Assessment of ingestion dose due to radioactivity in selected food matrices and water near Vizag,India

Activity concentrations of ²³⁸U, ²³²Th, ²²⁶Ra, ⁴⁰K and ¹³⁷Cs were measured in milk, egg, fruit and fish samples collected around a proposed site for setting up nuclear facilities, near Vishakhapatanam. The activity concentrations of the radionuclides ranged from 0.002 to 10.6, 0.002 to 2.8, 0.1 to 7.2, 3 to 110.8, 0.03 to 3 mBq g^?1 for ²³⁸U, ²³²Th, ²²⁶Ra, ⁴⁰K and ¹³⁷Cs considering analysed food matrices. Natural uranium was measured in drinking water samples and the values were below 15 ppb. The average ingestion dose was 2.07 ± 2.01, 2.81 ± 4.38, 7.66 ± 8.24, 1.28 ± 0.84 and 0.04 ± 0.05 μSv year^?1 for ²³⁸U, ²³²Th, ²²⁶Ra, ⁴⁰K and ¹³⁷Cs in milk, egg, fruit, fish and water. The ingestion dose received was the highest for milk, due to its high ingestion rate. It was observed that ²²⁶Ra is the largest contributor of measured radionuclides in this study for the different food matrices analysed due to its high dose conversion factor. The study was carried out as a part of baseline data generation for this region with which future changes in the radiological scenario can be compared.     

Natural and Artificial Radionuclides in Selected Lignites from Istanbul

The radioactivity levels of Istanbul environs lignites were determined. The gamma-spectrometric technique has been used for the determination of activity levels of naturally occurring radionuclides ^235+238U, ^228+232Th, ⁴⁰K, ²²⁶Ra and fallout radionuclides ¹³⁷Cs in lignites taken from 7 different parts of Istanbul. Concentration of ²³⁸U, ^228+232Th, ⁴⁰K, ²²⁶Ra ¹³⁷Cs and ²³⁵U were found up to 1.6 ppm, 1.7 ppm, 4.9 ppm, 56.8 Bq/kg, 34 Bq/kg, 1.8 Bq/kg, 1.6 Bq/kg, respectively. In addition total alpha- and beta-activity levels in lignite samples were found to be 7.6 and 15 eps, respectively.     

A simple correction method for isobaric interferences induced by lead during uranium isotope analysis using secondary ion mass spectrometry

The present study is to determine the activity concentration of radioactive nuclide in plant fertilizers used in agriculture in Iraqi Kurdistan region using high- purity germanium detector (HPGe) gamma spectrometer. The results showed that the range of activity concentrations for ²²⁶Ra, ²³²Th, ⁴⁰K and ¹³⁷Cs in chemicals and organic fertilizers are (0.1–134), (0.1–74), (1–12,000) and (0–1) Bq/kg respectively, based on the measured activities that were used to assess the radiological hazards. Radium equivalent activity in some samples exceeds the value (370 Bq/kg) which recommended by the OECD.     

Application of tracer technique in remediation of Sr(II) from simulated low level radioactive waste

Journal of Radioanalytical and Nuclear Chemistry - Activity concentrations of natural (40K, 226Ra, 228Ra, 232Th, 238U) and artificial (134Cs, 137Cs) radionuclides were measured in powdered milk...     

Distribution of137Cs and228Ra in the sediments of Aswan High Dam lake

Sediment samples of the High Dam lake were investigated for their¹³⁷Cs,²²⁶Ra,²²⁸Th, and⁴⁰K content, using low-level -spectroscopy. The results show that at the begining of the lake (500 km from the High Dam), where sediments consist mostly of sand, the level of¹³⁷Cs is very low (0.1 Bq kg^–1). The maximum value (22.3 Bq kg^–1) was found 40 km from the wall of the High Dam, where the composition of the sediments is nearly 50% clays. The distribution of the natural nuclides²²⁶Ra,²²⁸Th, and⁴⁰K shows a different trend.     

Radioactivity levels in soil of three selected sites at and around Riyadh City

In this work the naturally occurring as well as some man-made radionuclidesin soil samples have been experimentally determined to establish the backgroundradioactivity levels in three selected sites at and around Riyadh City. Concentrationsof ²³⁸U and ²³²Th radionuclides together with theirdaughter ²²⁶Ra, ⁴⁰K, ¹³⁷Cs and ¹³⁷Csin soil samples, collected from different locations in the selected siteshave been measured using a hyper-pure high-resolution germanium spectrometer.The obtained concentrations of the studied radionuclides in soil in the selectedsites are presented in tabular form in Bq/kg.     

