ISSN: 0972-0464 |
radiology and nuclear medicine
Published by Medknow Publishers
VOL 34 NUMBER 4 (2013)
- Radiological protection aspects of natural radioactivity of building materials
Radiation Protection and Environment 2011 34(4):220-220
- Assessment of electron and gamma-induced dna damage in human peripheral blood by alkaline comet assay
Praveen Joseph, Narayana Yerol, Rajesha Nairy, Ganesh Sanjeev, NN Bhat
Radiation Protection and Environment 2011 34(4):221-224
In the present study, the effect of electron and gamma irradiation on the induction of DNA damage in human peripheral blood cells was investigated using comet assay. Blood samples were irradiated with an 8 MeV pulsed electron beam at a dose rate of 100 Gy min -1 . Gamma irradiation was carried out at a dose rate of 2 Gy min -1 using 60 Co gamma source. The total dose delivered to the samples was varied from 0 to 4 Gy. Samples were maintained at 0° C before irradiation, and the comet assay was carried out immediately after irradiation. Electrophoresis was performed at a field strength of 0.74 V cm -1 for 25 min at 4°C. A dose-dependent increase in DNA damage was observed. From the observed DNA damage, the relative biological effectiveness (RBE) for electron radiation with reference to gamma radiation on induction of DNA damage has been calculated.
- Study on airborne radioactivity levels in dwellings of Tumkur district, Karnataka state, India
A Jayasheelan, J Sannappa, K Umeshareddy, C Ningappa, S Manjunatha
Radiation Protection and Environment 2011 34(4):225-228
Radon is a radioactive gas produced by the decay of 226 Ra present in the soil, rock, water and in atmosphere. Radon, thoron and their progeny are present in indoor and outdoor atmosphere. The concentration of these gases in indoor atmosphere is higher than that of outdoor. In the present study, the concentrations of radon, thoron and their progenies in some taluks of Tumkur district were estimated and the doses due them were calculated. Twin cup dosimeters with alpha sensitive films, LR- 115 type-2, were used for the measurement of concentrations of radionuclides. The mean indoor gamma radiation dose was found to be 0.64 mSvy−1 with highest of 0.75 mSvy−1 in Kunigal taluk. The concentrations of radon in good ventilated dwellings with granite floorings varied from 20.66 Bqm−3 in Tumkur city to 27.61 Bqm−3 in Kunigal. In poor ventilated dwellings, the concentrations of radon varied from 35.56 Bqm−3 in Tumkur to 44.87 Bqm−3 in Turuvekere. The dwellings with granite flooring showed higher concentration of radioactive gases than with marble as flooring and other floorings. The dwelling situated near the granite rocks showed higher concentrations.
- Measurements of the natural radioactivity in building materials (raw and manufactured), other than granites in Kingdom of Saudi Arabia
A Aydarous, S Zeghib, M Eldaghmah
Radiation Protection and Environment 2011 34(4):229-234
In this work, we have measured the natural radioactivity contents of the building materials (raw and manufactured) using HPGe detector. The intensities of γ-ray emitted by radioactive nuclides present in the samples were determined. Efficiencies of the detector at different energies were determined using standard sources, so that radioactivity content of the samples can be estimated. Samples from different areas in Kingdom of Saudi Arabia were collected. These samples were prepared in the form of fine powder suitable to be used by Marinelli beakers. Software equipped with the detector electronic system had been used to analyze the data; hence the results were recorded. The highest measured activity concentrations in the samples are: 48, 42, and 971 Bq/kg for 232 Th, 226 Ra, and 40 K, respectively, which are in the range of the corresponding typical worldwide values. The absorbed dose rates, effective dose rates, radium equivalent activities as well as the radiation hazard indices were estimated. The maximum radium equivalent activity (Ra eq ) was 186 Bq/kg, which is lower than the limit of 370 Bq/kg set by the Organisation for Economic Cooperation and Development.
- Study of radon exhalation rate from soil, Bangalore, South India
GV Ashok, N Nagaiah, NG Shiva Prasad, MR Ambika
Radiation Protection and Environment 2011 34(4):235-239
The 222 Rn exhalation rate measurements are useful in identifying the locations of high radon exposure. On the other hand, atmospheric 222 Rn concentrations have been observed as an effective tracer for terrestrial air mass movements and atmospheric mixing mass movements. In view of this, year-long measurements of 222 Rn and its exhalation rates were carried out at J B Campus of Bangalore city, and the diurnal and seasonal variations have also been studied. Diurnally, exhalation rate was found to be high during night and early morning hours and low during afternoon hours. The diurnal variability of temperature difference between the lower and upper layers of the soil was found to be responsible for the observed diurnal variations. The monthly average of 222 Rn exhalation rate ranges from 10.63 ± 1.75 to 4.95 ± 0.65 mBq m -2 s -1 . The annual mean value of radon exhalation rate was found to be 8.27 ± 1.83 mBq m -2 s -1 .
- Estimation of atmospheric dilution factors for trombay site using the air pollution model
R Shrivastava, SP Indumati, MB Pote, RB Oza, VD Puranik
Radiation Protection and Environment 2011 34(4):240-241
This paper presents the application of The Air Pollution Model (TAPM) in estimation of atmospheric dilution factors for Trombay site for unit release rate in different wind sectors. The values obtained from the model are compared with those obtained from routinely collected meteorological data at 10 m height. The measurement carried out at 10 m height is extrapolated to the release height using power laws with stability-dependent coefficient. The maximum value of dilution factor at 1.6 km, computed using model data is 0.1039E-06 s/m 3 while that obtained using measured data is 0.1238E-06 s/m 3 ; however, the two are occurring in different sectors. Thus, model-generated dilution factors can be used in case if only the maximum impact of the releases need to be studied and no measured data are available. In general, it was found that except few sectors, model-generated dilution factors remain within a factor of two as compared to that generated using measured data. The main application of this study is for upcoming sites where representative measured meteorological data may not be available; however, computation of atmospheric dilution factors is required for environmental impact assessment.
- Radiation exposure control by estimation of multiplication factors for online remote radiation monitoring systems at vitrification plant
Umesh V Deokar, VV Kulkarni, AR Khot, P Mathew, Kamlesh , RG Purohit, PK Sarkar
Radiation Protection and Environment 2011 34(4):242-245
Vitrification Plant is commissioned for vitrification of high-level liquid waste generated in Nuclear Fuel Cycle operations by using Joule Heated Ceramic Melter first time in India. Exposure control is a major concern in operating plant. Therefore, in addition to installed monitors, we have developed online remote radiation monitoring system to minimize number of entries in amber areas and to reduce the exposure to the surveyor and operator. This also helped in volume reduction of secondary waste. The reliability and accuracy of the online monitoring system is confirmed with actual measurements and by theoretical shielding calculations. The multiplication factors were estimated for remote online monitoring of Melter off Gas (MOG) filter, Hood filter, three exhaust filter banks, and overpack monitoring. This paper summarizes how the online remote monitoring system had helped in saving of 128.52 Person-mSv collective dose (14.28% of budgeted dose) and also there was 2.6 m 3 reduction in generation of Cat-I waste.
