Keywords: 
• heavy metal /
• health risk assessment model /
• sediment quality guidelines /
• biological effect database

Abstract: In high flow period and low flow period， concentrations of the Cu，Zn，Cd，Pb in water environment of Teilonglanni Dam to Liangqiao were studied. Health risk assessment associated with these four metals were conducted using health risk assessment model from US EPA. Results showed that among the non-carcinogenic risks， the highest risk was the risk associated with Cu， followed by Pb， and then Zn. In high flow period and low flow period， the average health risk associated with Cu were 2.14×10-7 a-1， 4.13×10-7 a-1 respectively， much lower than the maximum allowance levels recommended by ICRP（5.0×10-5 a-1）.In high flow period and low flow period， the average health risk in terms of carcinogens associated with Cd were 4.53×10-4 a-1，3.52×10-4 a-1 respectively， much higher than the maximum allowance levels recommended by ICRP. The health risk of carcinogens was 3~4 orders of magnitude higher than that of non-carcinogens. In addition， the total heavy metals of sediment were studied. Results showed that the highest concentration located at Langqiaocaoduikeng tributary， because of pH in water. The potential biological toxicity of heavy metals was analyzed using sediment quality guidelines（SQGs）established by biological effect database. Results showed that the values of mean effects range median quotients（mERMQ） were larger than 1.5 at each sampling point， besides Lengshuijing. So the heavy metals in sediment had greatest potential toxic risk to the local benthic life.