Estimation of radon concentration in drinking water in and around Honavar taluk, Uttara Kannada district, Karnataka

Water is an essential factor for most life on the planet, and as such the quality of drinking water is an important parameter for a person's health. Radioactive elements such as radon (²²²Rn) and radium (²²⁶Ra) are found in water. Measurement of radon concentration in drinking water has been conducted by many countries in all over the globe. However the interest of this study has been increased throughout the world because of the hazardous effect of radon on health of the human beings. This study was conducted primarily to measure radon activity concentration in drinking water. Thirty Five drinking water samples were taken in and around Honnavar taluk of Uttara Kannada district. Activity concentration of ²²²Rn was measured by using emanometry technique. Physico-chemical properties such as pH, electrical conductivity and TDS were estimated using standard technique. Radon activity concentration in water has been found to vary from 1.42±0.18 Bq.l^-1 to 19.4±1.8 Bq.l^-1 with an average value of 7.68±0.76 Bq.l^-1. Upon comparing radon concentration level obtained in the study with EPA, it was found that 74.3% of samples are far below the maximum contamination level of 11.1 Bq l^-1 with an exception of 25.7%. The total average annual effective doses of all the samples are much lower than the safe limit of 100 µSv.y^-1. There is no significant correlation between radon concentration and physico-chemical properties. (author)