Measurement of ambient gamma radiation levels and radon concentration in drinking water of Koppa and Narasimharajapura taluks of Chikmagalur district, Karnataka, India

Abstract

This study presents the results of indoor and outdoor ambient gamma dose rates and radon concentration in groundwater at different locations of Koppa and Narasimharajapura taluks of Chikmagalur district, (13°40' north latitude and 75° 62' east longitudes). The total annual effective dose ranged between 0.67 mSv/y and 1.76 mSv/y with an average value of 1.16 mSv/y. The calculated total annual effective dose was found to be higher than the world average. The radon concentration in groundwater was analyzed using radon emanometry technique. The measured radon concentrations ranged from 3.96 Bq/l to 90.63 Bq/l with an average value of 35.34 Bq/l. This study reveals that 80% of drinking water samples have radon levels higher than the maximum contaminant level of 11 Bq/l recommended by the United States Environmental Protection Agency. All the recorded radon concentration values were found to be well below the action level of 100 Bq/l recommended by the World Health Organization. It is also found that the dose due to borewell water samples is higher compared to dose due to water from other sources such as hand pump, open well, and tap water.