Study of radon exhalation and radium content in different types of building materials in and around Tumkur, Karnataka, India

Radon, the immediate daughter radium is a gas, which enters human body through breathing which may affect the health. In the present study, can technique is used to measure radon and radium activity concentrations in the building materials such as soil, marble, glazed tiles, white granite, pink granite, clay brick, cement brick, fly ash bricks, sand and mosaic samples collected from different locations of Tumkur district. The alpha tracks recorded were counted by a spark counter and the track densities were converted into radon and radium concentration. The radium content in glazed tiles samples is found be the lowest value 7.59 Bqkg-1 and highest for pink granite 17.77 Bqkg-1. The radon concentration, mass and surface exhalation rates for glazed tiles were 463.8 Bqm-3, 6.29 mBqkg-1h-1 and 163.3 mBqm-2h-1 for pink granites 1085.4 Bqm-3, 14.72 mBqkg-1h-1 and 382.1 mBqm-2h-1 respectively. The radon concentration and exhalation rates for soil, sand, mosaic and pink granite with grain sizes were found to be -0.82, -0.85, -0.84 and -0.96 respectively. The concentration level of radon and radium in building materials in Tumkur is found to be low in comparison with data available in Indian and global average. (author)