The Experts below are selected from a list of 16965 Experts worldwide ranked by ideXlab platform
Rosaline Mishra - One of the best experts on this subject based on the ideXlab platform.
-
Simultaneous measurements of radon, thoron and their progeny for Inhalation Dose assessment in indoors of Srinagar, J&K, India
Journal of Radioanalytical and Nuclear Chemistry, 2020Co-Authors: Salik Nazir, Rosaline Mishra, Shakeel Simnani, Tanu Sharma, Sajad MasoodAbstract:A variety of toxins are known to affect indoor air quality, thereby affecting the health of the inhabitants of that region. One such natural contaminant is radon, which is a dense, colourless, odourless and inert gas. As per BEIR-VI report (Chauhan and Chauhan in J Environ Radioact, 2015. https://doi.org/10.1016/j.jenvrad.2015.03.009 ), Radon alone contributes to more than 50% of the total natural background radiation and is the second leading element causing lung cancer after smoking. Therefore, its quantification is vital to assess any risk to human health. In order to assess health risks, a recently developed LR-115 detector based technique was employed for time-integrated passive measurements of radon, thoron and their progeny concentrations. The annual average radon concentration was found to be 35.6 Bq m^−3 and thus lies well below the global average of 40 Bq m^−3. However, thoron concentration exceeded the global average value of 10 Bq m^−3.
-
EFFECT OF AIR VELOCITY ON Inhalation DoseS DUE TO RADON AND THORON PROGENY IN A TEST CHAMBER.
Radiation protection dosimetry, 2020Co-Authors: Rosaline Mishra, R.p. Rout, R. Prajith, Jalaluddin Sriamirullah, Balwinder Kaur SapraAbstract:Inhalation Doses due to radon and thoron are predominantly due to the Inhalation of progeny of Radon and Thoron. The progeny/decay-products of radon and thoron are particulates unlike their parent gas and exhibit different physical properties like attachment to the aerosols and deposition on different surfaces. All these properties in turn depend on the environmental conditions such as air velocity, aerosol concentration, attachment rate, etc. The role of air velocity on deposition on surfaces decides the progeny particles left in the air for Inhalation. Therefore, in the present work, we have studied the effect of air velocity on the Inhalation Dose due to radon and thoron progeny at the centre of a 0.5-m3 calibration chamber as well as on all surfaces. Hence, the studies were carried out at different air velocities, and Inhalation Doses were measured using deposition-based direct radon and thoron progeny sensors.
-
Inhalation Dose and Source Term Studies in a Tribal Area of Wayanad, Kerala, India.
Journal of environmental and public health, 2017Co-Authors: Reshma Bhaskaran, Ravikumar C. Damodaran, Visnuprasad Ashok Kumar, Jojo Panakal John, Danalakshmi Bangaru, Chitra Natarajan, Bala Sundar Sathiamurthy, Jose Mundiyanikal Thomas, Rosaline MishraAbstract:Among radiation exposure pathways to human beings, Inhalation Dose is the most prominent one. Radon, thoron, and their progeny contribute more than 50 per cent to the annual effective Dose due to natural radioactivity. South west coast of India is classified as a High Natural Background Radioactivity Area and large scale data on natural radioactivity and dosimetry are available from these coastal regions including the Neendakara-Chavara belt in the south of Kerala. However, similar studies and reports from the northern part of Kerala are scarce. The present study involves the data collection and analysis of radon, thoron, and progeny concentration in the Wayanad district of Kerala. The radon concentration was found to be within a range of 12–378 Bq/m3. The thoron concentration varied from 15 to 621 Bq/m3. Progeny concentration of radon and thoron and the diurnal variation of radon were also studied. In order to assess source term, wall and floor exhalation studies have been done for the houses showing elevated concentration of radon and thoron. The average values of radon, thoron, and their progeny are found to be above the Indian average as well as the average values reported from the High Natural Background Radioactivity Areas of Kerala. Exhalation studies of the soil samples collected from the vicinity of the houses show that radon mass exhalation rate varied from below detectable limit (BDL) to a maximum of 80 mBq/kg/h. The thoron surface exhalation rate ranged from BDL to 17470 Bq/m2/h.
