Mechanism of Accumulation of Methylmercury in Rice (Oryza sativa L.) in a Mercury Mining Area

Citations Over TimeTop 10% of 2018 papers

Abstract

Rice consumption is the primary pathway for methylmercury (MeHg) exposure at inland mercury (Hg) mining areas of China. The sources and processes of formation and translocation for MeHg in rice plant are complex and remain largely unknown. In this study, rice ( Oryza sativa L.) was exposed to isotopically labeled dimethylmercury (DMe199Hg) in field experiments using open top chambers to explore the response of MeHg accumulation in rice tissues to different levels of DMe199Hg in air. Rice leaves assimilated DMeHg from air, which was subsequently largely stored in aboveground tissues, including the rice grain, with only a small amount reaching the root. Combining these experimental results with field investigations of DMeHg concentrations in air beneath the rice canopy in a Hg mining area, we estimate that 15.5%, 10.8%, and 8.50% MeHg in the brown rice, the leaf, and the upper stalk, respectively, could be derived from atmospheric sources of DMeHg, while 99.5% of MeHg in rice root originated from the rice soil-water system. These findings help refine the mechanism of MeHg accumulation in rice that, in addition to soil, a fraction of MeHg in rice plants can be derived from DMeHg emissions from flooded rice paddies in Hg mining areas.

Related Papers

• → Accumulation of methylmercury and inorganic mercury in the brain(1989)122 cited
• → Form of mercury in stream fish exposed to high concentrations of dissolved inorganic mercury(1995)57 cited
• Mercury methylation in an aquatic environment.(1973)
• → THE ROLE OF SEDIMENTS ON MERCURY TRANSPORT (TOTAL- AND METHYL-) IN A RIVER SYSTEM(1979)11 cited
• → Mercury: A Challenge for Lake Monitoring(2000)1 cited