Rn-222 concentration of some water samples in Upper Egypt determined with gamma-spectrometric Measurements

Abstract

Measurements of radon concentrations in different environmental media(1-a>have been extensively studied for many reasons such as: (1) evaluate health hazards due to the presence of radon in potable water supplies, (2) study nuclear waste migration,

(3) explore for uranium deposits,

(4) predict earthquakes, and

(5) estimate fluid age based on

4 He and radon content.

1. 1-Radon:

Radon is a radioactive, odorless, colorless, and noble gas that is chemically inert. It's solubility in water inversely proportional to temperature. There are three isotopes of radon arising from the decay chain of uranium-238, uranium-235, and thorium-232. They are radon-222, radon-219, and radon-220, respectively. The longer-lived radon-222 with a half-life of 3.82 days from the U-238 decay chain is the isotope of principal interest for epidemiological concerns. Radon has a coefficient of diffusivity in minerals and in non-porous rocks that is negligible. It's diffusivity in dry, porous materials on the other hand is measurable. Radon in standard, dry sand probably migrates less than 30 centimeters in it's life time in tile absence of a pressure gradient or in a vacuum. The transport of large volumes of radon in natural systems is, therefore