Natural Radioactivity Concentrations Research Articles

The radioactivity distribution and radiation hazard in honey samples from Italian large retailers

The natural (40K) and anthropogenic (137Cs) radioactivity concentration in twenty-five honey samples of five different typologies (acacia, chestnut, wildflower, linden and honeydew), coming from Italian large retailers, was investigated by High Purity Germanium (HPGe) gamma spectrometry.The study was carried out in order to estimate the background levels of detected radionuclides in various honey samples, as well as to assess the dose levels due to their ingestion, taking into account the average yearly direct consumption in Italy and assuming this requirement satisfied from a single kind of honey.Experimental results were compared with the total natural radioactivity value (external + internal) for humans, in order to evaluate any possible radiological health risk.

ASSESSMENT OF RADIOLOGICAL HAZARD FOR VARIOUS FOOD COMMONLY USED IN REPUBLIC OF NORTH MACEDONIA

Consuming food containing radionuclides is particularly dangerous. If anyone ingests or inhales a radioactive particle, it continues to irradiate the body as long as it remains radioactive and stays in the body. However, studies on the radioactivity of consumable foods assume importance as it is necessary to estimate the ingestion dose to the public. Due to all this, the focus of this research was on determining the activity concentrations of 226Ra, 40K and 232Th. Forty-nine samples in three categories of vegetables, cereals (rice, wheat, corn), and milk, were collected from local markets (city of Skopje) in the Republic of North Macedonia and they were analyzed by using high-purity germanium (HPGe) detector to assess natural and artificial radioactivity. The average activity concentrations of 226Ra, 40K and 232Th of the tested samples were 2.85±1.15, 2.48±0.85, and 80.64±5.45 Bq kg-1, respectively. No artificial radionuclide was found in any of these samples. The average value of the radium equivalent activity in all samples was 12.56 Bq kg-1, which was less than the maximum permitted value of 370 Bq kg-1. The values ​​of the external hazard indices for vegetables, cereals and milk samples vary with an average value of 0.11, which is less than one in all samples indicating the non-harmfulness of the samples. The mean activity concentrations of 226Ra, 40K and 232Th (Bq kg-1) in the samples were used to calculate the absorbed dose rate whose mean value for all food samples was 6.16 Bq kg-1. It was determined that the measured values are within the globally accepted values, i.e., they are quite lower than the data in literature. These data would be useful to establish a baseline for natural radioactivity concentrations in food products consumed in the Republic of North Macedonia.

INITIAL EVALUATIONS OF NATURAL ( 226Ra, 232Th and 40K) AND ARTIFICIAL ( 137Cs) RADIOACTIVITY OF ESKIKÖY MINERALIZATION AREA (GÜMÜŞHANE, TÜRKIYE)

Within the scope of this study, the natural (226Ra, 232Th and 40K) and artificial (137Cs) radioactivity concentrations of the Eskiköy Mine area within the borders of Gümüşhane, which is located in an important metallogenic belt of Turkey, were investigated. In order to determine the natural and artificial radioactivity of the field soils developed due to mineralization, hydrothermal alteration and weathering, 12 soil samples were taken and activity concentrations of 232Th, 226Ra, 40K and 137Cs radio isotopes were measured with a gamma detector. It was observed that the 40K natural radio isotope activities of the area mostly exceeded the weighted world average, and the 232Th, and 226Ra natural radio isotope activities exceeded the weighted world averages at 5 of the 12 sampling points. It was determined that the artificial 137Cs activity concentrations in the area were above the detection limit at 9 sampling points and above 3 Bq/kg at 8 sampling points. It has been evaluated that the high 137Cs activities detected in the Eskiköy mine area are due to the Chernobyl nuclear power plant accident and similar anthropogenic effects. The mine area was also evaluated in terms of radiation risk in the context of medical geology, with parameters of radiological hazard indices, radium conjugate activity value, absorbed dose rate and annual effective dose rate, and remarkable findings were obtained. When all these findings of the study area are evaluated together, it has been concluded that the Eskiköy mining area should be studied in more detail in terms of natural and artificial radioisotope activity concentrations and their effects on human health.

Investigations on baseline levels for natural radioactivity in soils, rocks, and lakes of Larsemann Hills in East Antarctica.

