Source apportionment and source-oriented health risk assessment of heavy metal(loid)s in soils of Zibo City, a typical industrial City in China: insights from APCS-MLR and Monte Carlo simulation.

Soil heavy metal(loid) pollution in industrial cities has become an increasingly concerning issue worldwide. The contamination status, source and health risk of Cr, Ni, Cu, Zn, As, Cd, Pb and Hg in the soils of Zibo city, a typical industrial city of China, were investigated. Results demonstrated that 2.33%, 1.16%, and 0.75% of samples exceeded the thresholds for Cu, Zn, and Cd, respectively. Cu, Zn, and Hg exhibited moderate pollution, and 1.50% of the sampling sites were classified as heavily polluted. According to the Influence Index of Comprehensive Quality (IICQ), the soil-vegetable systems in some plots of Zhangdian, Boshan, and Zichuan districts were classified as heavily contaminated. The heavily polluted areas were mainly concentrated in the central region. Source apportionment using the absolute principal component scores-multiple linear regression (APCS-MLR) model suggested that Zn, Cd, and Pb were mainly associated with industrial emissions and traffic, Cr and Ni with natural parent material, As and Hg with agricultural activities and atmospheric deposition, and Cu with multiple sources. Monte Carlo simulation-based health risk assessment indicated that soil heavy metal(loid)s posed a tolerable risk to local residents, with As and Ni being the main contributors to local health risks. Source-oriented health risk assessment further suggested that agricultural activities and atmospheric deposition were the priority pollution sources, and arsenic should be the target heavy metal(loid) for prioritized soil management. These findings could provide technical support and scientific reference for investigating soil heavy metal(loid) pollution and safeguarding public health in industrial cities.