European Geothermal Energy Council

Geothermal hot springs are critical clean energy resources, yet their utilization requires balancing environmental sustainability with public health protection. This study presents a comprehensive analysis integrating probabilistic health risk modelling with fine-scale physiotherapy classification for geothermal springs in China's Jiaodong Peninsula. Fifteen hot springs were analyzed using Piper diagrams, Fluoride Pollution Index, Inverse Distance Weighting, and Monte Carlo simulations to quantify fluoride exposure risks during balneotherapy. Results revealed weakly alkaline (pH 7.0−8.5), low-to medium-temperature (50−93°C) geothermal hot springs dominated by Na+ and Cl-, classified into seven hydrochemical types. The water quality of these hot springs met both the physiotherapy hot mineral water standard and the therapeutic hot mineral water quality standard, indicating that they were beneficial to human health. The combination of health risk assessment and Monte Carlo simulation values showed that the non-carcinogenic risk was negligible (HQ<1.0), but the HQ value for children was 1.9 times higher than that for adults. Spatial analysis identified elevated risks in central-northern hilly regions. To ensure the safe use of geothermal resources, age-specific bathing guidelines and dynamic fluoride monitoring should be developed. The study advances the methodology for probabilistic risk assessment of geothermal systems and provides actionable insights for global regions facing similar challenges.