferous Soils in Lianchen County, Fujian Province, China

Abstract

Seleniferous red soils cover a large area in the southern part of China. These agricultural soils are enriched in selenium (Se), heavy metals, and rare earth elements and have been cultivated for more than 1000 years for rice production without any consideration of the effects of selenium, heavy metals, and rare earth element bioaccumulation in the food plants produced. To address this knowledge gap, this study focuses on the investigation of Se, heavy metals, and rare earth elements within soils and plants in the region. The rice (Oryza spp.) plants studied were grown in the Gutian (GT), Gechuan (GC), and Pengkou (PK) villages in Lianchen (LC) County, Fujian Province. The surface soils and harvested rice tissues were collected to determine the Se, Cd, Zn, Pb, La, Ce, and Nd concentrations in the soils and plant tissues. Different rice cultivars possessed various potentials for elemental accumulation. Generally, rice plant tissues accumulated certain amounts of these elements; however, the elemental concentrations found in rice grain were within the acceptable ranges stipulated by the National Security Standard of Food. The Hongbaoshi (HBS) Indica red rice produced in the PK village accumulated more selenium, heavy metals, and rare earth elements than those in the plant tissues of the Xinyinzhan (XYZ) and Wushansimiao (WSSM) rice cultivars because HBS had more root hairs and finer root distribution. Thus, in the interest of food safety, increased attention needs to be given to the careful selection of the optimum crop species planted in these types of seleniferous red soils.