[Evaluation of the natural gamma radiation level in residential zones and determination of annual effective exposure dose in the residents of Hamadan province, Iran, 2012]

Human is always exposed to natural background ionizing radiation which may have harmful effects; therefore, measurement of the natural background radiation is important. In this study, was measured the dose of effective natural background gamma radiation in indoor residential zones of Hamadan Province. In this cross-sectional study, we selected four stations along the main geographic directions and one in the center of city for measurement of the indoor dose rate in each of the cities in Hamadan Province. Based on the household numbers, some houses were selected randomly in every station and natural background indoor dose was measured by using RDS-110 survey meter. Then, using the results of our previous study about measuring the level of outdoor natural gamma radiation in this province, we determined the level of annual effective exposure dose from natural gamma radiation in Hamadan residents. In Hamadan province cities, maximum and minimum indoor natural background radiation [gamma ray] belonged to Razan City [1.41 +/- 0.079 mSv] and Asadabad City [0.955 +/- 0.044 mSv], respectively. Mean annual equivalent indoor dose in Hamadan Province was 1.20 +/- 0.070 mSv. Also the maximum indoor natural background radiation dose [gamma ray] in the buildings with the age of more and less than 25 years were 1.42 +/- 0.219 mSv and 1.44 +/- 0.149 mSv, respectively. According to the results of this study and our previous study about outdoor gamma natural background radiation, the annual effective dose in Hamadan Province residents was 0.83 mSv. According to the results of this study, it seems that annual effective equivalent dose due to indoor gamma radiation in Hamadan Province exceeded the mean external exposure amount reported by UNSCEAR [0.5 mSv]. Also the annual effective dose due to gamma background radiation in Hamadan Province residents is 0.83 mSv, which is higher than the global average [0.48 mSv] reported by UNSCEAR - 2000. Therefore epidemiological studies to assess the prevalence of chronic diseases associated with natural radiation exposure among Hamadan Province residents are recommended

[Effective dose rate of radon gas in Jooshan hot spring of Kerman Province]

Human beings are constantly exposed to different radiations that have always been recognized as a health hazard. Radon-222 and its daughter products are major sources of natural radiations and a significant total inhalation dose is related to them. Hence, the measurement of radon activity in the environment has gained an increasing importance. In this study, with the measurement of radon concentration, the indoor radon activity level and radon effective dose rate in Jooshan hot spring were determined. Concentration of radon gas inside the pool of Jooshan hot spring was measured using the active detector Rad7 type and the annual effective dose was estimated for individuals inhaling the indoor air of this pool for a specified period of time. Concentration of indoor air radon gas was 98.3 +/- 4.9 Bq/m3 and for a person staying in the pool twice a week and each time for two hours, the annual effective dose rate, due to the inhalation of radon, equals to 0.06 +/- 0.003 mSv/y. Comparison of the obtained effective dose with the standards of Environmental protection Agency and Health physics Society, it can be concluded that for individuals that normally use Jooshan hot spring pool, the resulted dose is in the recommended range

Environmental monitoring of radon, thoron and their progeny in some dwellings of northern Haryana (India).

The problem of randon is an important global problem of radiation hygiene concerning the world population. Radon and its progeny are the major contributors in the radiation dose received by general population of the world. Keeping this in mind, the environmental monitoring of radon, thoron and their progeny in some dwellings of northern part of Haryana state of India has been carried out. The radon thoron twin dosimeter cups were used for the study. Three pieces of LR-115 solid-state nuclear track detectors were fixed in the dosimeters and were suspended in the dwellings for three months during a season. The first detector indicated radon, thoron and progeny concentration, the second showed radon and thoron concentration, while the third detected only the radon concentration. The aim of study was to carry out possible health risk assessment in the dwellings under consideration. During summer season, the radon concentration in northern region of Haryana varied from 66-97 Bq m(-3), while the thoron concentration in the same dwellings varied from 27-65 Bq m(-3). During winter season, radon concentration in northern region of Haryana varied from 73-104 Bq m(-3) with an average of 88 + 7 Bq m(-3), while the thoron concentration in the same dwellings varied from 35-69 Bq m(-3) with an average of 55 +/- 8 Bq m(-3). The radon-thoron progeny levels and annual doses received by the inhabitants in the dwellings under study have also been calculated.

Indoor radon in Thailand: a study with particular reference to its sources.

Measurements of radon gas were carried out on each floor of the four tall concrete buildings. The results show clearly that levels of radon concentration on the higher floors of the buildings were mostly comparable and occasionally were much higher than the ground-floor in contact with the earth. Hence, the findings indicate that the source of indoor radon is not only the surrounding soil but also other sources in the buildings, i.e. most likely radium-containing building materials.