- Radiological safety study of clad failed fuel handling during fifty years of operation of cirus
TR Meena, RK Yadav, SK Prasad, SS Deolekar, KS Babu, N Ramesh, Rakesh Ranjan
Radiation Protection and Environment 2011 34(4):246-248
CIRUS reactor, the nucleus of nuclear programme of India is a 40MW research reactor commissioned in July 1960. The reactor was operated efficiently for nearly five decades before it was shutdown permanently on 31 st December 2010. During the reactor operation, incidences of Clad Failed Fuel (CFF) were considered as Safety Related Unusual Occurrences (SRUOs). Incidences of CFF could sometimes lead to severe contamination of system resulting in personnel exposure and generation of large amount of liquid and solid radioactive wastes. CFF detection system used earlier was Gaseous Fission Product Radiation Alarm (GFPRA), which was replaced with new gamma based Failed Fuel Detection (FFD) system during refurbishing of Cirus during 1997-2002. CFF rods handling during nearly five decades of CIRUS reactor operation were studied in detail. Important radiological data related to identification and removal of CFF rod were also analyzed. Collective dose consumption and waste generated both solid and liquid for each CFF was also studied in detail. The use of the new gamma-based FFD system resulted in lowering of collective dose from 110 to 12 Person-mSv per incidence and also reduction in spread of contamination.
- A study of gamma radiation induced changes in electrical properties of Aℓ/TeO 2 /n-Si/Aℓ mos capacitor for dosimetric applications
G Chourasiya, TK Maity, SL Sharma, J Sarkar, JC Vyas
Radiation Protection and Environment 2011 34(4):249-252
The study of the effects of ionizing radiation on MOS devices has been an active area of research due to their wide range applications. Some attempts have recently been made to investigate the influence of ionizing radiation on properties of the MOS capacitor prepared by replacing SiO 2 layer by any metal oxide layer of large band gap and then to understand its response. The effect of gamma radiation on electrical properties of the Aℓ/TeO 2 /n-Si/Aℓ MOS capacitor has been studied in detail for the first time in the present work in order to understand its applicability in the post-exposure gamma radiation dosimetry. The effect of gamma radiation on the real and imaginary parts of the permittivity, dielectric loss, series resistance, ac conductivity and surface state density has been determined. These properties have been obtained by analyzing C-V and G/ω-V characteristics, recorded at a frequency 1.0 MHz of the small ac signal, for the MOS structure exposed to different levels of the gamma radiation dose. The linear variation of the dielectric constant with the gamma radiation dose over a wide range of doses, observed corresponding to the accumulation region of the MOS capacitor, possesses high potential for its application as the post-exposure gamma radiation dosimeter.
- Performance of LaCl 3 detector for environmental radioactivity measurements
K Narayani, S Anilkumar, AK Rekha, D. A. R. Babu
Radiation Protection and Environment 2011 34(4):253-256
Assessment of natural radioactivity in the environment using gamma spectrometry is common method. NaI (Tl) detectors and HPGe detectors are used for gamma spectrometry in general. The recent arrival of Lanthanum Halide detectors have better resolution compared to NaI (Tl) detectors. In the present work, the performance of Lanthanum Chloride (LaCl 3 ) detector for the natural radioactivity estimation is studied and compared with NaI (Tl) and HPGe detectors.
- Thoron interference test of different continuous passive radon monitors
CG Sumesh, A Vinod Kumar, RM Tripathi, VD Puranik
Radiation Protection and Environment 2011 34(4):257-261
The instruments measuring radon concentration without energy discrimination may have some sensitivity towards thoron concentration. In the present paper, thoron interference tests of a pulse - ionization - chamber - type instrument - Alpha Guard and a semi - conductor - based instrument - Radon Scout Plus (RSP) have been studied in detail. The instruments are compared with a standard active radon - thoron discriminating monitor - RAD7. As a result 9% interference in measured radon concentration for the Alpha Guard monitor and 4% interference for the RSP monitor were observed. The results obtained indicate that the interference of thoron in radon monitors depends on the area of diffusion of gas, volume of detection and sensitivity factor of the monitor.
- Analysis of neutron streaming through the trenches at linac based neutron generator facility, IGCAR
Usha Pujala, L Thilagam, TS Selvakumaran, DK Mohapatra, E Alagu Raja, KV Subbaiah, R Baskaran
Radiation Protection and Environment 2011 34(4):262-266
Shielded LINAC hall has been built to accommodate a radio frequency quadrupole (RFQ) linear accelerator (LINAC) based pulsed neutron generator at RSD, IGCAR. The concrete neutron shield wall thickness for the LINAC hall is finalized by adopting NCRP-51 methodology. The dimensions of the trenches and labyrinth are decided based on the neutron generator installation requirements. As per the AERB safety criteria, the radiation dose levels in the occupancy area should be less than 1μSv/h. However, the refined dose estimate with the inclusion of actual trench and labyrinth dimensions indicates an increased dose rate of ~3.10 μSv/h in LINAC control room. Hence, the control room is declared as controlled area. Additional shielding has been proposed for the trenches and labyrinth to make the control room as full occupancy area. For designing the additional shielding, experimental and theoretical analyses are needed to estimate the radiation streaming through the trenches and labyrinth. To start with, the neutron streaming through trenches have been studied using 185 GBq (5Ci) 241 Am-Be neutron source for qualifying the trenches. The 241 Am-Be source position is selected at the trench entrance such that it contributes the same neutron flux as that of neutron generator. Neutron dose rate and spectral measurements have been carried out at five locations along the trench from the entrance (LINAC hall side) to the exit (Control room side) of the trench.The experimental results are validated with the theoretical calculations using Monte Carlo N particle (MCNP) code. The analysis shows that the trenches are having a dose reduction factor better than 800 with respect to that of entrance dose. The observed dose rate at the trench exit is found to be less than 450nSv/h. In this paper, both the theoretical and experimental neutron streaming analyses through the trenches of LINAC hall are presented.
- Radiation levels and radionuclide distributions in soils of the gogi region, a proposed uranium mining region in north Karnataka
I Yashodhara, N Karunakara, K Sudeep Kumar, Rudra Murthy, RM Tripathi
Radiation Protection and Environment 2011 34(4):267-269
This paper reports the results of systematic studies aimed at generating a baseline database on the radiation levels and radionuclide distribution in the Gogi region, which has been identified as a prospective uranium mining region. A total of 39 villages in a 0-30 km radius zone of the Gogi region were covered under this study. The ambient gamma absorbed dose rates were measured using portable gamma dosimeters. The activity concentrations of 226 Ra, 232 Th, and 40 K in the soil samples were measured by the HPGe gamma spectrometry method. The ambient gamma absorbed dose rate varied in the range of 126-428 nGy h -1 , with a median value of 143 nGy h -1 . The activities of 226 Ra, 232 Th, and 40 K in the soil varied in the range of 5-176 Bq kg -1 , 9-687 Bq kg -1 , and 81-1493 Bq kg -1 , with the corresponding median values of 36 Bq kg -1 , 85 Bq kg -1 , and 859 Bq kg -1 , respectively. The study showed a highly non-uniform distribution of primordial radionuclides in the soil, with activity concentrations varying significantly within a small area. The results observed in the present study were compared with the literature values reported for other parts of India and the worldwide average values, and discussed.
