It is well known that the different radionuclides are not in radioactive equilibrium with each other due to differences in mobilization from the rock and water chemistry .So, for example, radon activities can be three to five orders of magnitude higher than U or Ra activities, probably due to absorption of the U and Ra in to the host rock, while the gaseous Rn diffuses along micro crystalline imperfections into the interstitial waters (Wallner and Steininger,2007). High levels of radon in drinking water represents a potential health risk due to human exposure through both inhalation and ingestion of radon. In water prior to drinking, alpha particles emitted by radon and its decay product quickly lose their energy and are taken up by other compounds in water. The refore, the exposure of the ingested radon along with the in-take of water is less than the inhaled radon from the radon ex-halation from the same water (Somashekar and Ravikumar,2010). In the case of radium, human exposure through the ingestion/ consumption of radium in drinkable water should be taken in to account.