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Open Journal of Soil Science 2013年第7期3卷 289-296页

作者： Saher M. Darwish Samia M. El-Bahi Amany T. Sroor Najat F. Arhoma Nuclear Physics Laboratory Ain Shams University Fac- ulty of Girls Heliopolis Cairo Egypt. Physics Department Faculty of Science Cairo University Giza Egypt Physics Department Faculty of Science Cairo University Giza Egypt

The activity concentrations of naturally occurring 238U, 232Th and 40K in surface soils along Qarun Lake and Wadi El Rayan located in Faiyum, Egypt were determined. The measurements were carried out through gamma-ray spectrometry using a coaxial HPGe detector. The results were compared with those reported in the literature. The radiological hazard radium-equivalent activity index, external and internal indices, radioactivity level index, absorbed dose rate, annual effective dose rate and total absorbed dose rate associated with radioactivity in all samples were evaluated and compared with recommended values. Correlation studies between pairs of radionuclides were performed and discussed.

关键词： Natural radioactivity Radiological Hazards HPGe Detector Gamma-Ray Spectrometry

Magnetic Susceptibility and Natural Gamma radioactivity as Indirect Indicators of Impurities in Limestones of the Sabinas Basin: Possible Relationships with the Sedimentation Environment

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Journal of Geoscience and Environment Protection 2017年第10期5卷 77-91页

作者： José A. Batista Rodríguez Joaquín A. Proenza Fernández Gloria I. Dávila Pulido Mitzué Garza García Itzayana Y. Zamora Medellín Universidad Autónoma de Coahuila Escuela Superior de Ingeniería Coahuila México Departament de Cristallograia Mineralogia i Dipòsits Minerals Facultat de Geologia Universitat de Barcelona Barcelona Spain

This study presents an analysis of magnetic susceptibility and natural gamma radioactivity as indirect indicators of impurities in Cretaceous limestones of the Sabinas basin, as well as of the possible relation of these physical properties with the changes in the sedimentation environment. Both of these physical properties indicate changes in the degree of impurities and the mineralogical composition of this rock, principally in its organic matter and detritus content. Considering that the sedimentation environment determines the impurities in these rocks, possible environmental conditions at different levels of the Cretaceous were suggested using the magnetic susceptibility, total gamma radiation and potassium values, as well as the uranium and thorium concentration in the limestones. The analyses suggest variations in the depth of water table of the basin, which are mainly related to transgressions and marine regressions.

关键词： Magnetic Susceptibility Natural Gamma radioactivity Limestones Environment Sedimentation Sabinas Basin

Estimation of Natural radioactivity of Some Medicinal or Herbal Plants Used in Iraq

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Detection 2015年第1期3卷 1-7页

作者： Laith A. Najam Nada F. Tafiq Fouzey H. Kitah Physics Department College of Science University of Mosul Mosul Iraq Physics Department College of Science Al-Nahrain University Baghdad Iraq Ministry of Science and Technology Baghdad Iraq

Nine medicinal or herbal plants used in Iraq were analyzed to determine natural radioactivity. The radionuclides were determined by Gross alpha, beta and gamma spectrometry Proportional counter + NaI(Tl) detector type(XLB5) and gamma-ray spectroscopy with (HPGe) techniques. The activity concentration of 40K ranged from 124.1 Bq/kg in (Crust sample) to 88.3 Bq/kg in (Chamomile sample), for gross alpha ranged from (N.D.) in (Flax sample) to 0.4 cpm in (Anise sample), while for beta ranged from 5.7 cpm in (Flax sample) to 25.6 cpm in (Latency sample) and for gamma ranged from 0.6 cpm in (Thyme sample) to 5.10 cpm in (Coriander and Flax samples).

关键词： Medicinal Plants Alpha Cross Natural radioactivity Beta Cross Gamma Spectroscopy

Simulation of Dose Assessment for Special Environmental radioactivity Distribution Using Monte Carlo Technique

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Open Journal of Modelling and Simulation 2014年第3期2卷 91-96页

作者： Kh. Allam Nuclear Law department Nuclear and Radiological Regulatory Authority (NRRA) Cairo Egypt

Many researchers use the estimation method of exposure doses due to natural radioactivity adopted by UNSCEAR equation, which is based on an infinite plan source modeling. The results in most cases are acceptable within acceptable accuracy and error. However, in many cases, this approach cannot be applied e.g., for more complicated source geometry, composition, radioactivity distribution and so on. In previous situations, simulation and modeling are needed for exposure dose calculation to get more acceptable and accurate results. In the present work, modeling and recalculation of exposure dose rate are performed for an important previous published study about Hammam Pharaon. The study is selected because of its special physical characterization parameters and possible effects on Egyptian tourism. The effects of radionuclides distribution with soils and source composition, density, and geometry as recommended by NCRP 129 have been taken into consideration. The results for depth profile calculation show the conformation with the NCRP 129, which indicates a reduction in the free air exposure dose due to the fact that the above soil covered the active slab by 20% - 25% for 1 cm cover-up to 95% - 100% for 30 cm cover. In addition, the effect of density variation in dose rate is studied. A comparison with previous results has been performed.

