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1.
The natural radioactivity levels and magnetic measurements in sediment samples of Bharathapuzha river for the first time have been determined. Bottom sediments from 33 locations were collected to determine 226Ra, 232Th and 40K using a HPGe detector based on the high-resolution gamma spectrometry system, and magnetic susceptibility by using Bartington MS2 magnetic susceptibility meter. The calculated activity concentrations of 226Ra, 232Th and 40K have been found to vary from 21.21 to 66.03 Bq kg?1, 33.49 to 93.10 Bq kg?1 and 232.25 to 899.66 Bq kg?1, respectively. The results have been compared with worldwide recommended values and also with radioactivity measurements in river sediments of India and other parts of the world. The air-absorbed dose rate, indoor and outdoor annual effective dose rates and radium equivalent activity are calculated with an aim to access the radiation hazards arising due to the use of these materials in the construction of buildings and their mean values obtained are 74.83 nGy h?1, 367.08 μSv y?1, 91.77 μSv y?1 and 157.09 Bq kg?1, respectively. The mass-specific magnetic susceptibility values ranged widely from 35.4 to 2,160.5 × 10?8 m3 kg?1 and compared with other rivers in South India. Multivariate statistical analyses were performed to describe the magnetic and radioactivity relevance of the different groups of samples. The data obtained in the present study may be useful for radiological and magnetic mapping of the study area in the future.  相似文献   

2.
In this study, radioactivity measurements in the environment of Akhisar, Gölmarmara, Gördes and Sindirgi regions in Western Turkey were investigated in order to evaluate the implications of any excess radioactivity in the environment of geological formation. The radioactivity concentrations of 40K, 238U and 232Th radionuclides in the soil samples were measured by a NaI(Tl) gamma spectrometer system, and the radium activity concentrations in the water samples were also analyzed by an ZnS(Ag) alpha counter by the collector chamber method. The radioactivity of 40K, 238U and 232Th in soils ranged 2.80–2,347.77, 9.90–256.19 and 9.66–106.53 Bq kg?1, respectively. The activity of 226Ra in the water samples ranged from 0.03 Bq L?1 (0.89pCi/L) to 0.80 Bq L?1 (21.58pCi/L). In addition, the external terrestrial gamma dose rate in air (nGy h?1), annual effective dose rate (mSv year?1) and radium equivalent activity (Bq kg?1) were calculated and compared with international standard values.  相似文献   

3.
Oil mineral leases (30, 58 and 61) in Delta and River States are the major oil blocks in the oil and gas rich Niger Delta region of Nigeria that is characterized by environmental degradation from oil and gas activities. This research work presents an analytical approach on natural radioactivity assessment in soil and sediment in 15 oil fields of these OMLs. Concentrations of natural radionuclides (226Ra, 232Th and 40K) were determined using gamma spectroscopy. The mean activity concentration of 226Ra, 232Th and 40K for OML30 is 40.2 ± 5.1, 29.9 ± 4.2 and 361.5 ± 20.0 Bq kg?1, respectively; the corresponding values obtained for OML58 is 20.9 ± 2.8, 19.4 ± 2.5 and 260.0 ± 14.1 Bq kg?1, respectively. While the mean activity concentration of 226Ra, 232Th and 40K for OML61 is 29.3 ± 3.5, 21.6 ± 2.6 and 262.1 ± 14.6 Bq kg?1, respectively. These values obtained show enhanced NORMs, but are well within the world range and values reported in some regions and countries of the world, and are slightly above control values, values obtained in Southwestern region of Nigeria and some countries reported average values. The study also examined some radiation hazard indices, the mean values obtained are 86.6 ± 9.3 Bq kg?1, 0.6 Bq kg?1, 40.8 ηGy h?1, 0.05 μSv y?1, 0.2 and 0.3 for radium equivalent activity (Raeq), representative level index (Iγ), absorbed dose rates (D), annual effective dose rates (E ff dose), external hazard index (H ex) and internal hazard index (H in), respectively. These calculated hazard indices to estimate the potential radiological health risk in soil and sediment are well below their permissible limits. The soil and sediments from the study area provide no excessive exposures for the inhabitants and can be used as construction materials without posing any radiological threat or harm to the public users. However, oil-field workers and host community residents are cautioned against excess exposure to avoid future accumulative dose of these radiations from sludge and sediment of this area.  相似文献   

