In the present investigation, a total of 62 potable water samples were analyzed to assess uranium concentrations and the associated toxicological and radiological risks from the eastern region of Kumaun Himalaya, India, using LED fluorometry technique. The Oakton Benchtop device was used to measure physicochemical parameters, including pH, temperature, total dissolved solids and electrical conductivity. Uranium concentration in water samples ranged from 0.5 ± 0.1 to 96.1 ± 0.7 µg/L, with a mean value of 23.5 ± 27.7 µg/L; with 16 % of the water samples exceeding the provisional guideline value (30 µg/L) provided by the World Health Organization. Comparative analysis reveals that hand-pumped water showed a higher average (40.3 µg/L) than tap and spring water sources. Nevertheless, all samples remain below the radiological-based limit set by the Atomic Energy Regulatory Board. Radiological risks were evaluated by calculating annual effective doses and excess cancer risk. Results indicated that estimated annual effective ingestion doses for different age groups and genders were comparatively higher in males. Further, chemical risks were quantified by estimating the lifetime average daily dose and health quotient. The average excess cancer risk was found to be 3.23 × 10-5, with lifetime average daily dose ranging from 0.003 to 2.75 µg/kg/day, averaging 0.66 µg/kg/day. The investigation found no significant chemical toxicity from uranium in water, as the computed health quotient was below 1. A strong correlation was observed between uranium and total dissolved solids, with a Pearson's r value of 0.82. Statistical model, including ANOVA, indicates that the rock/soil types of the study area contribute to the uranium distribution over the region. Further, cluster analysis was also performed on the obtained data. The findings of the present study indicated that the sedimentation zone near river confluences shows elevated uranium content, likely due to the leaching of soil/rocks from the upper Himalayan terrain.

Access to clean water is essential for human survival and well-being to sustain life. The present study investigates the radon levels in potable groundwater sources across various locations of the Champawat district of the Lesser Kumaon Himalaya, India, using a scintillation-type Smart RnDuo Monitor coupled with a water bubbler. Alongside radon measurements, key physicochemical parameters were also recorded. Radon concentrations in water samples ranged from 0.5 ± 0.1 to 177.4 ± 4.6 Bq/L by showing a wide variation, with a mean (± SD) of 23.8 (± 39.7) Bq/L. The mean exceeds the USEPA guideline of 11.1 Bq/L but is below the WHO limit of 100 Bq/L. Notably, groundwater shows higher values of radon compared to spring and tap water sources. Spatial distribution mapping of radon and TDS was carried out for visualization purposes. A notable positive correlation, indicated by a Pearson r value of 0.62, was found between radon concentration and total dissolved solids. Radiological dose assessment displayed that the adults received a higher age-dependent annual effective ingestion dose (322.14 µSv/y) than infants and children, with groundwater posing a greater exposure risk than other sources. Comparatively, the organ-specific effective dose analysis indicated that the stomach and lungs received a higher dose of 38.66 µSv/y for adult males, with a corresponding elevated excess lifetime cancer risk. Overall, geological heterogeneity and thrust zones suggest spatial variation in radon levels by highlighting the role of geology and geomorphology in radon mobilization. The current findings will significantly improve water quality and provide valuable insights for epidemiological studies in the future.

Naturally occurring radioactive gas, radon is a decay product of radium present in the soil. Radon flux reaches the atmosphere through exhalation from soil surface. This study aims to estimate the radon diffusion length and diffusion coefficient in soil matrix on the premises of HNB Garhwal University campus at Tehri Garhwal, India. Soil gas radon concentration was measured at different depths (15, 30, 45, 60, 75, and 90 cm) using a Smart RnDuo (Scintillation-detector) at 14 different locations in the university campus. Simultaneous measurement of surface and mass exhalation rates was also carried out for each location. Gamma-ray spectrometry was used to estimate the radium content in soil samples. Results of the present study suggest that soil gas radon concentration increases with increasing sampling depth. The diffusion coefficient and length were calculated using the soil gas radon concentration gradient within the soil matrix. The average value of diffusion length (l) and diffusion coefficient (D) were obtained as, ls = 0.70 f 0.22 m, Ds = 0.0054 f 0.0049 m2 s- 1 and la = 0.77 f 0.63 m, Da = 0.0073 f 0.014 m2 s-1 by Fick's diffusion model and analytic models, respectively.

