Evaluation of the natural radioactivity in food and soil around uranium mining region

Journal of Radioanalytical and Nuclear Chemistry - To evaluate the radiological risk to human health associated with the ingestion of radionuclides in foods, some different plant foods cultivated...     

Environmental assessment of heavy metal and natural radioactivity in soil around a coal-fired power plant in China

Concentrations of heavy metals and natural radionuclides in soil around a major coal-fired power plant of Xi’an, China were determined by using XRF and gamma ray spectrometry, respectively. The measured results of heavy metals show that the mean concentrations of Cu, Pb, Zn, Co and Cr in the studied soil samples are higher than their corresponding background values in Shaanxi soil, while the mean concentrations of Mn, Ni and V are close to the corresponding background values. The calculated results of pollution load index of heavy metals indicate that the studied soils presented heavy metal contamination. The concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K in the studied soil samples range from 27.6 to 48.8, 44.4 to 61.4 and 640.2 to 992.2 Bq kg^?1 with an average of 36.1, 51.1 and 733.9 Bq kg^?1, respectively, which are slightly higher than the average of Shaanxi soil. The air absorbed dose rate and the annual effective dose equivalent received by the local residents due to the natural radionuclides in soil are slightly higher than the mean values of Shaanxi. Coal combustion for energy production has affected the natural radioactivity level and heavy metals (Cu, Pb, Zn, Co and Cr) concentrations of soil around the coal-fired power plant.     

Assessment of natural radioactivity and heavy metals in water and soil around seismically active area

The natural radioactivity concentration and some heavy metals in various water and soil samples collected from seismically active area have been determined. Gross-alpha and beta concentrations of different 33 water samples and some heavy metal (Fe, Pb, Cu, K, Mn, Cr and Zn) concentration in 72 soil samples collected from two major fault systems (North and East Anatolian Active Fault Systems) in Turkey have been studied. This survey regarding gross-alpha and beta radioactivity and some heavy metals concentrations was carried out by means of Krieger method using a gross-alpha and beta-counting system and atomic absorption spectrometry (AAS), respectively. Also, gross annual effective dose from the average gross-alpha activity in waters were calculated.     

Effect of soil properties on radioactivity concentrations and dose assessment

This study evaluated the correlation between radioactivity concentrations and soil properties, and determined the total annual effective dose near an underground geologic repository for transuranic wastes. Soil samples were collected from two historical monitoring areas (Near Field and Cactus Flats). Alpha-particle spectrometry was used for the analysis of ²⁴¹Am, ^239+240Pu and ²³⁸U, while ¹³⁷Cs, ⁴⁰K, ²³²Th and ²²⁶Ra were detected by gamma ray spectrometry. Higher radioactivity concentrations and stronger positive correlations between radioactivity concentrations and soil properties were obtained in Cactus Flats compared to Near Field. The total annual effective dose was lower than the recommended limit of 1 mSv y^??1.

     

Spatial variability and radiation assessment of the radionuclides in soils and sediments around a uranium tailings reservoir,south of China

Journal of Radioanalytical and Nuclear Chemistry - The concentrations of 238U, 226Ra, 232Th and 40K and gross α, β were measured in soils and sediments around a uranium tailings reservoir...     

Partitioning of natural radionuclides in sediments around a former uranium mine and mill

Partitioning of natural radionuclides in sediments from streams affected by the waste piles of the former uranium mine and mill located at ?irovski vrh, Slovenia, was performed by applying a sequential extraction procedure. The sediments were collected at three sites located upstream and three sites located downstream of the waste piles. Then the four-step Community Bureau of Reference (BCR) sequential extraction protocol was applied to the samples and the natural radionuclides ²³⁸U, ²³⁰Th, ²²⁶Ra, ²¹⁰Pb and ²¹⁰Po were analysed in each extraction fraction. It was expected that the fractionation of natural radionuclides originating from the waste piles would differ from that upstream of the influence of waste piles because their chemical environment had been altered during the processes of uranium extraction. This difference could allow tracing of the radionuclides coming from the waste piles downstream of the affected watercourses. The results definitely showed that the total activity concentrations at sites downstream of the influence of the waste piles were higher than at sites upstream of the piles. However, this difference was geographically very limited and could no longer be detected already at a distance of about 5 km downstream. Unexpectedly, the fractionation of radionuclides upstream and downstream of the area of influence of the waste piles did not appear to be significantly altered. The sole differences found were for ²³⁸U and ²²⁶Ra in the second fraction (the “Fe/Mn oxides” fraction) and for ²¹⁰Po in the fourth fraction (the “residue” fraction) of the BCR sequential extraction protocol.     