-
Radon and thoron Inhalation Doses in dwellings with earthen architecture: Comparison of measurement methods.
The Science of the total environment, 2016Co-Authors: Oliver Meisenberg, Rosaline Mishra, S.d. Kanse, T.k. Agarwal, Manish Joshi, R.p. Rout, Stefanie Gierl, Lu Guo, Josef Irlinger, B.k. SapraAbstract:The radioactive noble gas radon (222Rn) and its decay products have been considered a health risk in the indoor environment for many years because of their contribution to the radiation Dose of the lungs. The radioisotope thoron (220Rn) and its decay products came into focus of being a health risk only recently. The reason for this is its short half-life, so only building material can become a significant source for indoor thoron. In this study, dwellings with earthen architecture were investigated with different independent measurement techniques in order to determine appropriate methods for reliable Dose assessment of the dwellers. While for radon Dose assessment, radon gas measurement and the assumption of a common indoor equilibrium factor often are sufficient, thoron gas has proven to be an unreliable surrogate for a direct measurement of thoron decay products. Active/time-resolved but also passive/integrating measurements of the total concentration of thoron decay products demonstrated being precise and efficient methods for determining the exposure and Inhalation Dose from thoron and its decay products. Exhalation rate measurements are a useful method for a rough Dose estimate only if the exhalation rate is homogeneous throughout the house. Before the construction of a building in-vitro exhalation rate measurements on the building material can yield information about the exposure that is to be expected. Determining the unattached fraction of radon decay products and even more of thoron decay products leads to only a slightly better precision; this confirms the relative unimportance of the unattached thoron decay products due to their low concentration. The results of this study thereby give advice on the proper measurement method in similar exposure situations.
-
Probing the application of Fourier Transform Infrared (FTIR) spectroscopy for assessment of deposited flux of Radon and Thoron progeny in high exposure conditions
Nuclear Instruments and Methods in Physics Research Section A: Accelerators Spectrometers Detectors and Associated Equipment, 2016Co-Authors: Rosaline Mishra, B.k. Sapra, R.p. Rout, R. PrajithAbstract:Abstract Direct measurement of Radon and Thoron progeny in the atmosphere and occupational environments such as Uranium mines, Uranium and Thorium handling facilities has gained importance because of its radiological significance in Inhalation Dose assessment. In this regard, Radon and Thoron Progeny sensors (DTPS and DRPS) are the only passive solid state nuclear track detector (SSNTD, LR115) based devices which are being extensively used for time integrated direct progeny measurements. An essential component of the analysis is the chemical etching of the detectors, followed by spark counting of tracks and then estimation of the Inhalation Dose using appropriate calibration factors. Alternatively, the tracks may be counted using image analysis techniques. However, under high exposure conditions, both these methods have inherent limitations and errors arising due to increased frequency of tracks. In the present work, we probe the use of Fourier Transform Infra Red (FTIR) spectroscopy to analyse the deposited fluence of the progeny particulates based on change in transmittance of the nitric group vibrational bands of the LR115. A linear relationship between the transmittance and the deposited fluence was observed, which can be used to estimate the deposited fluence rate and the Inhalation Dose. This alternative method of analysis will provide a faster and non-destructive technique for Inhalation Dose assessment, specially for routine large scale measurements.
B. K. Sahoo - One of the best experts on this subject based on the ideXlab platform.
-
A novel method based on 220Rn (thoron) exhalation rate of indoor surfaces for robust estimates of 220Rn concentration and equilibrium factor to compute Inhalation Dose.
