Total Effective Dose Research Articles

Assessment of annual effective doses from indoor radon and thoron in Doi Lo, Chiang Mai, Thailand.

This study aimed to determine the annual effective dose resulting from radon and thoron progeny inhalation. The levels of radon, thoron, and progeny were assessed in residences situated in the Doi Lo region of Chiang Mai, Thailand. Indoor radon and thoron concentrations were detected using passive discriminative detectors. Using a progeny deposition rate detector, this study evaluates radon and thoron progeny [equilibrium-equivalent radon concentration (EERC) for radon and equilibrium-equivalent thoron concentration (EETC) for thoron]. Data were collected from 44 dwellings between March and May 2020. The results found that indoor radon concentrations ranged from 17 to 118Bqm-3, while thoron concentrations ranged from 12 to 72Bqm-3. The radon progeny (EERC) ranged from 4 to 173Bqm-3, whereas thoron progeny (EETC) ranged from 1 to 15Bqm-3. The total annual effective dose received from radon and thoron progeny inhalation varied from 0.5 to 5mSv y-1.

Long-Term Investigation (1968–2023) of 137Cs in Apples

Due to the consequences of nuclear and/or radiological accidents in the past (Chernobyl, Fukushima, etc.), and potential future events of that kind, the constant monitoring of environmental radioactivity is important. There are different pathways of the transfer of radionuclides from environment to humans (ingestion, inhalation and external). Food ingestion greatly contributes to the total effective dose; hence, it is of great importance to investigate exposure to radionuclides through food. This paper presents the results of a long-term investigation of 137Cs activity concentration in apples in northwestern Croatia for the period 1968–2023. The highest 137Cs activity concentration in apples was measured in 1986, decreasing exponentially ever since. The Fukushima-Daiichi accident in 2011 did not cause a significant increase in 137Cs activity concentration, although the presence of the consequent fallout was detected via the appearance of 134Cs in some parts of the environment. The observed residence time for 137Cs in apples was estimated to be 4.5 and 3.9 years for the pre-Chernobyl and post-Chernobyl periods, respectively. The correlation between 137Cs in fallout and apples is very good, the correlation coefficients being 0.99, which indicates that fallout is the main source of contamination. The estimated effective dose received by adult members of the Croatian public due to intake of radiocaesium from apples over the overall observed period is 6.4 µSv. Therefore, the consumption of apples was not a critical pathway for the transfer of radiocaesium to humans.

Evaluation of natural radioactivity levels and radiation hazards of Nkalagu limestone deposit, southeastern Nigeria.

Levels of natural radioactivity due to 40K, 232Th, and 226Ra in limestone deposits and corresponding surface soil samples from the Nkalagu community of Ebonyi State were investigated. Gamma spectroscopic analysis using a NaI (TI) detector was employed to measure the activity concentrations (ACs) of the natural radionuclides in the collected samples. The average AC of 226Ra, 232Th, and 40K was found to be 64.62 ± 11.63, 54.27 ± 8.52, and 313.06 ± 25.33Bq/kg, respectively, in limestone, whereas in the soil, the value was 60.80 ± 11.71, 44.97 ± 10.74, and 185.90 ± 18.20Bq/kg, respectively. Except for 40K, the obtained mean ACs of the radionuclides were in excess of the worldwide averages reported by the United Nations Scientific Committee on the Effect of Atomic Radiation (UNSCEAR). The mean value of Raeq, Hex, Hin, Iγ, and AUI was obtained as 166.33Bq/kg, 0.45, 0.62, 1.18, and 1.28, respectively, in the limestone, and 139.42Bq/kg, 0.38, 0.54, 0.98, and 1.12, respectively, in the surface soil. The radiation doses in limestone ranged from 120.78-168.89 nGyh-1 and 63.86-88.88 nGyh-1 for indoor and outdoor, respectively, whereas in the soil, the range was 104.47-129.77 nGyh-1 and 54.60-68.02 nGyh-1 for indoor and outdoor, respectively. The total annual effective dose ranged from 0.671 to 0.937 mSvy-1 with an average of 0.800 mSvy-1 in limestone and 0.579 to 0.720 mSvy-1 with an average of 0.667 mSvy-1 in the soil. Values of representative gamma index and activity utilization index, and indoor and outdoor radiation doses in limestone were above the recommended world average of ≤ 1, and 84 nGyh-1 and 59 nGyh-1, respectively, suggesting a restriction in the use of the limestone in construction of houses. The study therefore recommends that the use of limestone in building construction, especially in house interiors, should be discontinued.

