Natural radioactivity of some local building materials in the middle Euphrates of Iraq

People are exposed to ionizing radiation from the radionuclides that are present in different types of a natural sources, of which building materials is one of the most important sources. Radionuclides in building materials belonging to ²³⁸U, ²³²Th series as well as radioisotope of Potassium ⁴⁰K are the major contributors of outdoor terrestrial natural radiation. This study is the first ever in Iraq. In order to estimate the radiological impact to the dweller, the activity concentration of radionuclides present in various Iraqi building materials were analyzed using Gamma-spectrometry. The radiation hazard indexes were calculated based on the above results. The results showed that the activity concentration of ²³⁸U, ²³²Th and ⁴⁰K was between 32.9 Bq/kg (Najaf gypsum)–179.32 Bq/kg (Karbala cement), 1.98 Bq/kg (Najaf sand)–17.43 Bq/kg (Qadisiya brick) and 108.73 Bq/kg (Karbala sand)–977.79 Bq/kg (Najaf brick), respectively. All values of Radium equivalent activities were found to be less than the maximum permissible limit and the internal hazard indexes (except Karbala cement) were less than unity for the radiation hazard. Some samples have external annual dose and external hazard index values greater than unity.     

Natural radioactivity in Zambian building materials collected from Lusaka

Samples of natural and manufactures building materials collected around Lusaka have been analyzed for natural radionuclides using -spectrometry. A simple comparison of the specific radioactivities of primordial radionuclides in these materials to the world averages for soil (25 Bq kg^{–1 238}U, 25 Bg kg^{–1 232}Th, 370 Bq kg^{–1 40}K and 89 Bq kg^–1 Ra_eq) shows that, of the nine types of samples analyzed, only burnt clay bricks (for²³⁸U,²³²Th and⁴⁰K), cement roofing tiles (for²³⁸U), building and river sands (for²³²Th and⁴⁰K) have greater activities than does soil. Radiological evaluation of specific radioactivities in these materials indicates that all materials meet the external -ray dose limitation of 1.5 mSv y^–1, that is, all samples have a radium equivalent activity of less than 370 Bq kg^–1.     

Investigation of radioactivity level in soil and drinking water samples collected from the city of Erzincan,Turkey

This study is part of an effort to assess the level of background radiation for Erzincan Province of eastern Turkey. Radionuclide activity concentrations in soil samples were measured through gamma-ray spectrometry and the average activities were determined as 8.93, 11.39, 281.94, and 9.52 Bq/kg for the radionuclides ²³⁸U, ²³²Th, ⁴⁰K, and ¹³⁷Cs, respectively. The average annual effective dose from these natural radioactivity sources (²³⁸U series, ²³²Th series and ⁴⁰K,) was calculated to be 27.9 μSv. Radioactivity levels in drinking and potable water samples were studied using a multi-channel low level proportional counter. The average gross alpha activity concentration was found to be 0.0477 Bq/L (min. 0.007 Bq/L; max. 0.421 Bq/L) and the average gross beta activity was measured as 0.104 Bq/L (min. 0.008 Bq/L; max. 1.806 Bq/L). These values lead to an average annual effective dose of 9.75 μSv from the alpha emitters and 56.34 μSv from the beta emitting radionuclides in water. The radioactivity levels in the water samples investigated were found to comply with the reference levels recommended by WHO and the regulations set forth by the Turkish Health Ministry.     

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.     

Determination of naturally occurring radionuclides in selected rocks from Hetaunda area,central Nepal

The specific activities of the naturally occurring radionuclides ²³⁸U, ²³²Th, and ⁴⁰K were measured in rock samples from the Hetaunda area, central Nepal, using gamma spectrometry. The specific activities were found to be in the range of 17–95 Bq kg⁻¹ for ²³⁸U, 24–260 Bq kg⁻¹ for ²³²Th and 32–541 Bq kg⁻¹ for ⁴⁰K. From these data absorbed dose rates in air and annual effective doses were calculated and compared with respective data from the UNSCEAR compilation. The results from our study open the door to the safe applicability of most of the investigated materials as a cheep building material.     

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.     

