NATURAL RADIATION EXPOSURE TO THE PUBLIC IN MINING AND ORE BEARING REGIONS OF CAMEROON

2019 ◽  
Vol 184 (3-4) ◽  
pp. 391-396 ◽  
Author(s):  
Saïdou ◽  
Shinji Tokonami ◽  
Masahiro Hosoda ◽  
Ndjana Nkoulou II Joseph Emmanuel ◽  
Naofumi Akata ◽  
...  
Keyword(s):  
Radiation Exposure ◽  
Indoor Radon ◽  
Natural Radionuclides ◽  
Survey Method ◽  
Natural Radiation ◽  
Joint Research ◽  
The Public ◽  
Activity Concentrations ◽  
Joint Research Project ◽  
Thoron Progeny

Abstract Within the framework of a joint research project on natural radiation exposure and its health effects in Cameroon from 2014 to 2017, the Institute of Geological and Mining Research and the Hirosaki University worked together to carry out natural radiation survey in mining and ore bearing regions of Cameroon. Air kerma rates were measured using car-borne survey method. In-situ gamma spectrometry was used to determine activity concentrations of 238U, 232Th and 40K in soil. A total of 450 RADUET detectors and 350 thoron progeny monitors were deployed in dwellings of the study areas for 2–3 months, collected and analysed. Although natural radioactivity level seems to be normal in most of the surveyed areas, there are many points where activity concentrations of natural radionuclides are largely above the world average values. Indoor radon, thoron and thoron progeny results show the importance to put in place the national radon plan in Cameroon. It was also pointed out that thoron cannot be neglected when assessing inhalation dose.

scholarly journals A comparison of the dose from natural radionuclides and artificial radionuclides after the Fukushima nuclear accident

2016 ◽  
Vol 57 (4) ◽  
pp. 422-430 ◽  
Author(s):  
Masahiro Hosoda ◽  
Shinji Tokonami ◽  
Yasutaka Omori ◽  
Tetsuo Ishikawa ◽  
Kazuki Iwaoka
Keyword(s):  
Effective Dose ◽  
Indoor Radon ◽  
Natural Radionuclides ◽  
Temporary Housing ◽  
Radon Activity ◽  
Artificial Radionuclides ◽  
Activity Concentrations ◽  
Fdnpp Accident ◽  
Effective Doses ◽  
Average Effective Dose

Abstract Due to the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, the evacuees from Namie Town still cannot reside in the town, and some continue to live in temporary housing units. In this study, the radon activity concentrations were measured at temporary housing facilities, apartments and detached houses in Fukushima Prefecture in order to estimate the annual internal exposure dose of residents. A passive radon–thoron monitor (using a CR-39) and a pulse-type ionization chamber were used to evaluate the radon activity concentration. The average radon activity concentrations at temporary housing units, including a medical clinic, apartments and detached houses, were 5, 7 and 9 Bq m −3 , respectively. Assuming the residents lived in these facilities for one year, the average annual effective doses due to indoor radon in each housing type were evaluated as 0.18, 0.22 and 0.29 mSv, respectively. The average effective doses to all residents in Fukushima Prefecture due to natural and artificial sources were estimated using the results of the indoor radon measurements and published data. The average effective dose due to natural sources for the evacuees from Namie Town was estimated to be 1.9 mSv. In comparison, for the first year after the FDNPP accident, the average effective dose for the evacuees due to artificial sources from the accident was 5.0 mSv. Although residents' internal and external exposures due to natural radionuclides cannot be avoided, it might be possible to lower external exposure due to the artificial radionuclides by changing some behaviors of residents.

scholarly journals Determination of radon levels in dwellings and social objects and evaluation annual effective dose from inhalation of radon in Stepnogorsk area Northern Kazakhstan

2020 ◽  
Vol 4 (4) ◽  
pp. 343-349
Author(s):  
D.S. Ibrayeva ◽  
M.N. Aumalikova ◽  
K.B. Ilbekova ◽  
M.M. Bakhtin ◽  
P.K. Kazymbet
Keyword(s):  
Effective Dose ◽  
Annual Effective Dose ◽  
Noble Gas ◽  
Indoor Radon ◽  
Radioactive Decay ◽  
Annual Dose ◽  
Natural Radiation ◽  
Mining Sites ◽  
Decay Products ◽  
Activity Concentrations

