Kamal, Ali and Salahaddin /JZS (2015) 17-2 (Part-A) Measurement of 222 Rn Concentrations in the Air of Qaysery Naqeeb Bazaar Located in Sulaimani Governorate of Kurdistan Region-Iraq Kamal O. Abdullah 1 , Ali H. Ahmed 2 , Salahaddin A. Ahmed 3 1.Faculty of Science and Science Education- University of Sulaimani, Sulaimani-Iraq, kamal.abdullah@unisul.edu.iq mail: - E 2. College of Science- University of Salahaddin Erbil –Iraq, E-mail: aha66sara@yahool.com 3. Faculty of Science and Science Education- University of Sulaimani, Sulaimani -Iraq. E-mail: Salahaddin.ahmed@univsul.edu.iq Article info Abstract Original: Revised: Accepted: 22-2-2015 Published online: In this study the level of 222 Rn concentration at 35 positions in air of the big ancient famous bazaar (Qaysery Naqeeb) which contains 110 shops and located in the center of Sulaimani city have been assessed. During the winter and summer seasons of 2014, 222 Rn concentrations have been measured by using (CR-39) solid state nuclear detector. In winter, the maximum and minimum values of 222 Rn concentration were (206.901±10.958) Bq/mᵌ and (44.978±5.109) Bq/mᵌ respectively, with an average value of (132.849± 8.780)Bq/mᵌ; while in summer the maximum and minimum values of 222 Rn concentrations were (255.476± 25.809) Bq/mᵌ and (99.852± 6.306) Bq/mᵌ ,respectively, with an average value of (158.215± 12.578)Bq/mᵌ, this difference reveals the role of higher temperature and humidity rates in the variation of radon concentrations were high radon concentrations corresponds to high temperature and low humidity rates. In several positions the obtained values were nearly within the acceptable range of radon level recommended by the International Commission on Radiological Protection and the limit recommended by World Health Organization (WHO), but in the most other positions these limits were exceeded due to the structures of material building and lack of ventilation. The effect of temperature on radon concentration was also observed. Key Words: Radon, SSNTD, CR-39, Air, Activity concentration. Introduction Radon has three radioactive gas isotopes 219 Rn, 220 Rn and 222 Rn with half-lives of (3.96sec, 55.6sec and 3.8d) respectively, they are produced from the decay of the natural radioactive (Actinium, Thorium and Uranium) series. 222 Rn can be considered to be one of the most dangerous radioactive nuclide in the environment and as a noble gas can be spread out through the atmosphere while 219 Rn and 220 Rn are not important as 222 Rn due to their short half-lives [1,2]. The 222 Rn is a terrestrial source of radiation produced by the decay of radium ( 226 Ra) in the uranium series, therefore, it can be present whenever uranium is found and especially in the Earth’s crust [2]. The indoor radon concentration depend mainly on the radon exhalation from surrounding materials like soil and building material (brick, rock, cement, gypsum, sand, etc.) which can be considered as a main natural sources of indoor radon [1,3]. 222 Rn and its airborne daughters can cause an effect on human health (lung and larynx cancers) especially when uranium or radium content in the soil is high or they are concentrated in an enclosed area in particular in dwelling and in a big markets or bazaar [4]. Several techniques have been used to measure radon concentration and one of these techniques is Solid State Nuclear Track Detector (SSNTD) through using LR-115 and CR-39. The SSNTD technique is a popular and Journal homepage www.jzs.uos.edu.krd Journal of Zankoi Sulaimani Part-A- (Pure and Applied Sciences)