Environmental Radiation Measurements Research Articles

Assessment of Environmental Background Gamma Radiation Variation in Minna Area of Nigeria

Radiation has been acknowledged to be responsible for deleterious conditions in living tissues. Hence, environmental background gamma radiation (BGR) measurement is crucial from an environmental and health perspective. In this study, due to the absence of comprehensive background gamma radiation data and the increasing numbers of anthropogenic activities that could increase the BGR level, such as where mining activities are active. The BGR in the Minna area of Niger State, Nigeria, was measured and analyzed in this study. In-situ measurement of the background gamma radiation level was carried out using a well-calibrated portable handheld GQ GMC-500 Plus nuclear radiation detector at an elevation of about 1.0 m above ground level. A global positioning system from Garmin (GPSmap 78s) was adopted for identifying geographical locations. A total of 1172 points were surveyed across the study area for background environmental radiation. The BGR values ranged from 0.102 to 0.147 μSv/h, with an overall mean value of 0.126 μSv/h. The average measured dose rate was more than twice the reported world average value of 0.059 μSv/h. The annual effective dose equivalent (AEDE) for the research area was calculated to be 0.221 mSv/y on average. The mean AEDE is lower than the ICRP recommended limit. This shows that the population of the Minna area is radiologically safe based on the estimated AEDE value. Similarly, the excess lifetime cancer risk (ELCR) value ranged from 0.626 × 10−3 to 0.901 × 10−3 mSv/y with a mean value of 0.774 ± 0.09 × 10−3 mSv/y. The mean value of AEDE is below the 0.24 mSv/y permissible limits as recommended by the International Commission on Radiological Protection (ICRP). The mean ELCR value exceeds the average world value of 0.29 × 10−3. Also, the mean organ dose values estimated for the whole body, liver, kidney, testes, bone marrow, ovaries, and lungs are 0.150 ± 0.02, 0.102 ± 0.01, 0.137 ± 0.02, 0.181 ± 0.02, 0.152 ± 0.02, 0.128 ± 0.02 and 0.141 ± 0.02 mSv/y respectively. The differences in the calculated mean of BGR were attributed to natural and human factors. Geological variation is a fundamental factor that influences the changes in BGR. Human activities, mining, building materials, and the use of phosphate fertilizers in agricultural practices are responsible for the differences in BGR. The ELCR implies that terrestrial gamma radiation does not pose any immediate radiological health effects on residents of the area, but there is a tendency for long-term health hazards in the future, such as cancer, due to the dose accumulated.

Determination of natural and artificial radioactivity levels and radiation hazard indices for soil samples in Kırşehir

Abstract The aim of this study is to create a radiological map of Kırşehir province in Turkey by analyzing the radioactivity levels of soil samples and environmental radiation measurements. 226Ra, 232Th, 40K and 137Cs radionuclides were analysed in soil samples collected from 47 locations using gamma spectrometry with an HPGe detector. According to the results obtained, gamma radioactivity concentration ranges and mean values for 226Ra, 232Th, 40K and 137Cs were determined as 133 ± 15–1515 ± 128 Bq/kg (599.40 Bq/kg), 0.3 ± 0.09–21.1 ± 1.7 Bq/kg (4.61 Bq/kg), 8.7 ± 0.9–128.5 ± 8.5 Bq/kg (29.66 Bq/kg) and 11.6 ± 8.6–273.8 ± 19.9 Bq/kg (48.80 Bq/kg) respectively. Average radioactivity levels for 40K and 232Th are above the world average. The mean radium equivalent activity (Raeq), gamma dose rate (D), annual effective dose equivalent (AEDE), external hazard index (H ex ), and the excess lifetime cancer risk (ELCR) were calculated as 145.45 Bq/kg, 122.13 nGy/h, 0.15 mSv/h, 0.39 and 0.29 × 10−3 respectively.

