Bq Kg-1 For 226Ra Research Articles

RADIOLOGICAL IMPACT OF USING DECORATIVE GRANITE AS AN ATTENUATOR OF IONIZING RADIATION.

Granite is a widely available rock, which can be used as a shielding material, for bulk in the form of the aggregate in concrete. It has the weakness that it is more radioactive than many other rocks, which can be used in concrete. This paper looks at its properties as a shielding material and the activity level. Thus, the concentrations of 226Ra, 232Th and 40K, in granite were measured using a high pure germanium detector (HPGe). They were ranged from (15±4 to 49±5) Bq kg-1 for 226Ra, (22±4 to 78±4Bqkg-1) for 232Th and (791±13 to 1231±15Bqkg-1) for 40K. Radiological indices of radium equivalent concentration (Raeq), external (Hex), internal (Hin) and annual effective dose were less than worldwide recommended limits. The results emphasized, the granite samples had no radiation hazard. Nevertheless, the mass attenuation coefficients of granite samples were measured for the gamma rays of energy range 122-1408keV. The mass attenuation coefficients of the studied granite samples were ranged from 0.05 to 0.15cm2g-1. In addition, the average the half-value layer of granite was varied from 1.8cm for 122keV to 5.2cm for 1408keV. The results are that the attenuation characteristics are typical and match the values given by NIST for 'concrete' and that the activity levels of the samples examined are acceptable. Thus the granite may be used as an attenuator for ionizing radiation.

Koncentracija aktivnosti prirodnih radionuklida u hrani za piliće u Republici Sjevernoj Makedoniji

The care of radioactivity level in animal feed is very important, as ingestion is one of the most common ways radionuclides enter living organisms. Thus, since humans consume products of animal origin (eggs and poultry, milk and beef), it is important to monitor radiation levels in animal feed, as part of the radioactivity that these animals are exposed to, could be transmitted to humans. Natural radionuclides such as 40K, 232Th and 226Ra find their way into the food chain from soil and air to plants and from plants to animals and humans as well. The goal of this study was to determine the activity concentrations of natural radionuclides in three commercial chicken feeds – starter, grower and finisher. The analyzes were performed by means of HPGe gamma spectrometry - gamma spectrometer (Canberra Packard) with a high-purity germanium detector. The obtained spectra from the measurement were analyzed by using the program GENIE 2000. Based on the performed tests, the mean values for the activity concentrations in the samples were the following 26.03±4.1 Bq kg-1 for 226Ra, 37.9±4.8 Bq kg-1 for 232Th, and 64.40±6.5 Bq kg-1 for 40K. The results obtained from the analyses of chicken feeds were compared to studies in other countries and it was found that 40K was present in the highest amount in all types of samples while the vales for the other natural radionuclides were within the nominal concentrations. Higher concentration of 40K can be associated with plants used in the production of animal feed, which were contaminated with fertilizer during their cultivation. The range of radionuclide concentrations in the samples was within the recommended values UNSCEAR.

Radioactivity content surveillance on canned food products in Nigeria

The radionuclides surveillance on imported can food products in Nigeria market has been investigated using High purity Germanium detector. The radioactivity concentrations of 226Ra, 232Th, 40K, 210Pb and 137Cs in selected brands of imported canned food products categorized into staple foodstuffs, beef and seafood were analyzed. The results obtained for staple foodstuffs shows a mean activity value of 12.33±3.68, 12.35±4.62, 51.48±15.12, 2.65±0.18 and 0.61±0.27 Bq kg-1 for 226Ra, 232Th, 40K, 210Pb and 137Cs respectively, while in beef food products, it is 14.41±4.79, 14.12±4.83, 50.44±14.80, 1.11± 0.07 and 0.32±0.20 Bq kg-1 respectively, and for seafood products it is 17.95±5.71, 16.24±5.48, 61.65±18.07, 1.17±0.13 and ND Bq kg-1 respectively. The overall results indicate that the natural radioactivity in the three categories of canned foodstuffs examined are well below the UNSCEAR and other regulatory bodies recommended permissible limits. The presence of 137Cs in some samples potent some degree of heavy metal contamination of those foodstuffs. The computed dose to essential organs and tissues indicates a highest dose level of 0.2 mSvy-1 which is well within the 1mSvy-1 recommended permissible level of the public. The calculated collective effective dose equivalent revealed that 97,463,16 of the total population are exposed to radiation from ingestion of the canned foods with adults most impacted. The total health detriment indicates radiological risk ratio of 1:2238 for infants, 1:2583 for children and 1:4238 for adults. From the estimated costdetriment, it is obvious that the economic benefits which is directly proportional to cost of purchase and importation put at about nine billion US dollars annually derived from consuming these imported canned food products is far above the health detriment.
 Keywords: Radioactivity surveillance, canned food, health detriment, Nigeria