Pollution characteristics and risk assessment of uranium and heavy metals of agricultural soil around the uranium tailing reservoir in Southern China

For the first time the pollution of the paddy soil within 2 km around the uranium tailing reservoir was investigated. The concentrations of U, Cd, Cr, Pb, Cu, Zn, Hg and As were determined by ICP-MS. The study showed that there was severe pollution in the first area (within 0–1 km of the tailing reservoir), which was caused by Cd, As, U and Hg. The pollution level of the second area (within 1–2 km) was relatively low. Hg and As were the main pollutants. In the first area, the contamination degree and risk of elements were positively correlated with the distance from the tailing reservoir. The second area was less polluted and influenced by mining and human activities because of mountain barriers.     

222Rn radioactivity in urban waters of fault zone in China: dose rate and risk assessment

Journal of Radioanalytical and Nuclear Chemistry - The exhalation of radon from waters surrounding active fault zones is at present not well understood. In this work, radon concentrations in urban...     

Translocation of radioactivity from substrate to macromycetes in the Crucea (Romania) uranium mining area

The present study follows the extent of translocation radioactivity from the substrates of the Crucea uranium mining area to the macromycetes spontaneously occurred during June–October 2008. To this end, radioactivity measurements (gross α + β and ¹³⁷Cs) on both macromycetes and their substrates were made. The resultants obtained were confirmed by FT-IR spectroscopy, evidencing the presence of characteristic bands around of 910 cm⁻¹, corresponding to the asymmetric stretching vibration of the uranyl unit and to the interaction between the UO₂ ²⁺ ions and the group belonging to various cellular components.     

Measurements of natural radioactivity in infant formula and radiological risk assessment

A set of measurements have been conducted to determine the levels activity of gamma-emitters present in infant formula. The study of different samples shows the presence of the following radionuclides: ²²⁶Ra, ²³²Th and ⁴⁰K with respectively average activity of 0.52 ± ?0.087, 0.51 ± 0.062, 371.98? ± 3.68 Bq/kg. The mean annual doses lead to 0.62 and 0.24 mSv/year whereas the total risk is about 7.91 × 10^?6 and 5.32 × 10^?6 respectively ≤ 1 year and 1–2 years old infants. The obtained results show that no significant radiation dose and no risk to the infants due to consumption of these milks.     

External gamma radiation levels and natural radioactivity in soil around a phosphate fertilizer plant at Mumbai

Fertilizers containing phosphate have been used worldwide in increasing quantities in order to replenish natural nutrients, which are being continuously depleted from the soil by virtue of farming activities. Phosphate rocks together with potassium ores and nitrogenous compounds are the main raw materials used for industrial fertilizer production. Rock phosphate ore processing and disposal of phosphogypsum contribute to enhanced levels of natural radionuclides in the environment. The levels of naturally occurring radionuclides such as ²³⁸U, ²³²Th, ²²⁶Ra and ⁴⁰K in soil samples collected around a phosphate fertilizer plant were estimated. Radium equivalent activity, external hazard index and external dose rate due to natural gamma background at various locations around the plant were also measured.     

Application of zeolitic rocks in the environment: assessment of radiation due to natural radioactivity

Journal of Radioanalytical and Nuclear Chemistry - The 238U, 226Ra, 210Pb, 228Ra, 228Th and 40K concentrations have been measured beside to radon emanation factor due to sample granulometric using...     

