Natural Radioactivity Concentrations Research Articles

Natural radioactivity concentrations and radiological risk assessment of farmed gilthead seabream (Sparus aurata L., 1758) from the Turkish coast of the Mediterranean Sea

Natural radioactivity concentrations in farmed and wild gilthead seabream were determined via samples collected from 20 different farms located in four different major cage farming areas to represent the overall Turkish production along the coast of the Mediterranean Sea. The 226Ra (2.06±0.28 Bq kg−1), 232Th (1.27±0.29 Bq kg−1) and 40K (157.77±4.81 Bq kg−1) concentrations in farmed fish were significantly lower (approximately 1.5–3 times) than their wild equivalents. In accordance with that, ingested dose (ID) values calculated for the consumption of per kg fish was significantly lower for farmed seabream than for wild seabream. Moreover, ID values calculated over the annual fish consumption of both EU and Turkish citizens were well below the recommended values by UNSCEAR 2000. Hence, it was concluded that both farmed and wild gilthead seabream originating from the Turkish coast of the Mediterranean Sea do not pose a serious radiological threat to human health.

Spatial distribution of natural and artificial radioactivity concentrations in soil samples and statistical approach, Nevşehir, Turkey

Abstract The concentrations of 226Ra, 232Th, 40K and 137Cs radionuclides in soil samples collected from 323 different regions of Nevşehir province were determined by using a gamma spectrometer with an HPGe detector. The mean gamma activity concentrations (ranges) of 226Ra, 232Th, 40K and 137Cs for districts were determined as 49.45 (7.40–193.90), 54.08 (<2.8–122.50), 698.43 (37.67–1370.20) and 8.26 (0.10–52.60) Bq kg−1, respectively. The mean activity concentrations of 226Ra, 232Th and 40K were higher than the world mean value. According to Kolmogorov–Smirnov test, distributions of 226Ra, 232Th and 137Cs show log-normal distributions. Whereas, 40K shows normal distribution. The mean radium equivalent activity was 181.68 Bq kg−1 which is lower than the recommended maximum value of 370 Bq kg−1. The mean external terrestrial gamma dose rate was found to be 85.12 nGy h−1. The calculated external hazard value was 0.49 and within the acceptable limit which is less than unity (Hex ≤ 1). Thermo Scientific RadEye NBR detector was used to determine environmental gamma dose rates. The gamma dose rates were measured at 445 points at a height of 1 m from land surface. The mean outdoor gamma dose rate (range) was found as 150.13 (50–480) nGy h−1. This mean value was found higher than world mean value. The fact that most of the Nevşehir province is based on volcanic rocks explains why the gamma dose rates are high.

Determination of Natural Radioactivity Concentration and Radiogenic Heat Production in Selected Quarry Sites in Ondo State, Nigeria

Determination of Natural Radioactivity Concentration and Radiogenic Heat Production in Selected Quarry Sites in Ondo State, Nigeria

Estimation of natural radioactivity content, lithium and trace elements in different types of rock aggregates with a potential to generate long-lived gamma-ray activity during operation of accelerators

Rock aggregates are major ingredient of concrete used for shielding against ionising radiation generated during the operation of nuclear particle accelerators. Their analysis for trace elements which may lead to neutron activation products during prolonged operation becomes important. Proper selection of ingredients helps in minimizing the radioactive concrete waste requiring disposal at the time of decommissioning.This work involves the collection of 42 samples of seven broad types of rock aggregates and their assessment for natural radioactivity (226Ra, 232Th and 40K), lithium and other trace elements that may lead to the formation of gamma emitting, long lived neutron activation products.

Determination of natural radioactivity levels and gamma radiation attenuation coefficients in propolis samples and the study of its antioxidant properties

Abstract Thanks to its rich content, propolis has been used to protect the hive from all kinds of external influences and for disinfection by bees. Furthermore, it is an important marker for monitoring environmental pollution because the main sources of propolis are plant and secretions. So, the present study aimed to research radiation attenuation capability and the natural radioactivity level of propolis samples. For this reason, both natural radioactivity concentrations (226Ra, 232Th and 40K) and attenuation coefficients (Linear and Mass) in the propolis samples collected from 10 different points in Turkey were measured using high purity germanium detector (HPGe). The average natural radioactivity concentrations in samples were found to be 0.56 ± 0.19, 2.65 ± 0.31 and 70.08 ± 2.42 Bq/kg for 226Ra, 232Th and 40K, respectively. These values were much lower than the average world values (35 Bq/kg for 226Ra, 30 Bq/kg for 232Th and 400 Bq/kg for 40K) reported by United Nations Scientific Committee on Effects of Atomic Radiation (UNSCEAR) in foodstuff. The average linear attenuation coefficient, mass attenuation coefficients and half value layer values for gamma rays with 59.54 keV energy were determined as 0.1970 cm−1, 0.1831 cm2 g−1 and 3.56 cm, respectively. In addition, antioxidant properties of the samples were measured using total phenolic content and ferric reducing antioxidant power. Their correlations with radioactivity were investigated.

