Soil radon and associated radiological risk indicators: a spatial and multivariate investigation in the Shaqlawa District, Iraqi Kurdistan.

In this study, concentrations of radon in soil and the corresponding radiological health effects have been assessed in the Shaqlawa District, Erbil Governorate, Iraqi Kurdistan. Soil samples were taken across urban, suburban and agricultural areas at 25 locations. Radon concentrations were determined using CR-39 solid-state nuclear track detectors. Results showed 222Rn concentrations from 39.5 to 95.4 Bq m-3 and an average of 68.0 Bq m-3. The average value of potential alpha energy concentration (PAEC) and annual effective dose (AED) was 11.03 mWL and 0.64 mSv y-1, respectively. ELCR ranged from 1.3 × 10-3 to 3.15 × 10-3 and with a mean value of 2.25 × 10-3. Dose estimates to organs showed a maximum mean exposure to the testes (0.41 mSv y-1) and bone marrow (0.35 mSv y-1), while the mean liver dose was minimal (0.24 mSv y-1). Most radon and radiological indices showed a near-normal distribution according to the statistical analyses, and radon concentration was significantly and positively correlated (r > 0.8) with hazard parameters. Kriging spatial mapping identified these high-radon areas related to fractured-calcerous lithologies, mainly the Shiransh-Aqrah-Bakhmah and Tayjru-Shiransh formations. Hierarchical cluster analysis revealed low, moderate and high radon clusters, which demonstrated that local variability exists and seems to be related to geology. These results provide an updated overview of soil radon levels and the expected health risks in the specific area of Shaqlawa, which is important baseline data to support better monitoring of environmental radiation, as well as planning for the health sector in this part of the region.