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In this study, natural radioactivity concentration and dosimetric values of fly ash samples were collected and evaluated from the landfill area of the coal-fired power plant (CFPP) complex at Binh Thuan, Vietnam. The average activity concentration of 238U, 226Ra, 232Th and 40K were 93, 77, 92 and 938 Bq kg−1, respectively. The average results of for radon dose, indoor external, internal, and total effective dose equivalent (TEDE) were 5.27, 1.22, 0.16, and 6.65 mSv y−1, respectively. The average emanation faction for fly ash were 0.028. The excess lifetime cancer risks (ELCR) were recorded as 20.30 × 10−3, 4.26 × 10−3, 0.62 × 10−3, and 25.61 × 10−3 for radon, indoor, outdoor exposures, and total ELCR, respectively. The results indicated that the cover of shielding materials above the landfill area significantly decreased the gamma radiation from the ash and slag in the ascending order: Geoline

Soil is the main source of concentration of radon and thoron gases in the indoor environment. The level of radon and thoron concentration mainly depends upon the radium, thorium contents and radon exhalation, thoron exhalation from the soil. The exhalation rate is the primary index to estimate the natural radioactivity potential of soil. The radium, thorium and potassium activity concentration were analyzed by NaI (Tl) gamma ray spectrometer. Radon and thoron surface exhalation rates were determined by scintillation-based detector SMART RnDuo Portable Radon Monitor. The geometric mean value of radon mass exhalation rate is 1.3 mBqkg-1h−1 and thoron surface exhalation rate is and 951.5 mBqm-2s−1. The geometric mean values of activity concentration of 226Ra, 232Th and 40K were 30.3 Bqkg−1, 45.8 Bqkg−1 and 339.9 Bqkg−1 respectively. The Radium equivalent activity concentration for all the soil samples was below the level of 370 Bqkg−1, recommended for building materials, by OECD 1979 (Organization for Economic Cooperation and Development).

The present study was carried out to assess the potential radiation hazards to the public, especially the persons who consumed onion and garlic plants widely during coronavirus disease in Thi Qar province South of Iraq. Nine samples collected from the market (5 samples onion and 4 sample Garlic), which classified according to their origin. Using 3″x3″ NaI (Tl) gamma ray spectroscopy system, the radioactivity concentrations of the natural radionuclides radium-226, thorium-232 and potassium-40 were determined. The results obtained showed that the average concentration of radioactivity of radium-226, thorium-232 and potassium-40 is 3.398 Bqkg−1, 4.667 Bqkg−1 and 216.738 Bqkg−1, respectively, for onion and 2.808 Bqkg−1, 3.524 Bqkg−1, and 172.064 Bqkg−1 for garlic. The results also showed that the average annual total effective dose of the three nuclides is 122.955 μSv.y-1 for onion and 97.231 μSv.y-1for garlic. Other relevant risk parameters were also calculated, such as equivalent activity concentrations, absorbed dose, excess lifetime cancer risks, and other health risk parameters. One of the most important conclusions reached by this study is that the natural radioactive elements in onions and garlic do not pose a great danger to their consumers, especially those infected with the COVID-19. Because the concentrations of these radioactive elements do not exceed the permissible limits recommended by recognized scientific organizations and agencies such as International Commission on Radiological Protection (ICRP), United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), and World Health Organization (WHO).

Numbers of radioactive tailings were produced in the process of uranium mining and milling.In this study,radiation environment monitoring was carried out on a decommissioned uranium mining and mill...

The Rooppur Nuclear Power Plant (RNPP), the first nuclear power plant in Bangladesh with a capacity of 2.4 GWe, is under construction on the bank of the river Padma, at Rooppur in Bangladesh. Measurement of background radioactivity in the natural environment adjacent to RNPP finds great importance for future perspectives. Soil and sediment samples collected from upstream and downstream positions of the Padma River (adjacent to RNPP) were collected and analyzed by HPGe gamma-ray spectrometry for primordial radionuclides. The average activity concentrations (in Bqkg−1) of 226Ra, 232Th and 40K radionuclides in soil samples were found to be 44.99 ± 3.89, 66.28 ± 6.55 and 553 ± 82.17 respectively. Respective values in sediment samples were found to be 44.59 ± 4.58, 67.64 ± 7.93, 782 ± 108. Relevant radiation hazard indices and dosimetric parameters were calculated and compared with the world average data recommended by US-EPA. Analytical results show non-negligible radiation hazards to the surrounding populace. Measured data will be useful to monitor any change of background radioactivity in the surrounding environment of RNPP following its operation for the generation of nuclear energy.

Building materials contribute significantly to the indoor radon and thoron levels. Therefore, parameters that influence the exhalation rates of radon and thoron from building material need to be analyzed closely. As a preliminary study, the effects of humidity on exhalation rates were measured using a system with an accumulation chamber and RAD7 detector for Korean brick, Korean soil, and Indonesian brick. Resulting doses to a person who resides in a room constructed from the building materials were assessed by UNSCEAR method for different air exchange rates. The measurements have revealed that Korean brick exhaled the highest radon and thoron while Indonesian brick exhaled the lowest thoron. Results showed that for a typical low dense material, radon and thoron exhalation rate will increase until reached its maximum at a certain value of humidity and will remain saturated above it. Analysis on concentration and effective dose showed that radon is strongly affected by air exchange rate (ACH). This is showed by about 66 times decrease of radon dose from 0.00 h−1 to those of 0.50 h−1 ACH and decrease by a factor of 2 from 0.50 h−1 to those of 0.80 h−1. In case of thoron, the ACH doesn't have significant effects on effective dose.

The present study was conducted to determine the activity concentration of 238 U, 232 Th and 40 K in coastal sediments samples from Poombuhar to Karaikal along East coast of Tamilnadu, India using gamma ray spectrometry. The average activity concentration for 238 U, 232 Th and 40 K were obtained as 36.82 (Bq kg −1 ), 50.11(Bq kg −1 ) and 320.38 (Bq kg −1 ), respectively. These obtained results were used to calculate the radiological hazard parameters like radium equivalent activity (Ra eq ), absorbed gamma dose rate (D R ), the annual effective dose equivalent (AEDE), Annual gonadal dose equivalent (AGDE), Activity utilization index (AUI), External hazard index (H ex ), Internal hazard index (H in ), Gamma representative level index (RLI) and Excess lifetime cancer risk (ELCR). The computed radiological parameters values are compared with the internationally approved recommended values. The multivariate statistical method is used to simplify and organize large data sets to indicate natural associations between samples and variables.