- Measurement of natural activities of 238 U, 232 th and 40 k in tin ore
Nassif A Mansour
Radiation Protection and Environment 2011 34(4):270-274
Tin ore is widely used in many industrial purposes. Such as tin ore contain natural radioactive nuclides at various concentrations. If this ore contain high concentrations of natural radioactive nuclides, workers handling them might be exposed to significant levels of radiation. Therefore it is important to determine the radioactive nuclides in this ore. The natural radionuclides ( 238 U, 232 Th and 40 K) and their daughter products contents of tin ore have been estimated in gamma-ray spectrometry and their levels using 70% Hyper-Pure` Germanium (HPGe) detector. The mean activities due to the three radionuclides ( 238 U, 232 Th and 40 K) were found to be 40 ± 3, 19 ± 2.2 and 97 ± 19 Bqkg−1 , respectively. The radium equivalent activity varied from 77.87 ± 11-12.03 ± .27 Bqkg−1 . The representative external hazard index values for the corresponding Tin Ore are also estimated. The results of this assessment obtained by the gamma-ray spectroscopic analysis, have indicated that the levels of natural radioactivity were lower than the international recommended limits.
- Natural radioactivity in the volcanic field north of Sana'a, Yemen
EE Saleh, AI El-Mageed, AH El-Kamel, A Abbady, S Harb
Radiation Protection and Environment 2011 34(4):275-281
The level of natural radioactivity in rocks and soil of 32 samples collected from locations at North Sana'a in Yemen was measured. Concentrations of radionuclides in rocks and soils samples were determined by gamma-ray spectrometer using HPGe detector with specially designed shield. The average radioactivity concentrations of 226 Ra, 232 Th and 40 K were determined and expressed in Bq kg−1 . The results showed that these radionuclides were present in concentrations of 21.79 ± 3.1, 19.5 ± 2.6 and 399.3 ± 16 Bq kg−1 , respectively, for rocks. For soil, the corresponding values were 48.2 ± 4.4, 41.7 ± 4.5 and 939.1 ± 36 Bq kg−1 . Also, the radiological hazard of the natural radionuclides content, radium equivalent activity, total dose rates, external hazard index and gamma activity concentration index of the (rocks/soils) samples in the area under consideration were calculated. The data were discussed and compared with those given in the literature.
- News and Information
Radiation Protection and Environment 2011 34(4):282-283
VOL 35 NUMBER 1 (2013)
- The new dose limit for the lens of the eye and its implications
Radiation Protection and Environment 2012 35(1):1-3
- A comparative study of 232 Th and 238 U activity estimation in soil samples by gamma spectrometry and neutron activation analysis technique
Rekha Anilkumar, S Anilkumar, K Narayani, D.A.R. Babu, DN Sharma
Radiation Protection and Environment 2012 35(1):14-16
Neutron activation analysis (NAA) is a well-established analytical technique. It has many advantages as compared to the other commonly used techniques. NAA can be performed in a variety of ways depending on the element, its activity level in the sample, interference from the sample matrix and other elements, etc., This technique is used to get high analytical sensitivity and low detection limits (ppm to ppb). The high sensitivity is due to the irradiation at high neutron flux available from the research reactors and the activity measurement is done using high resolution HPGe detectors. In this paper, the activity estimation of soil samples using neutron activation and direct gamma spectrometry methods are compared. Even though the weights of samples considered and samples preparation methods are different for these two methods, the estimated activity values are comparable.
- Occupational exposures in industrial application of radiation during 1999-2008
Suresh Shantaram Sanaye, Sujatha Baburajan, Suresh Ganpat Pawar, Shailesh Krishna Nalawade, Balvindar Kaur Sapra
Radiation Protection and Environment 2012 35(1):17-21
Radiation sources are used in various industrial applications like industrial radiography, industrial irradiation, industrial fluoroscopy, nucleonic gauges, well logging etc.. Gamma, beta X-ray as well as neutron sources are used for various applications. Number of radiation workers in this field has increased over the years. Due to operating conditions prevailing during the exposure as well as the strength of the sources used in some of the applications, radiation protection plays an important role in this field. Analysis of doses received by radiation workers in industry provides information on trends of doses as well as adequateness of radiation protection practices followed in this sector. In India, National Occupational Dose Registry System (NODRS) of Radiological Physics and Advisory Division (RPAD), Bhabha Atomic Research Centre (BARC) maintains personnel dose information of monitored radiation workers in the country. Analysis of occupational dose data of industrial radiation workers for last 10 years, i.e., 1999-2008 has been presented in this paper. It is observed that even though there is an increase in monitored radiation workers, percentage of persons receiving radiation exposure has come down during this period. There is also a decrease in the average annual dose as well as the collective dose. Further analysis of sub-categories shows that industrial radiography operations are the main contributor for collective dose (about 77%) followed by well logging and industrial X-ray operations (about 8% each). Thus, in addition to industrial radiography, attention is also to be given to operations in these areas.
- Radiological impact of soil as a source of building material
Francis Otoo, Emmanuel Ofori Darko, Geoffrey Emi-Reynolds, Aba Bentil Andam, Oscar Kwaku Adukpo
Radiation Protection and Environment 2012 35(1):22-28
The radiological hazards associated with naturally occurring radioactive materials in soil samples from different geological locations have been studied using gamma spectrometry. The average activity concentration of 226 Ra, 232 Th, and 40 K were (16.4-74.6 Bq/kg), (12.0-44.7 Bq/kg), and (215.4-498.6 Bq/kg). The highest values of 226 Ra and 232 Th occurred in Dodowa and Oyibi respectively. The 40 K recorded the highest activity concentration of 498.6 Bq/kg, measured in soil from McCarthy Hills. The radium equivalent activity (Ra eq ; 46.9-135.7 Bq/kg), the internal hazards index (H in ; 0.29-0.52) the external hazard index (H ex ; 0.22-0.37), the absorbed dose rate in air (23.3-75.8 nGy/h), and the annual effective dose (E T ) (44.4-79.4 uSv/y) were evaluated to assess the radiation hazard to the populace living in dwellings made of these soil as a building material. The results obtained were found to be within the acceptable limits for public exposure control recommended by the European Commission, International Commission on Radiological Protection, and Organization for Economic Cooperation and Development-Nuclear Energy Agency.
