Concentrations of uranium, cesium, and rubidium in drinking water and Monte Carlo–based age-specific health risk assessment of uranium

Freshwater is essential for life and the economy, yet its scarcity is worsening due to population growth, climate change, and unequal distribution. This study measures concentrations of uranium (U), cesium (Cs), and rubidium (Rb) in drinking water supplies across Arsanjan County, Iran, and evaluated the associated carcinogenic and non-carcinogenic risks of U using Monte Carlo simulation. Uranium concentrations were consistently below EPA and WHO guideline of 30 µg/L. The maximum Cs concentration was 0.63 µg/L, whereas Rb concentrations ranged from 2.04 to 13.94 µg/L. Non-carcinogenic risk assessment using Monte Carlo simulation showed that hazard quotient (HQ) values were below 1 for all age groups, indicating no significant adverse health effects. Children under 2 years had the highest hazard quotient values (HQ median = 0.028; HQ 5th–95th centile range = 0.012–0.061). The estimated excess lifetime cancer morbidity risk (ELCR median :1.58 × 10 − 6 ) and excess lifetime cancer mortality risk (ELCR median :1.02 × 10 − 6 ) were estimated across all age groups. Sensitivity analysis further revealed that U concentration was the most influential factor for both non-carcinogenic risk and excess cancer risk. Although concentrations were below WHO and EPA guideline values, the findings highlight the importance of continued monitoring and incorporating age specific vulnerability into regional water quality management strategies.