The activity concentration of 226Ra, 232Th and 40K were determined in clay samples collected from Tiruvannamalai district, Tamilnadu using gamma ray spectrometry. The determined activity concentration ranges from BDL to 16 Bq Kg−1, 18 to 192 Bq Kg−1, 288 to 901 Bq Kg−1 for 226Ra, 232Th and 40K respectively. The concentration of these radionuclides is compared with world average values. Radiological risk evaluation was done by calculating radium equivalent activity (Raeq), absorbed gamma dose rate (DR), annual effective dose rate (HR), annual gonadal dose equivalent (AGDE), criteria formula (CF), representative level index (RLI), activity utilization index (AUI), gamma index (Iγ), alpha index ((Iα), the external hazard (Hex) and internal hazard (Hin) due to internal exposure to radionuclides distributed in clay samples. Multivariate statistical techniques were used to study the relation between activity concentration and radiation hazards of clay samples.

Natural radioactivity in soil, rock, building materials, and water is very important for the radiological protection point of view. Radon is one of the carcinogenic radioactive gases. Radon causes ...

The natural radioactivity of ceramic and cement samples collected from Riyadh, Saudi Arabia, was analyzed using a gamma-ray spectrometry system with a high-purity germanium detector. The specific activities of 226Ra, 232Th, and 40K ranged from 45.0 ± 4.2 to 177.8 ± 7.5 Bq/kg, 49.1 ± 2.6 to 228.4 ± 6.8 Bq/kg, and 370.0 ± 5.3 to 1269.0 ± 12.2 Bq/kg, respectively, for the ceramic samples and from 11.4 ± 2.0 to 28.7 ± 5.3 Bq/kg, 8.4 ± 1.3 to 10.8 ± 1.1 Bq/kg, and 50.7 ± 2.1 to 209.7 ± 3.5 Bq/kg, respectively, for the cement samples. The radium equivalent activity, external hazard index, absorbed dose rate, and annual effective dose were calculated using the above measurements in order to assess the radiological hazard associated with the studied building materials. The average values of these radiological indices for the ceramic samples were 299.4 ± 94.8 Bq/kg, 0.8 ± 0.3, 138 ± 42.4 nGy/h, and 0.68 ± 0.21 mSv/y, respectively, and for the cement samples, these values were 36.8 ± 7.74 Bq/kg, 0.12 ± 0.02, 20.35 ± 4.39 nGy/h, and 0.10 ± 0.02 mSv/y, respectively. The radiological indices of the studied samples were found to be within the range of those reported in recent similar studies conducted in other countries. The majority of the ceramic samples can be safely used as building materials for dwelling construction, although some samples slightly exceeded the average radium equivalent of 370 Bq/kg and the external hazard index limit of 1; the hazard indices for the cement samples, however, were all below the recommended world limits and can be considered safe for inhabitants.

Top soil samples across the state of Kuwait numering ninety were collected and analysed using gamma-ray spectrometry, to evaluate the elemental concentration of 238U, 232Th and 40K and their depletion/enrichment. Results of elemental concentration ranges from 0.48 to 2.61 mg/kg, 0.87–5.23 mg/kg, and 0.24–2.23%, with a mean values of 1.39 mg/kg, 3.47 mg/kg, and 1.18%, for the 238U, 232Th and 40K, respectively. Further analysis was conducted amongst the five identified soil types, i.e. Aquisalids (S1), Calcigypsids (S2), Petrocalcids (S3), Petrogypsids (S4), and torripsamment (S5). The highest radioactivity concentrations from both uranium and thorium were recorded in the S2 (Calcigypsids) soil, with a value of 1.71 (mg/kg) and 4.45 (mg/kg), respectively. Minimum and maximum values of 40K are 1.1(%) and 1.27(%) and is prevalent in Aquisalids (S1) and Petrocalcids (S3) soil types, respectively. Ratios of elemental concentration for 232Th/238U, 40K/238U, 40K/232Th across the soil types are 2.53, 0.09 and 0.03, with a correlation coefficient of 0.92, 0.34, and 0.38, respectively. A progressively higher 232Th/238U ratio is observed moving south-wards, indicating lower 238U content in soils from the south relative to the northern part. Overall results indicate Kuwait to be relatively an area with low level of natural radioactivity. Keywords: Gamma-ray spectrometry, NORM, Radioactivity concentration, Elemental concentration, Concentration ratio, Depletion/ enrichment

This work is a first contribution to the knowledge of natural radionuclides (226Ra, 238U, 40K, and 232Th) activities in phosphate rock (NORM), phosphogypsum, and phosphogypsum foam (TENORM) from the coastal fertilizer plants of Gabes (Southeastern Tunisia) and the assessment of their radiation hazards on human health and the surrounding environment. In the three studied materials, activities were found to be in the range of 35.4 (40K)–375.1 (226Ra), 10.0 (40K)–220.2 (226Ra), and 79.2 (232Th)–1168.6 Bq kg−1 (226Ra), respectively. Considering the studied radionuclides and materials, the corresponding decreasing activity orders were found to be 226Ra > 238U > 40K > 232Th and PGF > PR > PG, respectively. All human health hazard indices exceeded the worldwide recommended safety limits, which show that the workers in Gabes phosphate fertilizer plants as well as the neighboring human community may potentially be exposed to significant radiation, which may cause several diseases and malformations. It is therefore recommended to avoid and/or reduce the potential fertilizer industry radioactive impact in the area.