- Study on natural radioactive elements in soil and rock samples around Mandya district, India
BC Shivakumara, L Paramesh, TS Shashikumar, MS Chandrashekara
Radiation Protection and Environment 2012 35(1):29-33
Context: The soil is a complex mixture of different compounds and rocks. In the natural environment, it is an important source of exposure to radiation due to naturally occurring, gamma emitting radionuclides which include 226 Ra, 232 Th and 40 K present in the soil. Aims: The study of distribution of these radionuclides in soil and rock is of great importance for radiation protection and measurements. Materials and Methods: The activity concentrations of 226 Ra, 232 Th, and 40 K in soil and rock samples collected in Mandya District, Karnataka state, India have been measured by gamma ray spectrometry. Results: The average activity concentrations of 226 Ra, 232 Th, and 40 K (Bq/kg) are found to be 40.2, 62.3, and 317.5 Bq/kg, respectively, in soil samples and 30.5, 34.4, and 700.2 Bq/kg, respectively, in rock samples. Conclusion: The concentrations of radionuclides in soil samples are found to higher than in rock samples. The concentrations of radionuclides in soil and rock samples in the study area are slightly higher than Indian average and world average values
- Study on the response of the ferrous ammonium sulfate - cupric sulfate dosimetry system of different salt concentrations at gamma chambers and radiation processing plant
Sayanti Ghosh, Kalpana Khedkar, Swati Kashid, Pratap Chakraborty
Radiation Protection and Environment 2012 35(1):34-42
Background and Aim: Gamma radiation is commercially used in food preservation by extending shelf life and the success of radiation preservation of food depends upon the ability of the processor of successful measurement of the radiation dose delivered to the foods. Several dosimeters are already used in radiation processing plant to measure the delivered dose. The aim of the present study was to develop a simple and appropriate chemical dosimetry system covering a wide dose range (1-30kGy) of food irradiation. Materials and Methods: The response of the ferrous ammonium sulfate (Fe(NH 4 ) 2 (SO 4 ) 2 ,6H 2 O) - cupric sulfate (CuSO 4 ,5H 2 O) dosimetry system was studied at two different gamma chambers of GC-5000 and GC-900 and at a radiation processing plant with four different salt concentrations and at the dose range of 1-30kGy. Results and Discussion: The system with highest salt concentration i.e. with 6x0.001mmol Fe(NH 4 ) 2 (SO 4 ) 2 ,6H 2 O + 6x0.01mmol CuSO 4 ,5H 2 O showed linear response in the applied dose range of 1kGy to 30kGy. Good reproducibility of the system was observed at both GC-5000 and GC-900 with different dose rate and irradiation temperature. Routine dosimetry and dose mapping at radiation processing plant with the standard Ceric-cerous dosimetry system with same salt concentration also showed good agreement with 5% difference. The system was stable upto 7 days before and after irradiation at 4 o C and at darkness. The estimated overall precision for the dose assessment over the dose range of interest was about 2% irrespective of the dose rate and irradiation temperature. Conclusion: The ferrous ammonium sulfate (Fe(NH 4 ) 2 (SO 4 ) 2 ,6H 2 O) - cupric sulfate (CuSO 4 ,5H 2 O) dosimetry system with highest salt concentration i.e. with 6x0.001mmol Fe(NH 4 ) 2 (SO 4 ) 2 ,6H 2 O + 6x0.01mmol CuSO 4 ,5H 2 O can be successfully used as chemical dosimeters in the dose range of 1-30kGy.
- The derived radiological parameters associated with beach mineral sand deposits prevail in the south west coastal regions of India
Deva Sigamony Deva Jayanthi, Chavarachirayil Govindan Manian, Subramania Pillai Perumal
Radiation Protection and Environment 2012 35(1):4-8
The distribution of natural radioactivity in beach sand samples collected from naturally high background radiation areas of south west coast of Tamil Nadu in India is studied by gamma spectrometry. The activity concentration of radionuclide collected from the study area ranges from 18.9 ± 4.6 Bq/kg to 260.5 ± 29.4 Bq/kg for 226 Ra, 534.5 ± 34.0 Bq/kg to 2961.4 ± 33.7 Bq/kg for 232 Th, and 40.6 ± 7.2 Bq/kg to 148.7 ± 17.9 Bq/kg for 40 K. The measured activity of 226 Ra and 232 Th in soil samples collected from the study area is higher than the activity of 40 K. The external hazard index, internal hazard index, absorbed dose rate, and annual effective dose equivalent are calculated and tabulated. It is found that all the evaluated values are higher than the safe limit. The annual effective dose of radiation ranges from 0.41 mSv to 2.35 mSv due to naturally occurring radionuclide.
- Natural radioactivity and dose rates for soil samples around Tiruchirapalli, South India using γ-ray spectrometry
Bojarajan Senthilkumar, Sabapathy Manikandan, Mohamed Saiyad Musthafa
Radiation Protection and Environment 2012 35(1):43-51
The activity concentrations and the gamma-absorbed dose rates of the naturally occurring radionuclides 226 Ra, 232 Th, and 40 K were determined for 40 soil samples collected from Tiruchirapalli, South India, using g-ray spectrometry. The average activity concentrations of 226 Ra, 232 Th, and 40 K in the soil samples were found to be 29.9, 39.0, and 369.7 Bq kg−1 , respectively. The measured activity concentrations of both 226 Ra and 40 K in the soil were lower than the world average, whereas, the activity of 232 Th was higher than the world average. The concentrations of these radionuclides were also compared with the average activity of the Indian soil. The radiological hazard index was calculated and compared with the internationally approved values. The average external absorbed gamma dose rate was observed to be 79.9 nGy h−1 , with a corresponding average annual effective dose of 97.9 mSv y−1 , which was above the world average values. The values of Ra eq and H ex were found to be within the criterion limit, whereas, the radioactivity level index ( Ig) and total gamma dose rate were above the worldwide average values.
- Bulk laundry monitoring system
Vaishali M Thakur, Amit Jain, Amit Verma, NR Rande, S Anilkumar, D.A.R. Babu, DN Sharma
Radiation Protection and Environment 2012 35(1):52-54
Protective wear (like boiler suits, hand gloves etc.) is necessary while handling radioactive material in plants/laboratories. During the course of work, it is quite possible that protective wear may get contaminated. These protective wear are packed in laundry bags and send to Decontamination Centre (DC) for washing. There is a need for monitoring the laundry bags at the time of receipt, as well as before dispatch to respective locations to comply with AERB guidelines. To avoid cross contamination during wash cycle, contaminated bags (>0.5 mR/h on surface) need to be segregated. Present paper describes the development of such system for monitoring surface dose rate on bags at the time of receipt.
- Basis for the ICRP dose limits
Radiation Protection and Environment 2012 35(1):55-56
- Studies on radon concentration in aqueous samples at Mysore city, India
BM Rajesh, MS Chandrashekara, P Nagaraja, L Paramesh
Radiation Protection and Environment 2012 35(1):9-13
Context: Natural radionuclides are wide spread in air, water, soil, plants and in consequence in the human diet. 222 Ra is the daughter product of 226 Ra which belongs to 238 U radioactive series. Aims: Radon enters the human body through ingestion of water and inhalation. Since alpha emitters are the most dangerous, studies on water containing dissolved radon are very important. Materials and Methods: The activity concentration of 222 Ra has been analyzed in water samples collected from lakes, open wells, drilled wells, taps and rivers in and around Mysore city, Karnataka State, India using radon emanometric technique. Results: The present study shows a wide range of radon concentration in water, which varies from below detection limit to 643.9 BqL -1 with a median of 15.8 BqL -1. An annual effective dose with a median of 0.043 μSv y-1 was estimated from the ingestion of 222 Ra through water. Conclusions: 222 Rn concentration in 80% of bore-well water samples are higher than the maximum acceptable contaminant level of 11.1 BqL -1 as prescribed by the environmental protection agency.
VOL 35 NUMBER 2 (2013)
- LNT theory is still not experimentally proved!
