Study on Pollution Characteristics, Sources, and Health Risks of Potentially Toxic Elements in Groundwater of Dongting Lake Basin, China

Groundwater is one of the most critical drinking water resources on Earth, and its safety significantly impacts the ecological environment and human health. This study focuses on the pollution characteristics, sources, and health risks of potentially toxic elements (PTEs) in the groundwater of the Dongting Lake basin in China. It highlights the concentration distribution and pollution causes of common toxic elements such as manganese (Mn), copper (Cu), zinc (Zn), arsenic (As), mercury (Hg), iron (Fe), chloride ions (Cl−), and fluoride ions (F−). The results indicate that the Mn concentration reached 28.6 times the background value, followed by Cu at 16.7 times. The groundwater pollution level in the study area reached a severe contamination level, with Zn classified as severely polluted and Mn categorized as moderately to heavily polluted. Approximately 47.05% of the study area was severely contaminated by PTEs. The study further reveals that the primary sources of pollution are anthropogenic activities, including agricultural fertilization, industrial discharges, and urbanization processes, which have significantly elevated PTE concentrations in groundwater. Additionally, natural geochemical processes contribute substantially to the high concentrations of specific elements in certain areas. Health risk assessments indicate that long-term exposure to PTEs in groundwater may pose various potential threats to human health, particularly in terms of carcinogenic and non-carcinogenic risks. Children are identified as the most vulnerable group. This research provides a systematic scientific basis for the management of groundwater pollution in the Dongting Lake basin, emphasizing that the current pollution levels pose serious threats to regional ecosystems and public health. The findings not only offer guidance for groundwater management in the Dongting Lake basin but also serve as a valuable reference for groundwater pollution management in similar regions.