For the sake of completeness of the surveillance process concerning the spread of depleted uranium (DU) in the Arabian Gulf region, we have applied a simple gamma spectroscopy technique to evaluate its content in Al Jolan, Nazzal and Askari districts in Al Fallujah area, Iraq for the first time and after more than one decade. The measurements were carried out along the lines of the wars that have been witnessed in Iraq last period and expected to be the region of impact of residuals of a large quantity of DU. The observed radionuclides are 4 K and other naturally occurring radioactive members of uranium and thorium series. The obtained results show that, the average specific activity concentrations of 226Ra, 232Th, 4 K, 210Pb 238U and 235U in different soil samples collected from Al Fallujah area, Iraq in range of 20.09 ± 4.0 to 21.94 ± 2.4, 11.51 ± 2.3 to 11.75 ± 3.2, 96.53 ± 8.0 to 112.13 ± 49.8, 19.98 ± 4.6 to 20.76 ± 4.8, 25.4 ± 3.9 to 26.1 ± 6.0 and 1.28 ± 0.18 to 1.34 ± 0.21 respectively. The obtained values of Raeq for all the investigated samples are less than the recommended limit of 370 Bq kg−1 and those for Hex are less than one. These results have been compared with the previous works and the world mean values specified by the UNSCEAR reports. The mean ratio of 238U/235U activity in all cases is about the natural value (21.73) which is less than its value in case of DU (76.92). The present obtained results of DU levels show that although a large amount of DU was released in Iraq during the Gulf wars, the tested samples are DU free. This may be attributed to the reduction of DU from the soil surface by wind or sandstorms and the downward leaching process.

A measurement of technologically enhanced natural occurring radioactivity materials (TENORM) in sand samples in the petroleum-producing communities of Ma'rib Province Yemen was carried out. The HPGe detector was utilized to perform the measurements. The samples were collected from 35 sites. All samples were placed in a properly cleaned container and sealed for 28 days to attain a state of secular radioactive equilibrium before analysis. The radioactivity concentrations for nuclides 40K, 232Th, 226Ra, and 238U ranged between 430.716 - 654.666, 4.347 - 43.935, 4.824 - 27.936, and 1.083 - 15.437 Bq kg-1 respectively, with averages 560.583, 20.676, 14.556 and 9.072 Bq kg-1 respectively. The results did not show any radiation risks.

Kargi is located between latitudes 2.476944 and 2.520833 N and longitudes 37.542778 and 37.601944 E covering an area of approximately 31.26 km2. Health facilities in the area have reported a number of cancer disease cases and deaths annually thus prompting for the study. 14 number water samples were collected in Kargi, Marsabit with the aim of assessing the area’s environmental radioactivity together with radiological health hazard. Radionuclides are considered as radiation exposure source which has been recorded to have damaging health effects for such populations living in high back-ground radiation areas. Natural radioactivity concentrations owing to 40K, 232Th and 226Ra radionuclides were measured by using gamma ray spectrometry employing a high purity germanium (HPGe) type detector at University of Nairobi’s Nuclear Science & Technology Institute, INST. To assess the natural radioactivity’s radiological hazard, absorbed dose rate, radium equivalent together with effective dose have been computed and results compared with internationally accepted values. The mean values for activities for 40K ranged from -0.88 to 81.22 Bql-1 (mean: 52.68±25.07 Bql-1), 232Th ranged from -2.00 to 7.99 Bql-1(mean: 2.20±2.74 Bql-1) and 226Ra ranged from -0.25 to 7.84 Bql-1(mean: 3.55±3.04 Bql-1). Mean 232Th and 40K values were 2 times and 5 times higher than the limit values respectively, hence the area can be categorized a high back-ground radiation area, HBRA. The mean values with their standard deviations for calculated and measured dose rates below and above surface (1 m from the ground) were 5.37±2.93 and 77.76±27.82 nGyh-1 respectively. The computed radium equivalent values of all 14 samples were lower than accepted limit of 370 Bqkg-1 (Lu Xinwei et al., 2006). The mean elemental ratio for Th/U was lower than 3, an indication of thorium depletion or enrichment in the area. Investigated waters in this area are acceptable for life-long human consumption since their values of annual effective doses proved lower than the world-wide values.

In the industrialized area of Lagos, vegetables are mostly cultivated through surface water irrigation. Untreated surface water has the potential of being contaminated with radionuclides fr...

The activity concentrations of 40K, 226Ra, and 232Th in the soil samples collected from Owo Local Government of Ondo state, Nigeria, were assessed by gamma spectrometric techniques using a ...

The main purpose of this study was to measure the natural radioactivity in some foodstuffs and agricultural soils from the Abyan Delta in Yemen and study the interaction between soil and foodstuffs...

Concentrations of natural nuclides (226Ra, 232Th and 4 K) and some heavy metals (Cu, Fe. Ni, Pb and As) were measured in groundwater collected from different locations in Makkah region in Saudi Arabia. In the radioactivity measurement, a high purity germanium detector system was used. In addition, chemical analysis was performed by an Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The average measured activity concentrations of the nuclides 238U, 232Th and 4 K were 0.558, 0.204 and 4.581 BqL−1, respectively. The total annual effective doses for ingestion of radionuclides in the water samples were 0.472 mSv for children and 0.169 mSv for adults. These results were lower than the recommended value (1.0 mSvy−1), as reported by WHO. The chemical analysis results showed that these water samples contain (Ca, Mg, Cu, Fe. Ni, Pb and As) elements. The concentration values were evaluated and compared with the internationally verified values. This study provides essential information for consumers and authorities; those at exposure risk from mineral water intake. Keywords: Natural radioactivity, Effective dose, Risk, Chemical analysis, Heavy metals

In this work, the natural radioactivity levels of several building materials used in Sri Lanka, were determined in terms of Bq kg−1, and to calculate the radiological effects caused by this radioactivity. Activity concentrations of 226Ra, 232Th and 40K in eighteen samples of manufactured building materials were measured using gamma spectroscopy based on high purity germanium detector with an efficiency of 48% at 1332.5 keV. The measurement of the activity concentration in building materials is required to estimate the excess dose to public dwelling in such buildings. BEGe detector is a well-chosen equipment for this purpose. The activity concentrations for 226Ra, 232Th and 40K from the selected building materials ranged from (5.0 ± 0.5 to 45.2 ± 2.9 Bq kg−1), (7.1 ± 0.6 to 68 ± 5.9 Bq kg−1) and (42.8 ± 3.8 to 1773 ± 54 Bq kg−1) respectively. Radium equivalent activities, absorbed dose rate, the value of external hazard indexes and alpha indexes were calculated for the measured samples to assess the radiation hazards arising from using those materials in the construction of dwellings. The average value of indoor annual effective doses of Sri Lankan building materials was 0.22 mSv. Also the average value of outdoor annual effective doses of Sri Lankan building material was 0.05 mSv. It has been noted that the values of annual effective dose of Sri Lankan building materials were below the world average value of terrestrial annual radiation exposure which was 0.48 mSv. Therefore, the types used in the current study are quite safe to be used as building materials.