Same-Day Positron Emission Tomography/Computed Tomography with 68Ga-Radiolabeled Fibroblast Activation Protein Inhibitors and 18F-Fluorodeoxyglucose Imaging for Gastrointestinal Cancers.

Objective: We investigated the clinical practicability of same-day 68Ga-radiolabeled fibroblast activation protein inhibitors (68Ga-FAPI)-first and 18F-fluorodeoxyglucose (18F-FDG) imaging and compared it with same-day 18F-FDG-first or 2-day procedures in diagnosing gastrointestinal cancers. Materials and Methods: Sixty-five patients with confirmed gastrointestinal cancers were divided into same-day 68Ga-FAPI-first group (Group A), same-day 18F-FDG-first group (Group B), and 2-day group (Group C). Low-dose CT and low injection activity were performed on 68Ga-FAPI positron emission tomography/computed tomography (PET/CT). Interval times, radiation dose, diagnostic performance, and detectability were assessed among groups. Additionally, the uptake, tumor-to-liver ratio (TLR), diagnostic efficacy, and TNM stage were compared between the two modalities. Results: The total waiting time for Group C was significantly longer than that for Group A or B (both p < 0.001). The total dose-length product and effective dose decreased in all groups. There were comparable detectability and diagnostic performance among groups (all p > 0.05). The within-group analysis in Group B indicated that 68Ga-FAPI PET/CT had higher uptake in the primary and recurrent lesions than 18F-FDG without differences in TLR, due to higher liver background on 68Ga-FAPI PET than Group A or C (both p < 0.001).68Ga-FAPI PET/CT possessed higher accuracy than 18F-FDG and changed staging in 14 patients (14/65, 21.54%). Conclusions: The same-day 68Ga-FAPI-first and 18F-FDG imaging reduced examination waiting time without increased radiation dose, simultaneously achieving excellent diagnostic performance and improving clinical staging in diagnosing gastrointestinal cancers.

Quantifying of highly radioactive and radiotoxic polonium-210 intake from cannabis (Cannabis sativa L.): impacts of different smoking and vaporization techniques.

This study investigates the radiation dose that humans receive from naturally occurring uranium-series radionuclides, with a focus on alpha-emitting polonium-210 (210Po), which has a half-life of 138.4days. Polonium is efficiently absorbed by living organisms and is estimated to contribute approximately 7% of the total effective dose from ingested natural internal radiation. The primary source of atmospheric 210Po is the decay of radon-222 (222Rn), which precipitates onto land and water surfaces, including crops. In Cannabis sativa, 210Po accumulates primarily through direct deposition on leaf surfaces and from fertilizers, particularly phosphate fertilizers. This study examined 10 samples of dried hemp (Cannabis sativa L.) legally available in Poland, assessing 210Po concentrations through radiochemical analysis. Various consumption methods were analyzed, including smoking with a glass pipe, a water pipe (bong), a cigarette (joint or spliff), and vaporization. The desorption of 210Po during combustion and vaporization was measured, revealing significant differences based on the method used. Results showed that smoking with a glass pipe resulted in the highest desorption of 210Po (approximately 80%), while water pipe and blunt smoking exhibited lower desorption rates (around 40%). The efficiency of 210Po adsorption in filters varied, with water filters showing about 8% absorption and cellulose filters about 20%. Vaporization results indicated that the desorption of 210Po increased with temperature. These findings underscore the importance of considering the method of consumption when calculating the radiation dose from 210Po, as the differences can significantly impact the accuracy of dose assessments. The study highlights the need for further research to optimize safety guidelines for cannabis consumption in relation to radioactive contaminants.

Patient radiation risk reduction by controlling the tube start angle in single and dual source spiral CT scans: A simulation study.

Organ doses in spiral CT scans depend on the tube startangle. To determine the effective dose in single source CT (SSCT) and dual source CT (DSCT) scans as a function of tube start angle and spiral pitch value to identify the dose reduction potential by selecting the optimal startangle. Using Monte Carlo simulations, dose values for different tube positions with an angular increment of and a longitudinal increment of were simulated over a range of with collimations of , , and . The simulations were performed for the thorax region of six adult patients based on clinical CT data. From the resulting dose distributions, organ doses and effective dose were determined as a function of tube angle and longitudinal position. Using these per-view dose data, the individual organ doses, as well as the total effective dose, were determined for spiral scans with and without tube current modulation (TCM) with pitch values ranging from 0.5 to 1.5 for SSCT and up to 3.0 for DSCT. The dose of the best and worst tube start angle in terms of dose was determined and compared to the mean dose over all tube startangles. With increasing pitch and collimation, the dose variations from the effective dose averaged over all start angles increase. While for a collimation of , the variations from the mean dose value stay below for SSCT, we find that for a spiral scan with a pitch of 3.0 for DSCT with TCM and collimation of , the dose for the best starting angle is on average lower than the mean value and lower than the maximumvalue. Variation of the tube start angle in spiral scans exhibits substantial differences in radiation dose especially for high pitch values and for high collimations. Therefore, we suggest to control the tube start angle to minimize patientrisk.