关键词： Dose Rate Calculation Monte Carlo Simulation Environmental radioactivity

Research and implementation of the monitor for in situ radioactivity measurements in the marine environment

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Instrumentation 2015年第2期2卷 33-40页

作者： REN Guoxing WEI Zhiqiang WANG Xiaoying ZHANG Yingying ZHANG Guohua College of Information Science and Engineering Ocean University of China Shandong Academy of Sciences Insitute of Oceanographic Instrumentation Haier Group Technology R&D Center

As the traditional methods can not meet the requirements of marine radioactivity monitoring,a radioactivity monitoring sensor used in marine field has been proposed.This sensor is based on Nal(TI) scintillation crystal and employs the special shielding method,the anticoincidence design,the spectrum stabilization algorithm of characteristic peaks and the Monte Carlo simulation fitting calibration formula.Through the continuous tests of terminals and the activity test for target nuclide ^(40)K,it is found that the sensor is stable and the error is less than 10%.

关键词： marine in-situ radioactivity monitoring Monte-Carlo

Natural radioactivity Measurement and Assessment of Radiological Hazards in Some Building Materials Used in Bangladesh

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Journal of Environmental Protection 2018年第10期9卷 1034-1048页

作者： M. Azmary Khatun J. Ferdous M. M. Haque Department of Physics University of Rajshahi Rajshahi Bangladesh Health Physics Division Atomic Energy Center (AEC) Dhaka Bangladesh

The radioactivity concentrations of 226Ra, 232Th and 40K in 24 samples of natural and manufactured building materials commonly used in Bangladesh were measured using HPGe gamma ray spectrometer. The results in the present study were compared with the world average and also with the reported data available in literature. The radium equivalent activity, the absorbed dose rate, annual effective dose, external and internal hazard indices, gamma index, alpha index, annual gonadal dose equivalent and excess lifetime cancer risk were also evaluated to assess the potential radiation hazards associated with these building materials. All samples under investigation were found to be within the recommended safety limit and do not pose any significant radiation hazards. This study can be used as a reference for more extensive studies of the same subject in future.

关键词： Natural radioactivity Building Materials HPGe Detector Radiation Hazards

Evaluation of Natural radioactivity in Marine Sand Deposits from Offshore China

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Open Journal of Marine Science 2017年第3期7卷 357-378页

作者： Jun Li Bangqi Hu Jingtao Zhao Fenglong Bai Yanguang Dou Libo Wang Liang Zou Xue Ding Key Laboratory of Marine Hydrocarbon Resources and Environmental Geology of Ministry of Land and Resources Qingdao Institute of Marine Geology Qingdao China Laboratory for Marine Mineral Resources Qingdao National Laboratory of Marine Science and Technology Qingdao China

Natural radioactivity is very important for the assessment of the marine sand property and usability. By using gamma spectrometry, the concentration of the natural radionuclides 226Ra, 232Th and 40K have been measured in marine sand deposits from Liaodong Bay (LDB), North Yellow Sea (NYS), Zhoushan area (ZS), Taiwan Shoal (TS) and Pearl River Mouth (PR), offshore China, which are potential marine sand mining areas. The radiation activity equivalent (Raeq), indoor gamma absorbed dose rate (DR), annual effective dose (HR), alpha index (Ia), gamma index (Ig), external radiation hazard index (Hex), internal radiation hazard index (Hin), representative level index (RLI), excess lifetime cancer risk (ELCR) and annual gonadal dose equivalent (AGDE) associated with the natural radionuclides are calculated to assess the radiation hazard of the natural radioactivity in the marine sands offshore China. From the analysis, it is found that these marine sands are safe for the constructions. The Pearson correlation coefficient reveals that the 226Ra distribution in the marine sands offshore China is controlled by the variation of the 40K concentration. Principal component analysis (PCA) yields a two-component representation of the entire data from the marine sands, wherein 98.22% of the total variance is explained. Our results provide good baseline data to expand the database of radioactivity of building materials in China and all over the world.

关键词： Natural radioactivity Radiation Hazard Principal Component Analysis Gamma Spectrometry Marine Sand Offshore China

Environmental Impact Assessment of Natural radioactivity, Heavy and Major Metals in Primary Schools’ Drinking Water

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Journal of Geoscience and Environment Protection 2019年第9期7卷 67-78页

作者： Amal Hussain Al-Ghamdi Department of Physics Faculty of Science University of Jeddah Jeddah KSA

Measurement of natural radioactivity levels of major and heavy metals concentration was carried out for water samples collected from primary schools in Jeddah city, Saudi Arabia. The estimations were done for two different age groups, children (students 7 - 12 y) and adults (teachers and workers > 17 y) at the schools. The chemical analysis was performed by an Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and a high-resolution HPGe detector was used for the natural radionuclides measurement. The obtained results for the heavy metals (Fe, Cu, and Zn) and major and heavy elements (Na, K, Ca and Mg) concentrations in all water samples did not exceed the limits of WHO, EPA and TSE-266 guidelines for drinking water. Only Pb exceeded the safe limit. Generally, heavy metals and major elements’ concentrations in water samples were found decrease in sequence of Ca > Na > Mg > K > Zn > Pb > Cu > Fe. The radioactivity concentrations of 226Ra, 232Th and 40K in all studied samples were below the permissible safe limit value. The total average annual effective doses of (226Ra + 232Th + 40K) radionuclides were 0.259 mSv.y-1 for the children and 0.112 mSv.y-1 for adults, which are below the recommended annual dose level 1.0 mSv.y-1 as reported by WHO (2006). The present drinking waters are high quality waters and safe in terms of natural radioactivity and the results of the HQ values for the individual heavy metals showed that there was no health risk for humans due to consumption of these waters.