This paper presents the radiometric survey results of the Mrima-Kiruku high background radiation (HBR) anomaly complex of south coastal Kenya. Utilizing a portable γ-ray spectrometer consisting of a 2.0 l NaI(Tl) backpack detector integrated with GPS to perform the relevant in-situ radiometric measurements, a novel geospatial gating method was devised to represent the measurements. The goal of this study was to assess radiation exposure and associated natural radioactivity levels in the complex and to compare the results obtained with those from previous preliminary related studies. Absorbed dose-rates in air were found to range ± 19–603 ± 28 Bq kg−1, 68 ± 6–326 ± 24 Bq kg−1 and 386 ± 12–1817 ± 51 Bq kg−1 respectively. It was concluded that the high air absorbed dose-rate values that were measured (>600 nGy h−1) are due to elevated activity concentrations of 232Th. Therefore there is significant (>1 mSv/y) radiological hazard to the inhabitants of the area particularly those who reside at the foothills of both Mrima and Kiruku Hills.

This paper contains preliminary results of a study on the physical and radiological characterization of concrete samples containing NORM. The natural radionuclides content in term of 226Ra, 228Ra, 232Th, 40K and the radon exhalation rate of the samples were determined. Two series of samples of concrete were prepared: samples belonging to both series were made of the same basic components (Portland cement CEM I 42,5R as binder, aggregate and plasticizer) but different amount of NORM residues and mineral additives were used. The concrete samples were characterize in term of absolute density, permeability, total and open porosity. The radiological content was evaluated by using gamma spectrometry and the radon exhalation rate measurements were performed using the dynamic method. Moreover, the Activity Concentration Index (I), introduced by the 2013/59/Euratom Directive, has been used in order to evaluate if concrete samples could exceed the reference level for effective dose due to gamma radiation in building materials.

In 2013 the European Commission has published its latest basic safety standards for protection against the dangers arising from exposure to ionising radiation (Council Directive 2013/59/Euratom). The council directive regulates radiation exposure from building materials through the presence of radioactivity (226Ra, 232Th and 40K) in these materials. Pivotal to successful regulation is the availability of a harmonised test method for the determination of the radionuclide concentrations as these nuclides form the basis for dose assessment and compliance. In 2017 a Technical Specification (CEN, 2017) on the determination of the activity concentrations of 226Ra, 232Th and 40K in construction products was published by the European Committee for Standardization (CEN). The purpose of this work is to give an outline of the proposed method, with the protocols for sampling, measurement and data processing as well as a summary of the robustness testing and the expert comments that have been received following the final consultation.

The emission intensities of 186.21keV, 46.54keV, XL(Bi) and XK(Rn) photons were measured with calibrated HPGe detectors. The efficiency was computed with the MCNP Monte Carlo code and validated using experimental points. Sources of Ra-226 were prepared from two different radioactive materials. The X-ray emission intensities in Ra-226 decay were determined without X-rays from the daughter decay products using a radon emanation source. The standard CMI source with Pb-210 was used and compared with a source prepared from the NPL solution delivered under the EMRP project "Metrology for processing materials with high natural radioactivity - MetroNORM".

RESRAD-BUILD is a code developed by Argonne US National Laboratory for assessing the radiological doses resulting from the occupancy of buildings contaminated with radioactive material. This freely downloadable software allows to consider multiple sources of contamination and to assess not only the external exposure pathway but also the dose resulting from inhalation or ingestion of contaminated dust as well as the dose from inhalation of radon. The software offers the possibility to assess in a flexible way the external dose from the natural radioactivity of building materials. A room model similar to the one used for deriving the activity concentration index of the 2013/59/euratom directive may easily be implemented and gives consistent results. A comparison is made with the calculations performed in the CEN technical report on dose-assessment of gamma radiation from building materials. An example of assessment of the external dose resulting from multiple layers of building materials is given where measurements data are used for the activity concentrations. The assessment allows demonstrating compliance with the reference level set up in the directive.

Natural radioactivity content and heavy metal concentration in the intertidal zone sand samples from the southern region of Tamil Nadu coast, India, have been analyzed using gamma ray spectrometer and ICP-OES, respectively. From gamma spectral analysis, the average radioactivity contents of 238U, 232Th, and 40K in the intertidal zone sand samples are 12.13 ± 4.21, 59.03 ± 4.26, and 197.03 ± 26.24 Bq/kg, respectively. The average radioactivity content of 232Th alone is higher than the world average value. From the heavy metal analysis, the average Cd, Cr, Cu, Ni, Pb, and Zn concentrations are 3.1, 80.24, 82.84, 23.66, 91.67, and 137.07 ppm, respectively. The average Cr and Ni concentrations are lower, whereas other four metal (Cd, Cu, Pb, and Zn) concentrations are higher than world surface rock average values. From pollution assessment parameter values, the pollution level is “uncontaminated to moderately contaminated” in the study area.

Portland cement is considered as an important basic material used for building construction. One of the main concern is that people spend more than 80% of their time indoors and they are eventually exposed to the cement or its raw materials for a long time. Therefore, assessment of natural radioactivity levels and radiological hazards associated with these materials is necessary. In this study, a total of 25 samples of five Portland cement brands favorably used in Thailand were analyzed by using gamma-ray spectrometry technique. The observed specific activities of 226 Ra, 232 Th and 40 K together with the radium equivalent activities were compared with the reported data for other countries and the world recommended levels proposed by the UNSCEAR–all obtained values were found within the acceptable limits. Additionally, for evaluation of radiological risk, six hazard parameters were considered. The estimated values of absorbed dose rate, external and internal hazard indexes, gamma and alpha indexes, annual effective dose equivalent, and excess lifetime cancer risk, all of them were found below the international standard of the maximum acceptable limits. Therefore, these studied results primarily confirm that all five brands of Thai Portland cement type I are radiologically safe to be used as construction materials with no significant impact of radiological hazards provided.

