Geochemical anomalies and radiological significance of thorium-enriched soils: spatial pattern, low-activity endmember characterization, and hazard indices assessment (oil block)
摘要
This investigation was undertaken to study thorium-enriched soil regions and the lowest radiation activity concentration zones within designated areas of Kifri, Sulaymaniyah Governorate, Kurdistan region, Iraq. The research primarily addresses the spatial distribution, concentration patterns, and mineralogical associations of radionuclides, particularly thorium, derived from soil samples procured within the delineated study area. Thorium activity concentrations were observed to span a range from 10.3 to 210 Bq/kg, yielding an average value of 127.6 Bq/kg. This cumulative radiation, originating from natural radionuclides and specifically thorium, is implicated in an escalation of radiological hazards, consequently leading to elevated levels of several radiological indices. These indices include, but are not limited to, radium equivalent activity (Raeq), outdoor and indoor annual effective doses (E), and external and internal hazard indices (H). A substantial proportion of these identified hazards surpasses globally recognized thresholds. Furthermore, the radiological hazard emanating from the soil is projected to contribute to an incidence of 40–4547 cancer cases per million individuals over an average lifespan. These foundational data offer critical insights for environmental surveillance, inform regional radiation protection strategies, and identify a naturally occurring source of rare material, such as thorium-232, within an oil exploration block.