Abstract: Heavy metal risk assessment for the sites surrounding Pb-Zn tailing ponds is the basis for classifying the heavy metal pollution for the Pb-Zn tailing ponds into different levels, which may provide basis for the adaptive management of tailing ponds by environmental protection department. At present, the research in environmental risk assessment of the heavy metal pollution surrounding the Pb-Zn tailing pond sites is not enough. Here, we developed a method for evaluating heavy metal pollution risk of the Pb-Zn tailing ponds. In the construction of the evaluation system, this method mainly takes account of atmospheric environment and leakage water, as well as the toxicity of heavy metals. This method can quantitatively calculate each index and is easy to operate. Furthermore, we tested the feasibility and practicality of the method in a tailing pond site in Meizhou City, Guangdong Province. This study contributes to the establishment and improvement of the criteria and standards in heavy metal risk assessment for the surrounding area of the Pb-Zn tailing ponds.

Key words: tree ring, Quercus mongolica, spatial and temporal variability., climate warming, Phellodendron amurense, radial growth