Analysis of 36Cl in Savannah River Site radioactive waste

The present work shows the activity levels of ²²⁶Ra, ²²⁸Ra, ⁴⁰K and ¹³⁷Cs in bottom sediments collected from eight locations of Mumbai Harbour Bay. The study has shown that ⁴⁰K and ²²⁸Ra concentration is nearly uniform throughout the studied area while ²²⁶Ra and ¹³⁷Cs are more concentrated in the southern regions of the bay. The significant variation in the activity levels of radionuclides within the study site might be due to their sorption/desorption processes onto the surface of sediment materials. The low mean value of ²²⁶Ra/²²⁸Ra ratio (0.72) in the sediments indicates that ²³⁸U has relatively greater solubility and mobility than ²³²Th. Similarly, low activity ratio (0.18) for ¹³⁷Cs/⁴⁰K reflects the presence of very high content of ⁴⁰K in sediment due to presence of primary minerals in sediment. Silt and clay were reported to dominate the composition of the sediment. A significant positive correlation between ²²⁶Ra and ²²⁸Ra and ¹³⁷Cs and ⁴⁰K suggest a similar origin of their geochemical sources and identical behavior during transport in the sediment system.     

Radiation hazards and natural radioactivity levels in surface soil samples from dwelling areas of North Cyprus

Journal of Radioanalytical and Nuclear Chemistry - Due to increasing concern about environmental radiological protection, radioactivity concentrations of 226Ra, 232Th, 40K and 137Cs in surface soil...     

Assessment of radioactivity level and associated radiation exposure in topsoil from eastern region of Shangrao Prefecture,China

Natural and fallout radioactivity were estimated in topsoil samples collected in eastern region of Shangrao Prefecture, China. The average activity concentrations of ²³⁸U, ²²⁶Ra, ²³²Th and ⁴⁰K in the soil were nearly 2 times the world median value and Chinese average. The ¹³⁷Cs activity concentration decreased compared with the previously reported value in the same region. The absorbed dose rate and annual effective dose rate estimated in the study area are found to be both higher than the world average values. ²³⁸U/²²⁶Ra and ²³²Th/²²⁶Ra activity ratios were also considered in this study.

     

Radionuclide activities and elemental concentrations in sediments from a polluted marine environment (Saronikos Gulf-Greece)

The levels and depth distributions of the natural radionuclides ²³⁸U, ²³²Th, ²²⁶Ra, ⁴⁰K and the man-made ¹³⁷Cs were analyzed by γ-ray spectrometry, while the concentrations of 26 chemical elements were measured by INAA in sediment samples collected from the organic mud layer that covers the Keratsini–Psitalia strait, Saronikos gulf (Greece). The average activity concentration values of ²²⁶Ra, ²³²Th and ⁴⁰K were lower when compared, whereas that of ²³⁸U was comparable to the average Greek and world values. The elemental contamination of the sediments was estimated on the basis of the calculated EF values. The results revealed high EF values of As, Br, Cr, Ni, Sb, Se, Zn ranging from 160 for Br to 10 for Cr, whose main sources are probable related to contaminated sewage outfall from the area of Athens and the Piraeus Harbour.

     

Radioactivity measurements in epiphytic lichens of Uludağ Mountain in Western Anatolia

