Average Radon Concentration Research Articles

The natural radioactivity of Istria, Croatia

Because of the geological structure of the Istrian peninsula which mainly consists of limestone that is characterized by karstic topography on its surface, it is expected that there are areas with elevated radon levels in soil gas as well as inside buildings (e.g. houses, kindergartens, schools). Recently, from autumn 2013 until spring 2015, more than 1200 radon measurements at about 500 randomly selected locations (in houses as well as in schools and kindergartens) were performed. The average value of indoor radon in homes is 102 Bq m−3 while the average radon concentrations in kindergartens (181 Bq m−3) and schools (208 Bq m−3) are approximately two times higher than in homes. In fact, in 15.5% of kindergartens and 21% of schools, the average indoor radon concentration is higher than 300 Bq m−3 which is the reference level in Croatia.Radon concentrations in soil gas in the Istrian peninsula were measured from 2013 to 2015 with the AlphaGUARD and RM-2 measuring systems. The obtained average value of 90 kBq/m3 and geogenic radon potential of 74 classifies the soil of Istria County into soil of high geogenic radon potential. It is important to emphasize that there are areas with radon concentrations up to 500 kBq m3. Soil samples were collected according to the standard procedures of the IAEA at 48 different locations. Activity concentrations of selected radionuclides were determined by means of gamma spectrometry by using an ORTEC HPGe detector system. The correlation between radon and its parents radium/uranium were investigated. The linear relationship between GRP and indoor radon per grid cell was found. The influence of climate condition on indoor radon concentration was observed. In accordance with the obtained results, areas with elevated indoor radon levels as well as levels of radon in soil gas were identified and geogenic and indoor radon maps were generated.

Radon and thoron concentrations and resulting dose in air of southeast Baghdad regions

The levels of radon, thoron and their progeny concentrations in Al-Nayriya, Al-Musbah Street, Nawab Al-dhubat and Al-mashtel, as well as Canal Street in southeast Baghdad were studied by using The Twin Cup Dosimeter. A total of 15 samples selected from 5 regions (3 samples from each region) in Baghdad city have been placed in the dosimeters for 100 day. The average radon and thoron concentrations were found to be 45.47 and 43.15 Bq/m3 respectively. Their average progeny concentrations were found to be 4.91 and 1.16 mWL.The dose received by persons living in the studied areas is less than the internationally permissible limits, which were determined by the ICRP of 3-10 mSv /y.

INFLUENCE OF BUILDING FEATURES ON RADON ACCUMULATION IN KINDERGARTENS OF THE SVERDLOVSK REGION

Objective: To study the levels of radon accumulation in kindergartens in Sverdlovsk Region and to deter­mine the relationship between radon concentration, and building characteristics. To perform a detailed anal­ysis of radon entry and accumulation in the kindergarten, in which radon concentration exceeds the safety standards. Materials and methods : Track detectors REI-4 on the base of LR-115 film were used. Detectors were installed in playrooms and bedrooms for day nap. In each kindergarten, at least 3 rooms were examined. The measurements were carried out twice a year, during the warm and cold seasons. The duration of exposure of the detectors was 2–3 months in each season. The AlphaGUARD radon monitor was installed in the kinder­garten with a high level of radon concentration. Results: It is shown that the distribution of radon concentration in the kindergartens of the Sverdlovsk region can be described by a lognormal distribution with an average value of 60 Bq/m 3 , a geometric mean of 44 Bq/m 3 and a standard geometric deviation of 2.23. A statistically significant differ­ence was found between the mean values of radon concentration in subgroups of buildings constructed at different periods. For the kindergartens constructed in 1950–1969, the average radon concentration was 85 Bq/m 3 , for buildings built in 1970–1989 – 54 Bq/m 3 . When comparing subgroups of rooms with different types of windows (all buildings, ground floors) it was found that in rooms with PVC windows, radon concentration is almost twice as high then in rooms with wooden windows. For the kindergarten, in which the annual radon concentration in the playroom was 620 Bq/m 3 , it was shown, that if the proper ventilation regime of this room is observed, the average radon concentration during the presence of children does not exceed 120 Bq/m 3 . Conclusions . Factors affecting the indoor radon accumulation in the kindergartens are the type of building materials associated with different periods of building construction and the type of windows. When radon concentration measured in kindergartens reach sanitary standards, it is advisable to conduct an additional study of the daily radon variations, since during the active operation of the premises (working hours) radon levels may be significantly lower