An overview on radiometric assessment and excess lifetime cancer risk of soil in Pakistan by using High Purity Germanium (HPGe) detector.

The aim of this study is to compare the natural radioactivity and excess life time cancer risk (ELCR) factor of soil in different regions of Pakistan during last decade. Soil contains various elements and compounds including naturally occurring radioactive elements (238U, 232Th, 40K and 137Cs). Human being, animals and plants are in health risk by contaminations of natural radioactivity in soil and environmental radiometric pollution. Transferring of large amount of the natural radioactive elements in human body by nutrients may cause carcinogenic effects in human body. Pakistani soil has six types as Indus Basin Soil, Bongar Soil, Khaddar Soil, Indus delta soil, Mountainous soil and Sandy Desert Soil. In some northern region of Pakistan, naturally occurring radioactive rocks like uranuium-238 and iridium concentrations present in Gharwandi, Aram, Kingri S, Vitakri Fort Munro, Dera Bugti, Kohlu and Sibbi districts. In this reviewed data, gamma rays spectroscopy used to determine the concentrations of 238U, 232Th and 40K with the help of High Purity Germanium (HPGe) detectors. Only the data of HPGe detector collected because of comparisons of different regions of Pakistan. Mostly, different gamma rays energy peaks of relevant daughter radionuclides of radioactive element were used such as the energy peak lines of daughter radionuclides 214Pb (295.21 and 352KeV) and 214Bi (609 and 1,120KeV) used for calculating the 226Ra concentration in soil. In the recent study, it is concluded that average values of concentrations of natural radioactivity in soil in central and north regions of Pakistan are higher than permissible limit but found permissible range in south region of Pakistan. Mean values of ELCR factor were found higher, equal and lower in central, north and south regions than permissible limit, respectively. Generally, no serious health hazard due to natural radioactivity in soil were found.

An overview on the concentration of radioactive elements and physiochemical analysis of soil and water in Iraq.

In the last decade, radiation physics brought about a revolution in health science by improving scientific equipment and useful methodologies for measurement. Human beings are affected by ionizing radiations that radiate from radioactive elements. The quantity of radioactive elements is different inside and outside the earth's surface. Soil and water are exigencies of human lives which are contaminated by radioactive elements. These radioactive elements enter into the human body through drinking, eating and breathing. On reaching hazardous limits in the human body, these radioactive elements cause stomach cancer, lung cancer and leukemia. Measurement of radioactive elements in soil and water is helpful in monitoring the health issues caused by exposure to these elements. In Iraq, numerous studies about natural radioactivity, radon concentration and physiochemical parameters have been conducted by different researchers, of which most of the studies were conducted in Barsa, Nasirya, Najaf, Karbala, Baghdad, Balad, Kirkuk, Erbil, Mosul and Dohuk cities. This article aims to review and compile the studies conducted in these cities of Iraq from 2011 to 2019. In most articles, high-purity germanium (HPGe), RAD7 and CR-39 detectors are used for radioactivity and radon measurement. These cities are located in the low-high folded and Mesopotamian zones. From this study, it can be concluded that radon concentration in soil and water was greater in the Mesopotamian and lower in the low-high folded zones. Higher concentrations of natural radioactivity in water and soil were found in the low-high folded zone in Iraq. However, most of the conducted studies show that concentrations of radon and natural radioactivity are above the permissible limits recommended by the International Commission on Radiological Protection (ICRP) and World Health Organization (WHO). The values of physiochemical parameters were found to be greater in the Mesopotamian zone, but overall they are not above the permissible limits.

