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The study assesses environmental background radiation from radon, thoron, and thoron decay products across distinct geological settings in the Garhwal Himalaya region by using RADUET, CR-39 plastic track detectors, and deposition-based thoron (220Rn)progeny detectors. The measurements were conducted indoors throughout the winter, summer, and rainfall seasons during the year 2013. The annual inhalation doses from 220Rn progenies ranged between 0.83 and 2.99 mSv y−1, averaging 1.94 mSv y−1. The annual effective dose (AED), reflecting biological radiation impact, varied from 0.58 to 2.78 mSv y−1, with an average of 1.75 mSv y−1. [ABSTRACT FROM AUTHOR]

The measurements of radon concentrations in drinking water sources in and around the Main Central Thrust (MCT) region in Garhwal Himalaya, India, were carried out using the scintillation detector-based SMART RnDuo technique for radiation protection purposes. Radon values in the analyzed samples were observed between 1.1 and 183.9 Bq L−1 (AM = 19.7 Bq L−1). Radon values in 94% of the samples were found well below the World Health Organization (WHO) reference limit. The estimated radiation doses for different age groups were found higher than the WHO safe limit of 100 µSv y−1 (from all sources including radon) except for the age groups of 0–12 months infants and 1–3 years children. The results of this study may be useful for future studies on epidemiology, examining hidden faults, uranium exploration etc. [ABSTRACT FROM AUTHOR]

The present study focuses on measuring radon concentrations in soil gas at various depths, radon exhalation rate (surface and mass) from soil samples, and gamma dose rate along and across the Main Central Thrust of Garhwal Himalaya, India. Radon concentration in soil gas, surface, and mass exhalation rates was measured using a portable SMART radon monitor (RnDuo). Furthermore, the gamma dose rate was measured using a pocket radiation monitor. The soil gas radon concentration varied from 15 ± 4 to 579 ± 82 Bq m−3 at a depth of 25 cm, 10 ± 2 to 533 ± 75 Bq m−3 at a depth of 30 cm, and 9 ± 1 to 680 ± 95 Bq m−3 at a depth of 35 cm. The surface and mass exhalation rates were found 3 ± 0.7 to 98 ± 3 Bq m−2 h−1 (with AM ± SD = 36 ± 28 Bq m−2 h−1) and 1 ± 0.2 to 95 ± 2 mBq kg−1 h−1 (with AM ± SD = 30 ± 22 mBq kg−1 h−1), respectively. The gamma dose rate for the present study area varies from 0.11 ± 0.05 to 0.28 ± 0.05 µSv h−1 with a mean value of 0.17 ± 0.05 µSv h−1. The correlation analysis between the exhalation rates (mass and surface) and radon concentration of soil gas at various depths was carried out in the current study. [ABSTRACT FROM AUTHOR]

Background: Oral health is an integral component of pre-school health and well-being. Unfortunately, many children are afflicted with dental caries at an early age, even those as young as 12 months of age. The purpose of this study is to determine the association between Early Childhood Caries (ECC), Streptococcus mutans and genetic sensitivity levels to the bitter taste of, PROP among the children below 71 months of age. Materials and Methods: Total of 119 children belonging to the age group of 36 to 71 months of both sexes, were recruited from A. J. Institute of Dental Sciences, Mangalore (Karnataka). PROP sensitivity test was carried out to determine the inherent genetic ability to taste a bitter or sweet substance. One who tasted bitter as taster and one who was not able to differentiate/tasted like paper as non-tasters. Facial expression was observed during the tasting to support the verbal response. Estimation of S. mutans level and caries experience was recorded. The results were statistically analyzed using Mann'Whiteney-U Test and Kruskal value test. Results: In the total of 119 children, the mean DMFS was definitely higher in non.taster children compared to tasters and also had a high S. mutans level. Tasters had low ECC experience, low S. mutans level. The tasters had a mean DMFS value of 9.5120 (S.D. 7.0543) and non-tasters had a value of 7.7250 (S.D. 8.33147), which was statistically significant. Conclusion: Children who had higher level S. mutans had ECC and were non tasters. The PROP sensitivity test (filter paper test) proved to be a useful diagnostic tool in determining the genetic sensitivity levels of bitter taste. Age and low socio-economic status of pre-school children suggest a complex multifactorial relationship between S. mutans colonization, ECC and taste perception. [ABSTRACT FROM AUTHOR]

