Natural Radionuclides 226Ra Research Articles

Radiological impact assessment in the terrestrial environment of Greece using innovative tools – Adaptation of ERICA Tool to actual measurements

In the present study, the radioactivity levels in terrestrial non-human biota and the transfer pathways in the ecosystem are examined. Grass of Poaceae family and herbivore mammals (ruminants) of Bovidae family and soil samples were collected during the period of 2010 to 2014, from grasslands of the Greek rural territory where sheep and goats were free-range grazing. Natural background radionuclides (226Ra, 228Ra, 228Th) and artificial radionuclides (137Cs, 134Cs, 131I) were detected in the collected samples using gamma spectrometry. The actual measured activity concentrations and site- specific data of the studied organisms were imported in ERICA Assessment Tool (Version 1.2.1, February 2016) in order to provide an insight of the radiological dose rates. Natural radionuclides exhibited significantly higher contribution to the total dose rate than the artificial ones. The radiological exposure to Fukushima-derived radionuclides was quite low and owed to internal exposure, mainly derived through the ingestion pathway. According to the screening levels, the calculated dose rate to the studied non-human biota was below the threshold levels. However, the obtained results may be proved useful in further research regarding the possible impact of protracted low level ionising radiation to non-human biota on the various levels of life’s organization.

Determination of radionuclides in soil samples taken from Gura Topp (Jos) using sodium iodide thallium detector Nai(Ti)

The activity concentrations of natural radionuclides 40K, 226Ra and 232Th in soil samples taken from the tin mining area in Gura top, Jos were measured by gamma spectrometry using Sodium Iodide detector. The average specific activity concentrations of 40K, 226Ra and 232Th determined in the soil sample ranged from 11.26±3.16Bq/Kg to 543.35±0.64Bq/Kg with mean activity concentration of 161.96±7.56Bq/Kg for 40K, that of 226Ra ranged from 7.19±1.23Bq/Kg to 144.20±10.18Bq/Kg with the mean activity of 46.47±5.19Bq/Kg while 232Th ranged from 76.08±3.38Bq/Kg to 1267.91±15.37Bq/Kg, with mean activity concentration of 396.17±7.69Bq/Kg. The results indicates that the activity concentration of 40K was found to be below the world average while that of 232Th and 226Ra were detected to be above the world average value. This suggests that t the study area has excess thorium and radium activities which pose significant health hazard and is considered radio-logically unsafe for human to cultivate on the land.Keywords: Activity concentration, Gamma spectrometry, Natural radionuclides and Sodium, Iodide detector

Assessment of natural radionuclides and related occupational risk in agricultural soil, southeastern Nile Delta, Egypt

This study aims to determine the activity concentrations of natural radionuclides (226Ra, 232Th, and 40K) in the agricultural soil of southeastern Nile Delta, Egypt, in order to assess their influence on the occupational radiation health hazard indices. It was found that the mean activity concentrations of 226Ra, 232Th, and 40K were 35.53, 23.59, and 266.41 Bq kg−1, respectively. The effect of the industrial activities in the study area on the activity concentrations of radionuclides is slight for 226Ra while negligible for 232Th and 40K. Soil characteristics especially the fine particles play the major role in the distribution of 40K, while the distribution of 232Th is less influenced by the soil characteristics. On the other hand, the distribution of 226Ra shows no obvious association with these characteristics. The calculated radium equivalent activity index (Raeq) and external hazard index (Hex) fall within the save rang. However, those of absorbed dose rate (Dex) and annual effective dose (AEDex) exceed the world average values in about 16.7% and 61.1%, respectively. The calculated values of the excess lifetime cancer risk (ELCR) are higher than those of the world average. This implies the high probability of developing cancer over the lifetime of the farm workers. In this study, we recommend performing periodical inspection for the industrial activities and their wastes in the study area and monitoring the level of activity concentrations of different radionuclides in the studied soil as well as the cultivated crops.