Radiation Protection and Environment 2012 35(2):100-100
- Recent developments in internal dosimetry
Hemant Kumar Patni
Radiation Protection and Environment 2012 35(2):101-102
- Radioactivity in human body and its detection
Radiation Protection and Environment 2012 35(2):57-58
- Residential radon exposure in some areas of Bangalore city, India
GV Ashok, N Nagaiah, NG Shiva Prasad, MR Ambika, LA Sathish, N Karunakara
Radiation Protection and Environment 2012 35(2):59-63
Background: Two isotopes, 222 Rn and 220 Rn of the natural radioactive gas radon are generally of radiological importance. About half of the total radiation effective dose to the general public is due to the irradiation of the lungs by alpha particles following the inhalation of radon decay products. In view of this, 222 Rn and 220 Rn measurements were carried out for a period of 1 year in about 50 dwellings belonging to different residential areas of Bangalore city. The results obtained were systematically analysed and discussed. Materials and Methods: 222 Rn and 220 Rn measurements were carried using Solid State Nuclear Track Detectors. The gamma exposure rate measurements were also carried out in all the dwellings using a G M tube based Environmental Radiation Dosimeter. Results: The concentration of 222 Rn and 220 Rn was found to be highest in the dwellings having mud flooring (Bare) and lowest in the dwellings having mosaic flooring. The geometric mean values of the concentrations of 222 Rn and 220 Rn were found to be 24.1 ± 8.3 and 24.5 ± 10.8 Bq m -3 respectively. The annual mean value of the gamma absorbed dose rate is found to be 175.8 nGy y -1 . Conclusion: The mean value of radon concentration is well within the indian average (42 Bq m -3 ) and world average (40 Bq m -3 ) values. The mean effective dose was found to be 1.19 mSv y -1 and is well within the action level as prescribed by ICRP-65.
- Milk minerals in cow milk with special reference to elevated calcium and its radiological implications
Edison Mahiban Ross, Mamkuptipadapth Pisharath Rajan, Samuel Godwin Wesley
Radiation Protection and Environment 2012 35(2):64-68
Context: In Kudankulam, the South Eastern tip of India, a nuclear power station is under construction. Various studies have been carried out around this project site; however, there is no literature pertaining to the minerals in cow milk samples in this region. Further, various minerals in cow milk are analogs of natural and anthropogenic radionuclides and a study on stable elements would help to assess the behavior of their radioactive counterparts. Materials and Methods: Milk samples (n = 25) from the study area were analyzed for macro-minerals (potassium [K], magnesium [Mg] and calcium [Ca]) and micro-minerals (zinc [Zn], copper [Cu] and manganese [Mn]) using a Z5000 series Hitachi atomic absorption spectrophotometer. The performance of the method was evaluated by using an International Atomic Energy Agency (IAEA) reference material, i.e., the fish tissue homogenate (IAEA-407). Results: The concentration values of major and trace minerals in the milk samples were in the order Ca > K > Mg and Zn > Cu > Mn, respectively. Conclusion: The high-water Ca levels and the prevailing tropical semi-arid climatic conditions seem to be the reasons for the high-Ca levels observed in the investigated milk samples. A CaCO3 bed is present in this area and lime is being excavated by cement industries and it is also evident from the literature that elevated Ca levels would have an immense impact on the levels of natural and fall out radionuclides in cow milk.
- Experience during the monitoring of inactive scrap for the detection of inadvertent presence of radioactivity
Ranjit Sharma, Anoj Kumar, Vikas , Rajvir Singh, RP Patra, Vikas Kumar, KS Pradeepkumar
Radiation Protection and Environment 2012 35(2):69-72
Context: The paper describes about the experience gained during the radiation monitoring of inactive scrap generated at various nuclear facilities. This type surveillance is carried out to prevent the spread of radioactivity in public domain and also as requirement by regulatory authorities. Aim: The inspection and certification of scrap material from Nuclear facilities is a regulatory requirement to ensure that no radioactive material reaches public domain. This paper describes the methodology and experience in detection of radioactivity at inactive Scrap monitoring facility. Materials and Methods: Inactive scraps (metallic and non metallic) generated from various nuclear facilities of BARC, Trombay is dispatched to Trombay Village Store (TVS) for temporary storage before auction to the public. The monitoring at the facility includes visual inspection and radiation measurement before loading the scrap in the truck. An online PC based monitoring system and portable monitoring instruments in the range (nSv/h-μSv/h) are used to carry out radiation monitoring of inactive scrap loaded in a vehicle. Results: Radioactive source of high activity with potential for serious environmental hazard has not been detected, but few cases of presence of radioactive /contaminated material (MS plate/equipments with low level of Cs-137 contamination) have been detected and identified using portable gamma spectrometer. Conclusion: Implementation of strict regulatory measures and radiation monitoring at nuclear facilities can minimize the probability of radioactive material reaching the public domain. The methodology followed for monitoring of inactive scrap is found to be effective even for detection of presence of radioactivity in scrap if any.
- Measurement of gamma natural background radiation in Chamaraja Nagar district, Karnataka state, India
KM Nagaraju, MS Chandrashekara, KS Pruthvi Rani, L Paramesh
Radiation Protection and Environment 2012 35(2):73-76
Background: All objects in nature are exposed to ionizing radiation emitted by primordial radionuclides and cosmogenic radionuclides due to cosmic rays, the influence of which on living beings is very imminent and important to study. The amount of this background radiation received by an individual depends on altitude, latitude type of building and the building construction materials. Materials and Methods: In the present study, measurements of natural background radiation were made in the schools, temples, dwellings, and hill stations etc., in Chamaraja Nagar District, Karnataka State, India by using Environmental Dosimeter technique. Results and Conclusion: The absorbed dose rate in dwellings of different villages in this region varies from 98.3 ± 7.1 to 708.2 ± 59.3 nGyh−1 with an average of 291.8 ± 23.4 nGyh−1 , whereas in temples it varies from 71.4 ± 5.2 to 589.0 ± 46.3 nGyh−1 with an average of 240.5 ± 19.2 nGyh−1 .
- Estimation of uranium isotope in urine samples using extraction chromatography resin
Smita S Thakur, Jogendra Yadav, Devender Rao
Radiation Protection and Environment 2012 35(2):77-79
Introduction: Internal exposure monitoring for alpha emitting radionuclides is carried out by bioassay samples analysis. For occupational radiation workers who handle uranium in reprocessing or fuel fabrication facilities, there exist a possibility of internal exposure and urine assay is the preferred method for monitoring such exposure. Materials and Methods: Separation of Uranium is carried out by extraction chromatography using diamyl amyl phosphonate (U/TEVA) resin. This resin contains diamyl amyl phosphonate extractant supported on inert Amberlite XAD-7 (an acrylic ester) resin.The electrodeposited samples are counted using octet alpha spectrometery. Results and Discussion: The analysis time involved from sample loading to stripping is 2 h compared with the 3.5 h involved in conventional ion exchange method. The radiochemical yield was found in the range of 69-91%. Minimum detectable activity for uranium estimation for 3,60,000 s counting time at an average percentage recovery of 82 8 works out to 0.21 mBq/d. Conclusion: The technique gives good and consistent radiochemical yield of 82% on repeated use of the chromatographic column when compared with ion exchange technique. Analysis time involved from sample loading to stripping using UTEVA is 2 h compared with the time involved of 3.5 h by the conventional ion exchange method.
