Evaluation of environmental radioactivity and heavy metal pollution in mining areas in Malatya (Turkey)

Abstract

The radioactivity levels of ²²⁶Ra, ²³²Th, ⁴⁰K and ¹³⁷Cs radionuclides were measured in soil samples collected from Hekimhan-Kuluncak mining areas in Turkey using gamma spectrometry with high-purity coaxial Ge detector. In soil samples, the ²²⁶Ra, ²³²Th and ⁴⁰K concentrations obtained for the S-10 (Bıyıkboğazı) sample and the P15 (Deveci) sample are above the world average limit values. The average Ra_eq value was calculated as 87.8 Bq/kg. The Ra_eq values for all soil samples were below the world average value of 370 Bq/kg. Furthermore, the calculated average value of the air-absorbed gamma dose rate from terrestrial gamma radiation was 43.3 nGy/h. The average value obtained for the calculated values of the air absorbed gamma dose rate is lower than the worldwide recommended average value of 60 nGy/h. The average value calculated for the annual effective dose rate is 53.1 µSv/y, which is below the average value of 70 µSv/y. In addition, the mean values for the internal and external hazard indices were 0.31 and 0.28, respectively, which are smaller than the limit value of 1. Based on the results obtained, it can be said that the level of radioactivity in the region cannot cause radiological harm to the health of living organisms. The average excess lifetime cancer risk value for all samples in the study was 0.18×10^-3, which is lower than the world average of 0.29×10^-3. As a result of heavy metal analysis, the results obtained for Zn, Cr and Cu in soil samples were found to be below the limit values. The results obtained for Ni were below the limit values except for P3 (Çayköy) and P12 (Hasançelebi). All PLI values calculated for the present study are less than 1. This means that there is no pollution in the area under investigation.