Chemosphere, 2020Co-Authors: S.d. Kanse, B. K. Sahoo, J.j. Gaware, B.k. SapraAbstract:Abstract The research into 220Rn (thoron) has generated an increasing interest in recent times due to the realisation of its radiological importance in many indoor environments. Though it is assumed that the contribution of 220Rn, per se, to the Inhalation Dose is negligible in comparison with that of its decay products, this may not be always true. Correct estimation of Inhalation Dose due to thoron requires a reliable method to measure the concentration of both 220Rn and its decay products in indoor air. However, due to its very short half-life (55.6 s) 220Rn shows large variation in its indoor activity concentration. This makes it difficult to have a robust value of 220Rn concentration which can be considered representative of a house, thus making the Dose estimation unreliable. This issue has been addressed in the present study by developing a novel method that utilises the 220Rn exhalation rate from indoor surfaces as the basis for estimation of average 220Rn concentration in indoor air. The 220Rn concentration estimated in this manner can be converted to decay products concentration using a suitable equilibrium factor and finally the Inhalation Dose using appropriate Dose conversion factors. A wall mounting accumulator setup has been developed for easy in-situ measurement of 220Rn exhalation from room surfaces. The method has been validated through comprehensive measurements in 25 dwellings in two different regions of India. The developed method is very good for large scale field surveys because of fast and easy applicability.
-
Measurements of ^222Rn, ^220Rn and their progeny concentrations indoors around a coal/gas-based power plant and estimation of annual Inhalation Dose to the public
Journal of Radioanalytical and Nuclear Chemistry, 2020Co-Authors: Mukesh Kumar, Anshu Agrawal, Pankaj Kumar, B. K. SahooAbstract:In the present study, indoor radon (^222Rn), thoron (^220Rn), radon progeny (^214Po) and thoron progeny (^212Po) activity concentration have been measured in a region around the National Capital Power Station, Dadri, Uttar Pradesh, India. The mean values of the ^222Rn, ^220Rn and their progeny in the studied region are found to be 22.1 ± 10.0 Bqm^−3, 48.6 ± 13.5 Bqm^−3, 8.8 ± 4.8 Bqm^−3 and 0.49 ± 0.15Bqm^−3 respectively. The annual Inhalation Dose estimated from the observed concentrations varies from 0.29 ± 0.04 to 2.06 ± 0.121 mSv with a mean value of 0.75 ± 0.32 mSv and is well within the reference level. It has also been observed that ^212Po is a significant contributor (= 18.7%) to the total annual Inhalation Dose. Seasonal variations of ^222Rn, ^220Rn, and their progeny have also been reported.
-
A study on seasonal variability of ^222Rn–^220Rn parameters in dwellings around a thermal power plant, India
Journal of Radioanalytical and Nuclear Chemistry, 2017Co-Authors: Mukesh Kumar, Anshu Agrawal, Pankaj Kumar, Rajesh Kumar, B. K. SahooAbstract:The present study utilizes the latest solid state nuclear track detectors based single entrance radon-thoron twin chambers, direct radon/thoron progeny sensors to measure indoor radon, thoron, and their progenies. From the measured values of radon, thoron and their progenies concentrations, radon and thoron equilibrium factors and annual effective Inhalation Dose have been estimated. The mean values of equilibrium factor for radon and thoron in studied dwellings have been found to be 0.52 ± 0.19 and 0.013 ± 0.006 respectively. The mean value of annual effective Dose is estimated as 1.02 ± 0.41 mSv. Seasonal and different types of house wise variations of radon, thoron and their progenies are discussed in detail.
-
CONTRIBUTION OF THORON AND PROGENY TOWARDS Inhalation Dose IN A THORIUM ABUNDANT BEACH ENVIRONMENT.