This study examines radon and thoron emissions from soil samples in Pithoragarh, Uttarakhand, and their correlation with naturally occurring radionuclides (226Ra, 232Th, and 40K) in locally used construction materials. Radiological hazard parameters, including radium equivalent activity (Raeq), hazard indices (Hin, Hex), absorbed gamma dose rates (Dout), and annual effective dose equivalents (AEDEout), were analyzed. Average activity concentrations were 66 ± 11 Bq/kg (226Ra), 43 ± 8 Bq/kg (232Th), and 602 ± 77 Bq/kg (40K), showing variability attributed to geological heterogeneity. Radon and thoron exhalation rates highlighted localized hotspots, with Raeq averaging 173 ± 81 Bq/kg and hazard indices mostly below safety limits but with significant deviations. Correlation analysis revealed strong relationships, such as between 226Ra and 232Th, suggesting shared origins, while other parameters reflected diverse environmental influences. These findings emphasize the importance of continuous monitoring, targeted mitigation, and regulatory strategies to manage potential radiological risks and provide a baseline for future regional studies.

Radon measurement in the Himalayan region is crucial due to the unique geological composition that may lead to elevated radon levels in water sources, posing potential health risks to the local population. This study focuses on radon concentration in drinking water collected from 13 spring water samples and 13 groundwater samples (via hand pumps) across various locations in the Devprayag region. Radon levels were assessed using the SMART RnDuo continuous radon monitor. The concentration in spring water varied between 0.7 Bq/L and 64.4 Bq/L, while groundwater levels ranged from 0.6 Bq/L to 79.5 Bq/L. Although the radon levels in the samples fell within the safe limits set by the World Health Organization (WHO), the estimated annual effective dose from radon ingestion and inhalation surpassed the WHO's safety threshold of 100 μSv/year in several areas. These results highlight the necessity of ongoing radon monitoring in the region to reduce long-term health risks and guide safety standards for drinking water.

The present investigation was conducted to quantify the radiological exposure associated with inhalation of attached and unattached 222Rn and 220Rn progeny concentrations in indoor environments. The total progeny concentrations of 222Rn and 220Rn were estimated using direct progeny sensors, and the attached progeny concentrations of 222Rn and 220Rn were measured using wire-mesh-capped direct radon and thoron progeny sensors based on LR-115 type-II detectors. The obtained average unattached fraction of 222Rn progeny was 0.14, similar to the UNSCEAR recommended value, while the unattached fraction for 220Rn progeny was 0.09. In the different indoor conditions, the concentration of total progeny, attached and unattached progeny of 222Rn and 220Rn are higher in mud dwelling among mud, cement and stone dwellings. In addition to it, a seasonal variation was also studied, and a descriptive statistical analysis was done using a paired student's t-test to compare progeny fractions between dwelling types. Dose conversion factors for mouth and nasal breathing were further estimated separately and the average dose conversion factors for mouth and nasal breathing were found to be 19.5 ± 6.3 mSv/WLM and 8.5 ± 1.1 mSv/WLM, respectively. The annual effective dose is under the ICRP reference level, however, the inhalation dose estimated for mouth breathing was found to be more than twice that of nasal breathing. In the present study, the unattached radon progeny contributes 14.21 % to the annual effective dose (AEDR).

