Contamination characteristics of heavy metals in the water of Daqing Wetlands

Daqing Wetland was contaminated by heavy metals for holding lots of industrial and domestic waste water.Due to their high stability and non-degradation,heavy metals are possible to gather in human body through the food chain and then threaten health.Water samples were collected from Longfeng Wetland and lake marshes in the vicinity of Daqing City. The contents of heavy metals(Cd,Pb,Cr,Cu,Zn,Ni) were determined,and the contamination degrees were evaluated simultaneously.The results indicate that heavy metals of Zn,Ni,Cd,Cr and Pd have contaminated the Longfeng Wetland severely.In addition the concentrations of Cr and Cd in some lakes around oil wells are excessively high,and have overrun the grade V based on the threshold values of surface water given by the National Environmental Protection Agency of China. Some measures have to be taken to tackle heavy metal contamination of Longfeng Wetland and lake marshes in Daqing City.