State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, China.
University of Chinese Academy of Sciences, Beijing, China.
Environ Toxicol Chem. 2019 Jul;38(7):1577-1584. doi: 10.1002/etc.4443. Epub 2019 Jun 21.
Heavy metals are rich in seleniferous areas; however, the bioaccumulation and health risk of heavy metals are poorly understood, given the fact that selenium (Se) can inhibit the phytotoxicity and bioavailability of many heavy metals. The present study investigated the bioaccumulation of heavy metals in the soil-rice system in the Enshi seleniferous area of central China. Soils were contaminated by Mo, Cu, As, Sb, Zn, Cd, Tl, and Hg caused by the weathering of Se-rich shales. Among these heavy metals, Cd and Mo had the highest bioavailability in soils. The bioavailable fractions of Cd and Mo accounted for 41.84 and 10.75% of the total Cd and Mo in soils, respectively. Correspondingly, much higher bioaccumulation factors (BAFs) of Cd (0.34) and Mo (0.46) were found in rice, compared with those of other heavy metals (Zn 0.16, Cu 0.05, Hg 0.04, and Sb 0.0002). For the first time-to our knowledge-we showed that the uptake of Hg, Cd, and Cu by rice could be inhibited by the presence of Se in the soil. The probable daily intake (PDI) of Se, Cd, Mo, Zn, and Cu through consumption of local rice was 252 ± 184, 314 ± 301, and 1774 ± 1326 μg/d; and 7.4 ± 1.68 and 0.87 ± 0.35 mg/d, respectively. The high hazard quotients (HQs) of Mo (1.97 ± 1.47) and Cd (5.22 ± 5.02) suggested a high risk of Cd and Mo for Enshi residents through consumption of rice. Environ Toxicol Chem 2019;38:1577-1584. © 2019 SETAC.
富硒地区重金属含量丰富；然而，由于硒 (Se) 可以抑制许多重金属的植物毒性和生物可利用性，因此人们对重金属的生物积累和健康风险知之甚少。本研究调查了中国中部恩施富硒地区土壤-水稻系统中重金属的生物积累。土壤受到富硒页岩风化产生的 Mo、Cu、As、Sb、Zn、Cd、Tl 和 Hg 的污染。在这些重金属中，Cd 和 Mo 在土壤中的生物可利用性最高。Cd 和 Mo 的生物可利用分数分别占土壤中总 Cd 和 Mo 的 41.84%和 10.75%。相应地，在水稻中发现 Cd（0.34）和 Mo（0.46）的生物富集因子（BAF）远高于其他重金属（Zn 0.16、Cu 0.05、Hg 0.04 和 Sb 0.0002）。据我们所知，这是首次表明土壤中 Se 的存在可以抑制水稻对 Hg、Cd 和 Cu 的吸收。通过食用当地大米，硒、Cd、Mo、Zn 和 Cu 的每日可能摄入量（PDI）分别为 252 ± 184、314 ± 301、1774 ± 1326 μg/d；以及 7.4 ± 1.68 和 0.87 ± 0.35 mg/d。Mo（1.97 ± 1.47）和 Cd（5.22 ± 5.02）的高危害系数（HQ）表明，恩施居民通过食用大米，Cd 和 Mo 的风险很高。Environ Toxicol Chem 2019;38:1577-1584. © 2019 SETAC.