4.
An initial on-going survey of the activity concentrations of 226Ra, 232Th and 40K for sand samples collected within the coastal strip of 290 Ramsar site evaluated the external hazard index, the outdoor annual effective dose equivalent and the radium equivalent activity, to elucidate potential risks for the resident inhabitants. The range of mean activity concentrations in the whole area for 226Ra, 232Th and 40K were between 4.12?±?0.26 and 48.3?±?1.4, 5.47?±?0.55 and 194?±?13, 77.7?±?4.2 and 445?±?18 Bq kg?1, respectively. The Barra de Valizas–Aguas Dulces region had the highest activity concentrations of 226Ra and 232Th. The annual effective dose equivalent for this region was higher than the mean worldwide value, whereas it is lower than the recommended values for public exposure.  相似文献   

5.
Concentration of natural radionuclides in three major staple food crops cultivated around a fertilizer plant in Onne, Rivers State Nigeria and the cultivated soil samples were determined using gamma spectroscopy operated on a Canberra vertical high purity 3″ × 3″ NaI(TI) detector. The average activity concentration of 238U, 232Th and 40K was determined, for cassava flour (U 19.3 ± 5.0, Th 11.4 ± 3.3, K 426.9 ± 33.8) Bq kg?1, for yam flour (U 6.3 ± 1.8, Th 8.4 ± 2.6, K 227.0.9 ± 27.3) Bq kg?1 while for cocoyam flour (U 7.5 ± 2.7, Th 7.1 ± 2.3, K 195.8 ± 25.83) Bq kg?1. The mean activity concentration for soil samples is 18.7 ± 3.7 Bq kg?1, 18.0 ± 3.8 Bq kg?1 and 308.4 ± 22.4 Bq kg?1 for 238U, 232Th and 40K, respectively. These values obtained show enhanced 40K concentration which is attributed to the effluent discharge from a fertilizer plant and its applications to farmlands, but 238U, 232Th values are well within the global average and values reported in some regions and countries of the world. Radiation hazard indices obtained to estimate potential radiological health risk in both foodstuffs and soil samples are well below their permissible limit as set by UNSCEAR [Sources and effects of ionizing radiation (Report to the General Assembly), 2000]. The rate of radionuclides transfer from soil to crops was moderate with mean transfer factors of 232Th < 238U < 40K.  相似文献   

6.
A study of natural radionuclides and radon concentration of Hamirpur District of Himachal Pradesh, India is carried out using various methodologies. The activity concentration of the natural radionuclides viz. 226Ra, 232Th and 40K is measured using high-resolution-based HPGe detector. Indoor radon measurements in the dwellings of Hamirpur district is carried out using LR-115 type II cellulose nitrate films in the bare mode. The average activity concentrations of 226Ra, 232Th and 40K are 35.58, 54.95 and 580.58 Bq kg?1, respectively. The annual average indoor radon value in the study area varies from 173.90 to 198.25 Bq m?3, which is well within the recommended action level given by International Commission on Radiological Protection. The indoor radon values obtained in the present investigation are higher than the world average of 40 Bq m?3. Radon concentration in water samples is measured using RAD7, an active radon detector. The annual effective dose for stomach and lung is determined from the measured value of radon concentration in water. To assess the radiation hazard of the natural radioactivity in all samples to the people, the radium equivalent activity, external hazard index, lifetime fatality risk, absorbed dose rate and total annual effective dose is estimated. The results signify that the studied area does not possess any radiation hazards due to the presence of natural radioactivity concentration.  相似文献   