Radiation Measurements at Fukushima Medical University over a Period of 12 Years Following the Nuclear Power Plant Accident

Background: Fukushima Medical University (FMU) is located 57 km northwest of the Fukushima Daiichi Nuclear Power Plant. Our laboratory has been conducting environmental radiation measurements continuously before and after the nuclear accident. We aimed to report the observed behavior of radiation originating from the released radioactive materials due to the accident, predict future trends, and disseminate the results to the local residents.Materials and Methods: Measurements of the counting rate by a diameter of 76 mm and a length of 76 mm thallium-doped sodium iodide (NaI[Tl]) scintillation detector (S-1211-T; Teledyne Brown Engineering Environmental Services) in the central part of the laboratory, and the dose rate outward at the window by NaI(Tl) scintillation detector and digital processor (EMF211; EMF Japan Co. Ltd.) were conducted.Results and Discussion: Measurements by Teledyne S-1211-T showed that in the early stages, radiation from radioactive isotopes with short half-lives was dominant, while radiation from radioactive isotopes with longer half-lives became dominant as the measurement period became longer. Through nonlinear least squares regression, both short and long half-lives were successfully determined. It was also possible to predict how the radiation dose would decrease. The environmental radiation trends around FMU were measured by the EMF211. Both measurements were affected by rainfall and snow accumulation. Decontamination work on the FMU campus impacted measurements by the EMF211 especially.Conclusion: The results of two types of measurements, one at the center and the other at the window side of the laboratory, were presented. By applying a simplified model, radiation from radioactive isotopes with short and long half-lives was identified. Based on these results, future trends were predicted, and the information was used for public communication with the local residents.

Electron paramagnetic resonance spectroscopy for the detection of radiation exposure in dreissenid mussels.

Electron paramagnetic resonance (EPR) spectroscopy, established for radiation measurements in calcified tissues, was identified as a methodology that merits investigation for the purpose of environmental radiation measurements using dreissenid mussels from the Great Lakes. With the refinement of sample preparation and measurement protocols, a linear relationship of dose with the peak-to-peak height of the radiation-induced signal at g = 2.0034 was established. A dedicated analysis algorithm was developed to process batches of samples, eliminating the need for manual peak-to-peak height measurement. Varying background EPR signals were identified in different sampling groups, with samples gathered in winter having a markedly lower background signal. Through optimisation of spectrum acquisition normalisation methods, it was possible to resolve doses as low as 0.2 Gy. This work provides further validation that EPR dosimetry of shelled species has the potential to contribute to better characterisation of absorbed doses in aquatic environments.

Evaluation of Environmental Radiation and Image Quality by Type of High-Energy Electromagnetic Wave Radiation Computed Tomography

With the enhancement of national income level, the number of computed tomography (CT) exams to diagnose diseases is increasing more and more. To utilize the data for the safety control of X-ray, the image quality of the environmental radiation at the boundaries in the radiation zone of the exam rooms by type of CT using highenergy electromagnetic wave. The locations of the environmental radiation measurement were shielding wall of the door for patients, door for patients, door to CT control room, shielding wall of the door for CT control room, and window to see the patients, and the glass dosimeters were installed 150 to 170 cm above the floor considering the location of the device to be measured for 3 months and analyzed. The environmental radiations in the MDCT room were measured with 3.09 ± 2.31 mSv, 0.51 ± 0.12 mSv, 0.99 ± 0.43 mSv, 0.27 ± 0.03 mSv, and 0.18 ± 0.03 mSv at the door to the control room, the wall of the control room, door for patients, door wall, and window to see the patients, respectively. In the mobile CT room, the radiation was detected only at the door of the control room with 1.65 ± 0.15 mSv, and no radiation was detected at the other boundaries. In the PET-CT room, the radiations were detected with 0.18 ± 0.03 mSv and 0.27 ± 0.03 mSv at the door and door wall, respectively, without detection at the other boundaries. Upon the results of image quality by CT devices, very satisfactory outcomes were found in terms of contrast, clarity of the boundaries, and detection rate of lesions in all the acquired images, and also very satisfactory in the functional evaluations of the organs in PET-CT only. These results are anticipated to be used as the reference data to establish the systemic and efficient systems and policies in the safety control of X-ray in the future.

Environmental Gamma Radiation Measurement, Dose Rate and Lifetime Cancer Risk Assessment in Malatya Province and its Districts

Bu çalışmada, Malatya ilinde, 15 farklı noktada, gama doz hızı ölçümleri yapılmıştır. Ölçümler, her noktada hem yerde hem de yerden 1 m yükseklikte alınmıştır. Gama doz hızı ölçümleri NaI (Tl) kristaline sahip taşınabilir bir sintilasyon sayacı kullanılarak yapılmıştır. Gama doz hızlarına (DR) ek olarak, yıllık etkin doz oranları (YEDO) ve ömür boyu kanser riski (ÖBKR) değerleri de hesaplanmıştır. Yerden 1 m yükseklikte DR, YEDO ve ÖBKR için elde edilen ortalama değerler, sırasıyla, 48,47 nGy/h, 58,18 µSv/y ve 0,2110-3 olarak hesaplanmıştır. Bu çalışmada sunulan sonuçlar, Türkiye’nin farklı bölgelerinde yapılan benzer çalışmaların sonuçları ve UNSCEAR tarafından verilen dünya ortalama değerleri ile karşılaştırılmıştır.