A comprehensive measurement of concentrations of the natural radionuclides 238U,232Th and40K, and 226Ra in the soil and rocks along with natural uranium and tritium activity levels in lake water were carried out during the Indian expedition to Antarctica. The samples were collected from the Larsemann Hills region in Antarctica (latitude 69°20' S to 69°25'S, longitude 76°6' E to 76°23'E). The data on the natural radioactivity for this region is limited. The study was carried out to establish baseline levels of radioactivity in different terrestrial matrices of this region such as soil, rocks, and lake water. A radiation survey mapping for terrestrial radioactivity was conducted in the region before collection of soil and rock samples. The soil and rock samples were analyzed for natural radioactivity concentrations using high-resolution gamma spectroscopy system. The major contributor to elevated gamma radiation background is attributed to the higher concentration of 232Th and 40K radionuclides in both soil and rocks. Terrestrial components of gamma dose rate due to natural radioactivity have been estimated from the measured radioactivity concentrations and dose conversion coefficients. Several "hotspots" and high background areas in the region have been identified having significantly higher concentration of 232Th and 40K. Rocks in Larsemann Hills region showed high reserve of thorium mineralization in monazites and 40K in K-feldspar. The concentrations of 232Th in soil are found to be in the range of 106-603Bq/kg, whereas in rock it is in the range of 8-4514Bq/kg. Natural radioactivity U (nat) and 3H contents in the lake water samples in Larsemann Hills region were estimated as 0.4 and 1.3Bq/L and are well within the prescribed limit of radioactivity in drinking water as recommended by World Health Organization.

Natural radioactivity level in fly ash samples and radiological hazard at the landfill area of the coal-fired power plant complex, Vietnam

In this study, natural radioactivity concentrations and dosimetric values of fly ash samples were evaluated for the landfill area of the coal-fired power plant (CFPP) complex at Binh Thuan, Vietnam. The average activity concentrations of 238U, 226Ra, 232Th and 40K were 93, 77, 92 and 938 Bq kg−1, respectively. The average results 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 fraction 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: Zeolite < PVC < Soil < Concrete. Total dose of all radionuclides in the landfill site reached its peak at 19.8 years. The obtained data are useful for evaluation of radiation safety when fly ash is used for building material as well as the radiation risk and the overload of the landfill area from operation of these plants for population and workers.

Radioactivity monitoring and radiological assessment of radionuclides at western coastal of South Sulawesi

The concentrations of natural (226Ra, 232Th, 40K) and anthropogenic (137Cs) in Western Coastal of South Sulawesi were measured by gamma-ray spectrometry with a high-purity germanium (HPGe) detector connected to a multichannel analyzer. The maximum activity concentration of natural radionuclides was found 47.29 ± 4.14 Bq/kg for226Ra, 52.73 ± 5.28 Bq/kg for232Th and 744.00 ± 29.45 Bq/kg for40K. In general, the natural radioactivity concentration in marine sediment has been found lower than UNSCEAR data value and within the world range for similar study. The maximum activity of137Cs was found 0.34 ± 0.03 Bq/m3 for seawater and 1.95 ± 0.13 Bq/kg for sediment. Total dose rates from137Cs for organisms in marine ecosystem by trophic level organisms was found varied from 9.73 × 10−7 µGy h−1 in phytoplankton to 3.35 × 10−4 µGy h−1 in macro algae. The dose rate for all organisms in marine ecosystem were clearly below the screening level of 10 µGy h−1 indicating no significant impact of the137Cs exposure on these organisms.

Correlation of phytoplankton satellite observations and radiological doses in molluscs

In this work data of salinity, temperature, suspended particulate matter (SPM), chlorophyll-a, and phytoplankton concentration in the Gibraltar Strait coast, in the confluence of the Mediterranean Sean and the Atlantic Ocean, were analyzed together with 210Po, 40K, 210Pb and 234Th activity concentration in different types of bivalve molluscs at the same time-period. The physicochemical parameters were evaluated using the Copernicus Marine Environment Monitoring Service (CMEMS) products based on satellite observations. A multivariate statistical analysis, including contrasted natural radioactivity contents, allowed the discrimination of bivalve molluscs from Atlantic and Mediterranean coasts. Additionally, a cluster analysis determined a highly significant negative correlation 210Po concentration in molluscs and phytoplankton concentration suggesting that phytoplankton concentration in the water column is a determinant factor to regulate 210Po concentration in those animals. These results introduce a useful tool to calculate the radiological doses in seafood from chlorophyll satellite image.