Activity concentrations of gross-β, naturally occurring ²²⁶Ra, ²³²Th, ²¹⁰Pb, ⁷Be and anthropogenic ¹³⁷Cs in epiphytic lichens collected from Uluda? Mountain are presented and discussed with the aim of evaluating potential usability of lichens as a biomonitor. The activity concentrations of gross-β, ¹³⁷Cs, ⁴⁰K, ²²⁶Ra, ²³²Th, ²¹⁰Pb and ⁷Be in the lichen samples were found to be in the range of 177–707, 4.05–94.26, 86–211, below detection limit (BDL)—19.2, BDL—14.0, 229–872, and 72.1–220.7 Bq kg^?1 in dry weight, respectively. ¹³⁷Cs content in collected epiphytic lichens was in descending order: Parmelia sulcata > Lobaria pulmonaria > Pseudevernia furfuracea > Usnea filipendula. The best biomonitor for ¹³⁷Cs among the lichen species used in this study was determined as Parmelia sulcata. Pearson’s correlation coefficient was calculated between ¹³⁷Cs and ⁴⁰K activity concentrations using a statistical package program (SPSS ver. 17.0) and a negative correlation value (R = ?0,323, p = 0,222) was obtained. The highest ²²⁶Ra and ²³²Th activity concentrations were found in Bo?azova Yaylas? which has a geological structure including granitic rocks. It was found that ¹³⁷Cs and ⁷Be activity concentrations in species demonstrated an inverse behaviour. The effect of mean annual precipitation and temperature on ⁷Be activity concentration was determined using multi regression analysis. Also, correlations between the ¹³⁷Cs and ⁷Be, and ⁴⁰K and ⁷Be were investigated.     

Measuring <Superscript>137</Superscript>Cs, <Superscript>40</Superscript>K and decay products of <Superscript>226</Superscript>Ra and <Superscript>232</Superscript>Th in samples of different nature by a multidetector spectrometer

A coincidence method for measuring ¹³⁷Cs, ⁴⁰K, ²²⁶Ra and ²³²Th decay products activity in soil, vegetation and fish samples, was applied to the six-crystal gamma-coincidence spectrometer PRIPYAT-2M. In this way, some problems appeared in simultaneous measurement of ¹³⁷Cs, ²²⁶Ra and ²³²Th by NaI(Tl) detectors and the PRIPYAT-2M spectrometer were solved. The obtained results were agreeable with the HPGe spectrometer ones.     

A preliminary study on 226Ra, 232Th, 40K and 137Cs activity concentrations in vegetables and fruits frequently consumed by inhabitants of Elazığ Region, Turkey

Determining radioactivity levels in foodstuffs is of great importance for the protection of human health. In addition, the literature includes few studies related to this subject in Turkey. In this study, gamma spectroscopic system was used in order to measure ²²⁶Ra, ²³²Th, ⁴⁰K and ¹³⁷Cs activity concentrations in vegetables and fruits produced in Elaz?? Region. The average activity concentrations in vegetables was calculated as 0.64 ± 0.26 Bq kg^?1 for ²²⁶Ra, 0.65 ± 0.14 Bq kg^?1 for ²³²Th, 13.98 ± 1.22 Bq kg^?1 for ⁴⁰K, and 0.54 ± 0.04 Bq kg^?1 for ¹³⁷Cs. The average activity concentrations in fruits were 1.52 ± 0.34, 0.98 ± 0.23, 18.66 ± 1.13 and 0.59 ± 0.16 Bq kg^?1, respectively for ²²⁶Ra, ²³²Th, ⁴⁰K and ¹³⁷Cs. Total committed effective dose value was determined as 20 and 30.55 μSv y^?1, respectively for vegetables and fruits. The findings were compared with previous data reported for Turkey and other regions of the world.     

Levels and effects of natural radionuclides in soil samples of Garhwal Himalaya

Distribution of natural radionuclide gives significant parameter to assess the presence of gamma radioactivity and its radiological effect in our environment. Natural radionuclides are present in the form of ²²⁶Ra, ²³²Th and ⁴⁰K in soil, rocks, water, air, and building materials. Distribution of natural radionuclides depends on the type of minerals present in the soil and rocks. For this purpose gamma spectrometer is used as tool for finding the concentration of these radionuclides. The activity concentration of naturally occurring radionuclides ²²⁶Ra, ²³²Th and ⁴⁰K in these soil samples were found to vary from of 8 ± 1 Bq/kg to 50 ± 10 Bq/kg with an average 20 Bq/kg, 7 ± 1–88 ± 16 Bq/kg with an Average 26 Bq/kg and 115 ± 18–885 ± 132 Bq/kg with an average 329 Bq/kg, respectively. In this paper, we are presenting the radiological effect due to distribution of natural radionuclide present in soil of Garhwal Himalaya.     