Development and Applications of Compton Camera-A Review.

The history of Compton cameras began with the detection of radiation sources originally for applications in astronomy. A Compton camera is a promising γ-ray detector that operates in the wide energy range of a few tens of keV to MeV. The γ-ray detection method of a Compton camera is based on Compton scattering kinematics, which is used to determine the direction and energy of the γ-rays without using a mechanical collimator. Although the Compton camera was originally designed for astrophysical applications, it was later applied in medical imaging as well. Moreover, its application in environmental radiation measurements is also under study. Although a few review papers regarding Compton cameras have been published, they either focus very specifically on the detectors used in such cameras or the particular applications of Compton cameras. Thus, the aim of this paper is to review the features and types of Compton cameras and introduce their applications, associated imaging algorithms, improvement scopes, and their future aspects.

Measurements of non-ionizing environmental radiation from 1Hz to 9400 MHz in São José dos Campos, SP, Brazil

Measurements of non-ionizing environmental radiation from 1Hz to 9400 MHz in São José dos Campos, SP, Brazil

Development and Evaluation of a Mobile Environmental Radiation Measurement System That Can Switch between Low and High Dose Measurement Sections

Development and Evaluation of a Mobile Environmental Radiation Measurement System That Can Switch between Low and High Dose Measurement Sections

Development of a standard method for primary monitoring of exposure to environmental radiation

All living things are constantly exposed to background radiation. The presence of radioactive materials in the earth's crust and cosmic radiation are largely responsible for this exposure. The present study aimed to develop a new methodology of easy applicability and low cost to carry out measurements of environmental background radiation and to be able to establish a map of environmental radiation for primary monitoring of these exposures. For that, ionizing radiation measurements, Meteorological and Radiometric measurements were performed. Geiger Mueller Counter (GM) was used, as it is widely used in services that use radioactive sources and research centers. Measurements obtained showed that there were no statistically significant changes in the 24 hours of measurements with the GM, in relation to the variations presented in the Meteorological and Radiometric measurements that changed according to the time of day. The average value of the background radiation readings was 0.0194 mR/h, with an average variance of 1.8E-06 and an average standard deviation of 1.35E-03. GM proved to be useful for primary measurement of background radiation. The map was developed using open source libraries for the Python programming language. The map may be hosted on an open access website, so that professionals, students and researchers may contribute, sending new data from different locations. It is essential that the levels of radiation exposure are demonstrated and understood. Easy access to this information may contribute to health organizations, agriculture and research centers to establish a baseline for future research.

Research on dose correction method of vehicle-borne environmental radiation measurement equipment

Abstract This study establishes a near-ground reference radiation field based on typical radionuclides of the Fukushima accident in response to the need for vehicle-borne environmental radiation measurement equipment that can accurately evaluate the environmental dose of nuclear accidents. The Monte Carlo code FLUKA is used to study the environmental dose of such equipment in the early and mid-late reference radiation fields of nuclear accidents. Results of the air dose rate at 1 m above the ground were corrected to eliminate data difference between diverse measurement platforms. Simulation results show that t he dose correction factor (CF) fluctuates at approximately 0.8813 in the early reference radiation field and at approximately 0.6711 in the mid-late reference radiation field. This deviation of the dose CF in the early and mid-late reference radiation fields is within 2% and is not affected by the change in detector position. This research can be applied to obtain more accurate measurement of an ambient dose in the near-ground radiation field and support the vehicle-borne environmental radiation measurement technology.

Natural radiological characterization at the Gabal El Seila region (Egypt)

Stream sediment is a useful raw material used for building construction, mostly used in the desert parts of the world. Such sediment is a Naturally Occurring Radioactive Material (NORM), and, hence, it requires a radiological characterization to be used. This work aims to study the natural radioactivity in fifty points distributed in surface of stream sediments in the area of Gabal El Seila region, south-eastern desert of Egypt, since there is a lack of information about the radioactivity levels of the sediment samples from such recent growing interest area. The activity concentration of 238U, 232Th and 4 K natural radionuclides using a portable RS-230 γ-ray spectrometer were determined. Mean values are 38.51 ± 10.83, 33.35 ± 8.82, 659.18 ± 110.87 Bq/kg for 238U, 232Th, 4 K respectively. Radiological hazard indexes were computed and compared with the UNSCEAR and other worldwide ranges. All the results are statistically presented and discussed. They show that no significant radiation hazard coming from the studied area, with the most values lower than international recommended limits. The achievements of the present study fall within the measurements of natural environmental radiation in an unexplored area of great interest being a desert. The obtained results can be used as database for future research, and as tool for radiological awareness in the use of sediments as raw material.