Radiological hazard and radiogenic heat production in some building materials in upper Egypt</p> </p>

Summary Samples of limestone, sand, marble, clay brick, red brick, gypsum, Portland cement and white cement collected from upper Egypt used in building manufacturing have been analyzed for the natural radionuclides ²²⁶Ra, ²³²Th and ⁴⁰K usingg-ray spectrometry. The specific concentrations for ²²⁶Ra, ²³²Th and ⁴⁰K, ranged from 20-88, 13-115 and 54-304 Bq/kg, respectively. The average specific activities of these radionuclides were compared. Higher values of ²²⁶Ra and ²³²Th could be noticed in marble while that of ⁴⁰K was in red bricks. Radium equivalent activities, dose rate and the annual gonadal dose equivalents AGDE were calculated for the measured samples to assess the radiation hazard arising from using those materials in the construction of dwellings. The radioactive heat production values of the selected materials have also been determined. They vary from a minimum of 0.41 for white cement to a maximum of 5.52mW/m³ for marble samples. The calculated heat-production values are quite similar to those estimated in Corsica.</p> </p>     

Assessment of gamma-ray emissions from natural and manmade decorative stones

Decorative stones (32 natural and 18 manufactured) and five ceramic tiles that are used in home interiors were measured with gamma-ray spectrometry, to identify and quantify the naturally occurring radionuclides. Activity concentrations of the radioisotopes varied by more than two orders of magnitude across the stone samples, with maximal levels of 3380, 850, and 2130 Bq/kg, for ²³⁸U, ²³²Th, and ⁴⁰K, respectively. A radiation index and measurements with a radiation meter established that the annual effective dose rates due to a 1 h/day exposure to gamma rays emitted by the granite samples were often low, but can occur as high as 1 mSv/year.     

External dose-rates for natural gamma emitters in soils from an agricultural land in West Anatolia

The surveys of natural gamma-emitting radionuclides in soils from three basins of West Anatolia intensively used for agricultural purposes were conducted during 1998–2003. In the present study, part of the survey, the activity concentrations of ²³⁸U, ²³²Th and ⁴⁰K in the soil samples from 43 sites distributed all over the agricultural land known as Büyük Menderes basin were determined by scintillation gamma spectrometry. The average activity concentrations and ranges of the relevant radionuclides in the soils were as follows: ²³⁸U was 29 (7–84); ²³²Th, 22 (10–48) and ⁴⁰K, 464 (100–864) Bq kg⁻¹. The corresponding absorbed dose rates in air from all those radionuclides were in the range of 17–81 nGy h⁻¹ with a mean value of 46 nGy h⁻¹ and did not exceed the world-wide average values. All dosimetric calculations were performed based on the guidance of UNSCEAR 2000 report [1].     

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.     

Study of naturally occurring radioactive material (NORM) in top soil of Punjab State from the North Western part of India

The concentration levels of ²³⁸U, ²³² Th, ⁴⁰K and ¹³⁷Cs in top soils of State of Punjab located in the North Western part of India were measured using conventional low background gamma ray spectrometric setup as well as Compton suppressed gamma ray spectrometric setup. The radioactivity level of ²³⁸U and ²³²Th was found to vary between 15 Bq/kg and 27 Bq/kg and between 16 Bq/kg and 57 Bq/kg respectively. The radioactivity level of ⁴⁰K was found to vary between 266 Bq/kg and 799 Bq/kg. The mean radioactivity level of the NORM in general was found to be similar to what is expected as a result of their normal abundance.     

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.     

Geochemistry and health burden of radionuclides and trace metals in shale samples from the North-Western Niger Delta

Organic sedimentary rock samples were collected from three Oil Wells in the North-Western Niger Delta, Nigeria in order to determine their natural radioactivity and elemental geochemistry, with the aim of determining the concentrations of major radionuclides and their radiological and environmental health implication. The PIXE method of IBA technique and an accurately calibrated Si(Li) detector system was used to measure the elemental concentration of the sediment samples. The radionuclides identified belong to the decay series of naturally occurring radionuclides headed by ²³⁸U and ²³²Th along with the non-decay series radionuclide, ⁴⁰K. The activity concentrations of the radionuclides and their derived dose were then calculated. The average activity concentrations of ⁴⁰K were 248 Bq/kg for Well A, 261 Bq/kg for Well B and 273 Bq/kg for Well C. For ²³²Th the activity concentrations were 1,043 Bq/kg for Well A, 1,400 Bq/kg for Well B, 1,434 Bq/kg for Well C. ²³⁸U activity concentrations were 2,210, 3,508 and 250 Bq/kg for the Oil Wells A, B, C, respectively. The equivalent dose ranges from 8.5 ± 1.1 to 24.3 ± 2.1 mSv/year with a mean of 14.5 ± 2.2 mSv/year for Oil Well A, 2.4 ± 0.1–75.0 ± 1.2 mSv/year with a mean of 21.5 ± 1.1 mSv/year for Oil Well B and 3.7 ± 0.2–10.7 ± 0.6 mSv/year with a mean of 9.4 ± 2.5 for Oil Well C. The detected trace metals were majorly V, Ni, Pb, Fe, Cr, Cu, Zn, Co and their concentrations together with those of the radionuclides are compared with the relevant world standard limits. The results obtained were high, and hence, the radioactivity level and trace element content of the sediment samples from the North-Western Niger Delta Oil province could constitute health hazard to occupationally exposed workers, and to the public if not properly disposed. However, despite the careful disposal practice claims by the Oil industries, and given the high concentrations, the sediments could still pose an intrinsic health hazard considering their cumulative effects in the environment.     