Study of environmental radioactivity and radon measurement associated health effect due to coal and fly ash samples

The increasing demand for electricity generation in India primarily depends on coal-fired power plants. The burning of coal is known as fly ash and a prominent factor of pollution in the environment. Fly ash generation in plants leads to the creation of radon and radionuclide, which affects the health of the general public. Since the general public around the area adjoining power plants are at considerable risk of radiation exposure. Also, inhalation of radon gas at a high level increases the possibility of lung cancer. So monitoring radon and radionuclide concentrations is essential. In the present investigation, radon and thoron exhalation rates have been estimated by implementing the accumulation method-based active technique. Natural radioactivity concentrations have been found out using NaI(Tl) detector-based gamma-ray spectrometry. Since the radiation hazard index is less than unity, so fly ash retains not a considerable amount of radiation effect. The result obtained concludes that radon/thoron exhalation rate and radioactivity concentration from fly ash residues are within the limits prescribed by the competent authority. So, the uses of fly ash in coal-based power plants cause no effectively adverse effect on health.

Determination of Natural Radioactivity Concentrations in Ovit Dağbaşı Lake Water

Doğada yaşayan tüm canlılar sürekli olarak doğal ve yapay radyasyon kaynaklarından yayınlanan iyonlaştırıcı radyasyona maruz kalmaktadır. Bu nedenle, yaşam alanları ve ziyaret edilen bölgelerde radyoaktivite düzeylerinin belirlenmesi önemlidir. Bu çalışmada, Rize ili İkizdere ilçesine bağlı İkizdere-İspir karayolu üzerinde bulunan Ovit Dağbaşı Gölünden alınan su örneklerinde 226Ra, 232Th ve 40K radyoaktivite konsantrasyonları yüksek saflıkta germanyum dedektörü (HPGe), 3H radyoaktivite konsantrasyonları ise sıvı sintilasyon sayacı (LSC) kullanılarak belirlendi. Su örneklerinde 226Ra, 232Th, 40K ve 3H radyoizotop konsantrasyonlarının sırasıyla 0,36-2,82 Bq/L, 0,37-1,92 Bq/L, 13,28-20,96 Bq/L ve 2,51-3,53 Bq/L aralığında değiştiği belirlendi. Ortalama radyoaktivite konsantrasyonları ise 226Ra için 1,80±0,54 Bq/L, 232Th için 1,13±0,51 Bq/L, 40K için 17,22±2,61 Bq/L ve 3H için 2,88±0,47 Bq/L olarak bulunmuştur. Bulunan aktivite konsantrasyonları uluslararası kuruluşlar tarafından önerilen değerlerle kıyaslandı ve 232Th radyoizotopu hariç önerilen değerlerden daha düşük oldukları belirlendi. Sonuç olarak, yapılan çalışma ile Ovit Dağbaşı Gölü ziyaretçileri için incelenen radyoiztoplardan kaynaklı radyoaktivitenin bir sağlık riski oluşturmayacağı gösterilmiştir.

Tracking and Evaluating the Concentrations of Natural Radioactivity According to Chemical Composition in the Precambrian and Mesozoic Granitic Rocks in the Jangsu-gun Area, Central Southwestern South Korea

The Jangsu-gun area in the central Southwestern South Korea consists of a well-preserved Middle Paleoproterozoic gneissic basement, as well as the Late Triassic and Early Jurassic granitic rocks. Here, we present the detailed zircon U-Pb age data and whole-rock chemical compositions, including radioactive elements (e.g., U and Th) and activity concentrations of 226Ra, 232Th and 40K for the Middle Paleoproterozoic gneisses, and Late Triassic and Early Jurassic granitic rocks of the Jangsu-gun area. The Middle Paleoproterozoic gneissic basement, and the Late Triassic and Early Jurassic granitic rocks have ages of ca. 1988 Ma and 1824 Ma, 230 Ma and 187–189 Ma, respectively. Geochemically, the Middle Paleoproterozoic orthogneiss, Late Triassic granites and Early Jurassic granitic rocks show typical arc-related metaluminous to weakly peraluminous fractionated granite features with ASI (aluminum saturation index) values of 0.92 to 1.40. The mean values of U (ppm) and Th (ppm) of the Middle Paleoproterozoic orthogneisses (6.4 and 20.5, respectively), Late Triassic granites (1.5 and 10.9), and Early Jurassic granites (3.5 and 16.5) were similar to those (5 and 15) of the granitic rocks in the Earth’s crust. The mean 226Ra (Bq/kg), 232Th (Bq/kg), and 40K (Bq/kg) activity concentrations and radioactivity concentration index (RCI) are 62, 71, 1,214 and 0.96 for the Middle Paleoproterozoic orthogneisses; 16, 39, 1,614 and 0.78 for the Late Triassic granites; and 56, 70, 1031 and 0.88 for the Early Jurassic granitic rocks, respectively. The U, Th, 226Ra, 232Th, 40K, and RCI of the Middle Paleoproterozoic biotite paragneisses are similar to those of the Middle Paleoproterozoic orthogneisses. The trend of 226Ra, 232Th, and 40K activity concentrations, and the composition of U and Th from the Precambrian and Mesozoic rocks in the Jangsu-gun area indicates that monazite is the main accessory mineral controlling the concentration of natural radioactivity. Based on a detailed examination of the natural radioactivity in the rocks of the Jangsu-gun area, the Middle Paleoproterozoic orthogneisses and paragneisses, and Late Triassic and Early Jurassic granitic rocks show average high mean RCI values of 0.88−0.96, such that 32% of the rocks exceeded the recommended value of one in the guidelines for the RCI in South Korea. Especially, the RCI is closely related to the radon levels in the rocks. As a result, the Jangsu-gun area in South Korea is a relatively high radiological risk area, which exhibits higher indoor radon levels in the residences, compared with residences in the other areas in South Korea.