Total Radiological Dose and Safety Assessment of Workers in Radioactive Liquid Waste Storage Location in Al Tuwaitha Site

This study aims to determine the total effective dose (external and internal) in the radioactive liquid Waste Hall (WH) in the Radiochemistry Laboratories building (RCL) in Al- Tuwaitha site in order to estimate the radiation risk for workers in this place. The external effective dose was calculated by an indirect method using ThermoLuminescent Dosimeters (LiF: Mg, Ti (TLD-100)) by placing them in the waste hall for one month. The internal effective dose was estimated by collecting eight air samples (environmental samples) from different locations in WH using an air sampler pump (Sniffer) to collect air samples loaded with particles or dust which are deposited on cellulose filter papers (φ 125mm). This was done for two flow rates the lowest and the highest values of the air sampler pump of 5CFM and 20CFM, respectively.The filter papers were chemically treated using the digestion method. The radionuclides in these samples were measured using a gamma spectrometry system equipped with a high-purity germanium detector (HPGe), and the radioactivity concentration was measured using a gross alpha beta gamma system. The results showed 137Cs of low concentration was deposited on the filter paper. The total annual effective dose rate (external and internal) results showed that the highest in WH was (6358.97μSv/year) for the low probability scenario and (1589.74 μSv/year) for the realistic scenario.

Dose assessment from exposure to uranium and radon in groundwater in Safi province, Morocco

ABSTRACT In this study we evaluate the uranium and radon concentrations in groundwater from the Province of Safi. The samples were collected from 58 wells across five communes and analyzed using the LR-115 type II detector. Results indicate that uranium concentrations ranged from the Limit of Detection (LLD) to 3.73 µg/l, with a mean of 0.72 µg/l, well below the World Health Organization’s safe limit of 30 µg/l. Radon levels varied from LLD to 2.39 Bq/l, with an average of 0.60 Bq/l, also below the United States Environmental Protection Agency’s limit of 11 Bq/l. The estimated total annual effective dose due to uranium and radon ranged from 3.47 to 18.84 µSv/y, with an average of 7.54 µSv/y, which is significantly lower than the European Commission’s recommended limit of 100 µSv/y. This investigation represents the first study of uranium and radon levels in groundwater in the Province of Safi, providing valuable data for future research and public health.

Radiological impact assessment of a dirty bomb using Hotspot Code and AI: Insights from spent nuclear fuel isotopes

This study evaluates the potential radiological effects resulting from the use of a Radiological Dispersal Device (RDD), commonly known as a “dirty bomb,” in Dhamar City, Yemen, focusing on its impact on human health. Seasonal atmospheric variations were analyzed using the HotSpot Health Physics Code to model the Total Effective Dose Equivalent (TEDE) distribution following an explosion. The TEDE’s effect on different human organs was assessed, considering both external and internal radiation exposures. The study demonstrated that winter nights posed the highest radiation risk, with dose distribution areas of 0.018 km2, 0.14 km2, and 3.3 km2 for inner, middle, and outer zones, respectively, surpassing other seasonal and daily values. Conversely, summer recorded the lowest radiation spread. A detailed temporal analysis during winter nights showed an initial TEDE of 9.5 Sv at 0.1 min post-explosion, which decreased exponentially to 1.3 Sv after 2000 min (33.3 h) and further to 0.0038 Sv after 6500 min (108.3 h) with the aid of AI-enhanced “Long Short Term Memory Networks (LSTM)”. The highest radiation doses to human organs within a 100 m2 area during the initial 10 min post-detonation were significantly above permissible limits, with critical organs like the surface bone, liver, and red marrow receiving doses of 68 Sv, 12 Sv, and 5.5 Sv, respectively. These findings underline the need for robust emergency response strategies and long-term health monitoring to mitigate the adverse health impacts of RDDs. The comprehensive assessment presented in this study, enhanced by artificial intelligence, provides essential data for improving public health safety and emergency preparedness in regions susceptible to radiological threats.