Statistical relationship between activity concentrations of radionuclides 226Ra, 232Th, 40K, and 137Cs and geological formations in surface soil of Jordan

ABSTRACTAn extensive study was conducted to determine the activity concentrations of natural and artificial radionuclides 226Ra, 232Th, 40K, and 137Cs in soil samples of each governate of Jordan. A total of 370 samples have been measured using a high-purity germanium detector. The activity concentration for 226Ra, 232Th, 40K, and 137Cs has mean values of 42 ± 3, 23 ± 3, 309 ± 21, and 3.7 ± 0.9 Bq kg–1, respectively. The highest mean activity concentration for 226Ra was found to be 138 ± 4 Bq kg–1 in the Alkarak governate. In the Ajloun and Jarash governates, the highest mean activity concentration was 35 ± 3 Bq kg–1 for 232Th, and 14.2 ± 1.9 Bq kg–1 for 137Cs, respectively. Geological influence on the activity concentrations was investigated using the one-way analysis of variance (ANOVA) and independent samples. The ANOVA results indicate that there are strong significant differences between the activity concentrations of 232Th, 40K, and 137Cs based on geological formations the radionuclides occur. The main contribution to gamma dose rate was due to 226Ra activity concentration. Radium equivalent and external hazard index are associated with a mean value of 98 Bq kg–1, and 0.266, respectively.

Preliminary assessment of natural radioactivity and associated radiation hazards in a phosphate mining site in southern area of Togo

Because of the increasing use of phosphate in industries worldwide, especially in Togo, it is interesting to investigate the potential radioactivity exposure of phosphate ores, especially in the one being exploring in Togo nowadays. The contents of natural radionuclides (40K, 226Ra, 232Th, 235U and 238U) were assessed in phosphate soil samples from Kpogame, Dagbati and Kpeme in the maritime region of Togo by using gamma spectrometry-based Broad Energy Germanium detector (BEGe6530). Since no study was made prior to the exploitation, the samples from the control area of Anfoin-Kpota far away from the three others were considered as reference. The results are discussed and compared with the data from other countries. The activity concentration of 40K, 226Ra, 232Th, 235U and 238U are between (59.45 and 129.99), (20.19 and 779.93), (16.81 and 121.42), (2.26 and 52.03) and (16.66 and 841.14) Bq kg−1, respectively. The values obtained shows that the exploitation sites (Dagbati and Kpogame) and treatment site (Kpeme) have a very high level of radioactivity than the control area (Anfoin-Kpota). The Kpogame and Dagbati exploitation and Kpeme waste discharging phosphate deposit sites were found to have higher activity concentration than many others exploited phosphate sedimentary deposits around the world. The average annual effective dose of the above studied sites is 0.36, 0.24 and 0.48 mSv year−1, respectively. The value related to the discharge waste site is about 2% of the 1.0 mSv year−1 recommended by the International Commission on Radiological Protection as the maximum annual dose to the public. The obtained result of both radioactivity and radiological level in the studied areas will be considered as a pre-operational baseline to estimate the possible radiological impacts due to mining and processing phosphate industrial activities.

Soil concrete based on waste of heat power engineering and siftings of rock grinding

The possibility of recycling large-tonnage waste of heat power engineer-ing and mining industry in road construction is shown. Compositions of road-building materials were researched, containing siftings of rock grinding, fly ash, Portland cement, modified with a stabilizing additive of polymeric nature. X-ray phase analysis showed availability of quartz in fly ash, calcite, feldspars, goethite and X-ray amorphous phase, what is consistent with the data of infrared spectroscopy. By atomic emission spectrometry with inductively coupled plasma it was revealed that fly ash is latent-active and can be disposed in compositions in the presence of a stabilizing additive. The X-ray phase analysis of grinding siftings showed that it contains quartz, feldspars, chlorite, calcite and dolomite. The specific activity of natural radionuclides (226Ra, 232Th, 40К) of fly ash and grinding siftings was 248 and 110 Bq/kg, which allows using such waste in construction without restrictions. It was revealed that the initial mineral raw materials belong to multiphase polymineral systems; therefore, when modifying them with stabilizing additives, binding of finely divided particles should be taken into account. It was revealed that the optimal content of Portland cement and fly ash in samples is 8 and 10 wt.%. It was found that an increase in the mass fraction of fly ash in the composition of soil-concrete up to 30 wt.% leads to softening of the samples and a decrease in their strength characteristics.

Assessment Of Radiological Consequence Of Radioactivity In Monazite Beach Sand In South West Coastal Region In Southern India

Abstract The natural radionuclide ( 226Ra, 232Th and 40K) contents of sand samples at various locations in Sakthikulangara area in the south west coastal region of Kerala state have been determined using NaI(Tl) based gamma spectrometric measurement method and radiation hazard indices in the study area are evaluated. The specific activities of the radionuclides were found to vary from below detectable level to 32.38 BqKg-1, 34.77 BqKg-1 to 229.30 BqKg-1 and 20.76 BqKg-1 to 88.39 BqKg-1, respectively for 226Ra, 232Th and 40K. The radium equivalent activity (Raeq) was quite less than the recommended limit of 370BqKg-1. The radiological parameters such as internal and external hazard indices, absorbed dose rate, indoor and outdoor annual effective dose, alpha index and representative level index were also determined from the estimated value of the specific activity of 226Ra, 232Th and40K.