Radioactivity distribution of thorium in sediment core of the Sabah-Sarawak coast

Thorium activity concentrations were measured in seven marine sediment cores taken from Sabah-Sarawak coast on 2004 by using a gravity box corer. Collected sediments were generally homogenous mud which contained much more mixture of silt and clay compared to sand and relatively low content of organic carbon (i.e. less than 5% at all sampling stations). The results found that activity concentrations of ²³⁰Th, ²³²Th and ratios of ²³⁰Th/²³²Th were ranged from 6.5–20.4 Bq/kg dry wt., 6.8–27.8 Bq/kg dry wt. and 0.69–0.92, respectively. It seem that, ²³²Th activity concentrations are slightly higher than ²³⁰Th at all sampling stations and both radionuclides were generally high at Sabah compared to Sarawak coastal waters. ²³⁰Th activity concentrations in sediment core appear to be correlated with the activity concentrations of ²³²Th at some sampling station. These indicating both radionuclides were supplied from the same of environment and source origin of detrital from terrestrial and shallower water. The low ²³⁰Th/²³²Th activity ratio which is less than unity suggesting that ²³²Th was actively and rapidly regenerated compared to ²³⁰Th from ²³⁴U. It also can be attributed to less efficiently scavenge of ²³⁰Th onto particles prior deposited at the marine sediment bed.     

Assessment of natural radioactivity in silt samples from Moticher lake near Kakrapar Atomic Power Station,India

The naturally occurring radioisotopes such as ²³⁸U, ²³²Th and ⁴⁰K in the silt samples collected from Moticher lake, Gujarat were evaluated. The activity of ²³⁸U, ²³²Th and ⁴⁰K was found to be 4.4-9.7 Bq kg⁻¹ with a mean 6.4 ± 1.3 Bq kg⁻¹, 10.5–21.2 Bq kg⁻¹ with a mean 15.6 ± 2.5 Bq kg⁻¹ and 102–231 Bq kg⁻¹ with a mean 160 ± 40 Bq kg⁻¹, respectively. The depth profile study could not reveal any significant vertical correlation on radioactivity levels of ²³⁸U, ²³²Th and ⁴⁰K. Radium equivalent activity (Ra_eq), external hazard index (H _ex) and internal hazard index (H _int) were calculated by using the activity of ²³⁸U or ²²⁶Ra, ²³²Th and ⁴⁰K in silt samples. Annual Effective Dose Equivalent (AEDE) level in Moticher silt was found to be 24.8 ± 5.0 μSv year⁻¹, which is much lower than the worldwide average value. The relative contribution to dose due to ²³⁸U and ²³²Th series were found to be 14% and 53%, followed by the contribution of 33% due to ⁴⁰K.     

Determination of U and Th in soil and plants obtained from a high natural radiation area in China using ICP-MS and γ-counting

This study was carried out for the determination of ²³⁸U and ²³²Th concentrations in soil and various foods obtained in high natural radiation areas in China for estimating the internal radiation doses caused by these radionuclides. Knowledge of the daily dietary intakes of the nuclides through foods is essential to evaluate the internal radiation dose. Several analytical methods were evaluated for their applicability and quality assurance. The accuracy and precision of ICP-MS is considerably better for determining trace elements like U and Th in fine powder samples. The estimated annual effective dose is 0.302 μ Sv/y for ²³⁸U and 1.86 μ Sv/y for ²³²Th in the high natural radiation area, and 0.0101 μ Sv/y for ²³⁸U and 0.177 μ Sv/y for ²³²Th in the control area. Received: 25 September 1998 / Revised: 3 December 1998 / Accepted: 8 December 1998     