Radon is a noble gas that is one of the natural radioactive decay products of radium resulting from the disintegration of uranium. Humans are exposed to sources of natural radiation activity, being radon and its progeny breathing air responsible for more than 50% of the annual dose received from natural radiation. The aim of this study was to determine the radon concentration in the air in settlements’ dwellings and social objects and calculate the annual effective dose of population from radon on the territory mining activities in Stepnogorsk area. The study has shown that activity concentrations of indoor radon in the buildings ranged from 8 to 870 Bq · m−3 in Aqsu, 3-540 Bq · m−3 in Kvartsitka located close to former gold mining sites. The Einh corresponding to the activity concentrations ranged from 1-27 mSv · y−1 received by the settlements’ public. The highest value of Einh in Aqsu School reaches up to 68 mSv · y−1 received by the critical group of public was found at the territory of former mining the Stepnogorsk area. The results of this study show significant radiation hazards in Aqsu School which located at the territory of former mining site, and there is evidence of radon health risk to the members of the public.

Exemption Levels for the Recycling and Disposal of Residues With Enhanced Levels of Natural Radioactivity (TENORM) in Germany

2001 ◽  
Author(s):  
R. Barthel ◽  
W. Goldammer ◽  
M. Helming
Keyword(s):  
Radiation Exposure ◽  
Radiation Protection ◽  
The Public ◽  
Naturally Occurring ◽  
Activity Concentrations ◽  
Measurement Strategy ◽  
Naturally Occurring Radionuclides ◽  
Disposal Options ◽  
Mining Residues ◽  
Adequate Measurement

Abstract The new German Radiation Protection Ordinance contains for the first time a systematic framework of regulations protecting workers and the public against radiation exposures from residues of industrial and mining processes containing enhanced levels of naturally occurring radionuclides (TENORM). These regulations will satisfy the requirements of the European Council Directive 96/29/EURATOM and serve as a common basis for the radiation protection activities of the German states in this field. The consideration of exposures from materials containing naturally occurring radionuclides gains on this basis an increased level of significance within the German radiation protection efforts. The overall goal of the new regulations is to keep the additional effective dose for the population from the recycling and disposal of TENORM below 1 mSv/a. In order to achieve this objective, companies in which such residues arise have to carry out representative measurements of activity concentrations in these materials. If exemption levels defined in the new regulations are exceeded, restrictions on the recycling and disposal come into effect. These exemption levels are nuclide specific and distinguish between material types and different recycling and disposal options. This specific definition of exemption criteria serves the goal to minimise the number of companies and the amount of residues affected by the new regulations to the extent possible, focussing the efforts of operators and regulators to those materials having the potential to actually cause radiation exposure problems. The specific exemption criteria were derived on the basis of an analysis of typical amounts and activity concentrations of industrial and mining residues with enhanced radioactivity contents in Germany. In a second step, practically applied options for the recycling and disposal of these materials were investigated. On this basis, generic scenarios for the radiation exposure of the workforce and the public were defined and doses were estimated. All relevant pathways including possible long term effects (ground water) were considered in these analyses. Based on the 1 mSv/a criterion, a catalogue of relevant materials, potentially requiring radiation protection measures, was developed. For these materials the practically applied recycling or disposal options were grouped into categories, for which specific exemption levels were derived. The derivation of these criteria was based on realistic estimates of radiation exposure, for example taking into account the dilution of the residues with other materials in technological processes or during the disposal in landfills. The residues subject to the new regulations mostly arise in large quantities over extended periods of time. This leads to significant variations of radionuclide concentrations depending on feed materials and process parameters. To carry out representative measurements without the necessity of taking a too large number of samples, therefore, requires an adequate measurement strategy. Particular aspects to be considered are uncertainties of the measurements themselves and the heterogeneity of the residues. In addition, the measurement strategy has to be compatible with diverse situations in the different industries affected. The framework developed for designing individual strategies for the various industries and types of residues satisfies these requirements and can also provide guidance for measurement campaigns in other areas. The paper outlines the general situation with regard to TENORM in Germany. The main streams of residues and options for their recycling or disposal are described. On this basis, scenarios used for the radiological evaluation are defined and examples for resulting radiation exposures are given. The exemption levels derived from this analysis are discussed. Finally, the framework for the design and implementation of an adequate measurement strategy is outlined.

