Measurement of Contemporary and Retrospective Radon Concentration in Ramsar Dwellings Using Polycarbonate Detector

The origins of radon gas are the amount of uranium decay in the soil that is released into space and through the interior gaps of  buildings. Radon can enter the respiratory system and cause radiation hazards. Recently research has identified Radon as the second leading cause of lung cancer after cigarette smoking. The indoor concentration of Radon progeny is mentioned as an important issue regard to the point of view of health. Therefore, a more accurate measurement of the concentration of radon gas in order to assess the exposure of people is of great importance. The purpose of this research  is to measure radon gas with two contemporary and retrospective methods in Ramsar homes, which is known as a high level background radiation area, as well as comparison with previous measurements. In order to measure the Concentration of contemporary radon by  passive method using a radon chamber and solid state nuclear track detectors, a retrospective of the activity of polonium 210 implanted in glass objects was used to measure the concentration of radon gas. The solid state nuclear track detectors used in this research are polycarbonate, which is the first time used in this world for this type of polymer for the retrospective method. The average concentration of measured for contemperory radon is about 416 Bq /m3 and the resrospective radon is about 1299 Bq /m3. According to the comparison of the results  with the US Environmental Protection Agency standards, it was found that 45% of the radon gas concentration is above 148 becquerel per cubic meter, which is indispensable for reducing radon gas in these buildings. At the same time, the difference in the concentration of rare earth radiant gas with contemporary radon gas can be related to the change in the ventilation rate and the change in the concentration of aerosols and the ratio of the surface to the volume of the room.