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   2019| Jul-Sep  | Volume 42 | Issue 3  
    Online since November 6, 2019

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Occupational intake of radionuclides series of documents
Hemant Kumar Patni
Jul-Sep 2019, 42(3):65-67
  1,175 214 -
Evaluation of protection factor of respiratory protective equipment using indigenously developed protection factor test facility
G Ganesh, DS Patkulkar, MS Kulkarni
Jul-Sep 2019, 42(3):77-83
Protection factor (PF) of a respirator is a number that describes the effectiveness of various classes of respirators in providing protection against exposure to airborne contaminants (including particulates, gases, vapors, and biological agents). The PF is derived from the ratio of the concentration of an airborne contaminant (e.g., hazardous substance) outside the respirator (Co) to the concentration inside the respirator (Ci) (i.e., Co/Ci). As the PF increases, there is an increase in the level of respiratory protection provided to employees by the respirator. PF Test Facility for the estimation of PF for various respiratory protective equipment was designed, fabricated, and installed at the Respiratory Protective Equipment Laboratory of Health Physics Division. The test facility consists of established air flow at a breathing rate through respirator darn on a human dummy and two identical tapings for iso-kinetic sampling from outside and inside the respirator. These tapings are coupled to two identical optical particle counters (OPCs) for the measurement of aerosol concentration simultaneously, and data acquired by the two OPCs are analyzed for estimating PF for different particle sizes using GRIM AEROSOL software. The results obtained from the studies carried out using this unique setup – air-purifying respirators such as half face mask, full face mask, and powered air-purifying respirators – were found offering a PF of 14, 112, and 1328, respectively, for selected range of 0.28–0.3-μm size standard sodium chloride (NaCl) aerosols. Standard NaCl aerosols used in experiments are polydispersed. However, the 0.3 μ size range (0.28–0.3) was selected as a benchmark for efficiency ratings and PF of respirators because it approximates the most difficult particle size for filters to capture and the least filtration efficiency is obtained in this range. This article brings out the details of design features of the setup and studies and results obtained for various types of respirators used in nuclear facilities.
  1,196 190 1
Radio frequency nonionizing radiation exposure burdens to the population at major market centers in Ibadan metropolis, Nigeria
Nnamdi Norbert Jibiri, Enokela Pius Onoja, Idowu Richard Akomolafe
Jul-Sep 2019, 42(3):84-89
There has been proliferation of mobile phone base station towers in recent years due to an expansion of mobile telephone networks. This has been accompanied by an increase in the community concern about possible radiation exposure due to the radio frequency (RF) radiation emissions from antennae mounted on the base station towers. This work presents RF measurements and information on the levels at selected markets in Ibadan, Nigeria. The highest RF power density of 499.6 μW/m2 obtained at Global System for Mobile Communication (GSM) 1800 band occurred at Apete market. The lowest RF power density of 0.1 μW/m2 was also obtained at Alesinloye for GSM 1800, Dugbe, and Ogunpa for GSM 900; at this point of measurement, the base transceiver station was not in the line of sight. The measured RF levels were compared with the maximum permissible limit for nonoccupational exposure with respect to the Radiocommunications (Electromagnetic Radiation – Human Exposure) Standard 1999 which specifies a maximum nonoccupational exposure limit of 2 W/m2 (equivalent to 200 μW/cm2) at relevant base station frequencies. The results showed that the RF exposure levels were several orders of magnitude below the maximum permissible limits around the environments of the major markets in the city of Ibadan.