Presented are results of a study on accumulation of naturally occurring 210Po and 210Pb in ecological and conventional farming food products in Poland: fruits, vegetables and cereals. The main idea behind this research was to determine the activity concentrations of 210Po and 210Pb in ecological and commercial food as well as calculate and compare the effective dose (radiation) connected to different origin of analyzed food products consumption. The studies showed the majority of all compared food samples contained similar 210Po and 210Pb activities and statistically, the consumption of organic and commercial food would give similar annual effective dose.

In this study, nearly 84 marine sediment samples were collected from twelve points in four cities (Quseir, Safaga, Hurghada, and Ras Gharib) along the Egyptian Red Sea sectors. The collected samples were extensively examined to estimate the natural radioactivity level. The obtained results were compared to the reported ranges from other locations in different countries. Hazardous radiation parameters such as radium equivalent, annual dose, and external hazards were estimated and compared to United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) recommended levels. The values were recorded in the first natural radioactivity database of coastal sediments from Egyptian Red Sea cities. The dose rate for certain organs was evaluated. The results showed that Red Sea beach sediments are safe in terms of natural radioactivity. It can be concluded that they do not pose a risk to tourists going to the beaches for recreation or to sailors and fishers involved in economic activities along the Egyptian Red Sea coast.

In the present study, the activity concentrations of 226Ra, 232Th and 40K in the selected vegetables collected from different locations of Cameron Highlands, Pahang, Malaysia were determined using high purity germanium detector (HPGe). The average activity concentration of 226Ra, 232Th and 40K in vegetable samples were found as 6.05 ± 1.57, 4.91 ± 1.4 and 91.0 ± 14.74 Bq kg − 1 (dry weight), respectively. The activity results indicated that the highest activity concentrations of these radionuclides were measured in root vegetables as 9.42, 7.57 and 112.23 Bq kg − 1 , respectively. The annual effective dose due to intake of these radionuclides through ingestion of vegetable samples was estimated to assess radiological risks. The average annual effective dose was found as 213.27 μ Sv y − 1 . The annual effective dose was found to be within the recommended values (250–400) μ Sv y − 1 as given by WHO.

Due to the geological makeup of the various water bodies, mineral- and groundwater can be expected to contain levels of naturally occurring radioactive material (NORM) exceeding that of tap and surface water. Acknowledging mineral water to form a vital component of the intake in maintaining the healthy life of an individual, it nevertheless remains important to study the associated radiological implications of NORM content, especially in regard to the consumption of bottled mineral water, the presence of which is prevalent in modern urban society. In present study, various brands of bottled mineral waters that are commonly available in Malaysia were obtained from local markets, the presence of NORM subsequently being assessed by HPGe γ-ray spectrometry. The activity concentrations of the radionuclides of particular interest, 226 Ra, 232 Th and 40 K, were found to be within the respective ranges of 1.45±0.28‒3.30±0.43, 0.65±0.18‒3.39±0.38 and 21.12±1.74‒25.31±1.84 Bq/L. The concentrations of 226 Ra, of central importance in radiological risk assessment, exceed the World Health Organisation (WHO, 2011) recommended maximum permissible limit of 1.0 Bq/L; for all three radionuclides taken together, the annual effective doses are greater than the WHO recommended limit of 0.1 mSv/y, a matter of especial concern for those in the developmental stages of life.

We establish baseline measurements for radioactivity concentration in the soil samples collected from the Qatarian peninsula. The work focused on the naturally occurring and technically enhanced levels of radiation associated with 235,8 U and 232 Th natural decay chains and the long-lived naturally occurring radionuclide 40 K in 129 soil samples collected across the landscape of the State of Qatar. Three radiological distribution maps showing the activity concentrations of 226 Ra, 232 Th and 40 K were constructed. Two soil samples were found to be elevated to the favour of 226 Ra concentration and significantly above the average and global values. Notably, these samples were collected from an area within an oil field (NW Dukhan). The mean values of activity concentrations of 226 Ra, 232 Th and 40 K for the full cohort of samples were found to be 17.2±1.6, 6.38±0.26 and 169±5 Bq/kg, respectively. These values lie within the expected range relative to the world average values in soil samples of 30, 35 and 400 Bq/kg, respectively.

In this work a comparison of the activity content and radon exhalation rate of five concrete mixtures is carried out by NRG (NL) and SOREQ (IL) using the measurement standards applicable in the Netherlands and Israel, respectively. Comparison of the activity concentrations obtained by NRG and SOREQ for all concrete mixtures comply with proficiency requirements in literature and demonstrate that the results agree within a 99% confidence level. Variations in the weighted sum of the activity concentrations – computed according to the European and Israeli gamma indices – between the two laboratories are even smaller and well within the reported one standard deviation uncertainty. The measured radon exhalation rates agree within a confidence level of 90%, despite considerable differences in the applied methods and uncertainties in the material's radon exhalation that are beyond the measurement protocol. This includes the effects from humidity and aging, and it is mentioned that future guidance on the sample representativeness would be welcomed. Based on the findings of this work it is concluded that the methods for determining the activity concentration and the radon exhalation are equivalent methods and appropriate for testing of building materials that typically fall under radiation protection regulation. Furthermore, the methods can also be recommended for use in harmonised standards that are presently under development.