Assessment of heavy metals and radionuclides (238U, 232Th and 40K) concentration of beach sands collected from East Coast of Tamilnadu, India with multivariate statistical approach

ABSTRACT This paper discusses the relation between the heavy metal and radionuclide activity concentration in beach sand samples collected from East Coast of Tamilnadu. The elemental composition in beach sands is determined by EDXRF technique. The mean concentrations of elements followed in the order of Si > Ca > Fe > Al > Mg > K > Ti > Mn > Zr > Sr > Zn > Pb > Ni > Cu > Cd > Co in the study area. A NaI(Tl) gamma-ray spectrometer has been used to determine activity concentration of 238U, 232Th and 40K in sand samples. The measured activity in the sand samples ranged from 3.0 to 1766.8 Bqkg−1, 3.0 to 8326.88 Bqkg−1 and 11 to 1434.9 Bqkg−1 for 238U, 232Th and 40K, respectively. The measured natural radioactivity concentration was compared with worldwide average values as reported by UNSCEAR. The interrelation between the natural radioactivity and heavy metal concentration is determined using Pearson correlation coefficient, factor and cluster analysis for finding existing relation between them. The results showed that there is a significant relation of heavy metals for heavy minerals which can contribute radioactivity concentration based on the correlation and factor analysis.

Measurement of natural radioactivity concentrations in walnut collected from different markets in Sulaimanya city-Kurdistan region-Iraq

Walnut is one of the most important and necessary foodstuffs in our daily lives and there are many species in Iraqi Kurdistan from different sources. Therefore, the significant point in this works is gamma rays measuring to estimate various radiation hazards via walnut consumption for different markets. The samples have been collected from different markets and locations in Sulaimanya governorate in Kurdistan region-Iraq.The average specific activities for nuclides found with high probability for the walnut by using a vertical coaxial cylindrical High Purity Germanium Radiation Detector (HPGe). The specific activity for the shell of the walnut were for the three most important radionuclides 232Th, 226Ra and 40K were 14.842 ± 9.450, 7.226 ± 1.805, 107.2 ± 2.563 (Bq/kg) respectively, and for walnut pulp 232Th, 226Ra and 40K were 16.053 ± 8.861, 5.105 ± 1.540, 143.6 ± 2.884 (Bq/kg) respectively. The total average activities were within the average ranges of the accepted values in the world (45, 33 and 420 Bq/kg for 232Th, 226Ra and 40K respectively).

Influence of fertilizers on the natural radioactivity profile of soil samples of agricultural land in Villupuram District, Tamilnadu State, India

Besides the presence of naturally occurring primordial radionuclides at varying levels in soils, the source of additional natural radioactivity content in agricultural land soils is mainly due to the presence of NORM in the fertilizers. Natural Radioactivity content is determined in ten different types of fertilizers available in Villupuram District, Tamilnadu State and influence of these, if any, in fertilized agricultural soil samples is investigated and compared with virgin soil samples from nearby agricultural land where fertilizers were not used. Relatively higher radioactivity content of 238U and 40K are observed in single super phosphate and potash fertilizers respectively.

Assessment of radioactivity levels and its associated radiological Hazards in soil of Kifl city/Iraq

The aim of this study is to measure the natural radioactivity concentration in the soil samples of the kifl area by using NaI(Tl) detector. The levels of natural radioactivity were measured for 26 samples in Kifl district for three different depths (0-5) cm, (5-15) cm, (15-20). The average specific activity of potassium-40, thorium-232 and uranium-238 were (140±1.82, 14.28±0.59 and 8.50±0.47) Bq/kg in depth (0-5) cm, (134.28±1.78, 13.64±0.59 and 7.31±0.44) Bq/kg in depth (5-15) cm, (127.36 ±1.73, 12.72±0.55 and 6±0.419) Bq/kg in depth (15-20) cm. The results of the study were within the permissible limits when compared with the values on UNSCEAR organization (412 for 40K, 35 for 238U, 45 for 232Th, 370 for Raeq, <1 for H(ex), <1 for H(in), 6 for Iγ, 59 for D(out), 84 for D(in), 0.07 for AEDE(out) and 0.4 for AEDE(in).

Study of natural radioactivity and trace-element content capable of generating long-lived γ-ray activity in cements

Cement is an important component of concrete used as a shielding material in nuclear accelerators and reactors. Hence cement samples should be analysed for the presence of certain trace elements that may get activated by neutrons emitted during the production of radioisotopes in an accelerator, so as to minimize the low level radioactive waste to be handled during decommissioning. With this motivation the present work was undertaken and 44 samples of five broad classes of cements were analysed for natural radioactivity (226Ra, 232Th & 40K) and trace elements capable of generating long lived gamma radioactivity due to neutron activation.