  1,010 139 -
International Atomic Energy Agency's Analytical Laboratories for the Measurement of Environmental Radioactivity network: Experiences and perspectives in the North and Latin America region
Said Hamlat, P Pan, A Ferreira, B Mazzilli, N St-Amant, G Cerutti, I M. F. Gómez, LJ Ruiz Esparza, E Quintero Ponce, M Cubero, R Odino, O Pinones, A Pitois, M Rinker
Jul-Sep 2019, 42(3):68-76
The International Atomic Energy Agency (IAEA) Network of Analytical Laboratories for the Measurement of Environmental Radioactivity (ALMERA) is a worldwide network of laboratories capable of providing reliable and timely analysis of radionuclides in environmental samples during normal or accidental/intentional events that result in the release of radioactivity in the environment. ALMERA is coordinated by the Environment Laboratories of the IAEA and organized into five regional groups, including the North and Latin America region (NLAR), led by the Canadian Nuclear Safety Commission. Capacity building in the NLAR for the measurements of environmental radioactivity is achieved through qualitative study that consists of experiences of ALMERA core activities and perspectives of the regional initiatives, respectively. Outcomes' analysis showed that the ALMERA core activities have contributed to the improvements of the analytical capacity and capability, and the regional initiatives assisted in the strengthening of the collaboration and networking, in the NLAR region. The immediate impact of these achievements consisted of gaining technical competence in measuring environmental radioactivity and establishing a network of laboratories. In the long term, sustained efforts between ALMERA and the regional coordination will continue upgrading national and regional competence in the radio analytical services.
  906 125 -
Natural radionuclide transfer from soil to plants in high background areas in Oyo state, Nigeria
Augustine Kolapo Ademola
Jul-Sep 2019, 42(3):112-118
The activity concentrations of naturally-occurring radioactive materials present in soil, vegetables, and food crops and their transfer factor (TF) in some high background areas of northern parts of Oyo state, Nigeria, were measured using gamma spectrometry. The average concentration of226Ra,228Ra, and40K in soil is 25.3 ± 7.1, 26.2 ± 5.0 and 381.8 ± 16.0 Bq/kg, respectively in Agbaaru; 25.4 ± 3.1, 39.5 ± 3.8, and 401.9 ± 25.4 Bq/kg in Abuja; 26.5 ± 3.3, 39.2 ± 7.4, and 394.9 ± 18.6 Bq/kg in Arget; and 26.5 ± 3.5, 38.8 ± 2.5, and 389 ± 18.6 Bq/kg in Igbeti. The soil-to-vegetables TF for226Ra,228Ra, and40K is 0.123, 0.058, and 0.215, respectively, in Agbaaru; 0.065, 0.040, and 0.185 in Abuja; 0.093, 0.035, and 0.243 in Arget; and 0.080, 0.050, and 0.265 in Igbeti. Furthermore, the TF from soil to food crops is within the recommended value. Therefore, consumption of these vegetables and food crops will not pose any radiation health concerns to the consumers and the general population.
  875 143 1
Radiological protection and safety: A practitioner's guide
DD Rao
Jul-Sep 2019, 42(3):119-121
  845 158 -
Accumulation of 210Po in Medicinal Plants in the Environment of Mangalore, Southwest Coast of India
V Prakash, KM Rajashekara, Y Narayana
Jul-Sep 2019, 42(3):107-111
Systematic studies on the accumulation of210Po in 12 medicinal plants and activity concentration in associated soils have been carried out. The activity of210Po was measured using a ZnS (Ag) alpha counting system. The mean210Po activity concentration was found to be 27.8 and 8.3 Bq/kg for plant and soil, respectively. The plant-to-soil mean activity ratio of210Po was found to be 3.8. A good correlation was observed between the activity concentration of210Po in plant and soil. The absorbed gamma dose rates in the study area were also measured using a portable scintillometer and found to vary in the range of 34.8–52.2 nGy/h, with a mean value of 43.5 nGy/h. The results of these systematic investigations are presented and discussed in detail.