Natural Radioactivity Levels and Estimation of Radiation Exposure in Agricultural Soils from Skopje City Region

The aim of this study was to determine the activity concentrations of naturally occurring radioisotopes 226Ra, 232Th and 40K in 14 soil samples collected in the Skopje city surrounding, and to calculate the corresponding absorbed gamma dose rates. The radionuclides were measured applying a high purity Ge detector gamma-ray spectrometer with relative efficiency of 30 % at 1.33 MeV. The activity concentrations found in 14 soil samples varied in the range 24.1-41.9 Bq kg-1for 226Ra, 38.5-52.2 Bq kg-1 for 232Th, and 502-707 Bq kg-1 for40K. The mean radium equivalent (Raeq), for the area under investigation, was 143±16 Bq kg-1, while the outdoor radiation hazard index (Hex) was 0.39. The total absorbed dose rate due to three primordial radionuclides investigated lay in the range 55.3 - 79.0 nGy h-1 with mean value of 68.1±7.7 nGy h-1, yielding a total annual effective dose of (83.5±9.5) µSv y-1. The assessed radiological factors were lower than the recommended values, indicating low radiological health risk for the population living and working in the investigated area. The activity concentrations of radionuclides in soil samples were compared to the international values reported by United Nations Scientific Committee on the Effects of Atomic Radiation and previous studies on geographically close areas and some worldwide regions.

Evaluation of radioactive pollution in sediment samples of Borçka Dam Lake, Turkey

In this research, the concentrations of natural (226Ra, 232Th and 40K) and anthropogenic (137Cs) radionuclides were measured in sediment samples collected from the Borçka Dam Lake using a high purity germanium detector (HPGe). The activity values ranged from 4.79-21.46, 9.36–20.65, 238.01–721.26 and 0.79–6.81 Bq kg-1 for 226Ra, 232Th, 40K and 137Cs respectively. The average 226Ra, 232Th and 40K activity concentrations calculated for the sediment samples were found to be lower compared to world average values reported by UNSCEAR. In addition, radiological hazard indices were determined and compared with the international permissible values. The results of this study revealed that there is no significant health risk for people exposed to sediment samples in this region.

NATURAL RADIUM ISOTOPES PRESENT IN SOME COSMETIC PRODUCTS: DETERMINATION OF ACTIVITY CONCENTRATION AND DOSE ESTIMATION.

Since the early days, clays, plant extracts and raw materials have been used for therapeutic and beauty purposes. Nowadays, this use is widely spread, as a huge amount of companies have developed new cosmetics based on natural sources. This may lead to an accumulation of radionuclides that can be hazardous for people. Especially dangerous are radium isotopes (226,228Ra), which can be part of the raw materials that cosmetics are made from. In this paper, the concentration of radium isotopes of 18 natural cosmetics was determined. Concentrations resulted in the range 7.9 ± 5.0-37.6 ± 12.5 Bq kg-1 for 226Ra; and 2.5 ± 1.7-35.4 ± 2.6 Bq kg-1 for 228Ra. The effective dose in the skin has been estimated, obtaining a mean value of 13.1 ± 4.9 μSv y-1. This value is far from the reference level of 50 mSv y-1 for the public members. Therefore, no radiological risk derived from the use of these samples, has been found.

Experimental Evaluation of Radiological Hazards in Ceramic Tiles Used in the Jos-South, Area of Plateau State, Nigeria

Radiological hazards resulting from 5 different brands of ceramic tiles commonly used in homes and offices in Jos-south area ofplateau state were assessed in this study by carrying out radioactivity measurement of natural radionuclides (40K, 226Ra and 232Th) in them using a NaI(Tl) gamma ray spectrometer. The ceramic tiles had mean activity concentrations of 44.5, 59.6 and 417.4 Bq kg-1 for 226Ra, 232Th and 40K respectively. The average radium equivalent is within the recommended limit of 370 Bq kg-1 for building materials. The radiological hazard indices such as the gamma absorbed dose rate, annual effective dose, external radiation index (Hex), internal radiation hazard index (Hin), Alpha index (Iα), Gamma index (Iγ), excess lifetime cancer risk, and annual gonadal dose equivalent were evaluated. The results obtained show that the radiological parameters do not exceed the recommended safety limits and hence pose no significant radiological hazard when used as building material.

RADIOACTIVE DISEQUILIBRIUM AND DYNAMIC OF NATURAL RADIONUCLIDES IN SOILS IN THE STATE OF PERNAMBUCO-BRAZIL.