Comparison of single and double entry twin cup dosimeter in measuring indoor radon and thoron concentration in Mizoram, India

Indoor radon and thoron concentrations have been measured using solid state nuclear track detector (LR-115 type-ІІ) based twin cup dosimeter with single and double entry deployed side by side. The measurements have been carried out in 50 dwellings of 8 different villages/towns situated in Saiha and Lawngtlai districts, Mizoram. Dwellings were selected primarily from the gamma level measured using Micro-R survey meter and the construction type of the building. The average concentrations of radon and thoron were found to be 75.76 Bq/m3 and 96.50 Bq/m3 for single entry dosimeter and 63.47 Bq/m3 and 19.79 Bq/m3 for double entry dosimeter. The single entry dosimeter was found to give more reliable observations than that of double entry in terms of trends of seasonal data and also on the theory behind the manufacturing qualities.

Indoor Radon Levels and Effective Dose Estimation in Learning and Common Living Space of University

Radon which is natural component of air is a colorless and odorless radioactive gas. Radon exposure can also occur from some building materials if they are made from radon-containing substances by breathing. In this study, The radiation dose of radon concentration was detected at 8 buildings of the A university during 3-month from June. 2017 to August. 2017. We detected indoor radon exposure at 8 building of the university and estimated annual effective dose. The radon concentration of Hall G and Hall F of the A university represented 81 and 14 Bq/㎥ respectively and average indoor radon concentration represented 41.63 Bq/㎥. Average effective dose was estimated 0.40 mSv/y, maximum effective dose was 0.78 mSv/y and minimum effective dose was 0.13 mSv/y respectively. University is the place that students spend the almost whole time. We suggest ventilation and appropriate management of a building, which could reduce the natural radiation exposure by radon concentration.

Measurement of indoor radon gas concentration and assessment of health risk in Tehran, Iran

In recent years, technology development and using various tools have led to produce environmental contaminations. Radon (Rn-222), a natural radioactive gas, is one of the dangerous and fatal indoor air pollutants. Since radon is a major cause of lung cancer after smoking, in the present research, radon measurements have been done in 30 dwellings of Tehran using penetrative chambers. These measurements were done by passive method in a 3-month period. According to research achievements, the average radon concentration in Tehran is measured 104 Bq/m3. Maximum and minimum concentrations are 460.2 (Shahid Baqeri in west) and 31 Bq/m3 (Shahid Araqi in north), respectively. Risk assessment was done using Environmental Protection Agency method. Results showed that independent of age, the lung cancer death rates were about 14 and 12 times greater for ever smokers than never smokers among males and females, respectively. Moreover, it was concluded that females are more at risk than males. Generally, people who were older than 70 and also ever smokers are more at risk and must be followed up.

Study of the effect of electromagnetic fields on indoor and outdoor radon concentrations