To get an insight into the radiological features of potentially reusable by-products in the construction industry a review of the reported scientific data is necessary. This study is based on the continuously growing database of the By-BM (H2020-MSCA-IF-2015) project (By-products for Building Materials). Selection criteria were defined for manual data mining in such a way to avoid the collection of too heterogeneous datasets. Currently, the By-BM database contains individual data of about 431 by-products and 1095 construction and raw materials. The By-BM database only consists out of measurement information on individual samples and not out of processed data that only gives a rough summary (such as only a range or average) of experimental results. As a consequence of the statistical analysis of the data, it was found that in the case of the construction materials the natural isotope content had a wider distribution than the by-products. However, the average of the Ra-226, Th-232 and K-40 contents of reported by-products were 2.00, 2.11 and 0.48, while the median was found 1.97, 1.24 and 0.53 times higher than the construction materials, respectively. The calculated Radium equivalent concertation was greater than the accepted value for residential properties of 370 Bq/kg in the event of 10.3% of total construction materials and 42.4% of by-products, while the I-indexes were above 1.0 index value with 17.3% and 58.2%, respectively. From the obtained data, it can be concluded that the reuse of industrial by-products in construction materials for residential purposes, without due diligence, can pose elevated risks to residents as a result of their high-volume usage. (C) 2017 Elsevier Ltd. All rights reserved. The project leading to this application has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 701932. R. Doherty's time was also supported by the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 643087. The authors would also like to acknowledge networking support by the COST Action TU1301. www.norm4building.org.

The chemical composition and natural radioactivity of the northern area of the western desert groundwater were determined to evaluate hydrogeochemical facies and assess groundwater quality for different uses. Many the groundwater samples belong to the Na + - Cl − , Na 2 SO 4 − type, followed by Ca 2+ - Mg 2+ - Cl − type. Only a few samples are of the Na + - HCO 3 − type. The spatial distributions of the major ions describe similar anomalies, with the highest concentrations found at the extreme northeastern margin of the oasis, as well as in its northern and northwestern parts. Fe is the most abundant toxic metal, followed by Cu and Mn. Anomalies of Cr, Ni and Zn are also detected. Rock/water interactions strongly affect the chemical composition of the groundwater. Dissolution and cation exchange are the main processes controlling the hydrogeochemistry. Most of the irrigation groundwater problems in the study area may be resolved using an effective drainage system. The estimated total annual dose due to ingestion of 238 U, 232 Th and 40 K in groundwater samples reveals that the groundwater is safe for human consumption. However, the toxic metal content of the Bahariya groundwater exceeds the permissible levels for both irrigation and consumption, and the water must be filtered through suitable membranes to exclude these toxic metals. Regular monitoring of the quality of this water for drinking is strictly required.

Measurements of natural radioactivity in local and imported samples of commercial granites used in Saudi Arabia were carried out by using gamma-ray spectroscopy with hyper-pure germanium detector. The activity concentrations measured of granite samples were determined for 226 Ra(from 1.53 to 77.16 Bq kg −1 ), 232 Th (from 0.51 to 89.82 Bq kg −1 ) and 40 K (from 19.47 to 1632.37 Bq kg −1 ). The corresponding average activity concentrations for 226 Ra, 232 Th and 40 K were 28.82, 34.83 and 665.08 Bq kg −1 , respectively. The radiological hazard parameters (radium equivalent, gamma index, external index, internal index, absorbed dose and annual effective dose) were calculated to assess the radiation hazards associated with granite samples. The obtained results are lower than the recommended limits. The results were compared with the published data of other countries. The measurements will help in the development of standards and guidelines for the use and management of these materials.

Activity concentrations of primordial radionuclides in sand samples collected from the coastal beaches surrounding Penang Island have been measured using conventional γ-ray spectrometry, while in-situ γ-ray doses have been measured through use of a portable radiation survey meter. The mean activity concentrations for 226 Ra, 232 Th and 40 K at different locations were found to be less than the world average values, while the Miami Bay values for 226 Ra and 232 Th were found to be greater, at 1023 ± 47 and 2086 ± 96 Bq kg 1 respectively. The main contributor to radionuclide enrichment in Miami Bay is the presence of monazite-rich black sands. The measured data were compared against literature values and also recommended limits set by the relevant international bodies. With the exception of Miami Bay, considered an elevated background radiation area that would benefit from regular monitoring, Penang island beach sands typically pose no significant radiological risk to the local populace and tourists visiting the leisure beaches.

A laboratory measurement of the α -decay half-life of 190 Pt has been performed using a low background Frisch grid ionisation chamber. A total amount of 216.60(17) mg of natural platinum has been measured for 75.9 days. The resulting half-life is ( 4.97 ± 0.16 ) × 10 11 years , with a total uncertainty of 3.2%. This number is in good agreement with the half-life obtained using the geological comparison method.

In this study, the activity concentrations of the natural radionuclides in phosphate rocks and its products were measured using a high- purity germanium detector (HPGe). The obtained activity results show remarkable wide variation in the radioactive contents for the different phosphate samples. The average activity concentration of 235U, 238U, 226Ra, 232Th and 40K was found as (45, 1031, 786, 85 and 765Bq/kg) for phosphate rocks, (28, 1234, 457, 123 and 819Bq/kg) for phosphate fertilizers, (47, 663, 550, 79 and 870Bq/kg) for phosphogypsum and (25, 543, 409, 54 and 897Bq/kg) for single super phosphate respectively. Based on the measured activities, the radiological parameters (activity concentration index, absorbed gamma dose rate in outdoor and indoor and the corresponding annual effective dose rates and total excess lifetime cancer risk) were estimated to assess the radiological hazards. The total excess lifetime cancer risk (ELCR) has been calculated and found to be high in all samples, which related to high radioactivity, representing radiological risk for the health of the population.

The gamma ray pit at the API Calibration Facility, located on the University of Houston campus, defines the API unit for natural gamma ray logs used throughout the petroleum logging industry. Future use of the facility is uncertain. An alternative method is proposed to preserve the gamma ray API unit definition as an industry standard by using Monte Carlo modeling to obtain accurate counting rate-to-API unit conversion factors for gross-counting and spectral gamma ray tool designs.

