关键词: 土壤;重金属;蒙特卡洛模拟;风险评价;新成陆区域;长江口;上海市;

Abstract: In order to understand the characteristics and ecological risks of heavy metal pollution in the soil of the newly formed land areas at the Yangtze River Estuary, 8 kinds of heavy metals (Cu, Cr, Ni, Zn, Pb, Cd, As, and Hg) in the soil of 71 sampling points in East Hengsha Shoal of Shanghai City were detected and statistical analyzed, combined with Monte Carlo simulation to estimate the ecological risk. The results showed that: ① The concentration levels of heavy metals in the surface soil followed the sequence from highest to lowest as Zn, Cr, Ni, Pb, Cu, As, Cd, and Hg, and their average values were all lower than the soil environmental background values of Shanghai City. The concentrations of Cr, Ni, Zn, Pb, and Hg obeyed a lognormal distribution, while Cu, Cd, and As did not obey a normal distribution nor a lognormal distribution. ② The evaluation results of the Hakanson potential ecological risk index method showed that the potential ecological risk factors of various heavy metals ranked as : Hg> Cd> As> Ni> Pb> Cu> Cr> Zn. The potential ecological risk index (RI) of the 8 heavy metals was 36.80~150.96, at the stage of slight to medium ecological risk, and RI was mainly at a slight ecological risk level with a probability of 93.34%. The evaluation result of the ERL/ERM method claimed that the probability of frequently occurrence of ecological risks for 8 heavy metals was extremely low (<0.72%). Cd, Pb, Zn, Cu, Hg, Cr, and As had little or no negative ecological risks, while Ni occasionally had ecological risks (the probability was 95.04%). The overall level and frequency of ecological risks of the 8 heavy metals were relatively low, while some heavy metals such as Hg and Ni required certain attentions.

Key words: soil；heavy metals；Monte Carlo simulation; risk assessment；newly formed land area; Yangtze River Estuary；Shanghai City