Distribution characteristics, source apportionment and risk assessment of heavy metal pollution in typical redevelopment sites in Jinshan District, Shanghai, China

As urban renewal accelerates, heavy metals (HMs) pollution resulting from industrial activities in urban areas must be considered. This study examines 36 representative redevelopment industrial sites in the Jinshan District of Shanghai, where the concentrations of eight HMs in the soil were assessed. Based on this data, the characteristics of heavy metal concentrations and their sources in the region were investigated, followed by a risk assessment of HMs pollution. The results indicate that the soil in the study area exhibits low levels of pollution, with moderate ecological risks. Using Pearson correlation analysis and the Absolute Principal Component Score-Multiple Linear Regression (APCS-MLR) source apportionment model, the HMs were categorized into several sources: An industrial source dominated by Cu (74.84 %), a traffic source dominated by Zn (67.51 %), a natural source dominated by Cr and As (66.50 % and 64.98 %, respectively), and a mixed source. A probabilistic risk assessment was conducted using Monte Carlo simulation, which incorporates the probability distributions of various assessment parameters, thereby reducing uncertainty in the results. The findings show that the non-carcinogenic risk for all populations in the study area (children, adult females, and adult males) remains within acceptable limits. However, the carcinogenic risk proportional probabilities for these populations were found to be 48.13 %, 32.49 %, and 11.41 %, respectively, indicating a notable risk level. Uncertainty analysis results suggest that the heavy metals Cd and As exhibit high sensitivity in the model. This study provides theoretical support for the prevention and control of soil pollution during urban renewal.