7.
The main focus of this study was to assess radiation exposure to human and non-human biota due to natural radionuclides in soil of the Serbian capital. For the first time, ERICA tool was employed for calculation of gamma dose rates to non-human biota in this area. In analyzed soils, the mean values of 226Ra, 232Th and 40K specific activities were found to be 35, 43 and 490 Bq kg?1, respectively. The distribution of analyzed natural radionuclides in soils was discussed in respect to its statistically significant correlations with sand, silt, clay, carbonates, cation exchange capacity and pH value. The annual outdoor effective dose rates to the population varied from 48 to 98 μSv, and the total dose rates to terrestrial biota, calculated by ERICA tool, varied from 9.84?×?10?2 μGy h?1 (for tree) to 5.54?×?10+0 μGy h?1 (for lichen and bryophytes). The results obtained could serve as a baseline data for the assessment of possible anthropogenic enhancement of the total dose rate to human and non-human biota of the study area.  相似文献   

8.
In this study, natural and artificial radionuclide activity concentrations in surface soils of Kücük Menderes Basin have been measured using gamma spectroscopy. The soil samples were collected from agricultural lands in the Kücük Menderes Basin in Turkey. The activity concentrations of 226Ra, 232Th, 40K and 137Cs in the soils were found to be range of 12.63 ± 2.28–72.51 ± 11.23, 11.45 ± 2.4–58.12 ± 4.76, 234.8 ± 14.85–1058.52 ± 24 Bq kg?1 dw and 2.31 ± 0.18–7.75 ± 1.14 Bq kg?1, respectively. The natural gamma radioactivity of the terrestrial radionuclides in soil samples and the gamma absorbed dose rate, the annual effective dose equivalent, the radium equivalent activity, the external hazard index, were calculated and compared with the international recommended values.  相似文献   

9.
The activity concentrations of 226Ra, 232Th, and 40K are measured in soil samples from various locations in the Kadikoy and Uskudar district of Istanbul (Turkey). The 226Ra activity concentrations range from 19.97 Bqkg?1 to 50.80 Bqkg?1 and average 226Ra concentration value 31.40 Bqkg?1 was calculated. The 232Th activity concentrations range from 21.38 Bqkg?1 to 52.61 Bqkg?1 and average 232Th concentration value 34.44 Bqkg?1 was calculated. The 40K activity concentrations range from 464.06 Bqkg?1 to 711.27 Bqkg?1 and average 40K concentration value 619.59 Bqkg?1 was calculated. In addition, radium equivalent (Raeq), absorbed gamma dose rate (D), annual effective dose equivalent, (AEDE), excess lifetime cancer risk (ELCR) were calculated in this study. All of the calculations have been compared with both national and international standards and similar studies. As a result of this comparison, levels of natural radioactivity and radiological effects were slightly higher than the World average and Turkey.  相似文献   

10.
In this study, activity concentrations of 40K, 226Ra and 232Th in fertilized soil samples and different organic and inorganic fertilizers used in agricultural soil were analysed using gamma-ray spectrometry NaI (Tl) detector in order to access the implications of extended use of fertilizers in 2–3 years. The concentrations of radionuclides in some granular fertilizer brands were discovered to be higher for 40K, 226Ra and 232Th than those obtained in leafy fertilizer, animal fertilizer and fertilized soil samples. From the results, the highest overall mean concentrations of the specific activities of 40K, 226Ra and 232Th were 2301.8 (granular fertilizer), 42.5 (leafy fertilizer) and 327.1 (animal fertilizer) in Bq kg?1, while the lowest values observed in the specific activities of the same radionuclides were 357.7 (leafy fertilizer), 28.1 (animal fertilizer) and 36.5 (animal fertilizer). The radiological hazards of the radium equivalent (Raeq), normative value (NRN), outdoor radium equivalent (Raeq-out), external hazard index (H ext), internal hazard index (H in), dose rate, annual effective dose rate, activity utilization index and concentration accumulation index (CAI) and RaFZ due to the presence of these radionuclides in the investigated samples were calculated. Nevertheless, some of the fertilizer brands have higher concentration values than the recommended limit, and the values of hazard indices of fertilizer brands used in the selected teaching and research farms were within acceptable limit. Therefore, the fertilized soil samples in the studied farms are safe.  相似文献   

