Environmental risk assessment of radon and heavy metal levels in the surface water of the Bitlis Stream, Türkiye

Abstract In the present study, radon concentrations in water samples collected from the Bitlis Stream were analyzed, and the corresponding dose rates were calculated. The radon concentration was measured using the AlphaGUARD PQ2000 PRO radon monitoring system. The radon concentration levels in the studied samples ranged from 1.45 ± 0.34 to 4.27 ± 1.01 BqL −1 , with a mean value of 3.01 ± 0.72 BqL −1 . Annual effective dose rates through radon intake by ingestion and inhalation are given to assess health risks in different age-groups. These values were found to be lower than the standard values recommended by international organizations. In addition, the presence of potentially toxic metals such as Zn, Cu, Pb, Cr, and Cd in water samples was determined using the ICP-MS instrument. Based on the average concentration (mgL −1 ) values, the distribution of these metals in water samples is as follows in decreasing order: Fe(376.49) > Cr(56.47) > Mn (7.84) > Cu(1.80) > Pb(1.53) > Zn(0.61) > As (0.29) > > Cd. The obtained results reveal that the heavy metal concentrations in water samples exceed the permissible limit values ​​determined by the World Health Organization (WHO) for all metals except Cd, Zn, and Cu. Comprehensive statistical correlation analyses were performed to evaluate the possible relationship between radon concentration and heavy metal concentrations. Graphical abstract