Measurement of environmental radiation and analysis of microdosimetric spectra of cosmic rays during the 35th expedition to Indian station Bharati, Antarctica

Tissue equivalent proportional counter (TEPC) model HAWK FWAD-3 was used for the evaluation of absorbed dose, dose equivalent rate (ḢTEPC) and microdosimetric spectra measured (i) in the mixed radiation fields formed mainly by cosmic rays onboard aircraft during the flights between Mumbai and the Indian station Bharati (Progress air base), two polar flights at Antarctica, and (ii)ground level environmental radiation field at locations situated in three continents, namely Antarctica, Africa and Asia with different latitudes. The study also includes evaluation of absorbed dose rate, dose equivalent rate of cosmic rays and terrestrial radiation using active detectors namely RADEYE-G and BERTHOLD Rem counter. An effort was made to compare the measured dose equivalent rate by TEPC for the commercial flight routes to Antarctica with the values calculated by the software code EPCARD and a good agreement was observed. The 35th expedition to Bharati, Antarctica showed higher values of dose equivalent at the pole (Larsemann Hills region, 69°24′37.60″S, 76°11′01.70″E) than the world average for an evaluation period of six months during summer.

Hatay ve Çevresinde Çevresel Gama Radyasyon Ölçümü

Hatay ve cevresinde havada yapilan olcumlerde gama doz seviyelerini belirlemek icin 183 farkli noktada yerden yaklasik 1 m yukseklikte, cihazin belli bir dengeye gelebilmesi icin 2 dakika beklendikten sonra olcumler alinmistir. Olcumler ucuna SPA-6 model plastik sintilasyon dedektoru baglanmis Eberline Smart Portable (ESP-2) model bir cihaz kullanilarak yapilmistir. Acik havada sogurulan gama doz orani (ADR), gama doz kullanilarak radyocekirdeklerin varligina bagli, havadaki yillik etkin doz orani (AEDE) ve yasam boyu kanser risk degerleri (YFKR) belirlendi. Hatay ve cevresinde dis gama dozu kullanilarak, gama doz olcumlerinin aritmetik ortalamasi 61,9 nGy/h, yillik etkin doz esdegerinin ortalama degeri ise 75,91 μSv/y olarak bulunmustur. Bu calismada sunulan sonuclar, Turkiye'nin farkli bolgelerinde yapilan benzer calismalarin sonuclari ve dunya ortalamalari ile karsilastirilmistir

EPR measurement of environmental radiation using human fingernails

Abstract In this research work, human fingernails were utilized to estimate the radiation dose using EPR measurements of radiation-induced radicals. The limiting factors in this research were the presence of mechanical induced EPR signals due to the mechanical stress during the preparation of the samples. The mechanically induced signals overlap with the radiation-induced signal, which considerably can overestimate the dose. Thus, different treatment methods of fingernails were used to reduce the mechanical induced signals. The results demonstrate that the mechanical and radiation induced signals have apparently different microwave power saturation behavior. Also, mechanical induced signal shows a fading evolution vs. time and reaches to a constant value. Chemical treatment using the different reagents showed that the minimum mechanical induced signal was obtained using the dithiothreitol reagent. The dose response curves of the treated samples with dithiothreitol for 30 min demonstrated a more linearity, and closer curves in comparison to those treated in 5 min. Therefore, to find out an unknown absorbed dose in a fingernail sample using a calibration curve, it could be recommended to use the mentioned chemical treatment procedure to reduce the uncertainty.