Experimental Evaluation of Radiological Hazards in Ceramic Tiles Used in the Jos-South, Area of Plateau State, Nigeria

Radiological hazards resulting from 5 different brands of ceramic tiles commonly used in homes and offices in Jos-south area ofplateau state were assessed in this study by carrying out radioactivity measurement of natural radionuclides (40K, 226Ra and 232Th) in them using a NaI(Tl) gamma ray spectrometer. The ceramic tiles had mean activity concentrations of 44.5, 59.6 and 417.4 Bq kg-1 for 226Ra, 232Th and 40K respectively. The average radium equivalent is within the recommended limit of 370 Bq kg-1 for building materials. The radiological hazard indices such as the gamma absorbed dose rate, annual effective dose, external radiation index (Hex), internal radiation hazard index (Hin), Alpha index (Iα), Gamma index (Iγ), excess lifetime cancer risk, and annual gonadal dose equivalent were evaluated. The results obtained show that the radiological parameters do not exceed the recommended safety limits and hence pose no significant radiological hazard when used as building material.

СОДЕРЖАНИЕ УРАНА И РАДИЯ-226 В ПОДЗЕМНЫХ РАССОЛАХ СИБИРСКОЙ ПЛАТФОРМЫ

Activities of natural radionuclides 226Ra, 238U in underground brines of Cambrian sedimentary sequence in area of “Udachnaya” kimberlite pipe (Siberian plate) are considered. Activity of radium increases with the degree of the metamorphization of the underground brines. The work is done with the help of high-resolution semiconductor gamma-spectroscopy on state assignment of IGM SB RAS and on the project No. 18-45-140020 «Features of nuclear technogenesis by the example of the object of the peaceful underground nuclear explosion «Crystal» supported by the Russian foundation for basic research.

Preliminary studies on the spatial distribution of artificial 137Cs and natural gamma radionuclides in the region of the Ojców National Park, Poland

Abstract The aim of the research is to obtain preliminary information about the spatial distribution of gamma radionuclides in the soils taken from the Ojców National Park with emphasis on the behaviour of artificial radionuclides, with 137Cs as a representative. The natural radionuclides 40K, 226Ra (uranium series), and 228Th (thorium series), which are considered as background radiation, were also determined. In total, 18 soil samples were collected during the summer periods in 2015-2017, while the sampling points were selected with respect to differences in rainfall and local topography gradient. The method was based on gamma-ray spectrometry performed on high-purity germanium (HPGe) gamma detector (relative efficiency 34%). 137Cs was mostly deposited in the top soil layers, with activity in the range of 27.9÷586.6 Bq·kg-1. We found strong positive correlation of the 137Cs activity with the soil organic matter content, and at the same time, its dependence on the rainfall amount. Consequently, the soil types and local climate can control the spatial distribution of 137Cs on a small spatial scale. The quantity of natural radionuclides was highly similar in all samples with the following mean values: 38.0 Bq·kg-1for 228Th, 33.1 Bq·kg-1for 226Ra, and 479.9 Bq·kg-1for 40K.