In the present work, the effect of electromagnetic fields produced by high voltage power lines(132kV) and indoor equipments on the indoor and outdoor average radon concentrations in Al-Kazaliya and Hay Al-Adil regions in Baghdad city were studied using CR-39 track detectors and a gauss-meter.Results of measurements of the present study, have shown that the highest value for the indoor average radon concentration (76.56± 8.44 Bq / m3) was recorded for sample A1(Hay Al-Adel) at a distance of (20 m) from the high voltage power lines, while the lowest value for the indoor average radon concentration (30.46 ± 8.44 Bq / m3) was recorded for sample A3 (Hay Al-Adil) at a distance of (50 m) from the high voltage power lines. The indoor gaussmeter measurements were found to be ranged from (30.2 mG) to (38.5 mG). The higest value for outdoor average radon concentration and the highest gaussmeter measurements were found for sample (1), with values (92.63 ±11.2 Bq / m3) and (87.24 ± 2.85 mG), directly under the high voltage power lines respectively, while the lowest outdoor average radon concentration and the lowest gaussmeter measurements were found in sample (4),with values (34.19 ± 6.33 Bq / m3) and (1.16 ± 0.14 Bq / m3),), at a distance of (120 m) from the high voltage power lines respectively. The results of the present work have shown that there might be an influence of the electromagnetic field on radon concentrations in areas which were close to high voltage power lines and houses which have used many electric equipment for a long period of time.

UNCERTAINTY OF THE RESULTS OF THE RADON CONTROL IN HOUSINGS. PART 1. THE PROBLEM OF ASSESSMENT OF THE RADON CONCENTRATION AND MODERN CONTROL PRINCIPLES

Radon control in buildings is being performed for decades in different countries of the world, including Russia. However, there is a lack of unified standard for the assessment of the uncertainty of the results of the control, considering the protocol and duration of the measurements. It is obvious that the uncertainty of the control increases with the reduction of the duration of the measurements. The lack of data on confidence interval for the average annual radon concentration in housings does not allow correct and precise comparison with the regulatory level, both for the commissioned and operated buildings. Additionally, it complicates a development of the effective method, mass control strategy and identification of buildings with high radon concertations. A reliable method of control, considering time variations of radon and duration of exposure, was developed in Russia several years ago, but it is not well-known and not applied on practice. This paper is focused on a novel principle of radon control, based on simple criteria, widely used in metrology and complying to the modern standards. This principle introduces a new parameter – the radon time variation coefficient KV(t), which reflects main constituent of the uncertainty of the average annual radon concentration depending on the protocol and duration of the measurements. A novel algorithm for the estimation of KV(t) is proposed, developed on the base of the results of continuous annual radon monitoring in representative experimental housings. Additionally, the structure of the correcting coefficient is presented, considering an impact of the temperature on the radon behavior. The use of the corrective coefficient allows lowering the KV(t)value, but its application is limited.

Radon Levels in Indoor Environments of the University Hospital in Bari-Apulia Region Southern Italy.

Since 1988, the International Agency for Research on Cancer (IARC) has classified radon among the compounds for which there is scientific evidence of carcinogenicity for humans (group 1). The World Health Organization (WHO) recommends a reference radon level between 100 and 300 Bq/m3 for homes. The objective of this study is to measure the radon concentrations in 401 workplaces, different from the patient rooms, in 28 different buildings of the university hospital in Bari (Apulia region, Southern Italy) to evaluate the exposure of health care workers. Radon environmental sampling is performed over two consecutive six-month periods via the use of passive dosimeters of the CR-39 type. We find an average annual radon concentration expressed as median value of 48.0 Bq/m3 (range 6.5–388.0 Bq/m3) with a significant difference between the two six-month periods (median value: February/July 41.0 Bq/m3 vs. August/January 55.0 Bq/m3). An average concentration of radon lower than the WHO reference level (100 Bq/m3) is detected in 76.1% of monitored environments, while higher than 300 Bq/m3 only in the 0.9%. Most workplaces report radon concentrations within the WHO reference level, therefore, the risk to workers’ health deriving from occupational exposure to radon can be considered to be low. Nevertheless, the goal is to achieve near-zero exposures to protect workers’ health.