Radiation protection dosimetry, 2017Co-Authors: A. K. Visnuprasad, B. K. Sahoo, G Jaikrishnan, Christa E. Pereira, P. J. JojoAbstract:In an environment having thorium rich soil the activity concentration of thoron in soil gas and ground-level outside air is comparable to that to radon. Recent reports indicate that in terms of the energy of the alpha particle decays of thoron's progeny, its concentration in indoor air is significant, typically about half that due to radon progeny. We made a detailed radiometric profiling of Inhalation Dose to the population of the high background radiation area in the west southern coastal region of India. Here we report the results obtained from the long-term time integrated passive measurements of radon, thoron and their progeny concentrations in the high background radiation areas of Chavara and Neendakara hamlets of Kollam district. The equilibrium factors of radon and thoron with their progeny were determined for the region and was consistent with a previous study. The estimated value of total annual Inhalation Dose in the region ranged from 0.4 ± 0.06 to 3.7 ± 0.6 mSv y-1. The annual effective Dose due to thoron and thoron progeny contributes ~35% to the total Inhalation Dose which means that thoron and its progeny is significant in assessing the radiation Dose to the public.
-
a follow up study on indoor 222rn 220rn their decay product concentrations in a mineralised zone of himachal pradesh india
Radiation Protection Dosimetry, 2016Co-Authors: B S Bajwa, B. K. Sahoo, Parminder Singh, Prabhjot Singh, Komal Saini, Surinder Singh, B.k. SapraAbstract:A follow-up study was taken up in a mineralised zone situated in Hamirpur district, Himachal Pradesh, India, to investigate high values of radon concentrations reported in past studies as well to update the old radon data based on bare SSNTD technique. In the present investigation, the concentrations of indoor radon, thoron and their decay products have been measured using the newly developed radon/thoron discriminating diffusion chamber with single entry face, direct radon and thoron progeny sensors (DRPS/DTPS), respectively. The measurements have been carried out in 75 dwellings of 14 different villages where the previous studies were carried out using bare SSNTD technique. It was observed that high values of earlier reported radon concentrations were mainly due to thoron interference in the Solid State Nuclear Track Detector (LR-115 type II) exposed in bare mode. Now, the average concentration values and the estimated annual Inhalation Dose in these villages have been found to be within the reference level as recommended by the ICRP. The annual average indoor radon and thoron concentrations observed in these dwellings have been found to vary from 44±12 to 157±73 Bq m(-3) and 44±11 to 240±125 Bq m(-3), respectively. The equilibrium equivalent concentrations of radon and thoron decay products have been observed to be in the range of 10 to 63 and 1 to 5 Bq m(-3), respectively.
Antti J. Koivisto - One of the best experts on this subject based on the ideXlab platform.
-
dip coating of air purifier ceramic honeycombs with photocatalytic tio2 nanoparticles a case study for occupational exposure
Science of The Total Environment, 2018Co-Authors: Antti J. Koivisto, Kirsten I. Kling, Ana Fonseca, Anders Brostrøm Bluhme, Marcel Moreman, Anna Luisa Costa, Baldi Giovanni, Simona Ortelli, Wouter Fransman, Ulla VogelAbstract:Nanoscale TiO2 (nTiO2) is manufactured in high volumes and is of potential concern in occupational health. Here, we measured workers exposure levels while ceramic honeycombs were dip coated with liquid photoactive nanoparticle suspension and dried with an air blade. The measured nTiO2 concentration levels were used to assess process specific emission rates using a convolution theorem and to calculate Inhalation Dose rates of deposited nTiO2 particles. Dip coating did not result in detectable release of particles but air blade drying released fine-sized TiO2 and nTiO2 particles. nTiO2 was found in pure nTiO2 agglomerates and as individual particles deposited onto background particles. Total particle emission rates were 420 × 109 min−1, 1.33 × 109 μm2 min−1, and 3.5 mg min−1 respirable mass. During a continued repeated process, the average exposure level was 2.5 × 104 cm−3, 30.3 μm2 cm−3, <116 μg m−3 for particulate matter. The TiO2 average exposure level was 4.2 μg m−3, which is well below the maximum recommended exposure limit of 300 μg m−3 for nTiO2 proposed by the US National Institute for Occupational Safety and Health. During an 8-hour exposure, the observed concentrations would result in a lung deposited surface area of 4.3 × 10−3 cm2 g−1 of lung tissue and 13 μg of TiO2 to the trachea-bronchi, and alveolar regions. The Dose levels were well below the one hundredth of the no observed effect level (NOEL1/100) of 0.11 cm2 g−1 for granular biodurable particles and a daily no significant risk Dose level of 44 μg day−1. These emission rates can be used in a mass flow model to predict the impact of process emissions on personal and environmental exposure levels
-
Dip coating of air purifier ceramic honeycombs with photocatalytic TiO2 nanoparticles: A case study for occupational exposure.