关键词： Heavy Metals Major Elements radioactivity

A Study on the radioactivity Level in Raw Materials, Final Products and Wastes of the Phosphate Fertilizer Industries in Bangladesh

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Journal of Environmental Protection 2012年第10期3卷 1393-1402页

作者： Md. Abdus Samad Md. Abu Haydar Md. Idris Ali Debasish Paul Md. Mahbubur R. Bhuiyan Sheikh Mohammad A. Islam Department of Physics Comilla University Comilla Bangladesh Department of Physics Jahangirnagar University Savar Bangladesh Health Physics and Radioactive Waste Management Unit Institute of Nuclear Science and Technology Atomic Energy Research Establishment Savar Bangladesh

A study on the detection of probable radionuclides and their activity concentrations in the raw material (phosphate rock), final product (fertilizer) and waste samples collected from all the phosphate fertilizer factories (total two factories—A Diammonium Phosphate, DAP and a Triple Super Phosphate, TSP factory) in Bangladesh were carried out. A total of seven types of samples (grossly divided into solid and liquid types);liquid waste, waste-mixed river water, normal river water, phosphate rock, phosphate fertilizer, solid waste and normal soil;were analyzed under this study. Raw material samples were collected only from the TSP fertilizer factory. Fertilizer, solid and liquid waste samples were collected from both the factories under study. Moreover, normal soil and natural surface water samples from the suitable areas adjacent to the factories were also collected for the comparison purpose. The samples were analyzed by gamma ray spectrometry technique using a Hyper-Pure Germanium (HPGe) detector of 40% relative efficiency. The analysis of the samples showed that only natural radionuclides such as 226Ra, 232Th and 40K were present in the samples and no traces of artificial radioactivity were found in any of the samples. 40K was found below the detection limit in some samples. The analysis of the samples in the case of TSP fertilizer factory showed that the average activity concentrations of 226Ra and 232Th and 40K in raw materials were 851.27 ± 7.10, 19.63 ± 6.57 and 54.06 ± 5.93 Bq/kg, respectively, in final product 211.90 ± 4.74, 42.48 ± 10.56 Bq/kg and ND (Not Detected), respectively, in solid waste 187.49 ± 4.88, 70.06 ± 11.76 and 289.27 ± 40.24 Bq/kg, respectively and in liquid waste 6.26 ± 0.63, 10.01 ± 1.39 Bq/L and ND, respectively. The measured results in the case of samples collected from DAP fertilizer factory showed that the average activity concentrations of 226Ra and 232Th and 40K in the final product were 17.31 ± 3.92, 69.74 ± 9.88 and 48.46 ± 17.22 Bq/kg, respectively, in solid waste 24.47 ± 4.15

关键词： Raw Materials radioactivity Phosphate Fertilizers and HPGe Detector

An Evaluation of Health Hazards Indices of Natural radioactivity of the Sediments from Eko-Ende Dam, Osun State, Nigeria

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Open Journal of Ecology 2018年第11期8卷 607-621页

作者： Katherine Temitope Ogundele Emmanuel Ayodele Oluyemi John Adekunle Oyedele Oyekunle Oladotun Wasiu Makinde Sejlo Temidayo Gbenu Centre for Energy Research and Development Obafemi Awolowo University Ile-Ife Nigeria Department of Chemistry Obafemi Awolowo University Ile-Ife Nigeria

This study measured the radioactivity level in the sediments of Eko-Ende Dam in Ifelodun Local Government Area, Osun State, Nigeria and assessed the radiological impact associated. Thirty six (36) sediment samples were collected from three different points within the Dam for a period of 12 months. The samples were analyzed using Gamma Ray Spectrometer. The radiological hazards due to natural radionuclides content, such as absorbed dose rate (DR), annual effective dose rate (AEDE), effective life cancer risk (ELCR), activity utilization index (AUI), internal radiation hazard (Hin) and external radiation hazard (Hex) in the sediment samples were calculated. The calculated radiological parameters were compared with recommended safety limits and internationally approved values. The radium equivalent activity, internal hazard index, annual effective dose equivalent and effective life cancer risk values of the sediment samples were lower than the permissible limit. Thus, the study area might not pose immediate health implications to the general public, but prolonged exposure could lead to radiation related health hazards.

关键词： Natural radioactivity Radiological Parameters Dam Eko-Ende Nigeria