Determination of natural radioactivity in products of animals fed with grass: A case study for Kars Region, Turkey

In this research, the activity concentrations of 40 K, 232Th and 226Ra in 41 grass samples collected from Kars region, Turkey, were determined using gamma ray spectrometry. Natural radioactivity concentrations in animal food products were calculated based on activity concentrations of these radionuclides in pasture-grass samples and dry-grass consumption of animals. The average annual effective dose from these radionuclides for local consumers due to indirect ingestion of cow milk, sheep milk, poultry, mutton and beef consumption have been calculated as 9.01, 0.24, 1.76, 0.38 and 5.25 µSv y-1, respectively. Furthermore, the calculated average annual effective dose values for adults are within the values found in other countries worldwide. These results show that animal products can be safe for human consumption in terms of radiation exposure due to the natural radionuclides studied.

Natural radioactivity content in Italian bottled mineral waters

Bottled water consumption has a long history but nowdays bottled water industry is a fast-growing sector of the world industry. Most of the water in bottles comes from springs or underground aquifers. The mineral content of the aquifer is diluted in small amounts into the water and although consuming mineral water is thought to be a healthy practice, there are several cases where radioactivity is also present. Monitoring the bottled water natural radioactivity is very important especially for the cases people consume mainly this kind of water. Radioactivity accumulation in the human body if exists in excess, can pose a threat for the health. In the present work, thirty brands of Italian bottled water were measured for gross alpha and beta radioactivity, uranium, radium and polonium radioisotopes. Radioactivity content was determined using the LSC method and sorbtion on polyamide pieces covered with thin film of MnO2. The analysis using the MnO2 thin films showed that the radium activity in waters varied from 4.7-69.3 mBqL-1 and the polonium activity varied from 5.9-26.8 mBqL-1. The measurements with the LSC method showed uranium concentrations varying from 0.7- 93.1 mBqL-1, while the radium activities exhibited variations from 1.6-34.1 mBqL-1. Finally the gross beta activity values varied from 13.1-1584.9 mBqL-1 and the gross alpha from 2.4- 305.2 mBqL-1.

Heavy metals and natural radioactivity concentration in sediments of the Mediterranean Sea coast

Heavy metal assessment and natural radioactivity determination in sediments of North Cyprus (Mediterranean coast) were carried out using different analysis methods. The average activity concentrations (range) of 226Ra, 232Th, and 40K were found to be 20.1 (30.6–9.2) Bq kg−1dry weight, 18.4 (26.9–12.4) Bq kg−1dw, and 467.3 (619.9–147.6) Bq kg−1dw, respectively. The average activity concentrations of 226Ra and 232Th in the sediment samples were less than the acceptable limits, whereas the average activity concentration of 40K in the sediment samples was higher than the worldwide average concentration. With regard to the studied heavy metals, the corresponding decreasing average concentration orders were found to be Mn > Zn > Cr > Ni > Cu > Pb. The heavy metal concentration values that were determined for sediment samples were compared with the values obtained in other studies. According to contamination indexes, the results (except for Cu in S-9) indicated no significant contaminated area.

Assessment of Radioactivity and Radiological Hazard of Different Food Items Collected from Local Market in Bangladesh

Sixteen samples in three categories vegetables, cereals (rice, wheat, maize, pulse) and powdered milk were collected from local markets (Dhaka city) in Bangladesh and analyzed by using High Purity Germanium (HPGe) Detector for the assessment of natural and artificial radioactivity. In vegetables (potato, raw banana, giant taro, red amaranth), the average activity concentrations of 232Th, 226Ra, and 40K were found to be 37.82±11.57, 54.93±9.98 and 617.43±65.69 Bqkg-1 respectively, for cereals (rice, wheat, maize, pulse) 24.01±3.67, 31.46±4.00 and 474.83±27.68 Bqkg-1 respectively and for milk samples 15.01±3.65, 26.73±6.77 and 494.21±38.71 Bqkg-1 respectively. The average values of outdoor annual effective dose were found to be 92.18, 61.19 and 52.37μSvy-1 in vegetables, cereals and milk samples respectively. No artificial radionuclide was found in any of these samples. The average value of radium equivalent activity in all samples was 113.89 Bqkg-1 which was less than maximum permissible value 370 Bqkg-1. The values of external hazard indices for vegetables, cereals and milk samples varied from 0.31 to 0.66, 0.17 to 0.40 and 0.11 to 0.36 respectively which is less than unity in all samples that indicate the non-hazardous nature of the samples. The average values of annual effective ingestion dose rate from foods (for adult) were 274.33 μSvy-1, 533.60μSvy-1, and 132.73μSvy-1for 232Th, 226Ra and 40K respectively. These data would be useful to establish a baseline for natural radioactivity concentrations in food items consumed in Bangladesh.&#x0D; Journal of Bangladesh Academy of Sciences, Vol. 43, No. 2, 141-148, 2019

