Distribution characteristics, source analysis and risk assessment of heavy metals in sediments of Wanghu Lake of Hubei Province

To reveal the characteristics of heavy metal pollution in the sediments of Wanghu Lake in Hubei Province, the methods of spatial interpolation, principal component analysis, and geo-accumulation index were used to investigate the pollution features, source identification, and ecological risk status of heavy metal pollution. The results showed that the average concentration of five heavy metals decreased in the order of Zn>Cr>Cu>Pb>Cd, and all of them exceeded Hubei soil background values. Pearson correlation analysis revealed a positive correlation (P<0.05) between Zn and Cd, Zn and Pb, and a negative correlation (P<0.05) between Cu and Zn, Cu and Cr. Principal component analysis revealed that principal component 1 was consisted of Pb, Cd, and Zn, which were primarily influenced by river transportation and agricultural activities; principal component 2 was consisted of Cr and Cu, which were mainly affected by natural background such as mineral weathering and pollution from human activities such as industrial activities and aquaculture. The geo-accumulation index results suggested that heavy metals in Wanghu Lake were in a low risk condition, although Cd and Cu reached moderate pollution and were the major pollutants that should be monitored.