title: Prediction of methyl mercury uptake by rice plants ( Oryza sativa L.) using the diffusive gradient in thin films technique.
abstract: Rice consumption is the primary pathway for methyl mercury (MeHg) exposure at inland mercury (Hg) mining areas of SW China. Mechanistic information on MeHg accumulation in rice is, however, limited. The process of MeHg exchange between paddy soil and rice plants predominantly occurs in pore water. The detection of bioavailable MeHg in pore water is therefore important to predict MeHg uptake by rice plants ( Oryza sativa  L.). This study investigated MeHg dynamics and spatial MeHg trends in pore water during the rice growing season using the diffusive gradient in thin films (DGT) technique and tested the ability of DGT to predict MeHg uptake by rice. The MeHg uptake flux from soil to rice plants via roots was significantly correlated with the DGT-measured MeHg flux (R = 0.853, p < 0.01). Our study implies that DGT can predict the bioavailability of MeHg in rice paddy soil and that the DGT method can provide quantitative description of the rate of uptake of this bioavailable MeHg. The DGT technique is demonstrated as a useful indicator of the likely ecotoxicological risk that might be apparent where paddy rice is grown in MeHg contaminated soil.
authors.affiliation: State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, People's Republic of China.
authors.forename: Jinling
authors.initials: J
authors.lastname: Liu
authors.forename: Xinbin
authors.initials: X
authors.lastname: Feng
authors.forename: Guangle
authors.initials: G
authors.lastname: Qiu
authors.forename: Christopher W N
authors.initials: CW
authors.lastname: Anderson
authors.forename: Heng
authors.initials: H
authors.lastname: Yao
mesh_terms: D002681:China; D004784:Environmental Monitoring / Q000379:methods*; D008767:Methylmercury Compounds / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D012275:Oryza / Q000378:metabolism*; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*
chemical_list: D008767:Methylmercury Compounds; D012987:Soil; D012989:Soil Pollutants