Assessing radon hazard in drinking water: A comprehensive approach integrating deterministic and probabilistic methods with water consumption routines

The research aimed to determine the spatiotemporal distribution patterns of radon activity concentrations in tap water of Yerevan city and assess radon-associated hazards using both deterministic and probabilistic approaches. This was accomplished by integrating one-year monitoring data of radon in water with water consumption habits among adult population clusters, which were identified through food frequency questionnaire in Yerevan.The study findings indicated variations in radon activity levels across administrative districts. The highest average activity concentrations were detected in Davtashen (7.07 Bq/L), while the lowest average was observed in Kanaker-Zeytun (1.57 Bq/L). The overall pattern of spatiotemporal variation during monitoring period revealed higher prevalence of radon in water in the northern and western parts of the city compared to the east and south, indicating different sources of drinking water. The radon-associated hazard assessment from water, using a deterministic approach (e.g., inhalation, ingestion, radon dissolution in blood, total effective dose), revealed values below the individual dose criterion (IDC) of 0.1 mSv/y. Monte Carlo simulation revealed a probability of exceeding IDC in specific water consumption-based groups. Residents of Yerevan who drink more than 3 L water daily with the highest observed activity concentration of 11.4 Bq/L, have an 86.26 % chance of exceeding IDC. Residents consuming 2.1 L water daily have a 7.02 % chance of exceeding IDC.The study highlights the importance of applied principles and methodologies for radon monitoring, particularly considering actual water consumption data and different risk assessment approaches. Considering the worst-case scenario results, it is recommended to keep tap water consumption up to 3 L per day, keeping the tap open longer to reduce radon levels. It also emphasizes the need for continued monitoring, given the variations in radon activity. The study provides valuable insights into radon exposure assessment, mitigation, and action plans in terms of water safety and public health.

Assessment of Occupational Radiation Exposures at Ghana Research Reactor-1 Facility.

The annual occupational doses for workers at the Ghana Research Reactor-1 facility were assessed for the period 2018-2021. The dose records of monitored staff were retrieved and analysis done for dose distribution and collective effective doses. Thermoluminiscent dosimeters were used to monitor the occupational exposures. The dosimeters were evaluated for the cumulative radiation dose levels using the Harshaw 6600 TLD reader system. Annual dose of 1.52 mSv/year was the maximum acquired by an individual. An annual average effective dose range of 0.20-1.36 mSv was determined for all workers. The annual total collective effective dose was established to be in the range of 0.40-10.08 man-Sv. The 20 mSv annual limit for occupational exposure was not exceeded for monitored workers. The assessment shows that the GHARR-1 facility, in terms of radiation health effects, is a favorable environment for workers since exposures are mostly below occupational exposure limit.

Transfer functions for QA /QB international regulatory limits for the safe transport of radioactive materials

This paper presents a proposed revision of the International Atomic Energy Agency transport regulations, related to the A 1 and A 2 limit values used to determine the radioactive transport classification. Based on the ‘Q system’, a novel methodology was introduced to derive QA and QB values related to scenarios involving external exposure from a distant source. These values are key parameters that respectively represent the total effective dose and total equivalent dose to the skin, from all primary and secondary particles contributing to radiation exposure. The International Working Group (WG A 1/A 2) is established and associated with the TRANSSC Technical Expert Group on Radiation Protection. A review of the A 1 and A 2 values is performed in response to identified limitations within the existing Q system. The followed approach is based on Monte Carlo simulations that enabled the development of transfer functions aimed at reducing computational time and increasing the flexibility of dose evaluations for any radionuclide with known particle emission spectra. This method allows updating the QA and QB values to account for future data evolutions (decay data, fluence-to-dose conversion coefficients) and standardizing the calculation of regulation limits across all referenced radionuclides and scenarios related to external exposure. The transfer functions are established using three Monte Carlo simulation codes—FLUKA, Geant4, and MCNP—and address the previous limitations of the ‘Q system’, reflecting the latest International Commission for Radiation Protection recommendations and improvements in calculation techniques. The results of the WG show consistent agreement across the codes, with minor discrepancies observed at low primary energies due to statistical uncertainties and different handling of stopping power for electrons/positrons in the codes. This revised approach aligns with current standards and recommendations, ensuring that the radiological consequences of transport accidents are acceptable for the new A 1 and A 2 limits from a radiological protection perspective.