11.
In this study we investigate the radiological hazard of naturally occurring radioactive material in Tunisian and Algerian phosphorite deposits. Eight samples of phosphorite were collected from the phosphorite mines. The Tunisian and Algerian phosphorites occur in the Late Paleocene and Lower Eocene (Ypresian-Lutetian) in age (Béji Sassi 1984 and Zaïer 1999). Activity concentrations in all the samples were measured by alpha spectrometry and gamma spectrometry. Alpha spectrometry analyses show that the specific activity values of 238U, 234U and 235U in the samples of Tunisian phosphorite were 327?±?7 (321–327), 326?±?6 (325–331) and 14.50?±?0.72 (13.90–15.57) Bq kg?1, respectively. Specific activity measured by gamma spectrometry in the samples of the Tunisian and Algerian phosphorite shows a small difference. Specific activity levels of 40K, 226Ra, 232Th, 235U and 238U in the phosphorite samples from Tunisia were, respectively, 71.10?±?3.80, 391.54?±?9.39, 60.38?±?3.74, 12.72?±?0.54 and 527.42?±?49.57 Bq kg?1 and Algeria were 15.72?±?1.73, 989.65?±?12.52, 12.08?±?1.20, 47.50?±?1.52 and 1,148.78?±?7.30 Bq kg?1, respectively. The measured value of specific activity of 232Th and 40K in the Tunisian phosphorite samples is relatively higher than that found in the samples of Algerian phosphorite. The measured activity of uranium (238U) in the Tunisian phosphorite (527?±?49) Bq kg?1 is lower than in Algerian phosphorite. The measured activity of 238U in the Tunisian phosphorite samples was (527–1,315?±?65) 238U Bq kg?1 which is higher than its maximum background value of 110 Bq kg?1 in soils of the various countries of the world (Tufail et al. Radiat Meas 41:443–451, 2006). Different geological origins of phosphorites deposits are the main reason for the large spread in worldwide specific activities. The obtained results of uranium concentrations in phosphorites of different types (Algerian and Tunisian) demonstrate that the uranium concentrations are mainly governed by the phosphatic material. The present study reveals that phosphorite deposits contain natural radioactivity higher than background level.  相似文献   

12.
This study of environmental radioactivity was carried out in the soils of an urban area. Naturally occurring gamma-emitting radionuclides and man-made 137Cs were found in the soil profiles collected from four parks in the central Belgrade city area and the soil layer was examined every 10 cm and to a depth of 50 cm. Radioisotope activity concentrations (Bq kg?1) in the samples of urban soil using the gamma-ray spectrometry method were in the range of 14–46 for 238U, 33–50 for 226Ra, 29–63 for 210Pb, 1.2–3.4 for 235U, 28–50 for 232Th, 424–576 for 40K and 0.7–35.8 for 137Cs. Some of the basic physicochemical soil properties (pH, organic matter content, calcium-carbonate content, particle size distribution) were determined to investigate the impact on the vertical distribution of radionuclides. The results of this investigation showed that variations of activity concentration ratios of radionuclides that belong to the same (238U/226Ra) or different radioactive series (232Th/226Ra; 235U/238U), including 210Pb/137Cs ratios could well be explained by the properties of the soil. Alkaline pH reaction, the accumulation of organic matter in the uppermost and of carbonates in the deepest layers of urban soil had an effect on 238U/226Ra, and 210Pb/137Cs activity concentration ratio values, while 232Th/226Ra and partially 235U/238U ratios were associated with the particle sizes vertical distribution. A study of radionuclides in the samples of leaves of two deciduous tree species common for these parks was also conducted and 210Pb and 40K were found concentrated in leaves rather than other investigated radionuclides.  相似文献   

13.
The mean activity concentrations of 226Ra, 232Th, and 40K in Eshidiya phosphogypsum samples were measured as 351.4 ± 23.4, 3.8 ± 0.3, and 120.7 ± 8.3 Bq kg?1, respectively. The results show that the mean values of activity concentration of 226Ra, 232Th, and 40K are in the lower range of typical values reported for phosphogypsum samples collected worldwide. Radiological hazard indices such as the radium-equivalent activity (Raeq), the gamma index (I γ ) alpha index (I α ), the absorbed gamma dose rate (D in), and the corresponding annual effective dose (E in) were assessed for building materials for dwellings. The results of assessment exhibit that all phosphogypsum samples are higher than the recommended safe limit for building materials for dwellings, except for the radium-equivalent activity (Raeq). Overall assessment, it can be concluded that the possibility of using Eshidiya phosphogypsum in building materials in proportions lower than 100 % will be safe. The mixture of phosphogypsum with normal gypsum can dilute the concentrations of natural radionuclides allowing the use of the mixed building materials to be safe from a radiological point of view.  相似文献   