Natural radiation exposure to the public in the uranium bearing region of Poli, Cameroon: From radioactivity measurements to external and inhalation dose assessment

2019 ◽  
Vol 205 ◽  
pp. 106350 ◽  
Author(s):  
Saïdou ◽  
Tokonami Shinji ◽  
Masahiro Hosoda ◽  
Tchuente Siaka Yvette Flore ◽  
Ndjana Nkoulou Joseph Emmanuel ◽  
...  
Keyword(s):  
Radiation Exposure ◽  
Dose Assessment ◽  
Natural Radiation ◽  
Inhalation Dose ◽  
The Public ◽  
Radioactivity Measurements

Transfer of natural radionuclides from soil to plants in Savar Dhaka

2017 ◽  
Vol 7 ◽  
Author(s):  
M. Haque ◽  
J. Ferdous
Keyword(s):  
Soil Properties ◽  
Nuclear Reactor ◽  
Gamma Ray ◽  
Natural Radionuclides ◽  
Gamma Ray Spectrometry ◽  
Free Access ◽  
Transfer Factors ◽  
The Public ◽  
Activity Concentrations ◽  
Plant Transfer

The radioactivity of environmental samples from nuclear reactor sites must be analyzed before the public is given free access to the plants grown in these soils. Plant and corresponding soil samples were collected from a sample site around the Savar research reactor near Dhaka (Bangladesh) and the activity concentrations of natural radionuclides <sup>226</sup>Ra (<sup>238</sup>U-chain), <sup>228</sup>Ra (<sup>232</sup>Th-chain) and non-chained <sup>40</sup>K were measured using gamma ray spectrometry. Soils of Savar contained more radioactive <sup>40</sup>K than <sup>226</sup>Ra and <sup>228</sup>Ra. The influence of certain soil properties on the activity concentrations and transfer factors (TF) of natural radionuclides were investigated by correlating the observed data with those of soil properties. The activity concentrations of <sup>40</sup>K were much higher than those of <sup>226</sup>Ra and <sup>228</sup>Ra in plants due to higher uptake from soils. The transfer factors for <sup>226</sup>Ra, <sup>228</sup>Ra and <sup>40</sup>K were found to range from 0.04 to 0.10, 0.12 to 0.32, and 0.24 to 0.72, respectively. The soil to plant transfer factors for <sup>40</sup>K was found to be much higher in plants, which might be due to this element being vital in plants. This study showed that activity concentrations of these radionuclides in plants and their plant transfer factors seem to depend on the activity concentrations of the same radionuclides in soil.</p><p><strong> </strong>

Mapping the Geogenic Radon Hazard Index of Italy

2021 ◽  
Author(s):  
Francesca Giustini ◽  
Monia Procesi ◽  
MariaGrazia Finoia ◽  
Raffaele Sassi ◽  
Claudio Mazzoli ◽  
...  
Keyword(s):  
Probabilistic Models ◽  
Indoor Radon ◽  
Hazard Index ◽  
Fine Fraction ◽  
Fuzzy Classification ◽  
Research Centre ◽  
Indoor Radon Concentration ◽  
Natural Radiation ◽  
Joint Research ◽  
Soil Database

&lt;p&gt;Radon generation and migration from the soil toward the surface are natural processes that can lead to radon entry in buildings, thus constituting a health risk. The analysis and the modelling of these processes can be thought of as the contribution of different proxies representing the geological radon source (GRS) (e.g., geology, soil properties, radionuclide content), and the pathways (e.g., faults, karst) that favour the geological radon migration (GRM) in the subsoil. The aggregation of these quantities can be used to construct a geogenic radon hazard index (GRHI) map that can be understood as a measure of the susceptibility of an area to increased indoor radon concentration for geogenic reasons (Radon Priority Areas, RPA).&lt;/p&gt;&lt;p&gt;A number of direct and indirect models have been developed in order to create GRHI maps of a certain region by using both deterministic and probabilistic models. Here, we propose a bottom-up procedure through the integration of different factors (predictors and/or proxies) and by weighs their importance. In particular, we first propose to construct a GRHI map of the whole Italian territory using a GIS-based (spatial) multicriteria decision analysis (SMCDA). SMCDA uses the Analytical HierarchyProcess (AHP) to assess the importance of the factors and to derive their relative weights and, consequently, it determines the overall &amp;#64257;nal scores.&lt;/p&gt;&lt;p&gt;Lithologies of the National Geological Map of Italy (1:1000000) were reclassified in few homogeneous classes and ranked according to the associated mean content of uranium, thorium and potassium available from GEMAS (http://gemas.geolba.ac.at/) and FOREGS (http://weppi.gtk.fi/publ/foregsatlas/index.php) database by using a multivariate statistical approach. In this way the intermediate map of the GRS was obtained. SMCDA was then applied by using the GRS map and the maps of other factors, such as the fine fraction of the soil (LUCAS top-soil database, https://esdac.jrc.ec.europa.eu/projects/lucas), the fault density map (Italian national/regional datasets), the map of the karst areas (https://www.whymap.org/whymap/EN/Maps_Data/Wokam/wokam_node_en.html) and the map of the heat flow of Italy. All these factors were standardised by using fuzzy classification to transform input data to a 0/1 scale. The standardised factors are weighted by using AHP and then summed to obtain the final GRHI map. All maps are constructed at the same grid resolution of the European Atlas of Natural Radiation (10x10km) (https://remon.jrc.ec.europa.eu/About/Atlas-of-Natural-Radiation) published by the Joint Research Centre (JRC) of the European Commission.&lt;/p&gt;