Science of The Total Environment, 2018Co-Authors: Antti J. Koivisto, Kirsten I. Kling, Ana Fonseca, Anders Brostrøm Bluhme, Marcel Moreman, Mingzhou Yu, Anna Luisa Costa, Baldi Giovanni, Simona Ortelli, Wouter FransmanAbstract:Nanoscale TiO2 (nTiO2) is manufactured in high volumes and is of potential concern in occupational health. Here, we measured workers exposure levels while ceramic honeycombs were dip coated with liquid photoactive nanoparticle suspension and dried with an air blade. The measured nTiO2 concentration levels were used to assess process specific emission rates using a convolution theorem and to calculate Inhalation Dose rates of deposited nTiO2 particles. Dip coating did not result in detectable release of particles but air blade drying released fine-sized TiO2 and nTiO2 particles. nTiO2 was found in pure nTiO2 agglomerates and as individual particles deposited onto background particles. Total particle emission rates were 420 × 109 min−1, 1.33 × 109 μm2 min−1, and 3.5 mg min−1 respirable mass. During a continued repeated process, the average exposure level was 2.5 × 104 cm−3, 30.3 μm2 cm−3,
-
Concept to estimate regional Inhalation Dose of industrially synthesized nanoparticles.
ACS nano, 2012Co-Authors: Antti J. Koivisto, Mikko Aromaa, Jyrki M. Mäkelä, Pertti Pasanen, Tareq Hussein, Kaarle HämeriAbstract:The use of nanoparticles (NPs) in industry is increasing rapidly, but knowledge of the occupational health and safety aspects of NPs is still limited. This is because quan- titative NP exposure levels are scarce, and the metrics to describe Doses are unclear. This study presents one method for estimating workers' calculated regional Inhalation Dose of deposited particles from size-fractionated concentrations. It was applied to estimate workers' regional Inhalation Doserates andDoses separatelyfor NPsand NPs with backgroundparticlesduringNP synthesis. Dose analysis was performed in units of particle number (particles and particles min � 1 ), active surface area (μm 2 and μm 2 min � 1 ), and mass (ng and ng min � 1 ) for three respiratory regions: head airways, tracheobronchial, and alveolar. It was found that in NP synthesis NPs weredepositedmainlyin the alveolar regioninall units.However,whenthe Dose ofallparticleswasexamined,itwasfoundthatDoseandthemaindepositionregionweremainly definedbythesynthesizedNPsforparticlenumber,asactivesurfaceareawasdescribedbyboth NPs and background particles, and mass by background particles. This study provides fundamental data for NP Inhalation exposure risk assessment, regulations, Dose metrics for NP synthesis, and a basis for defining metrics of Dosebiological response and helps us understand the magnitude of Doses in NP synthesis. It also illustrates the necessity to obtain size-fractionated measurements of NP concentrations to support accurate Dose estimation.
B.k. Sapra - One of the best experts on this subject based on the ideXlab platform.
-
A novel method based on 220Rn (thoron) exhalation rate of indoor surfaces for robust estimates of 220Rn concentration and equilibrium factor to compute Inhalation Dose.