14.
The activity concentration and the gamma-absorbed dose rates of the terrestrial naturally occurring radionuclides (232Th, 226Ra and 40K) were determined in soil samples collected from ten different locations of Sirsa district of Haryana, using HPGe detector based on high-resolution gamma spectrometry system. The range of activity concentrations of 226Ra, 232Th and 40K in the soil samples from the studied areas varies from 19.18 Bq kg−1 (Moriwala) to 40.31 Bq kg−1 (Rori), 59.43 Bq kg−1 (Pipli) to 89.54 Bq kg−1 (Fatehpur) and 223.22 Bq kg−1 (Moriwala) to 313.32 Bq kg−1 (SamatKhera) with overall mean values of 27.94, 72.75 and 286.73 Bq kg−1 respectively. The absorbed dose rate calculated from activity concentration of 226Ra, 232Th and 40K ranges between 8.84 and 18.58, 37.02 and 55.78, and 9.24 and 12.97 nGy h−1, respectively. The total absorbed dose in the study area ranges from 60.40 to 82.15 nGy h−1 with an average value of 70.12 nGy h−1. The calculated values of external hazard index (H ex) for the soil samples of the study area range from 0.36 to 0.49 with an average value of 0.42.  相似文献   

15.
The activity concentrations and the gamma-absorbed dose rates of the primordial naturally occurring radionuclides 226Ra, 232Th and 40K were determined for sand samples collected from the Baoji Weihe Sands Park, China, using γ-ray spectrometry. The natural radioactivity concentration of sand ranges from 10.2 to 38.3 Bq kg−1 for 226Ra, 27.0 to 48.8 Bq kg−1 for 232Th and 635.8 to 1,126.7 Bq kg−1 for 40K with mean values of 22.1, 39.0 and 859.1 Bq kg−1, respectively. The concentrations of these radionuclides are compared with the typical world values and the average activity of Chinese soil. The measured activity concentration of 226Ra and 232Th in sand is lower than the world average while that of 40K is higher. . To evaluate the radiological hazard of the natural radioactivity, the radium equivalent activity, the external hazard index, the absorbed dose rate, and the effective dose rate have been calculated and compared with internationally approved values. The radium equivalent activity values of all sand samples are lower than the limit of 370 Bq kg−1. The values of the external hazard index are less than unity. The mean outdoor air absorbed dose rate is 69.6 nGy h−1 and the corresponding outdoor effective dose rate is 0.085 mSv y−1.  相似文献   

16.
Gamma activity from the naturally occurring radionuclides namely, 226Ra, 232Th, the primordial radionuclide 40K was measured in the soil of Cuihua Mountain National Geological Park, China using γ-ray spectrometry technique. The mean activity of 226Ra, 232Th and 40K were found to be 27.2 ± 6.5, 43.9 ± 6.2 and 653.1 ± 127.6 Bq kg−1, respectively. The concentrations of these radionuclides were compared with the typical world values and the average activities of Chinese soil. The radium equivalent activity, the air absorbed dose rate, the annual effective dose rate, and the external hazard index were evaluated and compared with the internationally approved values. All the soil samples have Raeq lower than the limit of 370 Bq kg−1 and H ex less than unity. The overall mean outdoor terrestrial gamma dose rate is 66.3 nGy h−1 and the corresponding outdoor annual effective dose is 0.081 mSv.  相似文献   

