Radionuclides, Metals, and Semi-metals in Water of Artisanal Mining Sites: A Monte Carlo Simulation Approach to Health Risk Assessment

Mining activities generate large volumes of waste, including tailings rich in natural radionuclides and potentially toxic elements. These wastes accumulate on-site and are washed into mining ponds, contaminating water used by miners and nearby communities, posing serious health risks. Water samples from gold and kaolin mining sites in the Ife-Ilesha schist belt were analyzed for radionuclides (40K, 238U, 232Th), metals, and semi-metals using gamma and atomic absorption spectroscopy. Using a Monte Carlo simulation (MCS) method, a probabilistic health risk assessment was performed to estimate the ingestion dose and excess lifetime cancer risk (ELCR) for exposed miners. MCS-based risk assessment revealed elevated cancer and non-cancer risks. Ingestion doses from naturally occurring radioactive materials range from a best-case scenario (0.56 mSv/y) to a worst-case scenario (0.92 mSv/y), which both exceed the World Health Organization recommended limit of 0.1 mSv/y for drinking water. To prevent long-term health effects, miners and local communities should avoid consuming these waters.