Appraisal of potential toxic elements pollution, sources apportionment, and health risks in groundwater from a coastal area of SE China

Abstract

Groundwater is a vital natural resource, but the presence of potentially toxic elements (PTEs) poses significant risks to both groundwater safety and human health. This study collected 120 groundwater samples from a coastal area in southeastern China during wet and dry seasons to assess PTE levels, identify their sources, and evaluate pollution and health risks. Results showed that Mn, Zn, and Al had the highest average concentrations in both seasons, with Mn, Cd, and Zn frequently exceeding safe limits. PTE levels were higher during the wet season. Natural background levels (NBLs) were determined, revealing that most elements met quality standards except for Mn and Cd. Four PTE sources were identified using principal component analysis and the APCS-MLR model: industrial emissions (25.5% dry, 23.8% wet), geological background (21.2% dry, 19% wet), natural sources (27.2% dry, 16.2% wet), and mining activities (20.8% dry, 23.4% wet). Heavy metal pollution was significant (moderate to heavy: 72.73% dry, 45.76% wet), but ecological risks were low (low risk: 92.73% dry, 66.10% wet). Health risk assessments and Monte Carlo simulations indicated low carcinogenic and non-carcinogenic risks, slightly higher in children than adults. Risks were more severe in the southwestern part of the study area. These findings support local groundwater management efforts.

Keywords: APCS-MLR model; Ecological risk; Health risks; Monte Carlo simulation; Natural background level; Potential toxic elements.