The use of a Radiation Alert Inspector device and a gamma-spectrometry system fitted with a Sodium Iodide (NaI) detector was used to determine the radioactivity concentration level of natural radionuclides 238U, 232Th, and 40K in soil in several locations in Orlu, Imo State, Nigeria. 19 soil samples were collected for analysis from several locations of factories, agricultural farming-lands, gullies and water eroded areas, and soil deposits very close to flowing waters from rocks, due to environmental concerns arising from human activities in this region. The activity concentration values for 238U, 232Th, and 40K were found to range from 0.14 to 9.34 Bq.kg−1, 0.03–3.75 Bq.kg−1, and 16.83–783.06 Bq.kg−1, respectively, with average mean values of 4.15, 1.64, and 134.13 Bq.kg−1. Radium equivalent activity, absorbed dose rate, and gamma index mean values for the samples were 16.822 Bq.kg−1, 8.528 nGyh-1, and 0.133 mSv respectively, the obtained values were below the safe limit values set by the United Nations Scientific Committee on the Effects of Atomic Radiation of 370.0 Bq.kg−1, 59.0nGyh−1, and 1.0 mSv. According to the findings, the regions under study are reasonably safe for human outdoor activities such as agriculture, construction, and factory operations., Highlights • Study area is devastated by landslides & water erosion, enhancing radio-exposure. • Aim of research is to measure Soil radionuclides; 238U, 232Th & 40K, in Orlu L.G.A. • Laboratory analysis was carried out at NIRPR, University of Ibadan, Nigeria. • The activity concentration of 40K exceeds the values of both 238U and 232Th. • Planting of bamboo trees in this regions should be encouraged., Terrestrial radionuclides; Radiological hazard; Radiation dose rate; Activity concentrations level; Orlu.

Radon daughters in the atmosphere of dwellings, public buildings, and workplaces cause lung cancer. Radiation safety in a situation of indoor radon exposure is ensured by means of controlling natural radioactivity during the buildings construction and maintenance. In recent decades the energy saving has resulted in increase of radon concentration in new buildings comparing to conventional buildings. High-rise buildings where building materials are the main source of radon entry are of particular interest due to considerable influence of ventilation on the radon dynamic. To justify and optimize protection of the population against radon exposure in new energy-efficient multi-apartment buildings, a comprehensive understanding of the processes of radon transport and accumulation is required. Developed dynamic model of radon entry and accumulation in an energy-efficient multi-apartment building consists of building and room model, radon source model, ventilation model, and mass transport model. The dynamic model takes into account the basic physical properties of radon transport – diffusion and advection. Data of model experiments and observations of the radon accumulation in the real dwellings were considered to choose appropriate values of the model. Basing on simulation results, the possible range of radon concentrations under the expected concentrations of 226Ra in building materials was estimated. Simulation of indoor radon behavior approved that increased indoor radon exposure in multi-storey energy-efficient buildings can arise due to low active ventilation frequency and high 226Ra concentration.

Thoron (220Rn) exhalation from building materials has become increasingly recognized as a potential source for radiation exposure in dwellings. However, contrary to radon (222Rn), limited information on thoron exposure is available. As a result no harmonized test procedures for determining thoron exhalation from building materials are available at present. This study is a first interlaboratory comparison of different test methods to determine the thoron exhalation and a pre-step to a harmonized standard. The purpose of this study is to compare the experimental findings from a set of three building materials that are tested, and to identify future challenges in the development of a harmonized standard.

Passive gamma ray spectrometry and neutron capture prompt gamma activation analysis (PGAA) were used to investigate powdered cow's milk samples [termed optimal (1), optimal (2) and optimal (3)] collected from local markets in the city of Cairo, Egypt. Standard material with a total average activity of 0.830 ± 0.2 μCi and a certified reference material [IAEA (A-14)] were used to study the accuracy of a passive multi-gamma ray measurement method. Three powdered milk samples of the same geometry and volume were used in this analysis. The specific activity of 226Ra ranged from 24.5 ± 2.1 to 114 ± 1.2 Bq/kg, 232Th from 8 ± 1 to 14 ± 1.2 Bq/kg and 40K from 444 ± 28 to 1826.1 ± 3.1 Bq/kg, all of which were higher than the activities corresponding to the United Nations Scientific Committee on the Effect of Atomic Radiation (UNSCEAR) (50, 50 and 500 Bq/kg for 226Ra, 232Th and 40K, respectively). The average dose rate at 1 cm for 40K ranged from 8.21E−02 ± 0.12 to 3.3E−1 ± 0.22 mSv/h/cm. We also showed that 208Tl81, 212Pb82 and 212Bi83 should be considered products of thorium. k0-PGAA was carried out using an integrated and calibrated prompt gamma ray system with a neutron flux of 106 n/cm2 per second. The thermal to epithermal neutron flux ratio (f) and cadmium ratio were measured using a thin gold foil technique (ration = 160). Different Cl concentrations were prepared as standards for k0-PGAA. The elemental concentrations of Na, Mg, Al, Ca, Mn, Fe, Cu, Ga, Zn, As, Se, Cs, Cd, In, Th and I were measured in the three powdered milk samples. The mean ± standard deviation ranges of the elements were as follows: Na = 1069 ± 49–1583 ± 53 ppm, Mg = 347 ± 13.64–385 ± 16.71 ppm, Al = 45 ± 1.30–72 ± 2.40 ppm, Fe = 5500 ± 110–7123 ± 130 ppm, Zn = 107 ± 3–123 ± 6 ppm, Ca = 4200 ± 72–5483 ± 81 ppm, Mn = 1269 ± 69–1784 ± 72 ppm, Pr = 1.7 ± 0.02–2.6 ± 0.07 ppm, Ga = 265 ± 5–293 ± 8 ppm, Cu = 57 ± 0.5–64 ± 0.9 ppm, In = 1000± 38.64–1574 ± 41.34 ppm, Cd = 6.1 ± 2.71–12.6 ± 4.11 ppm, I = 53 ± 0.09–62 ± 1.18 ppm, Cs = 4 ± 1.56–11 ± 4.22 ppm, As = 26 ± 0.66–29 ± 0.89 ppm, Se = 126 ± 4.8–144 ± 5.7 ppm, Th = 47 ± 1.0–78 ± 6.0 ppm.