Environmental radioactivity studies have been allowed establishing radiometric patterns in several area of the earth's crust. The work was conducted through radiometric analyses of regions with high levels of radionuclides and others with no history of anomalies. The research allowed establishing the radiometric profile of soils in the state of Pernambuco, Brazil, using a gamma spectrometry system. The specific activities ranged from 16.5 to 287.5 Bq kg-1 for 238U, 2.0 to 191.7 Bq kg-1 for 226Ra, 1.3 to 281.4 Bq kg-1 for 232Th and from 5.0 to 2600.9 Bq kg-1 for 40K. The results showed areas with low levels of ionizing radiation. However, for 40K some points presented high values, although non-representative of the number of samples investigated. The 226Ra/238U and 232Th/238U ratios allowed to determine the radioactive imbalance condition and to obtain information about aspects of soil availability providing an assessment of the dynamics of these radionuclides.

ASSESSMENT OF THE NATURAL RADIOACTIVITY AND RADIOLOGICAL HAZARDS IN LAO CEMENT SAMPLES.

The radioactivity concentrations of 226Ra, 232Th and 40K natural radionuclides in Lao Portland cement samples were measured using a gamma-spectrometry with a HPGe detector. The activity concentrations were found to vary from 28.32 ± 2.23 to 65.50 ± 2.83 Bq kg-1 with a mean value of 41.12 ± 2.44 Bq kg-1 for 226Ra; from 7.25 ± 2.00 to 44.01 ± 2.45 Bq kg-1 with a mean of 16.60 ± 2.37 Bq kg-1 for 232Th and from 49.19 ± 4.27 to 196.74 ± 4.75 Bq kg-1 with a mean of 141.48 ± 4.50 Bq kg-1 for 40K, respectively. The radiological parameters were estimated to assess the potential radiological hazard including radium equivalent activity, total external absorbed dose rate in outdoor air at 1 m above the earth's surface, the annual effective dose, the gamma and alpha-indices were calculated using the activity concentrations of 226Ra, 232Th and 40K. The results obtained in this study show no significant radiological hazards arising from using Lao Portland cement for building construction.

Potential Radiological Impacts of Phosphate Fertilizers Brands used in Southeast, Nigeria

The radionuclides present in phosphate fertilizers used in Southeast Nigeria were identified and their activity concentration determined to assess the potential radiological impact on the environment due to fertilizer applications in agricultural farm lands. The radioactivity concentration of 226Ra, 232Th and 40K in the fertilizer samples range from 13.22±1.83 to 87.37±8.98 Bqkg-1 for 226Ra (mean: 31.71±5.4 Bqkg-1), 0.78±0.07 to 47.65±6.05 Bqkg-1 for 232Th (mean: 10.88±3.06) and 575.07±18.08 to 1234.80±36.61 Bqkg-1 for 40K (mean 876.91±20.03 Bqkg-1). The mean activity concentrations of the natural radionuclides of 226Ra and 232Th in the superphosphate fertilizer formulation were found to be above the world’s average. This will have potential health impact on humans if the fertilizers are applied in crops cultivation. The absorbed dose range from 31.01±0.03 to 75.11±0.49 nGyh-1 (mean: 68.66±0.35 nGyh-1). The super phosphate brand of fertilizer with the highest value of activity concentration has its value of annual effective dose as 0.08μ SvGyh-1.

Preliminary survey of radioactivity level in Thai medicinal herb plants

In this research, the natural radioactivity concentrations and their respective annual effective dose of the naturally occurring radionuclides 226Ra, 228Ra and 40K in selected medicinal herb plants were investigated. Seven kinds of popular Thai medicinal herb plants had been studied: turmeric, ginger, safflower, moringa, gotu kola, garlic and alexandria senna. The radiological risk associated with the use of these medicinal plants was assessed. The activity concentrations of 226Ra, 228Ra and 40K were determined using the gamma-ray spectrometry technique. The radioactivity concentrations were found to range from less than 0.20 to 6.67 Bqkg-1 for 226Ra, less than 0.10 to 9.69 Bqkg-1 for 228Ra, and from 159.42 to 1216.25 Bqkg-1 for 40K. Gotu kola showed the highest activity concentrations of 226Ra and 228Ra, while ginger showed the highest activity concentration of 40K. The total annual effective dose due to ingestion of these herb plants were found to range from 0.0028 to 0.0097 mSvy-1 with an average value of 0.0060±0.0001 mSvy-1. The results conclude that the Thai medicinal herb plants samples from this research are considered safe in terms of the radiological hazard.

