Assessment excess lifetime cancer risk of soils samples in Maysan neighborhood adjacent to the middle Euphrates cancer center in Najaf / Iraq

Abstract

In this study, 30 samples of soils were taken from in Maysan neighborhood adjacent to the middle Euphrates cancer center in Najaf / Iraq, gamma-ray spectrometer system connected with the NaI detector was used to measure the specific activity of the (238U, 232Th, 40K) nuclei, the specific activity values were varied from(1.41±0.71Bq/kg) to (30.95±0.74 Bq/kg) with an average value(10.03± 1.04) for 226Ra, for 232Th from (0.71±0.27) to (15.44±0.30 Bq/kg) with an average value (4.96±0.37), The measurements of the specific activity of the 40K varied from 92.77±1.95 to 589.77±3.18 Bq/kg with an average value (198.43±3.13).Radium equivalent activity, outdoor and indoor absorbed doses, the Outdoor, Indoor and total annual effective dose equivalent (AEDE), external and internal hazard index (Hex, Hin) in the range of 32.415±1.817(Bq/kg), 16.104±0.827(nGy/h), 20.936±1.075(nGy/h), 0.019±0.001014(mSv/year),0.102±0.0052(mSv/year), 0.121±0.0061(mSv/year), 0.087±0.004, 0.114±0.007 respectively, Representative level index Iγr and excess lifetime cancer risk (ELCR), Representative Alpha index (Iα) and annual gonadal dose rate (AGDE) were calculated with range, 0.248±0.012(Bq kg-1), 0.423*10−3, 0.052(Bq/Kg), 119.404( mSv/y) respectively. These results were compared with recommended values (370 Bq/kg) for Raeq, 59 nGy/h for Dout, 84 nGy/h for Din,0.07 mSv/year for Deffout, 0.41 mSv/year for Deffin,0.48 mSv/year for Defftot, ≤1 for Hex and Hin, <1 for Iγr, <1 for Iα, 300 μSv/y for AGDE by UNSCEAR International Commission on Radiological Protection (ICRP) and European Commission (EC), and Their values were less than the permissible limits except for one sample out of 30 samples have specific activity values of 40K, Annual Gonadal Equivalent Dose (AGED) in sample (S6)higher than the worldwide average value (412 Bq/kg)and( 300 μSv/y) recommended by the UNSCAER, besides, the value of ELCR was lower than the world permissible value of 1.45×10−3 (UNSCEAR,2000). As a result, health hazards originated by natural radiation from soil samples in this region is low and insignificant.