Measurement of gross alpha radioactivity levels and estimation of annual effective dose in hazelnut kernels

Abstract The present study investigates gross alpha (GA) radioactivity levels in hazelnut kernels purchased from markets in Türkiye. 10 different hazelnut samples were crushed and made ready for counting. The alpha counts were obtained via ELSEC 7286 low level alpha counter with ZnS scintillator and EMI 6097B photomultiplier tube. The samples were placed in front of the detector to acquire the counts. All samples were counted isochronously. In addition to the GA activity measurement, total annual effective dose (AED) value for different age groups owing to ingestion was calculated for each sample. It was observed that the GA radioactivity levels in the samples were quite low, and total AED values were considerably lower than the WHO worldwide average AED value (290 μSv/year).

A comprehensive dosimetry analysis of barakah nuclear power plant: Integrating gaseous and liquid radionuclide dispersion across multiple units

Monitoring radioactive releases during the normal operation of power plants is crucial to ensure compliance with safety limits set by regulatory bodies for environmental safety. In the case of the Barakah nuclear power plant in the UAE, comprehensive multiunit dispersion modelling and radiological safety analysis have been conducted. Utilizing the HotSpot Health Physics Code and GENII (Second-generation environmental dosimetry), assessments were made for both 37 gaseous and 51 liquid source terms generated by GALE. Release rates for source terms were determined using GALE based on APR 1400 specifications. HotSpot employed the Gaussian Plume model to simulate the dispersion of gaseous source terms up to 80 km surrounding the plant, calculating Total Effective Dose Equivalent (TEDE) and Committed Effective Dose Equivalent (CEDE) in rural and urban areas. Findings indicated that neither scenario exceeded the 1 mSv threshold for the general public nor the 20 mSv limit for operational workers. Notably, skin, thyroid, and surface bones exhibited the highest CEDE, primarily influenced by iodide radionuclides. GENII's Surface Water module modelled the effects of liquid source terms, accounting for various contamination and exposure pathways such as external exposure and ingestion across different age groups. The calculated doses remained well below FANR's annual limits, with negligible cancer incidences and fatalities predicted for one year of exposure.

Assessment of naturally occurring radionuclides in surface soil and drinking water from western part of Yadgir district Karnataka, India.

Radionuclide activity of the selected radionuclides 238U, 232Th and 40K was measured in surface soil samples collected from 40 villages of the western part of Yadgir district of Karnataka. A 4″×4″ NaI (Tl) detector based on a gamma spectrometer is used for the estimation of radionuclides. The major type of soil in this region is sandy and red. The 222Rn activity concentrations in drinking water were determined by the Emanometry method. The 222Rn activity in ground water is found to vary from 1.73 to 155.6Bql-1. The total annual effective doses because of 222Rn inhalation and ingestion range from 4.72 to 424.84μSv y-1 with an average value of 108.8μSv y-1, respectively. Among the sampling stations, Shahapur and Shorapur soil samples show higher activity values than the Kembhavi and Hunasagi sampling stations soil samples.

Ambient gamma radiation level around Kaveri river basin, Karnataka state, India.

Studies on ambient gamma radiation in indoor and outdoor environment and their effect on human health have created interest among the researchers across the world. The present study represents the results of indoor and outdoor ambient gamma dose rates around the Kaveri river basin from Talakaveri (Madikeri district) to Mekedatu (Ramanagara district) by using portable Environmental Radiation Dosemeter. The annual effective dose in the present study area varies between 0.14mSv.y-1 and 0.58mSv.y-1 with an average value of 0.30mSv.y-1 for indoor radiation. The outdoor annual effective dose ranged between 0.01mSv.y-1 and 0.14mSv.y-1 with an average value of 0.06mSv.y-1. The total annual effective dose varies from 0.17 to 0.72mSv.y-1 with an average value of 0.36mSv.y-1. The calculated values of indoor and outdoor annual effective dose in the study area (are found to be lower than the world average values (1mSv.y-1 and 0.48mSv.y-1).

Assessment of radiation dose due to 238U, 226Ra, 222Rn and 210Po in groundwater of Kodagu district, India.

Natural radionuclides are universally spread and can be found in varying levels in rock, soil and water depending on the geology. A potential health threat may be caused by them to humans on consumption of water, food and inhalation of air due to the presence of radionuclides. In the present study, an attempt has been made to study the distribution of 238U, 226Ra, 222Rn and 210Po in groundwater samples of Kodagu district, India. The activity concentrations of 238U, 226Ra, 222Rn and 210Po were found to vary from 0.44 to 8.81μgL-1, 0.71 to 7.66 mBqL-1, 1.54 to 9.61BqL-1 and 0.47 to 4.35 mBqL-1, respectively. The associated dose due to radiation was assessed and was observed to be below the recommended standards. The total effective dose to the population was calculated and was found to be less than the recommended WHO standard of 100mSv.