Radon in the groundwater in the Amman-Zarqa Basin and related environments in Jordan

The occurrence of radon (222Rn) in environment (groundwater and indoor air) from geogenic sources is receiving an growing attention due to its adverse impact on human health worldwide including Jordan. Highlighting the current status of radon in Jordan, the present study of radon concentrations in ground waters in the Amman-Zarqa basin (AZB) was investigated. Groundwater samples were collected from fifteen wells located in three main areas of Ras Al-Ain, Al-Rsaifeh and Al-Hashemite. Radon concentration was measure using Liquid scintillation counting (LSC) Tri- Carb 3110 with discriminator and the highest values for radon concentration in water were observed in Al-Rsaifeh area and ranged from 4.52 up to 30.70 Bq/l with an average of 11.22 Bq/l, which were attributed to the decay of naturally distributed uranium in phosphate rock from Al-Rsaifeh mines. In Ras Al-Ain area, the radon concentration were noted ranged from 0.6 to 5.55 Bq/l with an average of 2.82 Bq/l, and also in Al-Hashemite area were ranged from 0.77 to 5.37 Bq/l with an average of 4.04 Bq/l. The overall average concentration of tested samples was 5.77 Bq/l and found within the acceptable international levels. Ground water samples of Ras Al-Ain area showed good quality as was tested of low salinity. It recorded the lowest average radon concentration of 2.82 Bq/l. Also, Radon indoor and building materials was reviewed. In conclusion, this study presented an urged need for developing national regulations and standards as well as awareness program concerning the radon status in Jordan.

Characterization of radon levels in soil and groundwater in the North Maladeta Fault area (Central Pyrenees) and their effects on indoor radon concentration in a thermal spa

Radon levels in the soil and groundwater in the North Maladeta Fault area (located in the Aran Valley sector, Central Pyrenees) are analysed from both geological and radiation protection perspectives. This area is characterized by the presence of two important normal faults: the North Maladeta fault (NMF) and the Tredós Fault (TF). Two primary aspects make this study interesting: (i) the NMF shows geomorphic evidence of neotectonic activity and (ii) the presence of a thermal spa, Banhs de Tredós, which exploits one of the several natural springs of the area and needs to be evaluated for radiation dosing from radon according to the European regulation on basic safety standards for protection against ionizing radiation. The average soil radon and thoron concentrations along a profile perpendicular to the two normal faults — 22 ± 3 kBq·m−3 and 34 ± 3 kBq·m−3, respectively — are not high and can be compared to the radionuclide content of the granitic rocks of the area, 25 ± 4 Bq·kg−1 for 226Ra and 38 ± 2 Bq·kg−1 for 224Ra. However, the hypothesis that the normal faults are still active is supported by the presence of anomalies in both the soil radon and thoron levels that are unlikely to be of local origin together with the presence of similar anomalies in CO2 fluxes and the fact that the highest groundwater radon values are located close to the normal faults. Additionally, groundwater 222Rn data have complemented the hydrochemistry data, enabling researchers to better distinguish between water pathways in the granitic and non-granitic aquifers. Indoor radon levels in the spa vary within a wide range, [7–1664] Bq·m−3 because the groundwater used in the treatment rooms is the primary source of radon in the air. Tap water radon levels inside the spa present an average value of 50 ± 8 kBq·m−3, which does not exceed the level stipulated by the Spanish Nuclear Safety Council (CSN) of 100 kBq·m−3 for water used for human consumption. This finding implies that even relatively low radon concentration values in water can constitute a relevant indoor radon source when the transfer from water to indoor air is efficient. The estimated effective dose range of values for a spa worker due to radon inhalation is [1–9] mSv·y−1. The use of annual averaged radon concentration values may significantly underestimate the dose in these situations; therefore, a detailed dynamic study must be performed by considering the time that the workers spend in the spa.

Estimate Level of Radon Concentration for Drinking Water in Some Regions of Baghdad City

In this study, the assessment of radon concentration in drinking water in some regions of Baghdad city in Iraq has been studied using CR-39 solid-state nuclear track detector technique. A total of 18 samples selected from 6 region (5 samples from each region) in Baghdad city have been placed in the dosimeters for 50 day. The average radon concentration was found to be 516.1 hbox { Bq/m}^{3} which is greater than the standard international limit (300 hbox { Bq/m}^{3}). The potential alpha energy concentration and annual effective dose have been calculated. A proportional relationship between the annual effective dose and radon concentration within the studied region has been certified.