Environmental Radiation Measurement and Assessment of Natural Radioactivity in Soil, Water and Vegetation

Environmental radioactivity is produced by radioactive materials in the human environment. While some radioisotopes, such as strontium-90 (90Sr) and technetium-99 (99Tc), are only found on Earth as a result of human activity, and some, like potassium-40 (40K), are only present due to natural processes, a few isotopes, e.g. tritium (3H), result from both natural processes and human activities. The concentration and location of some natural isotopes, particularly uranium-238 (238U), can be affected by human activity because of the constant exposure of Human beings to radiation caused by terrestrial, extra-terrestrial and anthropogenic radio nuclides, it is necessary to determine and estimate the activity of various radio nuclides in environmental media such as vegetation, soil, and water. In the present research, the activities of 226Ra, 232Th and 40K are measured in soil, vegetation and water samples, collected from Yangdong District, Yangxi County, and Yangjiang County of Guangdong Province, China using an HPGe based gamma spectrometry system. The measured mean activity of 226Ra, 232Th and 40K in soil samples was found to be 31.19 ± 1.2, 47.00 ± 2.30 and 589.31 ± 17.52 Bqkg-1, respectively. The measured mean activity of these radionuclides in all water samples was found to be below minimum detectable activity. The measured mean activity of 226Ra, 232Th and 40K in vegetation samples was 19.92 ± 3.09, 25.36 ± 8.11 and 4982.94 ± 85.68 Bqkg-1, respectively. No anthropogenic 137Cs was detected in these environmental samples. Mean radium equivalent activity (Raeq), external radiation hazard index (Hex), internal radiation hazard index (Hin) and absorbed dose rate (D) for the area under study were determined as 142.92 Bqkg-1, 0.38, 0.47 and 66.47 nGyh-1, respectively. The annual effective dose equivalent (AEDE) varied in the range from 0.03 to 0.12 mSvy-1. It is concluded that the surveyed area do not pose any significant radiological risk to the population and environment.

Source term assessment using inverse modeling and environmental radiation measurements for nuclear emergency response

A simple model ‘Assessment of Source Term for Emergency Response (ASTER)’ for estimation of time-dependent atmospheric source term based on real-time environmental gamma dose rate measurements is developed for application in Online Nuclear Emergency Response System (ONERS). The model inverts the measured dose rates to the airborne radioactive release rate using the dilution factors predicted by a random-walk particle atmospheric dispersion model called System for Prediction of Environmental Emergency Dose Information (SPEEDI) taking into account the real-time meteorological observations and location coordinates of the gamma radiation detectors. A point-kernel method for estimating the cloud-gamma dose rates at receptor locations is implemented in SPEEDI for this purpose. ASTER is validated against Ar-41 routine release data from a pressurized heavy-water reactor (PHWR) at Kalpakkam for over 100 days covering different seasons during 2014–2015. Comparison of ASTER-simulated overhead plume gamma dose rates with the measured dose rates at detector points gives a correlation of R = 0.59, bias of 89 nGy/h, and RMSE of 104.09 nGy/h indicating a slight overestimation of gamma dose rates at monitor points. Comparison of ASTER-predicted source term with Ar-41 release rates indicated that about 90% of the calculations fall within a factor of 5 of the actual source term. A correlation of 0.584, bias of 0.152 TBq/day, and RMSE of 0.192 TBq/day are found between the computed and actual daily source term values indicating reasonable agreement. The slight underestimation in the computed source term is due to the overestimation of the dose rate by the dispersion model, location of few monitors near buildings and tree canopies, uneven distribution of detectors in various wind direction sectors, and the use of daily source term values for comparison.

- Measurement of Environmental Radiation Using Medical Scintillation Detector in Well Counter System -

- Measurement of Environmental Radiation Using Medical Scintillation Detector in Well Counter System -

Development of environmental radiation monitoring system using inspector+ and FPGA board

In this report, we present the development of an environmental radiation monitoring system. The system includes Inspector+ dose meter, FPGA board, and LabVIEW interface. In the electronic board using FPGA, the embedded VHDL program is developed for FPGA board. Its functions are to accumulate pulse signals from the Inspector+, transmit data to the computer. Computer interface is written on LabVIEW platform. Its functions are to receive data from FPGA board, plot data, store data, as well as control the FPGA board. We evaluate the response of the system by using a standard pulse generator. With this system, we carry out the measurement of environmental background radiation in two experimental rooms and outside at Nuclear physics Department, University of Science, VNU-HCMC.

Determination of environmental gamma radiation in Bitlis

In this study; the environmental gamma radiation at the various points (16 points) in the districts of and in Bitlis, where it was located in the Turkey Eastern Anatolia region, were measured. The environmental gamma radiation measurement was made from two levels (the ground and one meter above the surface) by using portable gamma survey meter which consisted of 2″×2″ scintillation detector (NaI(Tl)). The obtained data were discussed in considering the geological structure of the region and the other factors.