- Estimation of intake by maximum likelihood method using follow up measurements of 131 I thyroidal burden
Vandana P Ghare, Hemant Kumar Patni, Deepak Kumar Akar, Devender D Rao
Radiation Protection and Environment 2012 35(2):80-83
Context: 131 I is widely used for diagnostic and therapeutic purposes. Since thyroid is the main deposition site for 131 I, so it can be detected by direct thyroid monitoring. Aim: This work presents results of follow-up measurements of an individual who was internally contaminated with 131 I with injected activity being determined by maximum likelihood method. Importance of dose per unit content is also shown in this study. Materials and Methods: The whole body monitoring system available in Radiation Safety Systems Division of Bhabha Atomic Research Centre is calibrated for estimation of 131 I in the thyroid of radiation worker using BOttle MAnnikin Absorber (BOMAB) phantom with neck part being replaced by American National Standards Institute (ANSI)/International Atomic Energy Agency (IAEA) neck. Results: The estimated intake was found to be 89.24 kBq and the committed effective dose is calculated as 1.96 mSv. The data are analyzed with autocorrelation and Chi-square test to establish goodness of fit with log-normal distribution. Conclusion: The overestimation of thyroid activity by use of mid axial hole in BOMAB phantom is removed by using ANSI/IAEA neck phantom. Measured retained thyroidal data on different days following the intake has closely fitted to the ICRP predicted retained activity.
- Measurement of radon activity in soil samples of some selected towns across the Lake Bosumtwi basin, Ghana
Charles Kansaana, Andam Bentil Aba, Eric Kotei T Addision, Emmanuel Ofori Darko, Oscar Kwaku Adukpo, Augustine Faanu
Radiation Protection and Environment 2012 35(2):84-89
Background: The potential hazard of radiation exposures to radon and its daughter products from natural background has been highlighted in the world of scientific press and has become a matter of concern. The Lake Bosumtwi is one of the interesting research areas in Ghana due to the geological nature of the area, and also of its great importance based on the different uses of the lake and its surroundings. There is therefore the need to investigate the levels of radon activity in soil samples around Lake Bosomtwi basin as part of the national effort to establish base line data of radon levels in Ghana. Materials and Methods: The study was conducted to measure the levels of radon activity in soil samples within the lake Bosomtwi basin. Samples were collected from five selected villages around the lake at depths of 10 cm and 20 cm. The Role's Method was employed and measurements were made using specific cell counters. The measurements were performed with a Radon Degassing Unit (RDU-200) and a Radon Detector Analyzer (RDA-200). The calculated cell efficiency was obtained as 0.55 cpm/dpm. Results: The average radon concentrations at the depths were calculated and the maximum concentration for the 10 cm depth was obtained from Tepaso with a value of 4801.71±678 Bq/m 3 and the minimum concentration was obtained from Abonu with a value of 3887.07±815 Bq/m 3 . The maximum and minimum concentrations for the 20 cm depth were obtained from Tepaso and Kusuasi with values of 5602.10±943 Bq/m 3 and 4877.93±404 Bq/m 3 respectively. The overall average radon concentration obtained was 4745.31±559 Bq/m 3 . The results obtained were high when compared with results from previous studies. The values obtained are less than the World Health Organization's acceptable level for outdoor radon activity which is quoted as 9250 Bq/m 3 and hence the public are not exposed to any significant radiological health hazard in these areas. Conclusions: The radon concentration at the depth of 20 cm was found to be higher than the 10 cm depth and this shows that radon gas in soil increases with depth. The values obtained are less than the World Health Organization's acceptable level for outdoor radon activity and life activities would not be at risk in these areas.
- Environmental radioactivity evaluation in the coastal stretch of Bay of Bengal from Pondycherry to Velanganni (South East coast of India)
G Satheeshkumar, P Shahul Hameed, G Sankaran Pillai, N Anbusaravanan
Radiation Protection and Environment 2012 35(2):90-95
Background: Since the Madras Atomic Power Station, Kalpakkam and Kudankulam Nuclear Power Plant, Kudankulam are sited in Bay of Bengal coast, radiological study of this coastal environment is imperative to assess the impact of operation of nuclear power plant, if any, on the radioactivity profile of the coast. Materials and Methods: In the present study the environmental radioactivity was evaluated by measuring activity concentrations of primordial radionuclides namely 238 U, 232 Th and 40 K. in the beach sand samples using high purity germanium gamma ray spectrometry. 10 sampling stations were fixed along a 290 km coastal stretch of Bay of Bengal from Pondycherry to Velangannni. Results: The activity concentration of 238 U is always much less than that of 232 Th and 40 K and it ranged from 9 Bq/kg (Pondicherry coast) to 93 Bq/kg (Karaikal coast). However, 232 Th concentration fluctuated from 12 Bq/kg (Pichavaram Mangrove) to 1075 Bq/kg (Karaikal coast). The activity concentration of 40 K varied within a narrow range from 162 Bq/kg to 474 Bq/kg. The distribution of primordial radioactivity was non-uniform along the entire stretch of Bay of Bengal. The elevated levels of 232 Th were recorded in Karaikal coast (S7) (1075 Bq/kg), Tirumullaivasal coast (S4) (215 Bq/kg), and Nagapattinam coast (S9) (146 Bq/kg) and attributed to the presence of thorium-rich monazite as beach placer in coastal sands. Conclusion: The total absorbed gamma dose contributed by the activity of 238 U, 232 Th, and 40 K varied between 29 nGy/h and 308 nGy/h with a GM value of 64.4 nGy/h. Similarly, the annual effective dose recorded for Bay of Bengal ranged from 0.04 mSv/year to 0.38 mSv/year, indicating that the Bay of Bengal, in general, falls under Normal Background Radiation Area.
- Simultaneous recording of high-energy photon spectrum using phoswich detector
M Manohari, R Mathiyarasu, V Rajagopal, B Venkatraman
Radiation Protection and Environment 2012 35(2):96-99
Phoswich detector with its pulse shape discrimination (PSD) electronics is being used for estimating actinides in lung as part of in vivo monitoring. In this application, only the signals from thin NaI (low energy measurement) are effectively utilized. The high-energy gamma interactions in thick CsI portion of phoswich are merely used for background reduction in the low-energy regions. The present PSD electronics was suitably modified; both lower and higher energy photon spectra from a single phoswich detector are recorded simultaneously. This feature helps in identifying any fission product gamma emitters and also detects the increase in background during lung counting measurements. This paper outlines the modifications incorporated in the PSD electronics and the suitability of phoswich detector as a gamma ray spectrometer. The typical spectrometric characteristics of the detector such as energy linearity, full width at half-maximum, point source efficiency, and so on, estimated through experiments, and some of the salient results are highlighted.