Determination of the activity concentration of 226Ra, 232Th, 40K and the concentration of 222Rn in soil samples of the Campos Gerais region (Paraná)

In the Campos Gerais region of Paraná there are few literature that evaluate the concentrations of natural radioactivity. Thus, the aim of the present work was to determine activity concentrations of 226Ra, 232Th, 40K and 222Rn concentration in soil samples from Telêmaco Borba, Tibagi, Curiúva, Ventania, Lageado Bonito and Ortigueira. The soil samples, with about 2 kg, were collected on the surface at points near the river bed, making sure that the soil is not under the agriculture influence. Gamma-ray spectrometry analyzes were performed with a NaI(Tl) scintillation detector, with dimensions of 76 mm in diameter, 152 mm in height and 8 cm of lead shield. The 222Rn concentration determinations were performed by means of the sealed can technique, using as track detector a polycarbonate of domestic manufacture. The results obtained for the activity concentration varied from &lt;4.2 ± 1.2 Bq.kg-1 to 290.2 ± 1.7 Bq.kg-1 for the 40K, of 23.3 ± 1.1 Bq. kg-1 to 36.5 ± 1.1 Bq.kg-1 for the 226Ra and from 52.6 ± 1.9 Bq.kg-1 to 70.5 ± 2 Bq.kg-1 for the 232Th. The results for the 222Rn concentration ranged from 4 ± 3 Bq.m-3 to 1147 ± 326 Bq.m-3. Two of the six soil samples presented radon concentrations above the threshold established by the European Commission for Radiological Protection of 200 Bq.m-3, for internal environments. The concentrations of 226Ra and 232Th are within the limits, showing the importance of future investigating the origin of this radon.

Distribution of natural and artificial radioactivity concentration in soils of two districts (Ballia and Deoria) of Uttar Pradesh, India

This paper presents the activity concentrations of naturally occurring radionuclide 226Ra, 232Th, and 40K and the anthropogenic radionuclide, 137Cs in soil samples collected from Ballia and Deoria district of Uttar Pradesh, India. The mean activity concentrations of radionuclides in 43 soil samples from the two districts were measured using HPGe gamma spectrometry system. The activity level in soil samples varied from 23 to 50 Bq/kg with a mean of 30 Bq/kg for 226Ra, 30–74 Bq/kg with a mean of 47 Bq/kg for 232Th, 287–728 Bq/kg with a mean of 466 Bq/kg for 40K, and ≤0.1–1.4 Bq/kg with a mean of 0.4 Bq/kg for 137Cs. The mean activity of naturally occurring 226Ra and 232Th is comparable with the international values reported by UNSCEAR while concentration of 40K is slightly higher. 137Cs activity is found to be comparable with the activities reported at other parts of India. Correlation of 226Ra and 40K activity with 232Th activity was observed as 0.85 and 0.75, respectively. A positive correlation (0.71) between 40K and 137Cs was found in the present study. The absorbed gamma dose rates in air were in the range of 44.6–98.3 nGy/h with a mean of 63.4 nGy/h, while the annual effective dose rates were observed in the range of 54.7–120.6 μSv/y with a mean of 77.8 μSv/y. The average value of radium equivalent activity in soil was 136.9 Bq/kg. This study provides a baseline data of natural radioactivity and 137Cs activity in soils of these two districts.