Determination of Radon Concentration and Annual Effective Dose Inside Houses in Left Side of Mosul City During Winter

In this study, radon concentration, annual effective dose, potential alpha energy concentration (PAEC), and average of lung cancer per million persons from radon were measured using (closed can technique) containing CR-39 nuclear track detector. Measurements were carried during winter season inside twenty four hoses in eight locations in the left side of Mosul City. The average radon concentration ranged between (52.97±5.315 to 74.98±5.433) Bq.m-3 with an average value (62.36±7.518) Bq.m-3 which is much lower than the recommended by ICRP action level (200-600) Bq.m-3. The results showed that the potential alpha energy concentration ranged between (5.71×10-3±0.566 ×10-3 to 8.11×10-3 ±0.586 ×10-3) WLM with an average value (6.7×10-3±0.820×10-3) WLM, while the annual effective dose ranged between (1.34±0.134 to 1.89±0.137) mSvy-1 with an average value (1.57±0.189) mSvy-1. It is observed that this value less than the recommended levels (3-10) mSvy-1 reported by ICRP. The average lung cancer cases per year per million persons were found to be 28.3±3.404, there were no induction of existence of radon problems in this survey

Effect of Radon on oncological morbidity of the population: comparative analysis of some regions of Ukraine and France

<p><span lang="EN-US">Radon contributes about 50% to the total annual effective dose of human radioactive irradiation. This gas is the main radiological pollutant of ecosystems. The question of studying the effect of radon on increasing the risk of the incidence of lung cancer is relevant in the context of European sanitary and hygienic research. We give in this article a comparative description of the results of experimental studies of volumetric activity of radon inside the air of the first floors of residential premises in Corsica island (France) and town of Rivne (Ukraine). «Kodak-alpha» integrated solid-state track detectors were used in France for three measurement campaigns between 1990 and 1999 (152 measurements in residential buildings and 638 in the schools of the island). In Ukraine, we did research using the “Alfarad Plus” Express Radon meter from 2013 to 2017 (200 measurements in the apartments of the first floors of buildings). The regions studied are similar in several parameters, which affect the increase in the percentage of cancer diseases: geology of underlying soils, the structure of housing and building material, the number of people and incidence of lung cancer, smoking factor, etc. We found that the volume activity (VA) of radon in indoor air in-house compared regions have close in value. The main reason is the similarity of the underlying granites in terms of radon emanation power. The average geometric value of radon VA in living quarters for various measurement campaigns in Corsica is in the range from 81 to 152 Bq/m<sup>3</sup> (the average of them is 134 Bq/m<sup>3</sup>). This value for Rivne is 127 Bq/m<sup>3</sup>. VA of radon in residential areas of Rivne have a lognormal distribution. Building norms for equivalent equilibrium volumetric activity (EEVA) of radon in the premises of Rivne are exceeded in 6.6% of buildings, Corsica - from 6 to 10% (this depends on the measurement campaign). Here, the average concentration of radon in housing is over 400 Bq/m<sup>3</sup>. We calculated the relative risk of lung cancer incidence due to radon for the population of the studied regions. The Jacobi and BEIR-VI models were used for Rivne for 70 years of exposure, and the BEIR-VI model was taken for Corsica for 110 years of exposure. The proportion of deaths from lung cancer is in Corsica from 30 to 48%, while for Rivne - about 50%. Consequently, the percentages of deaths from lung cancer caused by radon with an average value of VA in housing 134 Bq/m<sup>3</sup>, for men and women Corsica are 21.3% and 22.6% respectively (21.5% for the entire population) of the total number of deaths from this disease. In the quantitative form it is 33 people (men - 28, women - 5) out of 155 people died for a year from lung cancer. For residents of Rivne, the percentage of deaths from lung cancer is 25.1%, average value of VA in housing is 127 Bq/m<sup>3</sup>. 53 people die on average for a year from lung cancer caused by radon (men - 47, women - 6) of 214 deaths per year lung cancer lot. A preliminary assessment of the synergistic interaction between smoking and radon showed that there could be a 50% increase in morbidity due to radon for smokers, compared to non-smokers. However, these data are not sufficiently representative and therefore further research is needed.</span><span lang="EN-US">Rivne; Corsica; living rooms; volumetric activity of radon; lung cancer</span></p>