Assessment of Radiological in the Beach Sand from Pattani Province

Specific activities of natural (40K, 226Ra and 232Th) radionuclides in 250 beach sand samples collected from 5 beaches in 5 districts which are Rachadapisek beach in Nong Chick district, Talokapo beach in Yaring district, Panarae beach in Panarae district, Wasukri beach in Saiburi district and Pamai beach in Mai Kaen district in Pattani province, have been studied and measured. Experimental results were obtained by using a high-purity germanium (HPGe) detector and gamma spectrometry analysis system and also evaluated by using the standard reference materials IAEA-SOIL-6 which were obtained from Office of Atoms for Peace. Experimental set-up and measurement were operated and carried out at laboratory research building, Office of Atoms for Peace, Bangkok. It was found that, the mean values of specific activities of 40K in Rachadapisek, Talokapo, Panarae, Wasukri and Pamai beaches were 427.58 ± 14.09, 1090.62 ± 54.28, 463.95 ± 14.06, 449.07 ± 13.80 and 433.49 ± 12.77 Bq/kg, respectively. The mean values of specific activities of 226Ra were 31.10 ± 7.63, 160.68 ± 8.07, 84.41 ± 13.09, 33.98 ± 7.76 and 44.42 ± 10.17 Bq/kg, respectively. The mean values of specific activities of 232Th were 11.40 ± 1.75, 356.65 ± 6.59, 74.50 ± 3.07, 16.04 ± 1.78 and 26.86 ± 2.08 Bq/kg, respectively. Furthermore, the results of the specific activities of natural radionuclides (40K, 226Ra and 232Th) in this areas were also used to evaluate the gamma absorbed dose rates (D), the radium equivalent activity (Raeq), the external hazard index (Hex) and the annual external effective dose rate in this area. Furthermore, experimental results were also compared to research data in the southern region of Thailand, the Office of Atoms for Peace (OAP) annual report and the recommended values which were proposed by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR, 1988, 1993, 2000).The first section in your paper

Assessment of natural radioactivity in rice and their associated population dose estimation

ABSTRACTThe concentration of natural radioactivity in rice is an important parameter for the determination of population exposure by the ingestion of natural radionuclides during habitual consumption of food. All types of food including rice contain a detectable amount of natural radioactivity which successively relocate into the human body via the ingestion pathway. Rice is the main cultivated crop in Bangladesh and most of the Bangladeshi people consume rice as their staple food. Hence, studies on the evaluation of natural radioactivity in rice have been performed by gamma-ray spectrometry using High Purity Germanium (HPGe) detector in order to estimate various radiation hazards due to rice consumption. The average activity levels of natural radionuclides 226Ra, 228Ra and 40K in the rice samples were 1.09 ± 0.31, 0.17 ± 0.21 and 4.70 ± 1.59 Bq kg−1, respectively. The estimated effective doses for the respective radionuclides caused by the rice consumption were 43.69, 16.39 and 4.15 µSv y−1, respectively which was below the UNSCEAR compiled value. The calculated excess lifetime cancer risk (ELCR) values via rice consumption were found below the acceptable limit of 0.29 × 10−3 for radiological risk.

Geochemical and organic petrological study of bituminous sediments from Dahomey Basin, SW Nigeria

Abstract The Dahomey Basin, SW Nigeria, hosts a 3000-m-thick sedimentary succession of Cretaceous and Cenozoic age, of which the Turonian-Maastrichtian Afowo Formation includes sandstones, arkoses, shales, shelly limestones, unconsolidated sand, clay and most importantly, bituminous (tar) sand strata. Eighteen samples were picked up from outcrops exposed by streams and channels, and were examined applying sedimentological, mineralogical, petrographical, geochemical (inorganic and organic) and radiological techniques with the aim of assessing the origin and the thermal maturity of the organic facies. The samples represent mostly coarse-grained sands and subordinately shales, referred usually as ‘tar sands’; they consist of mainly quartz and kaolinite, with variable amounts of mixed clay layers of illite-montmorillonite, mica and pyrite, probably derived from weathering of the Migmatite Gneiss Complex exposed to the north of the basin; this can also explain the relative enrichment in the natural radionuclides 40K, 238U, 226Ra and 232Th for some samples, although the radioactivity falls within the range for world values for soils. The clastic material of Afowo Formation was deposited in a rather oxic shallow marine environment. The particulate organic matter of the bituminous sediments comprises solid hydrocarbons, coalified (huminite) and partially oxidized (inertinite) remnants of terrestrial plants, and minor amounts of both terrestrial and marine liptinite macerals. The random reflectance values of the indigenous huminite population ranges between 0.40 and 0.45% pointing to an immature stage for oil generation. The respective reflectance of the migrabitumens ranges from 0.49 to 0.59% corresponding to vitrinite equivalent reflectance values of 0.70–0.76% falling well within the oil window. This study concludes that the hydrocarbons contained in the Afowo Formation are upwards migrating from parts of the basin where Afowo Formation has subsided at depths corresponding well within the oil window; the source rock corresponds to the middle shale horizon, whereas the sandy horizons act as migration paths and/or reservoirs.

