Understanding the paradox of selenium contamination in mercury mining areas: High soil content and low accumulation in rice

• Published in: Environmental pollution (1987) Vol. 188; pp. 27 - 36
• Main Authors: Zhang, Hua, Feng, Xinbin, Jiang, Chengxin, Li, Qiuhua, Liu, Yi, Gu, Chunhao, Shang, Lihai, Li, Ping, Lin, Yan, Larssen, Thorjørn
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.05.2014; Elsevier
• Subjects: Agronomy. Soil science and plant productions; Bioaccumulation; Biological and medical sciences; Environmental Monitoring; Equivalence; Food consumption; Food toxicology; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Inert; Medical sciences; mercury; Mercury (metal); Mercury - analysis; Mercury - chemistry; Mercury mining areas; Mining; Oryza - chemistry; people; Precipitates; Precipitation; rice; selenium; Selenium - analysis; Selenium - chemistry; Sequential partial dissolution; soil; Soil (material); Soil - chemistry; Soil contamination; Soil Pollutants - analysis; Soil Pollutants - chemistry; Soil selenium contamination; Soil-plant relationships. Soil fertility; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Speciation; Toxicology; Soil selenium contamination; Sequential partial dissolution; Food consumption; Bioaccumulation; Mercury mining areas; Monocotyledones; Soil pollution; Cereal crop; Oryza sativa; Gramineae; Angiospermae; Mine; Selenium; Food; Rice; Pollutant behavior; Bioavailability; Dissolution; Heavy metal; Trace element; Poison; Spermatophyta; Biological accumulation; Mine soil; Mercury; Chemical contamination
• ISSN: 0269-7491; 1873-6424; 1873-6424
• DOI: 10.1016/j.envpol.2014.01.012

Rice is an important source of Se for billions of people throughout the world. The Wanshan area can be categorized as a seleniferous region due to its high soil Se content, but the Se content in the rice in Wanshan is much lower than that from typical seleniferous regions with an equivalent soil Se level. To investigate why the Se bioaccumulation in Wanshan is low, we measured the soil Se speciation using a sequential partial dissolution technique. The results demonstrated that the bioavailable species only accounted for a small proportion of the total Se in the soils from Wanshan, a much lower quantity than that found in the seleniferous regions. The potential mechanisms may be associated with the existence of Hg contamination, which is likely related to the formation of an inert Hg–Se insoluble precipitate in soils in Wanshan. •High soil Se content yet low Se accumulation in rice plant were observed in Hg mining areas.•Water-soluble species may play an important role in Se uptake by rice plant in Hg mining areas.•Bioavailability of Se in Hg mining areas are inhibited likely due to the interactions between Hg and Se. Understanding the paradox of the high content yet low bioavailability of soil selenium in a heavily Hg-contaminated area in China.