English

Fifteen iron ore samples collected from Wadi Sawawin, Duba, Saudi Arabia were analysed using X-ray diffraction in order to determine mineral composition. Atomic absorption analysis was used to determine concentrations of Al, Ca, Fe, K, Mg, Bi, Pb, Th and U. Natural radioactivity concentrations were determined using gamma-ray spectrometry based on a hyper pure germanium (HPGe) detector; concentrations ranged from 1.89±0.39 to 4.50±0.53 Bq kg-1, 1.21±0.16 to 3.60±0.56 Bq kg-1 and detection level to 10.33±1.32 Bq kg-1 for 226Ra, 232Th and 40K, respectively. In order to assess the potential radiological risks to human health, the absorbed dose rate, radium equivalent activity, annual absorbed dose and external hazards were determined and compared to limits recommended by UNSCEAR. Results were within recommended safe ranges, meaning that the area under study is radiologically safe for habitation and that local iron ores are radiologically safe to be used as construction materials.   Key words: Atomic absorption spectrometer, natural radioactivity, radiological hazard, X-ray powder diffraction (XRD).

Lifetime Cancer Risk of Gamma Radioactivity Results from Smoking

Smoking is one of the causes of heart attack, lung cancer and cancers of mouth and larynx. The latter could be arises from exposure of those sensitive organs to a combination of both chemical carcinogenic and radiological exposure results from naturally occurring radionuclides in tobacco leaves. Coal is also used in smoking some types of tobacco products that could be carcinogenic due to presence of a high percentage of an organic matter with inorganic matter such as minerals and trace elements. Varieties of commonly available tobacco products as well as coal samples were examined for their radioactivity content using gamma ray spectroscopy and calculate associated radiological hazards. Results shows that the average concentrations of 226Ra, 232Th, and 40K in tobacco samples vary from 2.6±0.2 to 8.9±0.7 (average 5.4), 1.9±0.1 to 9.5±0.8 (average 4.5), and 517.4±15.5 to 2401.2±72 (average 1360.4) Bqkg-1. Measured activity concentration for coal samples ranged from 10.8±1.1 to 64.4±2.1 (average 40.2), 3.5±0.1 to 28.3±0.3 (average 15.7), and 49.2±0.4 to 301.2±9.5 (average 215) Bqkg-1 for 226Ra, 232Th, and 40K respectively. 137Cs activity concentrations in cigarettes and coal samples were ranged from 0.1±0.01 to 1.3±0.02 (average 0.5) and 2±0.01 to 5.8±0.8 (average 3.1) Bqkg-1 respectively. Radium equivalent, total annual effective dose and excess lifetime cancer risk were calculated. ELCR was higher than world's average of 1.45x10-3 for tobacco and coal samples. In Egypt no special and clear regulations for monitoring radioactivity content in imported coal and tobacco leafs or its products, which appear to be necessary.

Brazil nuts: determination of natural elements and aflatoxin

A study was carried out to evaluate the association of levels of radioactivity, selenium and aflatoxin in shelled Brazil nuts, which were classified in different sizes, for export. The selenium determinations were performed by inductively coupled plasma optical emission spectrometry (LOQ = 3.0 µg g-1), and aflatoxins were detected by Liquid chromatography-mass spectrometry (LOQ = 0.85 µg kg-1), recovery rates were between 92 and 100%. Radioactivity was measured by high-resolution gamma spectrometry. The selenium mean concentration was (22.7 ± 7.4) µg g-1. (n = 30). Mean activities determined for the following radium isotopes were: 15.77 Bq kg-1 for 224Ra, 104.8 Bq kg-1 for 226Ra and 99.48 Bq kg-1 for 228Ra. For 226Ra, the levels did not vary significantly with nut sizes, although such differences were observed for 224Ra and 228Ra. There was no statistically significant association between the level of selenium and the activity of radionuclides, however, there was correlation between the radionuclides. Aflatoxins above the quantification limit were not found.

THE IMPACT OF INCREASED NATURAL BACKGROUND OF SOIL ON THE ANIMAL PRODUCTION OF RUMINANTS IN THE REGION LIVNO

In this paper, the impact of increased levels of uranium and radium in soil on the levels of activity and radiation-hygienic validity of animal products of ruminants was investigated.Region around Livno town is placed on coal layer with the in creased levels of uranium and radium compared with other coals used in Bosnia and Herzegovina. As a result of mixing between coal matrix and soil, in creased value of average absorbed dose rate at 1 m above the ground (144 nGy h-1) was measured. The highest average value of 238U and 226Ra in the samples of animal products of ruminants was measured in the samples of sheep cheese (0.070 Bq kg-1 for 238U and 0.207 Bq kg-1 for 226Ra). The levels of these two radionuclides in the rest of animal product of ruminants were aproximatelly similar and ranged 0.016–0.046 Bq kg-1 for 238U and 0.028–0.080 Bq kg-1 for 226Ra. Levels of 40K were in the range of average values for animal products (31.2–86.4 Bq kg-1). Calculated annual effective dose by ingestion of the animal products of ruminants were approximatelly 0.064 mSv with the highest dose contribution of 40K (96.4%). On the base of obtained results, animal products of ruminants produced in observed region, can be considered as valid for human consumption from radiation-hygienic aspect.