Radiological baseline around the Barakah Nuclear Power Plant, UAE

Destructive and non-destructive analysis techniques were used to establish a radiological baseline around the Barakah Nuclear Power Plant area in Abu Dhabi, United Arab Emirates. The natural radioactivity concentrations of 238U (226Ra), 232Th and 40K were measured for shore, soil and bottom sediment samples, using gamma spectrometry with a high-purity germanium (HPGe) detector. Alpha spectrometry was used to measure the 234U/238U ratio for some selected samples using a silicon surface-barrier detector. The measured gamma activity concentrations in shore samples are much lower compared to those in soil and bottom samples. The average activity concentrations of 238U (226Ra) are 4.43 ± 1.12, 13.54 ± 4.16 and 4.73 ± 3.01 Bq/kg in shore, soil and bottom sediment samples, respectively. The corresponding values for 232Th are 1.68 ± 0.49, 8.31 ± 3.87 and 1.83 ± 1.67 Bq/kg, and those for 40K, are 106.30 ± 50.68, 349.72 ± 107.16 and 105.23 ± 130.14 Bq/kg. The 234U/238U activity ratios span a wide range from 0.59 to 2.24, indicating a system where the daughter/parent is out of secular radioactive equilibrium. The hazard parameters, radium equivalent and absorbed dose rates, showed low levels compared to the world average level reported by the UNSCEAR in 2000. The estimated activity concentrations in this study were lower than the world average values and lower than the levels reported in nearby countries.

Radiometric survey of natural radioactivity concentration and risk assessment on dwellers around Ijako active dumpsite in Ogun State

Radiometric assessment of natural radioactivity concentration around Ijako dumpsite was done using hand held gamma spectrometer. A total of 10 in situ measurements were taken at the site. The U-238, Th-232, and K-40 radioactivity concentration obtained were used to assess the radiological hazard level in the area. Comparing the mean results of radiological parameter obtained with world average; Radium equivalent was far less than 370Bqkg-1, External hazard was less than 1, Annual effective dose equivalent was less than 0.08mSvy-1, Gamma index was less than 1, and Excess life cancer risk was less than 0.29 × 10-3. This implies that Ijako dumpsite poses no radiological hazard to the general public.

Measurement the natural radioactivity concentration levels of radionuclides in selected vegetables collected from Kirkuk, Iraq using HPGe detector

ABSTRACT The aim of this study is to determine the natural radioactivity levels and evaluate the radiological hazard in vegetable samples collected from Kirkuk city by using gamma-ray spectrometer HPGe. The results show that the highest specific activity of 226Ra and 232Th in vegetables was (9.65, 7.9) Bq.kg–1 in Vg27 (Root/Garlic) while, the highest specific activity of 40K was (221.08 Bq.kg–1 in Vg37 (Leguminous/kidney bean), respectively. The results show that the average specific activities in vegetable samples for 226Ra and 232Th, and 40K was (6.119, 4.763 and 135.595) Bq.kg–1, respectively, these results were found to be below natural radiation exposure reported by UNSCEAR, radium equivalent activity (Raeq) were varied from maximum value (30.345 Bq.kg–1 in Vg15 (Leafy/coriander leaves)) to minimum value 13.002 Bq.kg–1 in Vg37 (Leguminous/kidney bean)) with average value 23.371 Bq.kg–1, the total average annual effective dose in vegetable samples for adults, children (10 years old) and infants are estimated to be (60.487, 128.090 and 170.431 μSvy–1), respectively, than those below the WHO permissible limit of 0.3 m μSvy–1. The calculated values of external and internal hazard index in the samples which were lower than the worldwide average value 1, respectively; therefore, these values are found to be safe. The level of radioactivity concentrations in vegetables was determined to ensure consumer safety and the results provide useful information to assess the dose emitted from this radioactivity due to ingestion of these vegetables. This study is very important to investigate the level of radioactivity of vegetables and the findings of this study will useful to determine a baseline of radioactivity exposure to the human from ingestion of vegetables.

Natural Radioactivity in Drinking Water Sources in Kargi Area, Marsabit – Kenya

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.

