Geochemical anomaly of iron and manganese in drinking water: health risk assessment

Aim. To assess the non-carcinogenic health risks associated with elevated concentrations of Fe and Mn in drinking water. Water samples were collected from decentralized sources (wells, boreholes) in the western Tyumen region, where an iron-manganese biogeochemical anomaly has been identified. Methods. Quantitative analysis and Monte Carlo simulations were applied to account for natural factors influencing metal solubility. The model parameters included Fe, Mn concentrations, and metal bioavailability in water. Results. Fe exceeded permissible limits by ~10 times and Mn by ~2 times. Despite these high concentrations, non-carcinogenic health risks remained low in most cases. However, in 5% of cases, the hazard index approached critical values, requiring increased attention. Significant factors influencing metal solubility were water pH and organic matter content. Conclusions. Although the overall risk is low, regular monitoring and additional water quality improvements are necessary. Geochemical conditions (pH, Eh) and seasonal variations are critical factors affecting health risks associated with consuming water from these sources.