Estimation of residential radon exposure and definition of Radon Priority Areas based on expected lung cancer incidence

Radon is a naturally occurring gas, classified as a Class 1 human carcinogen, being the second most significant cause of lung cancer after tobacco smoking. A robust spatial definition of radon distribution in the built environment is therefore essential for understanding the relationship between radon exposure and its adverse health effects on the general population. Using Ireland as a case study, we present a methodology to estimate an average indoor radon concentration and calculate the expected radon-related lung cancer incidence. We use this approach to define Radon Priority Areas at the administrative level of Electoral Divisions (EDs).Geostatistical methods were applied to a data set of almost 32,000 indoor radon measurements, sampled in Ireland between 1992 and 2013. Average indoor radon concentrations by ED range from 21 to 338 Bq m−3, corresponding to an effective dose ranging from 0.8 to 13.3 mSv y−1 respectively. Radon-related lung cancer incidence by ED was calculated using a dose-effect model giving between 15 and 239 cases per million people per year, depending on the ED. Based on these calculations, together with the population density, we estimate that of the approximately 2,300 lung cancer cases currently diagnosed in Ireland annually, about 280 may be directly linked to radon exposure. This figure does not account for the synergistic effect of radon exposure with other factors (e.g. tobacco smoking), so likely represents a minimum estimate. Our approach spatially defines areas with the expected highest incidence of radon-related lung cancer, even though indoor radon concentrations for these areas may be moderate or low. We therefore recommend that both indoor radon concentration and population density by small area are considered when establishing national radon action plans.

Significant reduction in indoor radon in newly built houses

Results from two national surveys of radon in newly built homes in Norway, performed in 2008 and 2016, were used in this study to investigate the effect of the 2010 building regulations introducing limit values on radon and requirements for radon prevention measures upon construction of new buildings.In both surveys, homes were randomly selected from the National Building Registry. The overall result was a considerable reduction of radon concentrations after the implementation of new regulations, but the results varied between the different dwelling categories. A statistically significant reduction was found for detached houses where the average radon concentration was almost halved from 76 to 40 Bq/m3. The fraction of detached houses which had at least one frequently occupied room with a radon concentration above the Action Level (100 Bq/m3) fell from 23.9% to 6.4%, while the fraction above the Upper Limit Value (200 Bq/m3) was reduced from 7.6% to 2.5%. In 2008 the average radon concentration measured in terraced and semi-detached houses was 44 and in 2016 it was 29 Bq/m3, but the reduction was not statistically significant. For multifamily houses, it was not possible to draw a conclusion due to insufficient number of measurements.

A study of indoor radon, thoron and their exhalation rates in the environment of Fazilka district, Punjab, India

Over the last few decades, the study of radioactive radon gas has gained huge momentum due to its possible role in health related hazards. In the present work, pin-hole twin chamber single entrance dosimeters have been used for track measurements of radon and thoron. The annual average radon concentration varies from 50.3 to 204 Bq/m3 at all locations. Almost all the values are below the safe range provided by ICRP. Radon concentration is found to be higher in winter as compared to other seasons. Variation of radon with quality of dwellings is also discussed. The values of annual effective dose due to radon and thoron are also well within the range provided by ICRP and WHO. Radon and thoron exhalation rates are measured using SMART RnDuo monitor. The radon mass exhalation rates ranged from 11 to 71 mBq/kg/h while the thoron surface values ranged from 36 to 2048 Bq/m2/h. All the values are on the lower side. A weak correlation is found between radon and thoron concentrations and their exhalation rates. When compared with the values of other parts of northern India, the values of present investigation are on higher side.