Chemosphere, 2020Co-Authors: S.d. Kanse, B. K. Sahoo, J.j. Gaware, B.k. SapraAbstract:Abstract The research into 220Rn (thoron) has generated an increasing interest in recent times due to the realisation of its radiological importance in many indoor environments. Though it is assumed that the contribution of 220Rn, per se, to the Inhalation Dose is negligible in comparison with that of its decay products, this may not be always true. Correct estimation of Inhalation Dose due to thoron requires a reliable method to measure the concentration of both 220Rn and its decay products in indoor air. However, due to its very short half-life (55.6 s) 220Rn shows large variation in its indoor activity concentration. This makes it difficult to have a robust value of 220Rn concentration which can be considered representative of a house, thus making the Dose estimation unreliable. This issue has been addressed in the present study by developing a novel method that utilises the 220Rn exhalation rate from indoor surfaces as the basis for estimation of average 220Rn concentration in indoor air. The 220Rn concentration estimated in this manner can be converted to decay products concentration using a suitable equilibrium factor and finally the Inhalation Dose using appropriate Dose conversion factors. A wall mounting accumulator setup has been developed for easy in-situ measurement of 220Rn exhalation from room surfaces. The method has been validated through comprehensive measurements in 25 dwellings in two different regions of India. The developed method is very good for large scale field surveys because of fast and easy applicability.
-
Radon and thoron Inhalation Doses in dwellings with earthen architecture: Comparison of measurement methods.
The Science of the total environment, 2016Co-Authors: Oliver Meisenberg, Rosaline Mishra, S.d. Kanse, T.k. Agarwal, Manish Joshi, R.p. Rout, Stefanie Gierl, Lu Guo, Josef Irlinger, B.k. SapraAbstract:The radioactive noble gas radon (222Rn) and its decay products have been considered a health risk in the indoor environment for many years because of their contribution to the radiation Dose of the lungs. The radioisotope thoron (220Rn) and its decay products came into focus of being a health risk only recently. The reason for this is its short half-life, so only building material can become a significant source for indoor thoron. In this study, dwellings with earthen architecture were investigated with different independent measurement techniques in order to determine appropriate methods for reliable Dose assessment of the dwellers. While for radon Dose assessment, radon gas measurement and the assumption of a common indoor equilibrium factor often are sufficient, thoron gas has proven to be an unreliable surrogate for a direct measurement of thoron decay products. Active/time-resolved but also passive/integrating measurements of the total concentration of thoron decay products demonstrated being precise and efficient methods for determining the exposure and Inhalation Dose from thoron and its decay products. Exhalation rate measurements are a useful method for a rough Dose estimate only if the exhalation rate is homogeneous throughout the house. Before the construction of a building in-vitro exhalation rate measurements on the building material can yield information about the exposure that is to be expected. Determining the unattached fraction of radon decay products and even more of thoron decay products leads to only a slightly better precision; this confirms the relative unimportance of the unattached thoron decay products due to their low concentration. The results of this study thereby give advice on the proper measurement method in similar exposure situations.
-
a follow up study on indoor 222rn 220rn their decay product concentrations in a mineralised zone of himachal pradesh india
Radiation Protection Dosimetry, 2016Co-Authors: B S Bajwa, B. K. Sahoo, Parminder Singh, Prabhjot Singh, Komal Saini, Surinder Singh, B.k. SapraAbstract:A follow-up study was taken up in a mineralised zone situated in Hamirpur district, Himachal Pradesh, India, to investigate high values of radon concentrations reported in past studies as well to update the old radon data based on bare SSNTD technique. In the present investigation, the concentrations of indoor radon, thoron and their decay products have been measured using the newly developed radon/thoron discriminating diffusion chamber with single entry face, direct radon and thoron progeny sensors (DRPS/DTPS), respectively. The measurements have been carried out in 75 dwellings of 14 different villages where the previous studies were carried out using bare SSNTD technique. It was observed that high values of earlier reported radon concentrations were mainly due to thoron interference in the Solid State Nuclear Track Detector (LR-115 type II) exposed in bare mode. Now, the average concentration values and the estimated annual Inhalation Dose in these villages have been found to be within the reference level as recommended by the ICRP. The annual average indoor radon and thoron concentrations observed in these dwellings have been found to vary from 44±12 to 157±73 Bq m(-3) and 44±11 to 240±125 Bq m(-3), respectively. The equilibrium equivalent concentrations of radon and thoron decay products have been observed to be in the range of 10 to 63 and 1 to 5 Bq m(-3), respectively.
