title: Characterization of mercury species in brown and white rice (Oryza sativa L.) grown in water-saving paddies.
abstract: In China, total Hg (HgT) and methylmercury (MeHg) were quantified in rice grain grown in three sites using water-saving rice cultivation methods, and in one Hg-contaminated site, where rice was grown under flooded conditions. Polished white rice concentrations of HgT (water-saving: 3.3±1.6 ng/g; flooded: 110±9.2 ng/g) and MeHg (water-saving 1.3±0.56 ng/g; flooded: 12±2.4 ng/g) were positively correlated with root-soil HgT and MeHg contents (HgT: r2=0.97, MeHg: r2=0.87, p<0.05 for both), which suggested a portion of Hg species in rice grain was derived from the soil, and translocation of Hg species from soil to rice grain was independent of irrigation practices and Hg levels, although other factors may be important. Concentrations of HgT and other trace elements were significantly higher in unmilled brown rice (p<0.05), while MeHg content was similar (p>0.20), indicating MeHg infiltrated the endosperm (i.e., white rice) more efficiently than inorganic Hg(II).
authors.affiliation: State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 46 Guanshui Lu, Guiyang 550002, PR China. rothenberg.sarah@gmail.com
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Rothenberg
authors.forename: Xinbin
authors.initials: X
authors.lastname: Feng
authors.forename: Bin
authors.initials: B
authors.lastname: Dong
authors.forename: Lihai
authors.initials: L
authors.lastname: Shang
authors.forename: Runsheng
authors.initials: R
authors.lastname: Yin
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Yuan
mesh_terms: D000383:Agriculture; D002681:China; D003247:Conservation of Natural Resources; D056625:Endosperm / Q000737:chemistry / Q000378:metabolism*; D008628:Mercury / Q000032:analysis / Q000378:metabolism*; D008767:Methylmercury Compounds / Q000032:analysis / Q000378:metabolism*; D012275:Oryza / Q000737:chemistry / Q000378:metabolism*; D014867:Water
chemical_list: D008767:Methylmercury Compounds; D014867:Water; D008628:Mercury