Abstract: The indoor radon concentration was estimated based on the radon flux in soil and groundwater. The indoor radon concentration in Budhakedar area of Garhwal Himalaya, India is estimated to be 3.0–131.4Bq/m3 in summer and 4.6–92.4Bq/m3 in winter. Based on the available data from study area, the calculated value of diffusion coefficient for the soil ranges from 0.1×10−2 to 3.0×10−2 cm2 s−1 in the summer season and 0.1×10−2 to 0.4×10−2 cm2 s−1 in the winter season. The calculated value of diffusion flux in the study area is found to vary from 0.1×10−2 to 16.1×10−2 Bqm−2 s−1 in summer season and 0.1×10−2–12.2×10−2 Bqm−2 s−1 in winter season. The formulation was tested by comparing the results of radon values from two different seasons of a year. [Copyright &y& Elsevier]

Abstract: The radon content in groundwater sources depends on the radium concentration in the rock of the aquifer. Radon was measured in water in many parts of the world, mostly for the risk assessment due to consumption of drinking water. The exposure to radon through drinking water is largely by inhalation and ingestion. Airborne radon can be released during normal household activities and can pose a greater potential health risk than radon ingested with water. Transport of radon through soil and bedrock by water depends mainly on the percolation of water through the pores and along fractured planes of bedrock. In this study, radon concentration in springs and hand pumps of Kumaun and Garhwal Himalaya, India was measured using radon emanometry technique. The study shows that radon concentration in springs and hand pumps is controlled by geohydrological characteristics, which in turn is also governed by tectonic processes. [Copyright &y& Elsevier]

Radon was measured in soil-gas and groundwater in the Budhakedar area of Tehri Garhwal, India and related to the gamma dose rate in the same area. A laboratory experiment was also performed to measure the radon exhalation rate from soil samples collected from the same area. Radon exhalation rate from collected soil samples was found to vary from 0.1×10-5 Bq·kg-1·h-1 to 5.7×10-5 Bq·kg-1·h-1 with an average of 1.5×10-5Bq·kg-1·h-1. Radon concentration in soil and groundwater of the Budhakedar area varies from 1098 to 31,776 Bq·m-3 with an average value of 7456 Bq·m-3, and from 8 to 3047 Bq·L-1 with an average value 510 Bq·L-1, respectively. Surface gamma dose rate in the study area varied from 32.4 to 83.6 μR·h-1 with an overall mean of 58.7 μR·h-1. The observed value of the gamma dose rate was not found to be related to the value of radon concentration in groundwater but a weak positive correlation was observed between the gamma dose rate and soil-gas radon concentration. A weak negative correlation was observed between radon exhalation rate from soil and radon concentration in the soil. Radon exhalation rate from the soil was also not found to be correlated with the gamma dose rate, while it shows a positive correlation with radon concentration in water. [ABSTRACT FROM AUTHOR]

Abstract: Ionizing radiation exposure experienced by the general population is mainly due to the indoor radon. Major part of radon comes from the top layer of the earth. The radon emanation is associated with radon in soil and sleepy back radium in the soil. Both field and laboratory measurements were carried out for the instantaneous and integrated radon concentration in soil-gas. The radon exhalation rate from collected soil samples was measured using LR-115 Type II plastic track detector. The soil-gas radon concentration was measured with the help of radon Emanometry method. The effective radium content of the soil samples was also calculated. The correlation coefficient between radium contents in collected soil samples and soil-gas radon from the same locations was calculated as 0.1, while it is 0.2 between radon exhalation rate and soil-gas radon concentration. The results show weak positive correlation due to the geological disturbance in the equilibrium conditions and high mobility of radon in the same geological medium. [Copyright &y& Elsevier]

Abstract: Environmental radiation exists as a consequence of cosmic, terrestrial and man made sources. Terrestrial radiation are emitted from natural radionuclide present in varying amounts in all types of soils, rocks, air, water and other environmental materials; radon is emitted from the soil surface, although secondary contributors include the oceans, natural gas, geothermal fluids, volcanic gases, ventilation from caves and mines, and combustion of coal. Radon and thoron levels were measured in soil-gas, ground water and indoor air in Budhakedar area of Tehri Garhwal, India. Radon concentrations in soil and groundwater of the Budhakedar area were found to vary from to with an average value and to with mean value , respectively. Measurement of indoor radon, thoron and their daughter products were also measured in the houses of the same area for four different seasons (autumn, winter, summer and rainy) using LR–115 plastic track detectors. The detector is fixed in a twin chamber radon dosimeter, which can record the values of radon, thoron and their decay products separately. The film fixed in bare mode holder gives the concentrations of radon, thoron and their progeny while the films fixed inside the cup with filter and membrane modes give the concentrations of radon/thoron gases and of pure radon gas, respectively. Detailed analysis of the effects of seasonal variation on radon, thoron and their decay products inside the houses are reported in this paper. [Copyright &y& Elsevier]