This study evaluates indoor and outdoor terrestrial gamma dose rates and associated radiological parameters in the Devprayag region of the Garhwal Himalayas, India. Measurements were conducted at 34 georeferenced locations using a portable Geiger-Müller-based dosimeter and GPS mapping. Outdoor dose rates varied between 0.09 ± 0.005 and 0.15 ± 0.007 μSv/h (average 0.12 ± 0.006 μSv/h), while indoor dose rates ranged from 0.10 ± 0.005 to 0.16 ± 0.007 μSv/h (average 0.14 ± 0.006 μSv/h). The corresponding annual effective dose (AED) was found to be 0.60 ± 0.05 to 0.96 ± 0.07 mSv/y with an average of 0.82 ± 0.06 mSv/y, which remains below the recommended public dose limit of 1 mSv/y. Health risk indices were also evaluated. The Radiation Hazard Index (RHI) remained below unity at all sites, confirming that exposures are within permissible safety limits. The Annual Gonadal Dose Equivalent (AGDE) values, though spatially variable, were comparable to international averages and did not exceed reference safety levels. To complement field monitoring, Random Forest Regression (RFR) was applied using climatic parameters (temperature, rainfall, rainy days, and elevation) as predictors. The model achieved robust predictive accuracy (R2 > 0.80), capturing seasonal patterns of dose variation. Results indicated that monsoon conditions corresponded to the lowest predicted dose rates, while other seasons showed moderately higher values, reflecting the influence of rainfall and topography. Overall, the integration of spatial mapping with machine learning provides a cost-effective framework for radiological surveillance in mountainous terrains. The findings confirm that radiation levels in Devprayag are within internationally accepted limits, while highlighting the value of periodic monitoring and predictive modeling for long-term radiation safety management.

This study focused on assessing how natural background radiation levels vary due to spontaneous gamma emissions from the terrain of the Haridwar district. Gamma radiation levels are influenced by a mix of environmental and structural factors. Outdoor radiation is closely connected to soil composition and geology, while indoor radiation is affected by both external conditions and the characteristics of building materials. The range of observed indoor dose rates has been found from 0.07 to 0.31 µSv/h with an average value of 0.15 µSv/h, and outdoor dose rates from 0.06 to 0.28 µSv/h with an average of 0.13 µSv/h. The terrain of the administrative map of Haridwar district has been classified into two categories based on altitude, viz., Highland and Lowland. The results show that unexpectedly high radiation in certain areas and subtle variations between highlands and lowlands suggest unmodeled factors may be contributing to radiation exposure patterns. Indoor spaces showed higher gamma radiation compared to outdoors. Radiation exposure changes depending on age, with infants receiving the most. The interplay of potential outliers has been discussed in detail.

Alpha flux radiated from Rn-222, Rn-220 and progeny is the primary contributor of natural radioactivity to the inhabitants in the ambient atmosphere. The annual indoor Rn-222 and Rn-220 concentrations were found to be 85 +/- 43 and 84 +/- 36 Bq m(-3), respectively. The estimated annual indoor Rn-222 and Rn-220 concentration is below to reference value of 100 Bq m(-3) suggested by WHO. The calculated annual inhalation dose due to exposure to the alpha flux of Rn-222, Rn-220 and their progeny is well below the recommended reference level given by UNSCEAR and ICRP. The data were further checked for normalisation and found that Rn-222 and Effective Equilibrium Radon Concentration (EERC) data are not normally distributed.

This research investigates exhalation rates of radon ( 222 Rn) and thoron ( 220 Rn) from soil samples in the Jaunsar-Bawar region of the Indian Himalayas. Before sampling, gamma radiation rates were evaluated, ranging from 0.08 to 0.33 µSv/h. The observed 222 Rn mass exhalation rates range between 3.56 and 82.08 mBq/kg/h, with an average of 25.67 mBq/kg/h. Additionally, the surface exhalation rate of 220 Rn varies from 1.28 to 22.69 Bq/m 2 /s, averaging 7.90 Bq/m 2 /s. Projected 220 Rn mass emission rates span 154–2356 mBq/kg/s, with a mean of 939 mBq/kg/s. The dataset analysis employs best-fit statistics, revealing the Weibull distribution as the optimal model for gamma dose rate and 220 Rn mass emanation rates. Lognormal distribution suits 222 Rn mass exhalation rates, and the Gamma distribution excels for 220 Rn surface exhalation rates, aligning with log-likelihood estimator indications.

