Analysis of Groundwater Chemical Characteristics and Health Risk Assessment: A Case Study of Water Sources in the Tailai Basin

Groundwater nitrate pollution is a pressing threat to public health. To analyze the chemical properties of groundwater across various sources, samples from 15 groundwater outlets within the Tailai Basin were collected during both the dry and wet seasons. An assessment of human health risks based on drinking water habits and skin contact with various water sources was conducted to provide a foundation for the rational development and utilization of groundwater. The results revealed that the main source of chemical components in the groundwater in the study area was evaporite dissolution. Rock weathering and cation exchange predominantly affected the chemical composition of groundwater. The groundwater samples primarily contained Ca2+ cations and HCO3− anions. The concentration of groundwater nitrate at each water source was relatively high. The single-factor water quality evaluation demonstrated that SO42−, NO3−, and TDS exceeded the standard, where NO3− severely exceeded the standard. The water supply and dry seasons were more than 10 times higher than the standard. The HI exceeded 1 for most water sources, and the non-carcinogenic risk index for children significantly surpassed that for adults. This high hazard quotient suggests that groundwater from the majority of sources in the Tailai Basin may adversely affect residents’ health. Water resource management authorities should address groundwater nitrate pollution to ensure the residents’ health and safety. Meanwhile, efforts should focus on preventing and controlling nitrogen pollution in groundwater to support its sustainable development.