-
Probing the application of Fourier Transform Infrared (FTIR) spectroscopy for assessment of deposited flux of Radon and Thoron progeny in high exposure conditions
Nuclear Instruments and Methods in Physics Research Section A: Accelerators Spectrometers Detectors and Associated Equipment, 2016Co-Authors: Rosaline Mishra, B.k. Sapra, R.p. Rout, R. PrajithAbstract:Abstract Direct measurement of Radon and Thoron progeny in the atmosphere and occupational environments such as Uranium mines, Uranium and Thorium handling facilities has gained importance because of its radiological significance in Inhalation Dose assessment. In this regard, Radon and Thoron Progeny sensors (DTPS and DRPS) are the only passive solid state nuclear track detector (SSNTD, LR115) based devices which are being extensively used for time integrated direct progeny measurements. An essential component of the analysis is the chemical etching of the detectors, followed by spark counting of tracks and then estimation of the Inhalation Dose using appropriate calibration factors. Alternatively, the tracks may be counted using image analysis techniques. However, under high exposure conditions, both these methods have inherent limitations and errors arising due to increased frequency of tracks. In the present work, we probe the use of Fourier Transform Infra Red (FTIR) spectroscopy to analyse the deposited fluence of the progeny particulates based on change in transmittance of the nitric group vibrational bands of the LR115. A linear relationship between the transmittance and the deposited fluence was observed, which can be used to estimate the deposited fluence rate and the Inhalation Dose. This alternative method of analysis will provide a faster and non-destructive technique for Inhalation Dose assessment, specially for routine large scale measurements.
-
a study of indoor radon thoron and their progeny measurement in tosham region haryana india
Journal of Radiation Research and Applied Sciences, 2015Co-Authors: Prabhjot Singh, B. K. Sahoo, B.k. Sapra, Parminder Singh, Surinder Singh, B S BajwaAbstract:Abstract In the present study indoor radon, thoron and their decay products concentrations have been measured using the newly developed LR-115 type-ІІ based Radon-Thoron discriminating twin-cup dosimeters with single entry face, direct radon and thoron progeny sensors (DRPS/DTPS) respectively. The annual annihilation Dose has been assessed from measured radionuclide concentration to find out major contributor of lung cancer in the study area. The measurements have been carried out in NINETY dwellings of THIRTEEN different villages situated in and around the Tosham region. This region is known to be composed of acidic volcanic and associated granites. Dwellings were selected mainly targeting different type building material used in construction of houses like concrete–brick, mud-brick, and mud-thatches along with an idea of different ventilation conditions which affects the equilibrium factor (EF). The EF in this region has been varying from 0.20 to 0.72 and 0.03–0.13 for indoor radon and thoron respectively. The average Inhalation Dose observed in dwellings of different villages varies from 1.33 ± 0.31–3.36 ± 0.72 mSv/y that lies within the safe limits recommended by ICRP (2011).
R. C. Ramola - One of the best experts on this subject based on the ideXlab platform.
-
Indoor Inhalation Dose assessment for thoron-rich regions of Indian Himalayan belt.
