Application of Principal Component Analysis(PCA) for the Estimation of Source of Heavy Metal Contamination in Marine Sediments
运用主成分分析(PCA)评价海洋沉积物中重金属污染来源

Concentrations of heavy metals and organic matter in the bottom sediments of Jiaozhou Bay were determined and the average enrichment factors (AEFs) were used simultaneously to evaluate the extent of metal enrichment-contamination. Results show that heavy metal contamination in this bay could be divided into three groups: negligible to low contamination (AEFs < 2), which is the case of Zn (AEF = 1.11), Pb (AEF = 1.15), Cr (AEF = 1.52), Mn (AEF = 0.80) and Fe (AEF = 0.45); moderate contamination (AEFs = 2 - 3), which is the case of Cu (AEF = 2.79) and Cd (AEF = 2.52); certain to severe contamination (AEFs > 3), As (AEF = 3.03) and Hg (AEF = 8.08) being included in this group. Principal component analysis (PCA) was applied to estimate the sources of heavy metal contamination. Results that the first three components accounted for 52.61%, 17.37% and 15.60% of the total variance respectively exhibited that industrial wastewater, degradation of organic matter and erosion of rocks were the main sources of heavy metal contamination. The Q-analysis of PCA indicated that 14 stations could be divided into five groups. This result not only reflected the pollution characteristic of surface sediments, but also provided fundamental evidences for the putative analysis that industrial discharge is the main source of heavy metal contamination in Jiaozhou Bay.