Huda R. Algaim, Rifat M. Dakhil and Isa J. Al-Khalifa
Radon and thoron activity concentration levels have been determined in the soil of Basra Governorate, Iraq. The area of the study included three districts, they are Hayy-Alabas, Hayy-Aljameeat and Almuaficia.. In this investigation CR-39 and LR-115 type2 solid state nuclear track detectors and a cylindrical plastic container technique are used. The samples are taken from the surface and the depth 1m for each location. Maximum activity of radon levels observed is (16200 Bq.m-3) in Hayy-Alabas station number 10 for soil from the surface and minimum levels is (1560 Bq.m-3) were observed in Almuaficia station number 54 for soil from the surface. The activity of radon were measured in Hayy-Aljameeat and Almuaficia which are with in normal limits according to International Commission on Radiological Protection (ICRP). The high values of radon activity are measured in many locations in Hayy-Alabas and Hayy-Aljameeat. There are many anomalous values of radon activity in the soil in some stations of Hayy-Alabas has been observed in this study. The reasons of this anomalous has been discussed. The activity concentration of thoron is smaller than the activity concentration for radon (( 220 / 222 c c A A ) <1) over all study area. The reason of this result has been discussed. The average value of the activity of thoron concentration 220 c A in the soil samples from the surface equal 2073.33 Bq.m-3, 1893.75 Bq.m-3 and 1822.22 Bq.m-3 for Hayy-Alabas, Hayy-Aljameeat and Almuaficia respectively and the average value for the soil samples from the depth 1m equal 1666.66 Bq.m-3 , 906.25 Bq.m-3 and 1103.333 Bq.m-3 for Hayy-Alabas, Hayy-Aljameeat and Almuaficia respectively.