3. Results and discussion
Table1 summarises the concentration results of radon and radium in the 14 drinking water samples collected from the University Village. The highest radon concentration was measured in TDTT to be 0.367+- 0.06Bql 1. Mean concentrations of 222Rn in these water samples were calculated to be 0.117+-0.01Bql 1. Following that, the highest radium concentration was found to be
0.187+-0.08 Bql 1 in the QT and the mean concentration of 226Ra Was calculated to be 0.117+-0.02 Bql 1.
The annual effective dose contributions from radon and from radium in the drinking water samples are also given in Table1. It was found that the mean annual effective dose for ingestion(radon) rangedwascalculatedtobe0.7870.07 mSv y 1. The mean dose contribution from radium in water to the annual dose resulting directly from the water intake ranges was found to be 22.577+-3.74 mSv y 1
The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has provided the mean dose from radon in water .As a result of ingestion the mean radon dose is 2 m Sv y 1 (UNSCEAR, 2000). It is found that our average annual effective dose due to ingestion is well below the reference level values of UNSCEAR and hence does not pose any health problems as a consequence of the radon dose received from drinking water in the study area.