The influence from the manufacturing of compact fluorescent lamps (CFL) on mercury (Hg) speciation and distribution in river catchments nearby a typical CFL manufacturing area in China was investigated. Water, sediment, river snail (Procambarus clarkii), and macrophyte (Paspalum distichum L.) samples were collected. Total Hg (THg) and methylmercury (MeHg) concentrations in water ranged from 1.06 to 268 ng center dot L-1 and N.D. -2.14 ng center dot L-1, respectively. MeHg was significantly positively correlated with THg in water. THg and MeHg in sediment ranged from 15.0 to 2480 and 0.06 to 1.85 ng center dot g(-1), respectively. River snail samples exhibited high concentrations of THg (206-1437 ng center dot g(-1)) and MeHg (31.4-404 ng center dot g(-1)). THg and MeHg concentrations in root of P. distichum L. were significantly higher than those in shoot, indicating that THg and MeHg in the plant were mainly attributed to root assimilation. A very high bioaccumulation factor (20.9 A +/- 22.1) for MeHg in P. distichum L was noted, suggesting that P. distichum L. might have a potential role in phytoremediating MeHg contaminated soil due to its abnormal uptake capacity to MeHg.