A Survey of Heavy Metals in Sediments of Yangzonghai Lake in Yunnan Province:Their Source and Distribution

A survey was conducted in Lake Yangzonghai of Yunnan Province with the particular interest in heavy metals contamination of the sediments. The investigated heavy metals include Pb,Cu,Cr,Mn,Zn and As,which were analysed using X-ray fluorescence spectroscopy and the contamination levels of them were evaluated with the geo-accumulation indexes. The ranking of contamination was as Cu As Cr Zn Mn Pb,and according to the investigation of horizontal distribution of contamination levels in the sediments,heavy metal pollution can trace to the human activities such as industrial sources,and the bio-geochemical process,i.e,earth weathering.