Abstract: Research on earthquake-related radon monitoring has received enormous attention recently. Anomalous behaviour of radon in soil and groundwater can be used as a reliable precursor for an impending earthquake. While earthquake prediction may not yet be possible, earthquake prediction research has greatly increased our understanding of earthquake source mechanisms, the structural complexities of fault zones, and the earthquake recurrence interval, expected at a given location. This paper presents some results of continuous monitoring of radon in soil-gas in Garhwal Himalaya, India. Daily soil-gas radon monitoring with seismic activity and meteorological parameters were performed in the same laboratory system, located at H.N.B. Garhwal University Campus, Tehri Garhwal, India. Radon anomalies along with meteorological parameters were found to be statistically significant for the seismic events within the magnitudes M2.0-M6.0 and epicentral distances of 16–250km from the monitoring station. The frequent positive and negative anomalies with constant environmental perturbation indicate the opening and closing of micro cracks within the volume of dilatancy by strain energy. The spike-like and sharp peak anomalies were recorded before, during and after earthquakes occurred in the area. The variations in radon concentrations in soil-gas are found to be correlated with seismic activities in the Garhwal Himalaya. The correlation between radon level and meteorological parameters is also discussed. [Copyright &y& Elsevier]

Abstract: Radon concentrations in groundwater and soil–gas along with the terrestrial gamma radiation dose rate have been measured in the different geological formation of Kumaon Himalaya, India. Radon concentrations were found to vary from 1 to 392Bq/l with a mean of 50Bq/l in water and to with a mean value of 5.867kBq/m3 in soil–gas. The radium content in collected groundwater samples from the study area was found to vary from 0.11 to 0.75Bq/l with a mean value 0.35Bq/l. The terrestrial gamma radiation dose rate and uranium content in soil were found to vary from 21.67 to with a mean value of and 0.8 to 15.3ppm with a mean value 3.4ppm, respectively, in different lithotectonic units. The emanation of radon in groundwater and soil–gas are found to be controlled by the geological formation of the area. It was also found to be controlled by the tectonic structure of the area. Radon level was found higher in the area consisting of granite, quartz porphyry, schist, phyllites slates and lowest in the area having sedimentary rocks, predominantly dominated by quartzite rocks. The terrestrial gamma radiation dose rate in the area was found positively correlated with radon concentrations in groundwater and soil–gas. A strong positive correlation was observed between uranium content in soil and terrestrial gamma radiation dose rate. Soil–gas radon concentration was also found positively correlated with the uranium content in the soil. However, a weak correlation was found between uranium content in soil and radon concentrations in groundwater samples from the study area. No correlation was observed between radon concentrations in groundwater and soil–gas. [Copyright &y& Elsevier]

The exposure of human beings to ionising radiation from natural sources is a continuing and inescapable feature of life on earth. Natural radionuclides are widely distributed in various geological formations and ecosystems such as rocks, soil groundwater and foodstuffs. In the present study, the distribution of (226)Ra, (232)Th and (40)K was measured in soil samples collected from different lithological units of the Thauldhar and Budhakedar regions of Garhwal Himalaya, India. The collected soil samples were analysed using gamma ray spectrometry. The activity concentrations of the naturally occurring radionuclides (226)Ra, (232)Th and (40)K in these soil samples were found to vary from below detection level (BDL) to 131 +/- 18 Bq kg(-1), 9 +/- 6 to 384 +/- 53 Bq kg(-1) and 471 +/- 96 to 1406 +/- 175 Bq kg(-1), respectively. The distribution of radionuclides depends upon the rock formation and chemical properties within the earth. The activity concentrations vary widely depending on the sample origin. The external absorbed gamma dose rates due to (226)Ra, (232)Th and (40)K were found to vary from 49 to 306 nGy h(-1). The average radium equivalent activity from these soil samples was 300 Bq kg(-1).