The radon isotopes (Rn-222 and Rn-220) and their progenies are responsible for more than 50% of natural radiation dose and the second leading factor in the case of the development of lung cancer after smoking [1]. Rn-222 (radon) and Rn-220 (thoron) are generated in crustal materials from their natural Ra-226 (U-238 decay series) and Ra-224 (Th-232 decay series) content, respectively. As a resul...

Among radiation exposure pathways to human beings, inhalation dose is the most prominent one. Radon, thoron, and their progeny contribute more than 50 per cent to the annual effective dose due to natural radioactivity. South west coast of India is classified as a High Natural Background Radioactivity Area and large scale data on natural radioactivity and dosimetry are available from these coast...

Thoron 220Rn is one of four naturally occurring radon isotopes. It has a half-life T1/2 equal to 55 s. Radon isotopes are chemically inert radioactive gases that occur in the environment as a result of the decay of radioactive elements in soil and minerals. While radon 222Rn results from the decay chain of uranium 238U, thoron 220Rn results from the decay of thorium 232Th. Both uranium and thor...

As it is known, the radon (222Rn) gas and its progenies are considered to be the major contributors to human exposure from natural radiation sources [1]. Several surveys seem to have concluded that the radon in the living environment implies an increased health risk [3, 9, 18]. This is the reason why national authorities and international organizations issues guidelines concerning radon levels ...

Background: Separate radon and thoron measurements in soil are very important in assessment of internal exposure due to inhalation of such radioactive gases. Materials and Methods: In this study, a low cost, small size, passive diffusion chamber has been developed for simple measurement of Radon-222 and Radon-220(Thoron) gases separately in soil. The diffusion chamber consists of two films and ...

The present author has kept observation for concentrations of atmospheric radon, radon progeny and thoron progeny for several years at the campus of Fukushima Medical University. Accidentally, in the midst of an observation term, i.e., February 2005, the facility management group of the university changed a strategy for the manner of ventilation, probably because of a recession: (I) tidy everyd...

Background: The potential hazards of exposure to radiation from radon have been of great concern worldwide, as it is associated with an increased risk of lung cancer. Radon (222Rn) and its progeny are the main sources of radioactivity in the environment. The half-life of 222Rn (3.82 days) is long enough for it to diffuse into and build up in homes. 220Rn or thoron from the 232Th series, and 219...

Background: Radon and its daughters are amongst the most important sources of natural exposure in the world. Soil is one of the significant sources of radon/thoron due to both radium and thorium so that the emanated thoron from it may cause increased uncertainties in radon measurements. Recently, a diffusion chamber has been designed and optimized for passive discriminative measurements of rado...

This study presents the seasonal variation of indoor radon/thoron and their progeny concentrations measured in 50 dwellings Gurugram district Haryana state, India. Single-entry pinhole dosimeters were used for measurement radon thoron concentration, attached unattached progenies these gases, direct sensor with without wire-mesh employed. The absorbed inhalation dose to people area was calculate...

Online radon and thoron monitors have been developed using ZnS(Ag) detector for continuous monitoring of concentrations in occupational and general environments. Their performance has been tested successfully both in laboratory and field conditions. Special features of these monitors include low cost, high sensitivity and non-interference of humidity and trace gases. The capability of these rad...