A comprehensive approach for quantifying source-specific ecological and health risks of potentially toxic elements in agricultural soil

Given the pollution prevalence of potentially hazardous elements (PTEs) in agricultural soils worldwide, it is crucial to establish a comprehensive approach to accurately assess soil contamination, and quantitatively allocate sources and source-specific risks. In the study, soil contamination was assessed through environmental capacity based on the local geochemical baseline established using PTE contents of the subsoil. The sources of PTEs were quantified through positive matrix factorization (PMF) and GIS mapping. Ecological risk (ER) and human health risk (HHR) models based on PMF were used to evaluate source-specific ER and HHR. Taking Jieyang City as an example, obvious contamination of As, Pb, Cd, Zn and Hg was observed in agricultural soils, and 94.40% of sites had high-to-medium capacity for local PTE contamination. Four sources were apportioned including agricultural activities (17.36%), industrial activities (20.49%), natural sources (34.60%) and traffic emissions (27.55%). The study area was at moderate ER level (121.21) with industrial activities contributing the most (41.26%). The carcinogenic risks (3.21E-05 for children and 1.42E-05 for adults) were within the tolerable range, and non-carcinogenic risks (7.08E-01 for children and 7.70E-02 for adults) were not significant. Agricultural activities were the largest source to the carcinogenic (47.17% for children and 46.31% for adults) and non carcinogenic risks (53.55% for children and 53.03% for adults). Therefore, industrial activities and agricultural activities were the priority control sources to reduce ecological risk and protect human health, respectively.