Radiotoxic and chemotoxic probabilistic risks from uranium, thorium, and potentially toxic elements in groundwater...

Groundwater contamination near coal-fired power plants (CFPPs) poses a potential risk to human health. This study assessed groundwater uranium, thorium, and potentially toxic elements in the three CFPP areas in Serbia. While most elements complied with the World Health Organization (WHO) drinking water guidelines, exceedances were observed for As (18.2 %), Pb (36.4 %), Fe (51.5 %), and Mn (48.5 %), especially near ash ponds and waste storage sites, indicating significant anthropogenic influence. Human health risk was assessed using both deterministic and probabilistic approaches, including two-dimensional Monte Carlo simulation (2D MCS), which allowed for a more precise and more realistic estimation by accounting for both variability and uncertainty. According to the 2D MCS results, children near the Kolubara CFPP had the highest non-carcinogenic risk, with hazard index values ranging from 1.26 to 1.70. In contrast, adults in the same area faced the highest carcinogenic risk, with chemical incremental lifetime cancer risk between 1.59 × 10^-4 and 2.08 × 10^-4, and radiological excess lifetime cancer risk between 5.51 × 10^-5 and 8.07 × 10^-5. Multiple linear regression modeling determined population-related (exposure frequency, ingestion rate, and body weight) and environmental (As and Cr concentrations) criteria that could maintain health risks within acceptable ranges. These findings may support the development of targeted groundwater protection strategies.