Radiological characterization and environmental impact in northwestern coast of Egypt

A study of environmental radioactivity along the northwestern coast of Egypt was performed by the Central Laboratory for Environmental Radioactivity Measurements Inter-comparison and Training within the framework of the research project: Radiological Studies/Measurements of Natural and Man-made Radionuclides in the Environment. The present paper contains important conclusions, correlations and interpretations of the environmental measurements. The samples collection and measurements were conducted according to the Egyptian Atomic Energy Authority monitoring plan for locations along the northwestern coast of Egypt and its main tributaries of interest. The specific activities of ²²⁶Ra (²³⁸U series), ²²⁸Ra (²³²Th series), ⁴⁰K and ¹³⁷Cs (Bq/kg dry weight) were measured using gamma-ray spectrometers based on hyper-pure germanium detectors. The absorbed radiation dose rates in air (nGy/h) due to natural radionuclides in shore sediment and radium equivalent activity index (Bq/kg) were calculated. The specific activity ratios of ²²⁸Ra/²²⁶Ra were calculated for evaluation of the geo-chemical behavior of these radionuclides. Samples textures and CaCO₃ and total organic matter contents of sediments were also determined while the pH, major cations and anions such as Na⁺, K⁺, Ca⁺⁺, Mg⁺⁺and Cl^?, SO₄ ^– and HCO₃, respectively were also determined in water samples.     

Terrestrial absorbed dose rate measurement in the Jhangar valley of Pakistan

Specific activity of natural radionuclides; ²²⁶Ra, ²³²Th and ⁴⁰K were measured in the agricultural soil of eastern salt range of Pakistan using gamma ray spectrometry. The soil samples were collected within the ploughing region (up to 12 cm depth) and processed before analysis. The average specific activities of different radionuclides in the dry mass of soil samples were: ⁴⁰K, (666 Bq/kg), ²²⁶Ra (51 Bq/kg), and ²³²Th (59 Bq/kg). The average outdoor terrestrial absorbed dose rate in air from gamma radiation one meter above ground surface was found to be 93 nGy/h.     

Gamma dose rate due to natural and manmade radiation sources from a nuclear facility in Mexico

The environmental external gamma dose rate has been determined at the Mexican Nuclear Research Centre and surrounding communities, located in a forest area. Outdoor direct measurements of external gamma exposure and absorbed dose rates in air were performed using passive integrating thermoluminescent dosimeters. Radiological measurements were also carried out with a portable high pressure ionization chamber. The gamma dose rate was evaluated from data obtained along 10 years measurements. The activity concentrations of ⁴⁰K, ²²⁶Ra, ²³²Th, ¹³⁷Cs, and ²³⁵U in surface soil samples at sampling sites are also presented. The radionuclide activity concentrations were determined by low background gamma spectrometry with hyper-pure germanium detectors. A site specific lineal model to describe the relationship between the external gamma dose rate and the ²²⁶Ra concentration values in the soil is proposed.     

Preliminary analyses of natural radionuclides in selected Turkish power plant lignites

This preliminary study presents the experimental results concerning the concentrations of selected radionuclides (²³⁸U, ²³²K, ²²⁶Ra, ²³²Th) in Af?in-Elbistan, Çan, Çay?rhan, Erzurum, Göynük, Kangal, Orhaneli, Saray, Seyitömer, Soma, Tunçbilek, Yata?an and Yeniköy lignites, which are primarily utilized as fuel for thermal power plants in Turkey. Gamma-spectrometry of 39 representative lignite samples gave results with the following concentration ranges: 8 to 296 Bq/kg for ²³⁸U, 3 to 79 Bq/kg for ²³²Th, 17 to 360 Bq/kg for 40K, and 5 to 130 Bq/kg for ²²⁶Ra. The ²³⁸U results reported here are higher than other literature values for various world coals, earth's crust and world average.     

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.     

Radionuclide uptake in red macroalgae from the Bulgarian Black Sea coast

Summary Technogenic and natural radionuclide content in red macroalgae (Ceramium rubrum, Corallina officinalisand Callithamnion corymbosum) from the Bulgarian Black Sea coast, collected in the period 1992-2003, was studied by low-level gamma-spectrometry. The data show that the nuclide concentrations depend on macroalgae species and coast locations. The highest nuclide content was measured in Ceramium rubrumspecies. The ¹³⁷Cs mean value is 9.8 Bq/kg, 19.6 Bq/kg for ²²⁶Ra and 17 Bq/kg for ²¹⁰Pb. The radionuclide pollution is considerably small due to the absence of nuclear facilities along the Bulgarian Black Sea coast.