17.
South India is one of the regions in the world that has the highest background radiation levels. In this region, river sediments are used in large quantities as building material. Therefore, the knowledge of the radionuclides distribution in such sediments is important for assessing their potential adverse effects on humans residing in buildings made of sediment material. For this goal, we focus on the determination of the natural radioactivity levels and magnetic properties in sediment samples collected from 33 locations along the southwestern Bharathapuzha river originating from the Anamalai hills. The sediment samples were subdivided into two categories according to particle size. It is observed that the average activity concentrations of 226Ra, 232Th, and 40K in sediment samples varied greatly with granulometric and geological differences. The average values of 226Ra, 232Th, and 40K and its associated radiological hazard parameters for category II samples (particle size between 149 μm and 2 mm) were lower than category I sediment samples (bulk samples). Moreover, the average radionuclide activity concentrations (except for 40K) and the calculated radiation hazard parameters are higher in the lowland region compared to the highland and the midland regions. The mass-specific magnetic susceptibility values ranged widely along the river, as well as between physiographic regions, e.g., average values for category I sediment samples were 950.2 × 10?8, 351.1 × 10?8 and 131.8 × 10?8 m3 kg?1 (for high-, mid- and lowland regions, respectively). Differences between physiographic regions and sediment fractions from both radioactivity determinations and magnetic parameters were analyzed with statistical tests and multivariate analysis, which showed the advantages of using both independent techniques.  相似文献   

18.
The study referred to measure activity concentrations of some primordial radionuclides and anthropogenic of 137Cs in soil samples of Mami-water in the Menoua subdivision, Dschang employing gamma-ray spectrometry-based characterized Broad Energy Germanium (BE6350) detector and a comparison of radiological and safety impact parameters on human due to primordial radioactivity in soil with some internationally approved values. In addition, statistical analysis of primordial radionuclides of 226Ra, 232Th and 40K was performed to evaluate the distribution and the interrelation of radionuclides. Samples were randomly collected from a depth of about 0 to 5 cm from the top surface layer. Each of the sampling points was considered as being overlaid with a grid and subdivided into cells. The observed radioactivity level of 226Ra, 232Th and 40K in the investigated soil samples was compared with some published data available in some countries including Cameroon and observed varying within some reported data of radioactivity in soil from bauxite ore deposit. 235U and 137Cs were found in very few samples with a very low average of activity concentrations. In the majority of the samples, the observed radiological safety parameters seem to be greater than the internationally approved values. Consequently, using bricks made of soil as building materials might lead to an increase in radiation risk for the population. Multivariate statistical analysis of activity concentrations of primordial radionuclides performed showed an asymmetrical distribution with more peaked than Gaussian distribution and relatively flatter distribution of radionuclides in soil. In addition, a good positive interrelation between 226Ra and 232Th was observed and a weak negative one observed between 40K and 226Ra–232Th.  相似文献   

19.
Levels of naturally occurring radioactivity in sediment samples of Beni Haroun dam have been investigated. The activity concentrations of 238U and 232Th decay chains and 40K primordial radionuclide have been measured using high-resolution HPGe detector. Activity concentrations of 226Ra, 232Th, and 40K radionuclides were found in the ranges 9–66, 14–37, and 177–288 Bq/kg with the mean values 24.67, 25.98, and 208.10 Bq/kg, respectively. Radiological hazard parameters were estimated based on the activity concentrations for 226Ra, 232Th, and 40K to find out any radiation hazard associated with the sediments. Correlation studies between pairs of radionuclides were performed and discussed, and the obtained results are compared with international recommended values.  相似文献   

20.
In this work, accumulation of cosmogenic radionuclide 7Be in seven species of lichens was determined using HPGe detectors in autumn season. Ramsar city which is located in the north of Iran as one of the high-level natural radiation areas in the world was considered. Lichen species represented good potential in accumulation of 7Be radionuclide. The foliose species of Xanthoria parietina with the highest activity concentration value of 112.8 ± 1.8 Bq kg?1 was introduced as bioindicator for accumulation of 7Be radionuclide. Cladonia rangiformis species has got minimum concentration of 64.5 ± 0.8 Bq kg?1. Also from thallus morphology viewpoint, results showed that 7Be accumulation in foliose species is higher than in fruticose and crustose lichens species. Also there was relatively large positive correlation between 7Be and 226Ra activity concentrations in lichens species.  相似文献   

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