Fluoride hydrogeochemistry and associated human health risks implications are investigated in several aquifers along the southern edge of the Chinese Loess Plateau. Locally, 64% shallow groundwater samples in loess aquifer exceed the fluoride limit (1.5 mg/L) with the maximum of 3.8 mg/L. Presently, the shallow groundwater is the main source of private wells for domestic use, and this is clearly a potential risk for human health. Hydrogeochemistry and stable isotopes are used to elucidate the diversity of occurrence mechanisms. Enrichment of fluoride in groundwater is largely controlled by the F-containing minerals dissolution. Furthermore, alkaline condition and calcium-removing processes promote water–rock interactions. Stable isotopes of hydrogen and oxygen (δD and δ¹⁸O) in study area waters demonstrate that groundwater in loess aquifer is old, which means groundwater remains in the aquifer for a long time. Long residence time induces sufficient water–rock interactions, which play significant roles in the resolution of fluoride minerals. Samples from the shallow loess aquifer show elevated fluoride levels, which may pose human health risk for both adults (60%) and children (94%) via oral intake. To ensure drinking water safety, management measures such as popularizing fluoride-removing techniques and optimizing water supply strategies need to be implemented.

Knowledge of groundwater quality is a crucial issue for the scientific and sustainable exploitation of the groundwater resources in loess aquifer, northwest of China. In this study, analysis of water quality for drinking and irrigation were proceeded in a loess aquifer. Based on the analysis of 52 groundwater samples, the groundwater is characterized by high sodium, with 54% samples have sodium exceed WHO limit, observed in the central of loess tableland where the water table is shallow. EC, SAR, and SSR indices are used to appraise the water quality for irrigation. The results showed groundwater can pose high risks of salinity and medium sodium hazard, without any measures and management.