Environmental science and pollution research international, 2018Co-Authors: Poonam Semwal, T.k. Agarwal, Kuldeep Singh, Manish Joshi, G. S. Gusain, Bijay Kumar Sahoo, R. C. RamolaAbstract:222Rn, 220Rn, and their decay products are significant contributors to background radiation Dose. Their concentration level, pertaining exposure, and consequent Dose are prime concerns in indoor environments. The present study was performed in 101 dwellings of different villages of Almora district situated in Kumaun hills of Indian Himalayan belt. Measurement of gases and decay products were made in three different types of dwellings (i.e., mud, cemented, and stone with plaster) in three seasons (winter, summer, and rainy). Concentration values for 222Rn and EERC were found to be varying in the order of winter > summer > rainy while obtained least in rainy season for the case of 220Rn and EETC. Concentration values for 222Rn and EERC were found to be lesser for cemented houses. Relative standard deviation of concentration values was found to be higher for the rainy season. Yearly averaged concentration values for 222Rn, EERC, 220Rn, and EETC were noted to be higher than the global averages but comparable to some Indian studies. Annual Inhalation Dose due to 222Rn, 220Rn, and their progeny was found to be 0.55–4.71 mSv/year with an average value of 2.36 ± 0.83 mSv/year. These values were measured for the first time in the study area and provide a link for future studies in the dwellings representing higher concentration values.
-
Dose estimation derived from the exposure to radon thoron and their progeny in the indoor environment
Scientific Reports, 2016Co-Authors: R. C. Ramola, Tushar Kandari, Mukesh Prasad, Peter Bossew, R Mishra, Preeti Pant, Shinji TokonamiAbstract:The annual exposure to indoor radon, thoron and their progeny imparts a major contribution to Inhalation Doses received by the public. In this study, we report results of time integrated passive measurements of indoor radon, thoron and their progeny concentrations that were carried out in Garhwal Himalaya with the aim of investigating significant health risk to the dwellers in the region. The measurements were performed using recently developed LR-115 detector based techniques. The experimentally determined values of radon, thoron and their progeny concentrations were used to estimate total annual Inhalation Dose and annual effective Doses. The equilibrium factors for radon and thoron were also determined from the observed data. The estimated value of total annual Inhalation Dose was found to be 1.8 ± 0.7 mSv/y. The estimated values of the annual effective Dose were found to be 1.2 ± 0.5 mSv/y and 0.5 ± 0.3 mSv/y, respectively. The estimated values of radiation Doses suggest no important health risk due to exposure of radon, thoron and progeny in the study area. The contribution of indoor thoron and its progeny to total Inhalation Dose ranges between 13–52% with mean value of 30%. Thus thoron cannot be neglected when assessing radiation Doses.
-
estimation of annual effective Dose from radon concentration along main boundary thrust mbt in garhwal himalaya
Journal of Radiation Research and Applied Sciences, 2016Co-Authors: Tushar Kandari, Sunita Aswal, A A Bourai, Mukesh Prasad, R. C. RamolaAbstract:Abstract Indoor radon and thoron concentration plays a vital role in the total effective Dose in the indoor environments. In the present study, the measurement of indoor radon, soil gas radon concentration and the drinking water radon concentration was carried out in Rajpur area of Dehradun valley located near by the geological fault line named Main Boundary Thrust (MBT). The measurement was carried out using RAD-7, a solid state detector with its special accessory. The indoor radon concentration varies from 35 to 150 Bqm −3 with an average value of 85 Bqm −3 . The soil-gas radon concentration varies from 2 to 12.3 kBqm −3 with an average value of 6.5 kBqm −3 . Radon concentration in water samples varies from 1.7 to 57.7 kBqm −3 with an average value of 20 kBqm −3 . These results are helpful for estimation of annual effective Dose, ingestion Dose and Inhalation Doses. The annual effective Dose varies from 0.88 to 3.78 mSvy −1 with an average value of 2.13 mSvy −1 . The annual ingestion Dose due to drinking water was found to vary from 0.36 to 7.91 mSvy −1 with an average value of 3.92 mSvy −1 . The annual Inhalation Dose was found to vary from 0.0042 to 0.1454 mSvy −1 with an average of 0.0504 mSvy −1 .