This study focuses on investigating the release and dispersion of radon in diverse samples obtained from four designated sites (Rajpur, Maldevta, Kalsi and Dugadda) situated within the Main Boundary Thrust region of Garhwal Himalaya, Uttarakhand, India. In the Current research, we measured different radioactive parameters; including natural radioactivity (Radium content) and Mass exhalation rate. Using these measurements, we calculated the radon emanation fractions in 82 samples from four sampling sites. The radium content exhibited a range of 39 ± 8 Bq kg−1 to 442 ± 50 Bq kg−1, averaging at 88.2 ± 62.2 Bq kg−1. The Radon Exhalation rate displayed a range of 8.56 ± 3.1 mBq kg−1 h−1 to 144.9 ± 12.5 mBq kg−1 h−1 with an average rate of 48.4 ± 29.2 mBq kg−1 h−1. The variation in radon emanation fraction ranged from 0.62 to 8.52, with an average of 3.25 ± 1.60. Initially, the samples were categorized into rock and soil groups. To introduce an additional dimension, a secondary classification based on dry and wet conditions were subsequently incorporated. An increase in radon emanation fraction was observed for the wet samples due to higher moisture content.

Humans receive around 50% of natural radiation dose due to 222Rn (radon), 220Rn (thoron) and their decay products. Several field campaigns measuring these gases and the decay products in different regions of India have been conducted in the recent past. Some of these studies measured indoor activity concentration and/or dose due to these gases and the associated decay products. This work compares the fraction of 222Rn and decay products and 220Rn and decay products in inhalation dose for 10 studies conducted in Uttarakhand state. It is seen that AEDT (annual effective dose due to 220Rn and decay products) for these regions varies between 21 and 48% and it is significantly higher than the averaged worldwide reference value of 6%. Based on elaborative measurements performed in the Bageshwar district (present work), Almora and Nainital districts (our previous campaigns); the reasons for this high value have been explored. It was observed that a higher source term for mud houses could be the main reason for the high AEDT range. Interestingly, preliminary analysis revealed that the fraction is higher for the dwellings situated at higher altitudes thus indicating the role of the unavailability of modern building construction materials at remote locations. The study highlights the significant contribution of thoron in the Indian Himalayas.

This study examines 52 water samples from diverse locations in the Dehradun district, measuring radon activity concentrations with a scintillation-based monitor. The findings indicate an average concentration of 33.97 Bq/L, ranging from 3.35 to 99.25 Bq/L. Beyond this, the research estimates annual effective ingestion (µSv/y), inhalation (µSv/y), and total (µSv/y) doses attributed to radon in the drinking water samples, offering insights into potential health risks. Additionally, the study explores spatial patterns in the dataset, providing a geographic perspective on radon distribution across the region. This spatial analysis enhances our understanding of localised exposure risks, contributing valuable information for public health and environmental considerations in the Dehradun district.

The present study is conducted to assess the radiological and hydrogeochemical quality of earthly bore potable water in Haridwar, Uttarakhand, India. Radon activity concentrations in water samples ranged from 0.59 ± 0.04 to 57.32 ± 4.39 Bq/L. The average activity concentration of radon is estimated as 10.46 ± 1.05 Bq/L. Annual Effective Inhalation dose to humans ranged from 1.48 μSv/Y to 144.45 μSv/Y with an average value of 26.36 μSv/Y. Ca 2+ > Na + > Mg 2+ > K + and HCO 3 − > CaCO 3 − > SO 4 2− > Cl − > NO 3 − > F − were the concentration orders of the primary cations and anions. The majority of tests contained acceptable levels of ions and TDS, indicating that the region’s groundwater is safe for consumption. For irrigation purposes, the sodium absorption rate, sodium percentage, and magnesium risks were examined. The weathering of rocks was discovered to be the key factor influencing the chemistry of the groundwater in the region. The spatial patterns of observed fluctuations were investigated using the collected data set.

