Radio-elemental microzonation (RELMIC): a case study of Karadeniz Technical University Campus and surroundings (Trabzon, Turkey)

In situ radioactivity measurements were performed to describe and map the relationship between the radioactive concentration distribution on the surface and geological formations in the Karadeniz Technical University (KTU) campus and surrounding area located on the shore of the Black Sea in NE Turkey. The concentrations of radio-elements (eU, eTh, and K) and dose rate values were measured using a portable gamma-ray spectrometer with NaI(Tl) crystal at 150 points in the study area with a duration of 5 min for each measurement point. In addition, the geochemical radio-element ratios (eTh/eU, K/eU, and eU/eTh) give information about the origin of the rocks, and radiological hazard parameters for humans and the environment were also calculated. Average values of eU, eTh, and K concentrations, and dose rate, were calculated to be 3.59 ppm, 13.46 ppm, 0.84%, and 65.38 nGy/h, respectively. While the highest concentrations of radio-element and dose rate values were recorded at outcrops of Eocene-Neogene basaltic rocks and red clays, which are the weathering product of the Kabaköy formation, the lower anomaly zones coincide with brown and reddish brown forest and agricultural soils of volcanic origin in the study area. According to the average radio-element ratios, it was concluded that the rocks in the study area do not completely originate from the crust, but formed as a result of the mixture of upper mantle and continental crust. All the calculated hazard parameters seem to be lower than the internationally recommended values, and there is no cancer risk in and around the campus area.