Pollution characteristics and source analysis of heavy metals in surface sediments obtained from Shishi Wetland Park, Fujian,China

AbstractThirteen surface sediment samples were collected to study the metal content and pollution sources in the sediment of Shishi Wetland Park. Inductively coupled plasma mass spectrometry (ICP-MS) was used to analyse the contents of seven metals (Cr, Ni, Zn, Cu, Cd, Tl, and Pb) in the samples. The metal content was evaluated using contamination factor (CF), geological accumulation index (Igeo), and pollution load index (PLI). The pollution sources were qualitatively analysed using principal component analysis (PCA) and cluster analysis (CA), and the contribution rate of potential sources was quantitatively calculated using an absolute principal component score multiple linear regression model (APCS-MLR). The CF of Cd is greater than 3, indicating heavy pollution; Ni also causes heavy pollution, and the other metals evaluated showed lower values of pollution. The minimum degree of the coefficient of variation of Tl indicates contribution primarily from natural sources. The results of the geological accumulation index indicated that Cd was the most heavy pollutant. The pollution load indices of sampling points 7, 11, and 13 on the western side of the region were all greater than two, indicating severe pollution. The results of source analysis using multivariate statistical analysis showed that Cr, Ni, Cu, and Zn mainly originated from industrial and agricultural production activities, with an average contribution rate of 47.7%. Cd and Pb mainly originated from transportation sources, with an average contribution rate of 47.0%. Tl originated mainly from the parent material, with a contribution rate of approximately 33.4%.