ASSESMENT OF INDOR RADON, THORON AND THEIR PROGENY LEVELS IN RESIDENTIAL HOUSES OF HARDOI, UTTAR PRADESH, (INDIA)

2016 ◽  
Vol 2 (2) ◽  
pp. 62-67
Author(s):  
Anil Kumar ◽  
Alok Kumar Singh
Keyword(s):  
General Population ◽  
Radiation Exposure ◽  
Experimental Finding ◽  
Indoor Radon ◽  
Uttar Pradesh ◽  
Radon Progeny ◽  
Natural Sources ◽  
Equilibrium Factor ◽  
Thoron Progeny

Radon, thoron and their progeny levels are significant natural sources of radiation exposure for general population in both living and working places. The concentration of radon varied from 15 Bq/m3 to 78 Bq/m3 with an average of 46 Bq/m3, while thoron concentration varied from 11 Bq/m3 to 26 Bq/m3 with an average of 18 Bq/m3. The concentration of radon progeny (EERC) varied from 10 Bq/m3 to 26 Bq/m3 with an average of 18 Bq/m3, while the concentration of thoron progeny (EETC) varied from 0.56 Bq/m3 to 1.91 Bq/m3 with an average of 1.11 Bq/m3 .The value of equilibrium factor for radon varied from 0.19 to 0.76 with an average of 0.37 while for thoron it varied from 0.02 to 0.12 with an average of 0.06. Our experimental finding confirmed that the indoor radon, thoron and their progeny concentration were within internationally accepted norms.

scholarly journals Natural radiation exposure to the public in the oil-bearing Bakassi Peninsula, Cameroon

2015 ◽  
Vol 50 (1) ◽  
pp. 35-41 ◽  
Author(s):  
Saïdou ◽  
Abdourahimi ◽  
Y. F. Tchuente Siaka ◽  
M. G. Kwato Njock
Keyword(s):  
Radiation Exposure ◽  
Natural Radiation ◽  
The Public

scholarly journals Radon, gamma-ray exposure and natural radionuclides

2011 ◽  
Vol 1 (1) ◽  
pp. 285-287
Author(s):  
P. Wanabongse ◽  
W. Thorarit ◽  
N. Yimchalam ◽  
S. Bovornkitti
Keyword(s):  
Gamma Ray ◽  
Indoor Radon ◽  
Natural Radionuclides ◽  
Radon Exposure ◽  
Dose Rates ◽  
Naturally Occurring ◽  
Gamma Dose Rates ◽  
Activity Concentrations ◽  
Naturally Occurring Radionuclides ◽  
Exposure Levels

Abstract Measurements were conducted to determine residential radon exposure levels in provinces with high lung cancer incidence in three different regions of Thailand. The measurements revealed that the average indoor radon levels were 20.0, 24.4, and 13.1 Bq m−3, and that the average gamma dose rates were 145, 164, and 54 nSv h−1 in Chiangmai, Songkhla and Khonkaen provinces, respectively. The spectroscopic analysis of soil samples collected from the three provinces showed that the highest contents of Ra-226, Th-232, and K-40 were present in Songkhla, with values of 93.7, 71.9, and 786.9 Bq kg−1, respectively, and the lowest contents were present in Khonkaen, with values of 15.6, 19.0, and 46.8 Bq kg−1, respectively. The results of our analysis of the activity concentrations of naturally occurring radionuclides helped explain the lower levels of radon gas and gamma-ray exposure in Khonkaen.

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