Heavy metals in surface sediments from mangrove zone in Zhangjiang River estuary, South China
- 海洋环境－会议论文 
Concentrations of selected heavy metals (Cr, Cu, Zn, As, Cd, Hg and Ph) in surface sediments from 18 sites were examined in Zhangjiang Estuary Mangrove National Natural Reserve (ZEMNNR), which is the largest natural mangrove forest at the north of tropic of Cancer in China. The ranges of heavy metals expressed in mu g/g sediment dry weight were as following: Cr (48.14 to 110.01), Cu (18.15 to 43.18), Zn (119.53 to 136.13), As (12.05 to 16.16), Cd (0.25 to 0.58), Hg (ND to 0.10) and Ph (55.61 to 67.71). Slight distribution changes implicate inflow from Zhangjiang River offered most Zn, As, Cd, Hg and Ph; While for Cr and Cu, anthropogenic activities might he another important source. The levels of Ph exceed sediment quality criteria ( I Class) and may show a potential risk to ecosystems. The values of 1,,,, indicate that Zhangjiang estuary mangrove zone is moderately polluted by Ph and slightly polluted by Cd, As and Cr.