Volume No. 6 Issue No.: 1 Page No.: 34-40 July-Sept 2011

 

DISTRIBUTION OF INDOOR RADON AND THORON LEVELS

 

Sathish L. A.*1, Nagaraja K.2, Shobha S.3, Sundareshan S.4

1. Department of Physics, Government Science College, Bangalore (INDIA)
2. Department of Physics, Bangalore University, Bangalore (INDIA)
3. Department of Physics, Basaveshwara Degree College, Bangalore (INDIA)
4. Department of Physics, Vijaya Degree College, Bangalore (INDIA)
5. Department of CSE, Sri Balaji Chockalingam Engineering College, Tiruvannamalai (INDIA)

 

Received on : April 02, 2011

 

ABSTRACT

 

The sources of indoor radon levels are the soil-gas, building materials, tap water, natural gas used for cooking, etc. The concentrations of 222Rn, 220Rn and their progeny levels in dwellings were measured using Solid State Nuclear Track Detectors. The higher concentrations were observed in a room of lower volume than in higher volume. The concentrations in a dwelling of volume 35-300 m3 ranged from 6 to 93 Bq m–3. It is observed that the enhancement of volume by almost ten-fold reduces the concentration of 222Rn to 11.1% and that of 220Rn to 8.3% provided the rest of condition remains unaltered. The result clearly indicates that though the observations have been made almost for similar type of constructions and lifetime of the houses, but as the volume of the room increases the concentrations drops exponentially and it becomes almost constant above 200 m3. The variation in the concentration follows the exponential drop with the regression coefficients greater than 0.91. The present work reveals that the dwellers of lower volume houses will expose themselves to the higher dose rates and is 4.4 times of the dose received in higher volume houses. The volumetric variations of 222Rn, 220Rn and their progeny levels along with their doses in dwellings of various locations are discussed.

 

Keywords : Indoor radon, Thoron, Volume, Concentration, Dose

 

 

BACK