Determination of 226Ra, 232Th and 40K in teeth by use of gamma spectroscopy

ABSTRACTThis study entails the measurement of the specific activity of natural radionuclides (226Ra, 40K and 232Th) in 18 tooth samples obtained from the clinic of the Universiti Sains Malaysia (USM), Penang, by using an HPGe detector. The specific activity of 226Ra, 40K and 232Th was measured to estimate the hazard index of the radionuclides, radium equivalent activities (Raeq), external, internal hazard indices (Hex, Hin), and absorbed dose (Dout, Din). The maximum values of concentration of 226Ra, 232Th and 40K in the tooth samples were found to be 60.82, 60.29 and 594.22 Bq kg−1, respectively. Maximum values of Raeq, Hex, Hin, Dout and Din were found to be 192.78 Bq kg−1, 0.520, 0.685, 89.29 and 169.81 nGy h–1, Iγ and Iα as 0.702 and 0.304, respectively. The results were lower than the average world value (UNSCEAR). In addition, a strong correlation was found between the concentrations of 226Ra and Raeq, between energy and net area, as well as between radionuclides (226Ra, 40K and 232Th) in tooth samples and age of volunteers. This study showed that the concentrations and hazard indices of tooth samples are below the recommended safe levels; therefore, the study area is considered safe in terms of radiological health hazards.

Determination of natural radioactivity in soil samples around gold mining area in Khamkeut district, Bolikhamxay Province, Laos using gamma ray spectrometer with NaI(Tl) detector

This paper presented the method of determining the radioactivity of 40K, 226Ra and 232Th in soil samples by gamma-ray spectrometer using NaI (Tl) scintillation detector. The radioactivity of each isotope is calculated based on the net count rate in the energy window characteristic for the 40K, 226Ra and 232Th radioisotopes respectively. We have determined activity concentrations of the natural radionuclides 226Ra,232Th and 40K in 15 soil samples collected around gold mines of Khamkeut district, Bolikhamxay Province, Laos. The average activity concentrations of the natural radionuclides 226Ra, 232Th and 40K are 46.58 ± 7.36 , 71.19 ± 5.42 and 574.62 ± 25.02 Bq.kg-1, respectively. The average activity concentrations of 226Ra and 232Th in this work are higher than those of Bolikhamxay Province, Laos and the world average values. The estimated average outdoor annual effective dose (E) and radium equivalent actitvity (Raeq) are 0.10 ± 0.004 mSv.yr-1 and 192.64 ± 16.12 Bq.kg-1, respectively.

Assessment of natural radionuclides mobility in a phosphogypsum disposal area

The phosphogypsum (PG) stacks located at Huelva (SW Spain) store about 100 Mt of PG, and covers a surface of 1000 ha. It has been very well established in many studies that this waste contains significant U-series radionuclides concentrations, with average activity concentrations rounding the 650, 600, 400 and 100 Bq kg−1 for 226Ra, 210Po, 230Th and 238U, respectively. However, the radionuclide transfer from this repository into the environment by the aquatic pathway will depend on the mobility of each radionuclide.The mobility of the natural radionuclides (U-isotopes, Th-isotopes, 226Ra, and 210Po) contained in the PG piles were evaluated by using the optimized BCR sequential extraction procedure (BCR “Community Bureau of Reference”). The radionuclides were measured in the liquid fractions by alpha-particle spectrometry with semiconductor PIPS detectors. In addition, to validate the obtained results, waters from different locations of the PG piles (pore-water, perimeter channel and edge outflow leachates) were taken and the alpha emitter radionuclides determined.Uranium presents the highest mobility, being its total mobile fraction in the PG around 70%, while 210Po and 226Ra present an intermediate mobility of (around 50% and 30%, respectively). And finally, the Th-isotopes have very low mobility (mobile fraction < 5%), being fixed to the residual fraction. It is noteworthy that this behaviour has been also found in the water samples taken from the stacks, demonstrating that this sequential leaching operational methodology is a useful tool for assessing the release capacity of radionuclides by inorganic wastes.