Assessment of natural uranium and 226Ra concentration in ground water around the uranium mine at Narwapahar, Jharkhand, India and its radiological significance

A brief study on dissolved radionuclides in aquatic environment, especially in ground water, constitutes the key aspect for assessment and control of natural exposure. In the present study the distribution of natural uranium and ²²⁶Ra concentration were measured in ground water samples collected within a 10 km radius around the Narwapahar uranium mine in the Singhbhum thrust belt of Jharkhand, India in 2007–2008. The natural uranium content in the ground water samples in this region was found to vary from 0.1 to 3.75 μg L^?1 with an average of 0.87 ± 0.73 μg L^?1 and ²²⁶Ra concentration was found to vary from 5.2 to 38.1 mBq L^?1 with an average of 13.73 ± 7.34 mBq L^?1. The mean annual ingestion dose due to intake of natural uranium and ²²⁶Ra through drinking water pathway to male and female adults population was estimated to be 6.55 and 4.78 μSv y^?1, respectively, which constitutes merely a small fraction of the reference dose level of 100 μSv y^?1 as recommended by WHO.     

Natural radioactivity measurements and age-dependent dose assessment in groundwater from Al-Zulfi,Al-Qassim and Al-Majmaah regions,Saudi Arabia

In this study, the levels of natural radioactivity in the groundwater samples collected from 26 different locations in Al-Zulfi, Al-Qassim and Al-Majmaah regions were determined. The estimated average values of ²²⁶Ra, ²²⁸Ra, ⁴⁰K, gross α and gross β activities in the samples were 0.87 Bq L^?1, 1.33 Bq L^?1, 4.22 Bq L^?1, 36.82 mBq L^?1 and 831.91 mBq L^?1, respectively. We found that age-dependent effective ingestion dose from radionuclides in all samples were higher than WHO recommended levels of 0.1 µSv y^?1 for adults 0.2 µSv y^?1 for children and 0.26 µSv y^?1 for infants while 20 sampling locations have age-dependent effective dose equivalent from β contributors were higher than WHO recommended level of 0.1 mSv y^?1.     

Assessment of annual effective dose from natural radioactivity intake through wheat grain produced in Faisalabad,Pakistan

Wheat is staple food of the people of Pakistan. Phosphate fertilizers, used to increase the yield of wheat, enhance the natural radioactivity in the agricultural fields from where radionuclides are transferred to wheat grain. A study was, therefore, carried out to investigate the uptake of radioactivity by wheat grain and to determine radiation doses received by human beings from the intake of foodstuffs made of wheat grain. Wheat was grown in a highly fertilized agricultural research farm at the Nuclear Institute of Agriculture and Biology (NIAB), Faisalabad, Pakistan. The activity concentration of ⁴⁰K, ²²⁶Ra and ²³²Th was measured in soil, single superphosphate (SSP) fertilizer, and wheat grain using an HPGe-based gamma-ray spectrometer. Soil to wheat grain transfer factors determined for ⁴⁰K, ²²⁶Ra and ²³²Th were 0.118 ± 0.021, 0.022 ± 0.004 and 0.036 ± 0.007, respectively, and the annual effective dose received by an adult person from the intake of wheat products was estimated to be 217 μSv.     

Measurement of natural radioactivity and radiation hazard assessment in the soil samples of Visakhapatnam,Andhra Pradesh,India

The present work aims to measure and estimate radioactivity and hazardous radiation indices of the soil. Soil samples were collected from various locations in the Visakhapatnam district in Andhra Pradesh, India. The measurement of specific activity of ²²⁶Ra, ²³²Th, and ⁴⁰K radionuclides is carried out with the help of HP-Ge based gamma spectrometer system. Activity concentration of radionuclides in the samples ²²⁶Ra, ²³²Th and ⁴⁰K ranged from 20 ± 2 to 91 ± 2 Bq.kg^-1, 45 ± 3 to 365 ± 3 Bq.kg^-1, and 400 ± 9 to 607 ± 8 Bq.kg^-1, and the respective mean values are 53.36 Bq.kg^-1, 203.74 Bq.kg^-1 and 479.19 Bq.kg^-1. The measured mean value of the absorbed dose rate is 171.41 nGy.h^-1, which was beyond the worldwide mean outdoor value of 60 nGy.h^-1. Thus, the annual effective dose estimated from the above value is 1.04 mSv.y^-1. The correlation was done among the measured ²²⁶Ra, ²³²Th, and ⁴⁰K activity concentrations. The estimated radium equivalent dose is 381.60Bq.kg^-1. The estimated health hazard index and annual effective dose rates of dwellers of Visakhapatnam were studied and compared to Indian average values. The study will help to generate the baseline data for assessing hazard indices to the public and geological mapping of natural radiation in India.