Vol.5, No.1, 93-98 (2013) Natural Science http://dx.doi.org/10.4236/ns.2013.51015 Measurement of radon concentrations in soil and the extent of their impact on the environment from Al-Qassim, Saudi Arabia Wedad Reif Alharbi 1 , Adel G. E. Abbady 2,3* 1 Physics Department, Faculty of Science, King Abdulaziz University, Jeddah, KSA 2 Physics Department, Faculty of Science, South Valley University, Qena, Egypt; * Corresponding Author: wd_alharbi@yahoo.com 3 Physics Department, Faculty of Science, Al Jouf University, Al Jouf, KSA Received 5 November 2012; revised 8 December 2012; accepted 20 December 2012 ABSTRACT Soil gas radon 222 Rn concentration was meas- ured at 12 location in the Al-Qassim area, using radon gas analyzer-type Alpha GUARD 2000 PRQ from Genitron Instruments (Germany). In each location four different depths were taken for soil gas measurements, staring from the ground sur- face. The results suggested that the largest con- centration was 340 ± 22 Bq/m 3 for 60cm depth at in Al-Tarfia point sample P3, and the smallest concentration was 26 ± 5 Bq/m 3 for surface 0 cm depth at El-Bakria, point sample P5. The results obtained from this study indicate that the region has background radioactivity levels within the natural limits. Keywords: Natural Radioactivity; Radon; Soil; Alpha Guard 1. INTRODUCTION The knowledge on radioactivity contents of the vari- ous radio-nuclides in soil and rocks plays an important role in health physics. The naturally occurring radio- nuclides 226 Ra. 232 Th and 40 K are the main sources of radiation in soils and rocks, from which traditional build- ing materials are derived. These radio-nuclides pose ex- posure risks externally due to their gamma-ray emissions and internally due to radon and its progenies, which emit alpha particles [1]. The factors which influence the diffu- sion of radon from the soil into the air are: 1) The ura- nium and radium concentration in soil and rocks; 2) The emanation capacity of the ground; 3) The porosity of the soil or rock; 4) Barometric pressure gradient between the interfaces; 5) Soil moisture and water saturation grade of the medium; 6) Other variables [2]. Figure 1 presents Mechanisms of exhalation of radon and thoron from soil. Soils are naturally radioactive, primarily because of their Figure 1. Mechanisms of exhalation of radon and thoron from soil. mineral content. The natural radioactivity may vary con- siderably from one type of soil to another. The sources of radioactivity in soils other than those of natural origin are mainly due to: 1) Fallout from past atmospheric explosions of nuclear devices and following nuclear accidents-extensive use of fertilizers rich in phosphates for agricultural purposes; 2) Routine authorized low level radioactive effluent discharges or accidental release into the environment from nuclear fuel cycle installations, mineral extraction industries, industries working with mineral materials en- riched in naturally radioactive elements, (e.g. fertilizer factories) and various economic sectors in which natu- rally or artificially radioactive elements are used [3]. The health risks of radon gas have been clearly recog- nized by international organizations. Radon is a known human carcinogen and is estimated to be the second lead- ing cause of a lung cancer. Only smoking causes more lung cancer deaths. EPA [4] estimates that radon causes 21,000 lung cancer deaths each year in the US. By com- parison, roughly 17,400 people die in the US as a result of drunk-driving accidents; 8000 die from falls in homes; 3900 drowning, and 2800 die of injuries caused by fires, Copyright © 2013 SciRes. OPEN ACCESS