Estimation of Radioactivity and Associated Radiological Hazards of Cement Used in Sri Lanka

Cement used in construction work can cause internal and external radiation exposure due to the presence of natural radionuclides 226Ra, 232Th and 40K. The radiation exposure risk can be estimated by finding the indoor absorbed dose rate and the annual effective dose. If the annual effective dose is within the internationally accepted value, use of cement can be considered safe and the risk will be within acceptable levels. The specific activities of 226Ra, 232Th and 40K in 85 samples from eleven types of cement were measured using gamma spectroscopy with a HPGe detector and the annual effective dose was calculated to determine the radiological hazard from the natural radioactivity in the samples. The average specific activities measured in Bq kg-1 ranged from 21.4 ± 0.9 to 66.8 ± 1.2 ;13.8 ± 0.9 to 62.1 ± 2.3 and 83.7 ± 4.9 to 239.9 ± 5.7 for 226Ra, 232Th and 40K respectively. The highest activity of both 226Ra and 232Th were obtained in CEM III- PPC 1 cement which contains 25 % fly ash from a coal power plant. The lowest activities of 226Ra, 40K and 232Th were observed in CEM-X imported OPC 3 cement. It was observed that for all the studied cement samples the annual effective dose ranged from 0.15 to 0.51 mSv y-1.and less than the recommended maximum permissible public dose 1.0 mSv y-1. The results obtained in this study indicate that there is no radiological hazard arising from the use of the studied cement varieties in building construction.

Physicochemical and Radiation Hazardous Properties of Scale TENORM Waste: Evaluation by Different Analytical Techniques

The scale material in TENORM waste from petroleum industry was characterized using nuclear and non-nuclear techniques. The scale TENORM samples were collected from the Ras Shukeir area on the west bank of the Suez Gulf in Egypt during gas and oil production. These scales represent the TENORM deposits formed in the pipelines and removed during the periodical maintenance. X-ray fluorescence analysis showed that the main elements in all investigated fractions were Si, Fe, Mg, Ca, Sr, and Ba in addition to traces of some heavy elements, e.g. Pb, Cr, and Zn. The radioactivity concentrations of natural radionuclides 226Ra, 232Th, and 40K in seven particle size fractions were found to be in the range from 14.1 ± 0.4 to 28.9 ± 0.9, from 5.0 ± 0.2 to 9.5 ± 0.4, and from 0.25 ± 0.02 to 0.43 ± 0.02 kBq kg–1, respectively. The radiation hazard parameters were calculated. The values obtained are much greater than the accepted values. The results were compared to the values reported for other countries.

Environmental assessment of risks associated with the Ordovician Dictyonema shale in the eastern part of the Baltic Klint

The results of research considered in this article made it possible to expand the understanding of the environmental risks associated with the highly radioactive bituminous argillites of the Baltic Sea region. The natural patterns of the distribution of natural radionuclides 226Ra, 232Th and 40K are established along the strike and thickness of layers. The average value of the effective specific activity (ESA) for all samples in the Koporka River valley amounted 1270 Bq/kg. The minimum value of ESA was 650 Bq/kg (the closest to the seam roof level), and the maximum value was 3750 Bq/kg (the second from the seam floor level). Conversion to mass fractions of natural radionuclides (NRN) showed that the average content of uranium in the sample amounted up to 90.7 g/t, thorium up to 11.4 g/t and of potassium up to 4.1%. The high heterogeneity of the content distribution of NRN along the strike of the Dictyonema shale seam was confirmed by studies of separate outcrops of highly radioactive rocks along the banks of the Tosna River. In general, the level of the argillites radioactivity has abnormally high value and exceeds the natural background more than ten times. The average annual values of the effective dose amounted from 5,8 to 10,7 mSv/year, that should be classified as the territories of emergency ecological danger and zones of ecological disaster.

Study of radon flux and natural radionuclides (226Ra, 232Th and 40K) in the Main Boundary Thrust region of Garhwal Himalaya

The Himalayan region is subdivided lithologically into four regions in which the junction between the lower Himalaya and Shivalik is known as the Main Boundary Thrust (MBT). It is well known that the environmental radon concentration depends upon various geological factors including faults, thrust, cracks and the composition of the soil. Radon gas eventually comes out from the fault/thrust zones having radium as its prominent source. Hence, it is important to study the behaviour of emission of radon present inside the earth crust as well as the levels of natural radionuclides in soil. In this study, the levels of natural radionuclides and exhalation rates of radon in the soil of MBT region of Garhwal Himalaya, India, were determined by using gamma ray spectrometer and scintillation detector-based Smart Radon Monitor, respectively. The average activities of 226Ra, 232Th and 40K were found 71.9, 88.2 and 893.6 Bq Kg−1, respectively. The measured radon surface flux was found to vary from 13.08 to 1626.4 Bq m−2 h−1 with a mean value of 256.5 Bq m−2 h−1. The measured activity levels were used to assess the doses associated with the contaminated soil.