Natural radioactivity in surface marine sediments near the shore of Vizag, South East India and associated radiological risk

Naturally occurring radioactive materials were determined in surface sediments from the marine environment near the shore of Vizag in the South eastern part of India using gamma spectrometry technique. The mean activity concentration was found to be 36 ± 11, 34 ± 15, 75 ± 38 and 782 ± 223 Bq/kg and ranged from 19 to 48 Bq/kg, 11 to 57 Bq/kg, 31 to 145 Bq/kg and 363 to 1,024 Bq/kg for ²³⁸U, ²²⁶Ra, ²³²Th and ⁴⁰K, respectively. The mean radium equivalent activity, external hazard index, air absorbed gamma dose rate and annual effective dose equivalent are 203 ± 62 Bq/kg, 0.6 ± 0.2, 94 ± 27 nGy/h and 0.12 ± 0.03 mSv/year respectively. This data will serve as the baseline level for naturally occurring radionuclides in the study area and will be useful for tracking and assessing any pollution inventory in the environment of this region.     

Natural radioactivity in soil samples of Kocaeli basin, Turkey

The city of Kocaeli is in the western part of Anatolia in Turkey and has a population of approximately 1.000.000. There is no information about radioactivity in the Kocaeli soils samples so far. For this reason, the concentrations of the natural radionuclides in soil samples from 27 different sampling stations in Kocaeli Basin and its surroundings have been determined. The results have been compared with other radioactivity measurements in different country"s soils. The typical concentrations of ¹³⁷Cs, ²³⁸U, ⁴⁰K, ²²⁶Ra, ²³²Th found in surface soil samples ranged from 2±0.6 to 25±6 Bq/kg, from 11±4 to 49±10 Bq/kg, from 161±30 to 964±127 Bq/kg, from 10±4 to 58±11 Bq/kg, and from 11±3 to 65±13 Bq/kg, respectively.     

Radioactivity concentrations in sediment and mussel of Bosphorus and Golden Horn

In the present study, mussel (Mytilus galloprovincialis, Lamarck, 1819) and sediment samples were collected from the Bosphorus strait and the Golden Horn estuary in 2008 and 2009. Activity concentrations of ¹³⁷Cs, ⁴⁰K, ²³²Th and ²³⁸U were measured using a gamma spectrometer equipped with HPGe detector. Sediment samples were separated into <63 μm and >63 μm particle fractions. Analysis of radionuclides was carried out on these two fractions of sediment as well as the soft and shell tissues of mussels. Ranges of radioactivity concentrations in the soft parts of mussels were as follows: ¹³⁷Cs, 0.86–2.43; ⁴⁰K: 261.1–496.7; ²³²Th: 0.49–3.58; and ²³⁸U: BDL (below detection limit)-1.38 Bq kg⁻¹ in dry weight. Ranges of radioactivity concentrations in the <63 and >63 sediment fractions were as follows: ¹³⁷Cs, 8.58–67.92 and 1.12–26.40, ⁴⁰K, 341.4–683.0 and 281.9–662.2; ²³²Th, 10.97–20.16 and 7.18–19.18 and ²³⁸U, 13.97–27.25 and 6.41–18 Bq kg⁻¹ in dry weight, respectively. The effect of some physical–chemical parameters on the radionuclide accumulation was also examined in the sediment samples. All data in the current study were compared with data in the literature.     

Radioactivity on the Montenegrin Coast, Yugoslavia

Environmental radioactivity has been investigated on the Montenegrin Coast (Yugoslavia). Radioactivity was measured on 14 beaches and 5 hinterland localities by a method of in situ gamma-spectrometry. At each measuring site two photon countings were performed — in ground and above it. Specific activities of⁴⁰K,²³²Th,²³⁸U,¹³⁷Cs and corresponding exposure rates were then obtained from gamma-spectra and appropriate radiation field models. The results show a washing out effect of the sea-water: radioactivity level on the beach is significantly lower than on its hinterland. In situ spectrometry was also performed inside 16 hotels on the Coast. Radioactivity of building materials is found to be 8 to 20 times lower than the limit permitted by regulations. In 12 of these hotels, indoor radon concentrations were measured with track etch detectors. Winter radon concentrations were in a range (22–90) Bq/m³, i.e., much below the most stringent reference level.