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In order to assess the radiological impact of radon on >250,000 students, the total annual effective dose was estimated inside 204 Moroccan primary schools sampled in the Doukkala-Abda region. The measurement of indoor radon concentrations was conducted using the LR115 detector for each month, each season and throughout the year. The evolution of indoor radon concentrations showed a decrease in annual average radon concentrations of 20–26% and 10–14%, respectively, compared to the monthly and seasonal annual average radon concentrations. For this purpose, a corrective model of short-term radon concentrations was developed to calculate the seasonal correction factors in order to estimate the annual indoor radon concentrations. For the qualitative evaluation of these factors, a percentage of deviation between the measured and estimated annual radon concentrations was calculated. Almost half of the estimated annual concentrations were 10% less than the measured concentration and the majority of these estimated values were within 40%. The estimated total annual effective doses received by students, except those in the Sidi Bennour city, were higher than the world average (1.15 mSv/y). Nevertheless, all these doses remained below the permissible limit recommended by the International Commission on Radiological Protection (3–10 mSv/y). [ABSTRACT FROM AUTHOR]

The areas pertaining the hydrocarbon and non-hydrocarbon in the Attock district of Pakistan were selected for the measurement of indoor radon concentration. This area was not previously surveyed for such kind of study. CR-39-based NRPB radon dosimeters were utilized for this study. Attock city, Hassan Abdal and Jand belong to the non-hydrocarbon areas, where radon concentration was measured to be 57 ± 11, 58 ± 11 and 56 ± 11 Bq m−3, respectively. The hydrocarbon pertaining areas consist of Toot and Meyal villages, the concentration of radon was found to be 48 ± 10 and 37 ± 8 Bq m−3, respectively. The cap rock in the geological structures of the hydrocarbon areas may have restricted the migration of underneath radon. The annual effective dose in the studied locations was estimated to be 1.28 ± 0.25 mSv y−1, which is less than the action level recommended by the ICRP. Estimated excess lung cancer risks per million persons per year in the surveyed area show higher values 96, 69, 32–110 and 41–124 as compared to the world average reported by the BEIR-IV (1988), ICRP (1987), US-EPA (1986) and UNSCEAR (1993) models, respectively. Present results could be used as a reference for any future studies in Pakistan for the problems of radon emissions with respect to the types of rocks. [ABSTRACT FROM AUTHOR]

In continuation to our earlier studies concerning generation of the baseline indoor radon data, an indoor radon measurement survey was carried out in the districts Bagh and Kahuta, state of the Azad Jammu and Kashmir. In this context, 150 houses were selected in the aforesaid districts and CN-85-based box-type radon detectors installed in bedroom and living room of each house. The detectors were exposed to indoor radon for 3 months. After etching CN-85 detectors in 6 M NaOH at 70°C for 3 h, the observed track densities were related to the indoor radon concentration using calibration factor of 0.0092 tracks cm−2·h−1 per Bq·m−3. The measured indoor radon concentration ranged from 56 to 124 Bq·m−3 and 61 to 106 Bq·m−3 in the studied areas of districts Bagh and Kahuta, respectively. The mean annual effective dose ranged from 1.42 ± 0.15 to 3.12 ± 0.10 mSv·y−1 with an average of 2.16 ± 0.13 mSv·y−1 in the district Bagh and 1.54 ± 0.14 to 2.68 ± 0.12 mSv·y−1 with an average of 2.17 ± 0.13 mSv·y−1 in the district Kahuta. These values are within the safe limits recommended by the World Heath Organization. [ABSTRACT FROM AUTHOR]

Radiation doses from indoor radon exposure, before and after the 2005 earthquake, have been assessed from measurements taken in the city of Muzaffarabad and Jhelum valley, Azad Kashmir, Pakistan. Indoor radon concentration was measured in dwellings in Muzaffarabad city and the Jhelum valley after the devastating 2005 earthquake using CR-39 based radon box type detectors which were exposed to indoor radon for 60 days. After processing, the observed track densities were related to the indoor radon concentrations using a calibration factor of 0.0092 tracks cm-2 · hr-1 = 1 Bq m-3 of 222 Rn and compared with already published data obtained before the earthquake. The post-earthquake weighted average indoor radon concentration ranged from 65 Bq m-3 to 398 Bq m-3 for the dwellings of state capital city of Azad Kashmir where pre-earthquake values were in the range of 89 Bq m-3 to 167 Bq m-3. In the Jhelum valley, post-earthquake indoor radon concentrations varied from 81 to 509 Bq m-3 and 64 to 456 Bq m-3 in the bedrooms and kitchens, respectively while pre-earthquake radon concentration for Jhelum valley ranges from 86 to 236 Bq m-3 and 62 to 208 Bq m-3 in the bedrooms and kitchens, respectively. The post earthquake indoor radon concentration levels and hence radiation doses have been found higher than those of pre-earthquake values. [ABSTRACT FROM AUTHOR]