Radiological impact of hydrocarbon waste release on drinking water of ughievwen and udu communities, delta state Nigeria

Well water quality has been characterized with constant and continuous changes via the interaction of rock, soil and natural nano-filters which terminates at the aquiferous layer for clean well-water collection. The continuous exploration and production of crude oil has resulted significant increase of unwanted elements such as naturally occurring radionuclides in the water-bed which necessitates this study. The study determines the radionuclides based health impact or hazards associated with drinking water from crude oil exploration/production release in Ughievwen and Udu communities of Delta State, Nigeria. Sixty well water samples (three samples from each community) were collected and analyzed using sodium iodide (Nal (Tl)) detector. The obtained mean values of 238U, 232Th and 40K are 6.91 ± 1.62BqL−1, 4.39 ± 1.47 BqL−1 and 24.54 ± 1.59 BqL−1 respectively. The 238U, 232Th and 40K results showed that the measured values are higher than the world standard (UNSCEAR; WHO) and the control values The mean values of total annual effective dose of different age groups are: 11.08 mSvy−1, 2.54 mSvy−1, 1.93 mSvy−1, 2.52 mSvy−1, 7.03 mSvy−1 and 1.12 mSvy−1 respectively. While the mean committed effective dose of adult is 55.94 mSvy−1. The total annual effective dose, committed effective dose, cancer risks and hereditary effects are all lower than recommended limit (WHO; ICRP; USEPA) and reported scientific values except 11.08 mSvy−1 and 7.03 mSvy−1 that are higher than limit. It is evident from obtained results that the drinking water may not be radiologically safe for use by the public, which necessitates routine monitoring and caution to circumvent increase in radiation and the radiological of the studied communities’ drinking water. This is to avoid long term radiological risk arising from accumulation of such release in the studied communities.

Simultaneous indoor radon/thoron and in situ outdoor gamma dose measurements and estimation of annual effective dose in a tin mining area of Jos Plateau, Nigeria.

Radon, a radioactive gas can increase the risk of lung cancer when breathe in. Indoor Rn-222 and Rn-220 concentrations were determined using passive radon monitor in some dwellings in a Sn mining area of Jos Plateau. Outdoor gamma radiation was also measured with a hand-held survey meter. The range of Rn-222 and Rn-220 concentrations was from 7-53Bq m-3 to 41-267Bq m-3 with averages of 27±17 and 92±65Bq m-3, respectively. The mean total effective dose due to Rn-222+Rn-220 was estimated as 2.84±1.57mSv y-1. Rn-220 contributed between 50 and 95% to the total annual effective dose. There was no correlation between indoor Rn-220 and Rn-222 concentrations in the dwellings. Outdoor gamma radiation measured was between 0.31±0.06 and 0.62±0.08μSv h-1, and mean annual effective dose calculated was 1.14±0.21mSv y-1. It is concluded from this study that thoron should not be neglected in dose assessment.

Assessment of environmental radioactivity concentration and effective dose rates from radon gas exposure from water samples in Gezira State, Sudan

A study was conducted in Gezira State, Sudan, to estimate the concentration of radon and the annual effective dose rate in water samples based on inhalation, ingestion, and age group. The study collected 26 samples from different locations. The results showed that the mean concentration of radon was 7.68 ± 1.07 Bq.l−1, and the mean effective dose rate of radon released from water to indoor air was 19.17 ± 2.68 μSv.y−1. The average effective dose rates calculated from ingestion, inhalation, and the total annual effective dose rate were 18.81 ± 2.63, 19.34 ± 2.71, and 38.15 ± 5.34 μSv.y−1, respectively. The annual effective dose rates for infants, children, and adults were calculated to have mean values of 80.60 ± 11.27, 53.73 ± 7.51, and 38.38 ± 5.37 μSv.y−1, respectively. The study found that 23.1% of the samples exceeded the maximum contamination level, while 76.9% were below the reference levels set by the USEPA, WHO, and EU. Despite the increase in radiation dose with age and consumption rates, the radiation dose from water was lower than the recommended limits set by UNSCEAR and WHO. Additionally, the bronchial epithelium received twice the radiation dose compared to the stomach walls.