Paper Title
Measurement Of Radon Content In SILTY Sand Soil Using Rad7 And Cr-39 Techniques At WADI ARAR, Saudi Arabia: Comparison Study

Abstract
The radon concentration of silty sand soil (SM) that deposited in the most top meter depth of Wadi Arar, north of Saudi Arabia was measured using two different techniques of measurements: the passive method using the CR-39 detector instrument, and the active method using the RAD7 detector instrument. Both techniques showed a highly significant correlation coefficient which extent from 0.91 to 0.97.At the maximum reading, the radon content for both techniques almost are the same where the readings decrease from upstream to downstream from 46 to 33 Bq/m3. On the other hand, at the minimum reading of radon content for both techniques, the reading values of CR-39 decrease from upstream to downstream from 45 to 21 Bq/m3, while the reading values of RAD7 decrease from 25 to 16 Bq/m3 which is less from 20 to 5 Bq/m3 than the corresponding ones of CR-39.Standard deviations (SD) of radon content using RAD7 reflected higher readings than that of CR-39 with minimum range value equal to 3.21 Bq/m3 and maximum range value equal to 6.85 Bq/m3. The Coefficient of Variation (CV) of radon content using RAD7 reflected higher reading than that of CR-39. The maximum value of CV of RAD7 is 27.3% and the minimum was 20.8%, while the two corresponding readings of CR-39 were 16.0% and 2.5% respectively, with introducing that CR-39 is more efficient and stable.Also, according to the measured values of radon concentration along and across Wadi Arar, there is not appreciable hazards affects human due to constructional expansion in neighbouring of or upon the ground of the Wadi. Keywords- Saudi Arabia, Wadi Arar, Silty Sand, Radioactivity, Radon, CR-39, RAD7.