The Canary Islands archipielago (Spain) comprises seven main volcanic islands and several islets that form a chain extending for around 500 km across the eastern Atlantic, between latitudes 27°N and 30°N, with its eastern edge only 100 km from the NW African coast. The administrative province of Las Palmas comprises the three eastern Canary Islands (Lanzarote, Fuerteventura and Gran Canaria). An extensive study of terrestrial gamma dose rates in surface soils has been carried out to cover the entire territory of the province (4093 km2). The average outdoor gamma dose rate in air at 1 m above ground is 73 nGyh-1 at Gran Canaria, 32 nGyh-1 at Fuerteventura, and 25 nGyh-1 at Lanzarote. To complete the radiological characterization of this volcanic area, 350 soil samples at 0-5 cm depth were collected to cover all the geologic typologies of the islands. These samples were measured using high resolution gamma spectrometry to determine the activity concentrations of 226Ra, 232Th and 40K. The average values obtained were 25.2 Bq/kg, 28.9 Bq/kg, and 384.4 Bq/kg, respectively. Maps of terrestrial gamma activity, effective dose, and activity concentrations of 226Ra, 232Th and 40K for the region have been developed through the use of geostatistical interpolation techniques. These maps are in accord with the geology of the islands.

Sixty samples of different marble and granite tiles used as building materials, from local and foreign origins, were collected from different factories in the Al-Madinah Al-Munawarah region of Saudi Arabia. Natural radioactivity of the U–Th series and 40K in the samples were measured using an HPGE detector to conduct gamma-ray spectrometry. From the measured γ-ray spectra, the activity concentrations for different marble samples of Turkish, Egyptian, and Omani origin were 232Th (0.10 ± 0.07, 0.9 ± 0.09, 0.31 ± 0.06 Bq/kg), 226Ra (5.7 ± 0.3, 7.3 ± 0.40, 2.0 ± 0.1 Bq/kg), and 40K (0.9 ± 0.2, 0.96 ± 0.1, 0.8 ± 0.09 Bq/kg), respectively, whereas for Saudi, Chinese, and Indian granite, the concentrations were 232Th (48.6 ± 2.5, 22.9 ± 1.20, 80 ± 4 Bq/kg), 226Ra (56.4 ± 3.0, 32 ± 1.7, 10.1 ± 1.1 Bq/kg), and 40K (1492.8 ± 79.7, 762.5 ± 40.7, 1906.0 ± 43.6 Bq/kg), respectively. The calculated values of the radium equivalent activity Raeq for the studied marble samples ranged from 2.504 to 8.66 Bq/kg, and for granite, the values ranged from 127.8 to 244.19 Bq/kg. Moreover, a comparison study of the measured activity concentrations was presented. The values of external Hex and internal Hin hazard indices for the studied marble and granite samples are less than unity. The values of gamma-radiation hazard indices Iγr for the marble and granite samples are below 0.058 and 1.905, respectively. The values of the annual effective dose for the studied marble samples ranged from 0.011 mSv/y to 0.038 mSv/y, and that of granite ranged from 0.577 mSv/y to 1.169 mSv/y. Therefore, the use of these marble and granite samples under investigation in the construction of dwellings is considered to be safe for inhabitants, and the order of preference for marble is first Omani marble, then Turkish, and finally Egyptian marble. For granite, the preference is first Chinese granite, then Saudi granite, and finally Indian granite because the annual effective doses are comparatively lower.

In Tamil Nadu, India, sand from river beds are being used as a part of construction material. The radiological impact of natural radioactive materials present in river sands in Tiruchirappalli District are measured using gamma-ray spectroscopy. The average activity concentrations of 238 U, 232 Th and 40 K are measured to be 9.91 ± 4.74 Bq kg −1 , 18.30 ± 4.17 Bq kg −1 and 309.51 ± 23.23 Bq kg −1 , respectively. The average values of radiation hazards such as radium equivalent, hazard index, annual effective dose equivalent and annual gonadal dose equivalent are 55.29 ± 11.45 Bq kg −1 , 0.14 ± 0.02 and 0.19 ± 0.05 (Hex and Hin), 31.96 ± 5.85 µSv y −1 and 127.84 ± 23.4 µSv y −1 (outdoor and indoor) and 187.78 ± 30.60 µSv/y −1 , respectively. These values are compared with the international and Indian standard values and they lie below the recommended limits. Hence the sediment sand samples do not pose any significant radiological concern and could be used for construction purposes.

The natural radioactivity in building materials collected from Polur, Tamilnadu has been determined using gamma ray spectrometer. The radiological parameters such as radium equivalent activity (Ra eq ), absorbed dose rate (D R ), annual effective dose rate (H R ), alpha index (I α ), gamma-index (I γ ), internal (H in ) and external hazard indices (H ex ) were evaluated to assess the radiation hazard for people dwelling in the study area. The calculated radiological parameters were taken for multivariate statistical analysis to study the relation between radionuclides and radiological parameters. The values obtained in the study are within the recommended safety limits, showing that these building materials do not pose any significant radiation hazard and hence the use of these materials in the construction for dwelling purpose can be considered to be safe for the inhabitants.

Problem statement Sn–Zn solders are candidate alternatives to Sn–Pb-based solder alloys. With the increasing requirement for lead-free solders, the reliability of successor solders in microelectronics assemblies is in high demand. The elimination of radionuclides, heavy metals, and other poisonous elements in lead-free Sn–6.5Zn solders in the microelectronics industry is a worldwide goal. As a result, it is useful to identify the natural concentrations of radioactive nuclides, heavy metals and other poisonous trace elements (both macro- and micro-element contents), such as Au-196, Th-227, Ag-110M, Fe-59, Zn-65, Rb-89, Rh-106M, Bi-207, Cs-137, Eu-154, Sb-126, Eu-152, Co-56, Co-58, Co-60 and K-40. If this lead-free solder contains high concentrations of natural radioactive nuclides, then workers handling it might be exposed to significant levels of radiation. Therefore, it is important to determine the levels of radioactive nuclides in this solder to protect workers; these levels provide background for the safety rules and precautions that should be applied for those working in this field. Approach The levels of natural radionuclides ( 238 U, 232 Th, and 40 K) and their daughter products contained in Sn–6.5Zn solders have been estimated via gamma-ray spectrometry using a 100% Hyper-Pure Germanium (HPGe) detector. Results The mean activities due to radionuclides, heavy metals, and other poisonous elements were measured, and the results are summarised in tables. Conclusion The results of this assessment obtained by gamma-ray spectroscopic analysis indicated the presence of high levels of natural radioactivity, heavy metals and other poisonous elements. This result implies that a comprehensive study should be conducted to protect workers from high doses of hazardous substances.