EVALUATION OF COMMITTED EFFECTIVE DOSE OF RADON GAS IN DRINKING WATER IN AL-QADISIYAH PROVINCE, IRAQ

Scientific research is giving interest in determining the concentrations of Radon in drinking water and sediments due to the occurrence of serious diseases related to this chemical element. The solubility of Radon in water (potable and underground) allows percolation in soils and rocks. The concentrations of Radon natural radioactivity were measured in drinking water and sediment at a wastewater treatment plant (Al-Diwaniyah, Iraq) using trace detector RAD7 and CR-39 (diffusion chamber, Landauer). Sampling was carried out at 20 samples (10 of drinking water and 10 of sediment). The results of radioactivity showed that the concentration of 222Rn in drinking water varies from 0.05 to 0.47 Bq/L, with an average of 0.24 Bq/L. However, the 222Rn concentrations in the sediment vary from 29.16 to 60.52 Bq/m3, with an average of 42.43 Bq/m3. From the results, it was possible to calculate the contribution of Radon to drinking water associated with age. The effective annual doses were found below the recommended limit. Radon concentrations in drinking water and sediment showed high levels of radioactivity compared to the natural limit. However, the same results indicated low radioactivity levels compared to the United Nations Scientific Committee on the Effects of Atomic Radiation and the World Health Organization. In this way, all drinking water at these stations is safe to use.

Investigation a relation between radioactivity concentrations of 40 Potassium (40K) in tooth and the various ethnic groups and its impacts on the rate of tooth damage

A relationship between natural radioactivity concentrations and ethnic type has investigated in the human tooth using high purity germanium (HPGe) detector. Tooth samples (20 samples) collected from male non-smokers at private and public dental clinics located in Erbil city center for four ethnic types of population living in the Kurdistan Regain/ Iraq; Kurd, Arab, Turkman, and Syriac (Christian). In the tooth samples related to the above mentioned different ethnic groups high and low levels of radionuclides have been recorded. For example, searching for the naturally occurring radionuclides (40 K, 226Ra and 232 Th) the following maximum and minimum values of specific activity concentrations (measured in Bq/kg) have been found differentiated according to the different ethnic group: (434.92 ± 32.65) and (285.33 ± 15.22) (40 K), (86.24 ± 14.62) and (36.35 ± 8.15) (226Ra) for the Christian and Kurdish ethnics, and (285.33 ± 15.22) and (9.56 ± 1.62 Bq/kg) 232 Th for the Turkman and Arab ethnic groups, respectively, have been recorded.Therefore, strong correlations have been found between specific activity concentrations of the naturally occurring radionuclides with the particular ethnic group from which the samples have been originated.In addition, the above specific activity concentrations have enabled the authors the estimation of the hazard index, the radium equivalent activities (Ra), the external and the internal hazard indexes (Hex, Hin), and the absorbed dose (Dout, Din). In conclusion, the values reported in this paper have not turned out to be higher than recommended values of UNSCEAR (2000).

A study on natural radioactivity and potential of 222Rn, 220Rn exhalation from Deccan table land of Kolhapur district, Maharashtra, India

In this study, an investigation has been carried out on the potential of radon, thoron and natural radioactive content by collecting soil samples from the Deccan land of Kolhapur district, India. The mean value of radon mass exhalation rates is 12.66 ± 1.07 mBqkg−1h−1 and mean thoron surface exhalation rate is 2300 ± 261 Bqm−2h−1. The mean value of Radon emanation factor is 5.18%. The mean activity concentrations of 238U, 232Th and 40K in the soil samples are 9.33 ± 0.45 Bqkg−1, 16.60 ± 0.77 Bqkg−1 and 66.15 ± 4.33 Bqkg−1 respectively and well below the value recommended by UNSCEAR 2000.

Radiological characterization of natural building materials from the Campania region (Southern Italy)

The characterization of natural radioactivity content in thirty-one natural building materials representative of the Campania region (South Italy) was carried out. High resolution γ-ray spectrometry for the determination of the 226Ra, 232Th and 40K activity concentrations was used. Commonly-used radiation hazard indexes were computed to evaluate the human exposure to γ-radiation. The results are compared to limit values established by the 2013/59/Euratom Directive and by UNSCEAR: the comparison proves the high natural radioactivity content and the radiation exposure hazard coming from some samples of volcanic origin. The emanated fraction and the exhalation rate of the 222Rn and of the 220Rn from the investigated materials were also measured with the α-spectrometry of the ionized radon daughters. This study is justified by the ever-growing public concern about radon risk associated to building materials from Campania region, locally widely used and exported worldwide. The results show interesting differences about the radioactivity content and the capacity to generate radon, among the different materials. This work contributes to enriching knowledge about natural radioactivity in natural building materials used in Italy.