Indoor radon regulation using tabulated values of temporal radon variation

Mass measurements of indoor radon concentrations have been conducted for about 30 years. In most of the countries, a national reference/action/limit level is adopted, limiting the annual average indoor radon (AAIR) concentration. However, until now, there is no single and generally accepted international protocol for determining the AAIR with a known confidence interval, based on measurements of different durations. Obviously, as the duration of measurements increases, the uncertainty of the AAIR estimation decreases. The lack of the information about the confidence interval of the determined AAIR level does not allow correct comparison with the radon reference level. This greatly complicates development of an effective indoor radon measurement protocol and strategy.The paper proposes a general principle of indoor radon regulation, based on the simple criteria widely used in metrology, and introduces a new parameter – coefficient of temporal radon variation KV(t) that depends on the measurement duration and determines the uncertainty of the AAIR. An algorithm for determining KV(t) based on the results of annual continuous radon monitoring in experimental rooms is proposed. Included are indoor radon activity concentrations and equilibrium equivalent concentration (EEC) of radon progeny. The monitoring was conducted in 10 selected experimental rooms located in 7 buildings, mainly in the Moscow region (Russia), from 2006 to 2013. The experimental and tabulated values of KV(t) and also the values of the coefficient of temporal EEC variation depending on the mode and duration of the measurements were obtained. The recommendations to improve the efficiency and reliability of indoor radon regulation are given. The importance of taking into account the geological factors is discussed. The representativity of the results of the study is estimated and the approach for their verification is proposed.

Studies on ambient gamma dose rate and enrichment of radon, thoron, and progeny concentration in various types of dwellings and outdoor environments of Kalliasseri, Kannur district, Kerala

The major contribution of natural background radiation exposure comes from radon, thoron, and their progeny. The activity concentration of these radionuclides depends on various factors, and the concentration level varies from place to place. The indoor concentration in dwellings depends mainly on the materials used for building construction and ventilation patterns. In the present study, an attempt is made to estimate the indoor and outdoor radon, thoron, and their progeny concentration in various types of dwellings and outdoor environments of Kalliasseri Panchayat, Kannur district, Kerala. 222Rn and 220Rn measurements were carried out using LR-115 type II-based pinhole cup dosimeters. Indoor and outdoor gamma exposure rate measurements were also carried out in all the dwellings using scintillation-based microradiation survey meter. The average concentrations of radon and thoron were estimated in about 40 dwellings categorized according to the construction type. The seasonal variation in the enrichment of radionuclides concentration has also been studied. The respective radon and thoron progeny levels were also estimated. The average radon concentration from the present study was well within the action level (200 Bq/m3) recommended by the International Commission of Radiological Protection (ICRP). The annual effective doses due to indoor radon and thoron were within the action level 3–10 mSv/y as suggested by the ICRP.

Study on Radon and Thoron Levels in and Around Different Industries of Tumkur and Bangalore Districts

Radon, Thoron and their progenies were estimated in and around the industrial area of Tumkur and Bangalore rural district by using Solid State Nuclear Track Detector (SSNTD) method. In this study the rice mills, paint industries, bio fuels, tyre recycling industries, granite industries, stone crushing industries, brick industries, oil seed industries, and garments are selected for indoor radon thoron measurements. The study shows that the concentration of radon and thoron are widely varies and also depends on the industrial activity and type of construction of industry. The study shows that the concentration of radon varies from 35.51 ± 1.31 to 245.36 ± 1.21 Bqm-3 with an average value of 115.31 Bqm-3 and thoron varies from 25.95 ± 2.36to 312.72 ± 1.58 Bqm-3 with an average value of 110.44 Bqm-3. The average radon concentrations are less than the lower limit of the action levels (200-300 Bqm-3) as recommended by ICRP. The corresponding progeny level of radon varies from 0.24 to 13 mWL and thoron progeny varies from 0.11 to 11 mWL. The annual effective doses received by the industrial workers are slightly lower than the recommended action level (3-10 mSvy-1).