Abstract <p>It is important to monitor outdoor radon (²²²Rn) and thoron (²²⁰Rn) concentrations in order to assess the risk of respiratory cancer, and provide appropriate ways to reduce these concentrations, because the study samples were taken in Halabja city, which has previously bombarded by heavy weapon and chemical bomb. This study aimed to assess the ²²²Rn and ²²⁰Rn in dark brown soil samples using CR-39 detector. The results showed the mean values of ²²²Rn and ²²⁰Rn were 137.60 ± 25.67 and 76.13 ± 20.63 Bq m^–3 respectively. These results in each studied soil samples were lower than the global average recommended by ICRP. In order to determine whether the soil of the study area under investigation poses radiological risks, several radiological hazard parameters were used, including potential alpha energy concentration (<InlineEquation ID="IEq1"> <EquationSource Format="TEX">\({\text{PAEC}}\)</EquationSource> <!--SoilSci2560012Qadr-m1--> </InlineEquation>) annual effective dose (<InlineEquation ID="IEq2"> <EquationSource Format="TEX">\({\text{AED}}\)</EquationSource> <!--SoilSci2560012Qadr-m2--> </InlineEquation>), excess lifetime cancer risk (<InlineEquation ID="IEq3"> <EquationSource Format="TEX">\({\text{ELCR}}\)</EquationSource> <!--SoilSci2560012Qadr-m3--> </InlineEquation>), and effective dose rate to different body organ (<InlineEquation ID="IEq4"> <EquationSource Format="TEX">\({{D}_{{{\text{organ}}}}}\)</EquationSource> <!--SoilSci2560012Qadr-m4--> </InlineEquation>). The results were compared with the international safe limits. According to ICRP and UNSCEAR recommendation, all radiological hazard parameters had values below the world limit. Furthermore, Correlations between ²²²Rn and ²²⁰Rn concentrations as well as radiological hazard parameters were determined by Pearson correlation coefficient.</p>