  860 78 -
Assessing naturally occurring radionuclides in soil of Egbeda Local Government for a baseline data of Oyo State, Nigeria
Latifat Ronke Owoade, Samuel Mofolorunso Oyeyemi, Fatai Abiodun Lawal, Adekunle Joseph Adeyemo, Nojeeb Oyeyemi Adamoh, Faidat Mosunmola Adebowale
Jul-Sep 2019, 42(3):90-95
The activity concentrations of the natural radionuclides, namely226Ra,232Th, and40K were measured from soil samples collected from different locations of Egbeda Local Government Area, Oyo state, Nigeria, with the aim of establishing radioactivity baseline data for the area. High-resolution gamma spectrometry detector was used to determine the activity concentration of these radionuclides in 45 soil samples taken at a depth of about 15 cm in various communities of Egbeda Local Government Area. The concentration of226Ra was in the range 5.9–61.3 Bq/kg with an average value of 30.5 Bq/kg,232Th in the range 4.0–116.5 Bq/kg with an average value of 50.8 Bq/kg, and40K in the range 27–798 Bq/kg with an average value of 200 Bq/kg. The results obtained in this study were compared with those of different countries in the world. Radiological index parameters were used for the assessment of radiological exposure of the natural radioactivity, and the absorbed dose rate, the radium equivalent activity, the annual effective dose, the external exposure index, and internal exposure index were calculated. There is no radiological risk from soil that may threat the residents around Egbeda Local Government Area. Hence, the probability of occurrence of any of the health effects of radiation is insignificant. Therefore, the radioactivity measurements taken represent the baseline data of the study area.
  594 105 1
Investigation on the enrichment of radionuclides in an endosulfan-affected area, Enmakaje Panchayath, Kasargod
Sreerag Ramesh, V Vineethkumar, VV Sayooj, V Prakash
Jul-Sep 2019, 42(3):96-101
In the present study, systematic analysis of radionuclides concentration and radiological parameters of sediment samples collected from the banks of Kodankari stream situated in Enmakaje Panchayath, Kasargod, has been carried out. A total of twenty sediment samples were collected and analyzed for activity concentration of radionuclides, namely,40K,226Ra, and232Th using high-purity germanium detector. The activity concentration of226Ra ranges from 30.5 to 56 Bq/kg with a mean value of 41.6 Bq/kg, activity concentration of232Th ranges from 100.5 to 220 Bq/kg with a mean value of 144.4 Bq/kg, and activity concentration of40K ranges from 19.1 to 98.6 Bq/kg with a mean value of 64.7 Bq/kg. The radiological parameters such as absorbed dose, annual effective dose (indoor and outdoor), radium equivalent activity, and internal and external exposure indices were calculated and compared with the recommended safety limits prescribed by various agencies. The results of the systematic analysis are presented and discussed in detail in the manuscript.
  591 70 -
Distribution and enrichment of 210Po and210Pb in the environment of Mangalore, Southwest Coast of India
V Prakash, V Vineethkumar, KM Rajashekhara, Y Narayana
Jul-Sep 2019, 42(3):102-106
The article deals with the distribution and enrichment of210Po and210Pb in soil samples of Mangalore, Southwest Coast of India. The soil samples collected from the region were analyzed for210Po and210Pb activity using radiochemical analytical technique to understand the distribution and enrichment of these radionuclides. The210Po activity in soil in the environment of Mangalore varies from 1.5 to 26.9 Bq/kg with a mean value of 12.6 Bq/kg and that of210Pb varies in the range 7.6–67.5 Bq/kg with a mean value of 38.9 Bq/kg. The mean210Po/210Pb ratio observed was 0.3, and it shows that the radionuclides210Po and210Pb are not in equilibrium and the accumulation of210Pb in soil is more compared to210Po. A good correlation exists between the activities of210Po and210Pb with correlation coefficient r = 0.7. The absorbed gamma dose in the environment of the region varies from 39.4 to 78.8 nGyh−1, with a mean value of 48.2 nGyh−1. The activity of both210Po and210Pb in soil almost certainly depends on the physicochemical parameters of the soil. The results of the systematic studies on the distribution and enrichment of210Po and210Pb and the absorbed gamma dose rate in air are presented and discussed in this article.
  572 83 -