Radiation dose from dissolved radon in potable waters of the Bangalore environment, South India

Abstract

Potable waters from various locations of the Bangalore environment were investigated for their ²²²Rn concentrations by the emanometry method. About 94 groundwater (borewell) samples were analysed for ²²²Rn concentrations and found to vary in the range 5.3–283.4 Bq L⁻¹ with a mean value of 87 Bq L⁻¹. Frequency distribution showed the ²²²Rn concentration in a large number of samples in the range of 0–50 Bq L⁻¹. From the measured concentrations, the effective doses (lung and stomach) for the population of the region were estimated. The effective dose was found to vary from 42.6 to 2280.2 µSv y⁻¹ with a mean value 702.5 µSv y⁻¹. The effect of boiling of water showed a drastic reduction in the ²²²Rn concentration. The results of the present investigation are systematically analysed, compared with the literature values and discussed.

Keywords:

• Radon
• Emanometry
• Potable water
• Annual effective dose
• Effect of boiling
• Bangalore

Acknowledgments

The authors are thankful to Dr M.C. Radhakrishna, Chairman, Department of Physics, Bangalore University, Bangalore, for his keen interest and constant encouragement throughout the course of this work. The authors would like to express their thanks to Prof. Vajrappa, Department of Geology, Bangalore University, Bangalore, for valuable discussions on the geology of the study region. The authors are also grateful to Dr S.C. Sharma, Principal, RV College of Engineering (RVCE), Mr T Bhuvaneswara Babu, Head, Department of Physics and Dr D.N. Avadhani, Department of Physics, RVCE, Bangalore for many useful suggestions. We especially thank Dr Michael Brett‐Crowther for his encouragement and careful advice.