Study of the parameters affecting radon gas flux from the stream sediments at Seila area Southeastern desert, Egypt

Fifty-one locations distributed on two sites at Seila area, Southeastern desert of Egypt, were chosen to study the effect of the local controlling parameters, namely the activity concentration of ²³⁸U, density, and porosity of the stream sediments on the radon gas flux at this area. The average value of the activity concentration of ²³⁸U in the stream sediments at the first site is 41.68 Bq kg⁻¹ while it is 37.34 Bq kg⁻¹ at the second site. These values are higher than the worldwide average of 33 Bq kg⁻¹. The average value of the radon flux density from the stream sediments into the atmosphere is much lower than the worldwide value of 0.016 Bq m⁻² s⁻¹ at both sites of the studied area. It may be recommended for reliable radon measurements inside the stream sediments for any application that the porosity of these sediments should be studied to estimate the suitable hole depth. The passive measurements conclude that the radon concentrations are sensitive to the local parameters while the active measurements reflect the diurnal variations reliably.