VOL 35 NUMBER 3 (2013)
- Prospective survey of accelerator safety
Radiation Protection and Environment 2012 35(3):103-104
- Evaluation of internal hazards in medical cyclotrons
Radiation Protection and Environment 2012 35(3):105-110
A large number of medical cyclotrons of various types and makes are now in operation in India and their number is ever increasing. A careful analysis of the various safety issues particularly in case of possible accidental conditions is required for a realistic evaluation of their impact. Apart from the external dose involved, internal dose issues under normal operation and in case of abnormal operational conditions such as target rupture, accidents, spills, etc., which are generally neglected also need evaluation. There is a need for carrying out worst scenario analysis and the possible dose consequences to the operating staff as well as the public due to releases through the stack. The paper carries out an analysis for a typical release of activity into the vault environment and the dose implications. Along with any measured air activity measurements in the vault of operating cyclotrons this would resolve the issue one way or other. During radio pharmaceutical processing a substantial fraction of the volatile positron emitting radiopharmaceuticals are released into the atmosphere. In some cyclotrons a provision of an air trap for holding the air is mentioned. Analysis of possible dose to a member of the public using typical release rates is also presented and shown to be not negligible. A short review of such analysis in literature is carried out to show that the possible internal dose consequences cannot be ruled out and need to be addressed to in the safety analysis of these facilities for regulatory controls. Methods for proper calibration of stack monitors are indicated. In case of location of medical cyclotrons in crowded areas replete with high rise buildings, it may be necessary "to insure engineered safety features to ensure zero discharges from the machines."
- Overview of experimental works on secondary particle production and transport by high-energy particle beams
Radiation Protection and Environment 2012 35(3):111-125
This overview gives a brief summary on the experimental results on three topics: (1) Thick target neutron yields produced by protons, deuterons, He and heavier ions having wide energy range from MeV to GeV, (2) spallation products production data together with induced activities by proton to U ion and (3) benchmark experiments on neutron shielding using various accelerators of MeV to GeV energies. These three items are essentially important for radiation safety of accelerator facility.
- Radiation safety issues relevant to proton therapy and radioisotope production medical cyclotrons
Radiation Protection and Environment 2012 35(3):126-134
Medical cyclotrons are now constructed as turnkey facilities at nuclear medicine clinics, specialised particle therapy facilities and radioisotope production centres. Most medical cyclotrons usually accelerate protons to high energies and could be divided mainly in two categories: (a) Low energy (E P = 15-30 MeV) machines, dedicated for medical positron emission tomography and single photon emission computer tomography radioisotope production and (b) High energy (E P = 100-250 MeV) machines, predominantly used for radiotherapy of malignant tumours. Parasitic gamma and neutron radiation are produced during the operation of medical cyclotrons. Furthermore, high level of gamma radiation produced by the activated cyclotron components could impose radiation exposure to maintenance crew. Hence, radiation safety is imperative to safe and reliable operation of medical cyclotron facilities. A sound operational health physics procedure assures the minimisation of radiation exposure to patients and members of the public abiding the regulatory guidelines. This paper highlights the important radiation safety aspects related to safe operation of proton therapy and radioisotope production medical cyclotrons.
- Radiation safety for electron accelerators: Synchrotron radiation facility
Radiation Protection and Environment 2012 35(3):135-144
Radiation safety is reviewed for electron accelerators, mainly synchrotron radiation facilities. Accelerator radiation safety systems consist on safety interlock system, radiation shielding and radiation monitoring. These systems depend strongly on the characteristics of machines such as the maximum electron energy. In this paper, conceptual safety systems and radiation sources for synchrotron radiation facilities are overviewed including the evaluation methods of shielding.
- Radiological safety aspects of an accelerator driven system
Radiation Protection and Environment 2012 35(3):145-155
Accelerator driven systems (ADS) have the potential to generate nuclear power by coupling a high energy high current proton accelerator to a sub-critical nuclear reactor. The system has several advantages such as inherent safety from a runaway chain reaction, independence of the reactivity from delayed neutrons, resistance to nuclear proliferation, ability to transmute long lived minor actinides and fission products and, to convert thorium to 233 U. The radiological safety aspects of a typical ADS are discussed in which lead bismuth eutectic (LBE) is the spallation target as well as the coolant. In the irradiated target, residual activity is a major concern, particularly the amount of 210 Po. The time evolution of the major isotopes present in LBE is studied along with the prevailing residual gamma dose rates. Few issues that may surface while coupling a reactor to an accelerator are also discussed.
- Accelerator radiation protection: Recourse to nuclear reaction models
Radiation Protection and Environment 2012 35(3):156-163
Nuclear reaction models play a very crucial role in theoretical estimation of radiation environment in accelerator facilities where experimental data are scantily available. In this paper, we discuss the exciton and hybrid models for pre-equilibrium reaction, the Weiskopf-Ewing formalism for compound nuclear emissions and quantum molecular dynamics (QMD) model for spallation reactions. The choice of Fermi gas or Gilbert Cameron level density results in a variation of 21% in the neutron yield from p + Cu reaction at 20 MeV. The surface effects, which are more pronounced at higher energies influence the organ absorbed dose at most to 5% even at 60 MeV for the same reaction. The code EMPIRE and the hybrid model code ALICE give a reasonable estimate of dose and induced activity in proton accelerator facilities up to about 200 MeV until when pion production is not significant. The code HION can be a preferred choice for neutron dose simulation in low energy heavy ion (HI) accelerators. However, the model needs improvement for more accurate estimation of the angular distribution. QMD model can be used to estimate the induced activity and absorbed dose for proton and HI reactions at several hundreds of MeV to GeV per nucleon.
- Deterministic and probabilistic analysis of safety in particle accelerators
Radiation Protection and Environment 2012 35(3):164-174
The complexity involved in accelerator safety is discussed. Starting with the estimation of the source term the discussion includes design of radiation shield, safety interlock systems. The requirement of probabilistic safety analysis of accelerators and accelerator driven systems with emphasis on human reliability analysis is stressed.
VOL 36 NUMBER 1 (2013)
- Challenge for the future: NORM
Radiation Protection and Environment 2013 36(1):1-2
- Radioactivity measurements in the environment of Chamaraja Nagar area, India
KM Nagaraju, MS Chandrashekara, KS Pruthvi Rani, BM Rajesh, L Paramesh
Radiation Protection and Environment 2013 36(1):10-13
The knowledge of distribution of radionuclides and radiation levels in the environment is important for assessing the effects of radiation exposure to human beings. Terrestrial radiation is due to the radionuclides present in different amounts in rocks, soils, building materials, water and atmosphere. Radon is the main natural radiation source of exposure of human beings and has been recognized as a carcinogenic gas. Radium ( 226 Ra) and its ultimate precursor uranium ( 238 U) are the parent sources of radon. In the present study, radon exhalation rate and radium concentration in soil and rock samples around Chamaraja Nagar area of Karnataka State, India are measured using solid state nuclear track detector's employing "can technique" and LR-115 Type-II detectors. The result from the present investigation shows that radium activity in rock sample varies from 2.9 to 39.5 Bq/kg with a geometric mean of 13.4 Bq/kg. Mass and surface exhalation rate of radon in rock samples varies from 8.0 to 119.7 mBq/kg/h with the geometric mean of 24.8 mBq/kg/h and 93.9-1787.3 mBq/m 2 /h with a geometric mean of 562.5 mBq/m 2 /h respectively. Radium concentration in soil samples has been found to vary from 3.6 to 34.1 Bq/kg with a geometric mean of 14.7 Bq/kg. The mass exhalation rate of radon in soil samples has been found to vary from 10.0 to 31.4 mBq/kg/h with a geometric mean of 18.6 mBq/kg/h. The surface exhalation rate of radon varies from 142 to 918.4 mBq/m 2 /h with a geometric mean of 391.5 mBq/m 2 /h.
