Indoor Radioactive Pollution due to Radon and Its Daughters

Indoor radioactive pollutants such as radon and its daughters (Po-218 and Po-214) have been found to pose grave health hazards in the indoor environments. Radium-226, radon's immediate parent is present in significant concentrations in building materials, and recycled industrial waste products (such as cements). Radon, besides being emitted by different building materials, has been found to enter the houses through (a) the underlying soil or rocks and (b) through the water, drainage, and natural gas connections. The inhaled radon has been found to cause radiation damage to the lungs due to its alpha activity. Radon daughters, Po-218 and Po-214 are found to be even more dangerous than radon itself. They attach themselves to dust particles present in air, some of which enter the lungs. A fraction of the aerosols so produced are either retained by lungs or enter the blood stream. Radon and its daughters have been found to contribute at least 60% of the dose received by an individual from the natural radiation sources. The danger of indoor radon and its daughters is even higher in energy-saving houses and those having poor ventilation systems. The present paper gives a brief overview of the health hazards linked to these important indoor radio active pollutants. Some remedial and preventive actions have been described and recommendations for safer designs of new buildings and houses have also been suggested.