The present study focuses on the issue and investigation of exhalation and emanation of radon and thoron from the soil sample of the Pithoragarh district of Uttarakhand, India which is located in the upper Himalayan belt. A stratified random sampling method was used to collect the soil samples from 30 different villages in the Pithoragarh district. The averaged radon mass exhalation rates were found to be 65.05 ± 2.88 mBq/Kg/h and the surface exhalation rate is 11.17 ± 0.44 Bq/m 2 /s for thoron respectively. The data has been analyzed using simple linear regression equations to determine the influence of the various environmental factors on the emission of radon and thoron. Correlation studies have also been performed in this study.

In present study, 222 Rn, 220 Rn and progeny concentrations have been estimated by using passive techniques for radiological protection purpose. The average equilibrium factor for 222 Rn has been found to be 0.43, 0.29 and 0.30 for rainy, winter and summer seasons, respectively and 0.06, 0.05 and 0.05 for rainy, winter and summer seasons for 220 Rn. The annual equilibrium factor for 222 Rn was found quite close to the globally accepted value of 0.40 while for 220 Rn it was higher than the globally accepted 0.02. A statistically significant difference was obtained between inhalation dose estimated using global assumed equilibrium factors and calculated equilibrium factors.

In the present study, 80 samples of water from hand pumps and 63 samples of tap water were collected from the Bageshwar district of Uttarakhand, state of India. The radon activity concentration is varied from 1 to 21 Bq/L with a mean value of 7 ± 4 Bq/L in tap water samples while for handpump water samples radon activity concentration is varied from 3 to 42 Bq/L with a mean value of 20 ± 9 Bq/L. The average radon level in drinking water in the study region was higher than the radon level in water of Haridwar and Karanprayag districts of Uttarakhand and lower than the radon level in the drinking water of Dehradun, New Tehri, Pauri Garhwal and Pithoragarh districts of Uttarakhand. The mathematical estimation of radiological dose due to inhalation and ingestion of radon in water was calculated and discussed in detail in this study. Age dependent effective dose is estimated to compare the radiological effect on different age-groups. The trend of the mean values of radon ingestion dose in distinct age-groups is likely to be as infants > adults > children.

Man-made contamination is one of the most serious threats to our oceans. Discarded plastics and other household waste, as well as pesticide and synthetic chemical runoff, inevitably make their way into the sea, wreaking havoc on aquatic life and the ecosystems that they depend on.

Radioactivity is anatural phenomenon in general. Gaseous forms of radionuclides that present everywhere over the globe are responsible for the radiological dose to livings on Earth. Radon is a primary radionuclide in the radioactive series which exhalate in the atmosphere providing radiation dose to inhabitants. Easy detection and mitigation are essential for quantifying radiological dose to local populations. Active online radon monitors are a better way to estimate radon flux in local areas.

The present study had an objective to approximate radon and uranium as naturally occurring radioactive constituents in spring-water samples and assessment of AED (annual effective dose), radiological risks; and chemical toxicity, when spring-water is the source of drinking water. Based on the population density in study area (Bageshwar district of Uttarakhand, India), random sampling process was adopted for the collection of water samples from eighty natural springs. The concentration of radon was estimated using Advanced SMART RnDuo while for estimation of uranium, LED fluorimeter was used. The observed values were subjected to statistical analysis to illustrate the spatial distribution of radon and uranium in the study area as well as for determination of associated health risks for inhabitants. The results revealed that radon activity in spring-water samples varies from 3.4 to 101.3 Bq/L with a mean value of 34.4 +/- 3.8 Bq/L while the uranium concentration in water samples ranges from 0.1 to 28.4 mu g/L with the mean value of 1.6 mu g/L. In 35% samples radon concentration has been found more than the permissible limit prescribed by UNSCEAR. The observed values of electrical conductivity (EC) and total dissolve solids (TDS) were also found within the recommended limits of WHO. Therefore the relatively higher observed concentration of radon in spring water than the permissible limits of health regulatory agencies may be a matter of concern in radiological prospective as well as for chemical toxicity in infants and children inhibiting the study area.