Natural (226Ra, 232Th, 40K) and artificial (137Cs) radioactivity assessment of Kırkpavli and Hazine Cave ore deposits, Gümüşhane (Türkiye): Radiological risk and material utilization perspective

Environmental radioactivity is a critical factor for both ecological and human health risk assessment, particularly in mining regions with ongoing or historical settlement activities. This study evaluates natural and artificial radionuclide concentrations in soils from the Kırkpavli (KP) and Hazine Cave (HM) mining areas in Gümüşhane, northeastern Türkiye. Gamma spectrometry analyses were performed to measure 232Th, 226Ra, 40K, and 137Cs, and radiological risk indicators—including absorbed dose rates, annual effective dose, radium equivalent activity, hazard indices (Hex and Hin), Excess Lifetime Cancer Risk (ECLR), Activity Utilization Index (AUI), radon-related alpha index, and natural radioactivity-driven heat production (RHP)—were assessed. Results: showed spatial variability linked to lithology, with the HM site exhibiting elevated radionuclide levels in basalt-dominated units, while KP soils showed moderate values in sedimentary formations. Most radiological parameters remained below international safety limits; however, specific sampling points, particularly HM-2, exceeded thresholds, indicating potential health risks if the soils are used for local settlement, building materials, or domestic purposes. RHP analysis further identified areas of intense hydrothermal alteration correlating with higher natural radioactivity. Comparisons with international soils and rocks confirmed that the activity concentrations at both sites are comparable to or exceed global averages. These findings highlight the necessity of ongoing monitoring of naturally occurring radioactive materials (NORM) in inhabited mining regions and provide essential data for ensuring environmental safety, sustainable land and material use, and public health protection.