Potential radiological impact of the phosphate industry in South Africa on the public and the environment (Paper 1)

Phosphate rock is mined on a large scale as a source material for fertilizers and other phosphorous containing products, such as phosphoric acid and gypsum. The potential problem of high concentrations of naturally occurring radionuclides in the phosphate industry has been recognized for many years. The industry is responsible for the production of millions of tons of phosphogypsum waste, which is usually stockpiled and might impact the surrounding environment. The presented study aims to assess the natural radioactivity concentrations in raw and waste sub-products from phosphate mining and fertilizer production in South Africa and determine the potential radiological risk associated with the industry.Activity concentrations of 238U, 226Ra and 232Th in phosphate rock, phosphogypsum, tailings, fertilizer, soil and sediment were found to be similar to values reported in previous studies conducted in South Africa. Concentrations of the 232Th decay series were higher than those of the 238U series in rock and ore. The low concentrations of 238U and 226Ra in rock and ore, compared to other countries, makes it more suitable to be used for fertilizer production, and therefore increases the demand for export of rock phosphate and fertilizer from South Africa. 228Ra concentrations in phosphogypsum were higher than 226Ra. The activity of 228Ra was also enriched compared to 232Th, with a ratio of 0.45–19.8. Similar equilibria as described in literature were observed, with almost all the 228Ra and 226Ra present in the phosphate rock observed in the phosphogypsum. Only a low percentage of 232Th present in the original rock remained in the phosphogypsum, with more than 60% present in the fertilizer.The activity concentrations of all nuclides in the analysed samples from the phosphate industry were less than the 1000 Bq kg−1 exclusion value proposed internationally for regulation of NORM. With the exception of phosphate rock samples, concentrations in all solids were lower than the 500 Bq kg−1 limit proposed by the National Nuclear Regulator in South Africa. The obtained values of Raeq for all phosphogypsum, tailings and soil samples were less than the recommended limit of 370 Bq kg−1.The gamma index for the majority of samples was less than 0.5. The index exceeded the limit of unity only for phosphate rock and fertilizer samples, indicating some radiological risk to people living in the vicinity of the industry. The results suggested that members of the public were unlikely to receive any significant dose from the use of phosphate rocks and fertilizers, with an annual effective dose of less than 0.5 mSv.a−1. The highest external dose of 0.45 mSv a−1 is expected from phosphate rock.The suitability of use of phosphogypsum as building material was evaluated. Based on the calculated gamma index [Iγ = 0.52 ± 0.14] use of phosphogypsum as building material is permitted.

Radiological risk assessment of fish feed and feed raw materials

In this study, natural radioactivity concentrations of fish feed and feed raw materials were assessed. Several feeds and raw materials were provided from the suppliers who dominate the aquaculture sector. 226Ra, 232Th and 40K concentrations were determined by using a high-purity germanium detector. The measured activity concentrations of samples ranged from 3.28 ± 0.27 to 15.90 ± 1.36, from 1.27 ± 0.10 to 12.07 ± 1.21 and from 52.01 ± 2.60 to 1,158.96 ± 54.42 Bq/kg for 226Ra, 232Th and 40K respectively. The gamma dose rate and annual effective dose rate of samples were calculated to be in the range of 1.99–50.47 nGy/h and 2.44–61.89 µSv/yr respectively. Since the calculated radiological risk parameters of the samples were lower than the world wide average values, the radiation hazard is insignificant for human handlers.

Radiological hazards due to natural radioactivity and radon concentrations in water samples at Al-Hurrah city, Iraq

Radiological hazards due to natural radioactivity and radon concentrations in water samples at Al-Hurrah city, Iraq

Measurement of natural radioactivity concentrations and chemical composition of coal and its post-combustion residues in KSA

The variable values of 226Ra, 228Ra and 40K were identified in coal and coal combustion residuals (CCR) samples to redistribute radionuclides using 228Ra/226Ra activity ratios in CCRs and compared to their values in the corresponding feed coal. NORM concentrations in CCRs were found to be 6–12 times higher than the original coal. The effective dose rates in the original coal were calculated and ranged from 14.9 ± 0.9 to 370.3 ± 22.2 μSv year−1, whereas in CCRs ranged from 257.5 ± 20.6 to 1797.5 ± 143.8 μSv year−1. The average concentration of 40K (120 Bq kg−1 per 1% K2O in CCRs) was calculated. The chemical composition indicates that the majority of CCR samples are Type C, which has a high calcium oxide ratio, high melting points and low deposition.