- The Natural Radioactivity in groundwater from selected areas in Greater Accra region of Ghana by gross alpha and gross beta measurements
Eric Jilbert M Nguelem, EO Darko, MM Ndontchueng, C Schandorf, TT Akiti, AP Muhulo, E.K.P. Bam
Radiation Protection and Environment 2013 36(1):14-19
Gross alpha and gross beta in 26 groundwater samples from Adentan to Abokobi areas in the Greater Accra Region of Ghana were determined using Alpha/Beta counting system (Canberra iMatic TM ). The average activity concentrations of gross alpha and gross beta were 0.034 and 0.501 Bq/L for Adentan, and 0.066 and 0.470 Bq/L for Abokobi, respectively. The results obtained are below the guideline levels of gross alpha (0.5 Bq/L) and gross beta (1.0 Bq/L) in drinking water established by the World Health Organisation. These results show that consumption of groundwater for the study areas may not pose any significant radiological health hazards through ingestion to the population.
- The status of natural radioactivity and heavy metals pollution on soil at Assiut Zone in Central Upper-Egypt
Mohamed Amin Uosif, Shams A. M. Issa, Khaled Y Abuel-Fadl, Mustafa A. M. Taha, AM Mostafa
Radiation Protection and Environment 2013 36(1):20-26
Context: To examine the status of the environmental quality of the soils in Assiut zone in central Upper-Egypt, investigation was carried out to determine the concentration of natural radionuclides (radium [ 226 Ra], thorium [ 232 Th] and 40 K) and the contents of eight heavy metals (Cd, Pb, Ni, Fe, Mn, Cr, Cu, and Zn). Materials and Methods: The measurements of concentration of natural radionuclides were carried out by using the gamma spectrometry (NaI (Tl); 3× 3"). Results: The results indicate that the soil samples' radioactivity concentrations of 226 Ra, 232 Th, and 40 K were ranging from 10.4 ± 0.5 to 19 ± 1 Bq/kg; 6 ± 0.3-21 ± 3 Bq/kg and 103.6 ± 5-221 ± 10 Bq/kg respectively. The typical radiation doses (D o ), the external hazard index (H ex ) and annual effective dose rate values for the corresponding samples were also estimated. The concentration of heavy metals was measured by using the atomic absorption spectrometry method. Data were analyzed by using the statistical methods. The representative H ex values for the corresponding samples were also estimated. Generally, heavy metals and major elements concentration of the sediments were found decrease in sequence of Fe > Mg > pb > Zn > Cr > Cu > Ni > Cd. In some locations, the concentration for the investigated heavy metals exceeds the permissible limits recommended by the Canadian Environmental Quality Guidelines. The highest concentration of the most heavy metals (Cd, Pb, Ni, Cr, and Zn) was found in Arab Al-Madabegh region; the sewage irrigated zone. Whereas, the lowest ones was found in the not irrigated lands, which considered as a reference point of analyses. Conclusion: The maximum admitted concentrations of toxic heavy elements in the sensitive areas revealed to be exceed from three to thirty times than the non-irrigated zone.
- Assessment of natural radioactivity and the associated hazards in some local cement types used in Yemen
Muhammed El-Azab Farid, Abdallah Ibrahim Abd El-Mageed, Emran Eisa Saleh, M Mansour, Anwar Khadher Mohammed
Radiation Protection and Environment 2013 36(1):27-31
The cement industry is considered as one of the basic industries that plays a significant role in the national economy of developing countries. Activity concentration of 226 Ra, 232 Th, and 40 K in 38 samples of local cement types from different Yemeni factories has been measured by using the gamma ray spectrometry and their mean values were in the ranges (25.18-40.39 Bq/kg), (14.6-24.75 Bq/kg) and (160.01-596.38 Bq/kg), respectively. The average values obtained for 226 Ra, 232 Th, and 40 K activity concentration in different types of cement are lower than the corresponding global values reported in United Nation Scientific Committee on the Effect of Atomic Radiation publications. The obtained results show that the averages of radiation hazard parameters for all types of local cement in the current study are lower than the acceptable level of 370 Bq/kg for radium equivalent, 1 for level index (Iγ), the external hazard index ≤ 1 and (59 nGy/h) for absorbed dose rate. The measured activity concentrations for these natural radionuclides were compared to the reported data for other countries. Therefore, the natural radioactivity of cement samples under study was lower than the recommended values in the established standard and hence safe for use in building constructions.
- Geological significance of radon gas in soil and underground water: A case study of Nurpur area, District Kangra, Himachal Pradesh, India
Dinesh Kumar Sharma, Ajay Kumar, Arvind Kumar, Sunil Dhar, Surinder Singh
Radiation Protection and Environment 2013 36(1):3-9
Remote sensing satellite data have been used to recognize structures having tectonic significance. Based on satellite data, lineament map of Nurpur and its adjoining area of District Kangra, Himachal Pradesh, has been generated. LR-115 solid state nuclear track detectors have been used for the measurement of soil gas radon at 71 different locations of the study area. Radon monitoring in underground water at 26 different locations of the study area has been carried by scintillometry. The results indicate zones of lineament density and tectonically induced radon in soil and underground water. The results are co-relatable with regional geology of the area.
- Dissolved uranium, 226 Ra in the mine water effluent: A case study in Jaduguda
NK Sethy, VN Jha, SK Sahoo, PM Ravi, RM Tripathi
Radiation Protection and Environment 2013 36(1):32-37
Effluent water from uranium mines, mill tailings ponds were studied for dissolved radionuclide. The concentration of uranium and 226 Ra in untreated effluent water was found to be elevated. The concentration of dissolved radionuclide in the adjacent aquatic streams and river were found to be of lower than the authorized prescribed limit provided by Indian regulatory agencies. The removal process of dissolved radionuclide in the effluent treatment plant is found to be effective with an average decontamination efficiency of >95% for both uranium and 226 Ra. The uranium mining and ore processing activity has not significantly modified the aquatic environment due to effective effluent management system.
- Effect of gamma irradiation on germination, growth, and biochemical parameters of Terminalia arjuna Roxb
Akshatha , KR Chandrashekar, HM Somashekarappa, J Souframanien
Radiation Protection and Environment 2013 36(1):38-44
The impact of gamma irradiation on Terminalia arjuna (T. arjuna), one of the potent medicinal plants for cardiac disease is described in this article. The seeds of T. arjuna were irradiated with different doses of gamma radiation ranging from 0 to 200 Gy using the 60 Co source. The effect of gamma radiation on the growth and biochemical constituents were compared with the control plants. Germination speed at 25 Gy was found to be 0.65, which was double compared to the un-irradiated seeds. An increase in germination percentage, vigor index, and relative growth rate, in terms of dry weight was noticed at lower doses of the radiation treatment. The proline content increased with increasing doses. The chlorophyll content was found to have increased to 12.2 mg/g FW at 100 Gy compared to the control level of 8.44 mg/g FW. Increased phenolic content and radical scavenging capacity was observed at 25 and 150 Gy. Hence, lower doses of radiation treatment may be used to increase the germination, growth, and vigor, and also the enhancement of plant metabolites like proline and phenolics in T. arjuna.
- News and Information
Radiation Protection and Environment 2013 36(1):45-46