scholarly journals The annual effective dose due to natural radionuclides in the reservoir and tap water in Yaoundé area, Cameroon

2009 ◽  
Vol 27 (1) ◽  
pp. 61 ◽  
Author(s):  
R. Marie Lydie ◽  
R. Martin Nemba
Keyword(s):  
Effective Dose ◽  
Rainy Season ◽  
Specific Activity ◽  
Annual Effective Dose ◽  
Tap Water ◽  
Adult Population ◽  
Natural Radionuclides ◽  
Dry Season ◽  
Reservoir Water ◽  
Naturally Occurring Radionuclides

The average concentrations of radionuclides of reservoir and tap water in the Yaoundé area, with a population of 1.5 million inhabitants were estimated from measurements of mean specific activity using a well calibrated Canberra NaI(Tl) detector system. Water samples were collected from reservoirs and taps during the dry and the rainy seasons respectively in December 2002 and July 2003. The radionuclides observed with regularity belonged to the decay series naturally occurring radionuclides headed by 238U and 232Th as well as the non-series nuclide 40K. The average specific activity values obtained for 40K, 226Ra and 228Ra, respectively were for reservoir water 70 ± 11 BqL–1; 8.7 ± 3.5 BqL–1; 0.6 ± 0.2 BqL–1 during the dry season, and 50 ± 9 BqL–1; 8.5 ± 3.7 BqL–1; 0.6 ± 0.2 BqL–1 during the rainy season and for tap water, we have respectively 111 ± 17 BqL–1; 11.4 ± 3.7 BqL–1; 1 ± 0.3 BqL–1 during the dry season, and 51 ± 10 BqL–1; 9 ± 3.5 BqL–1; 0.7 ± 0.2 BqL–1 during the rainy season. The annual effective dose received by Yaoundé adult population as a result of ingestion of this drinking water is respectively 0.925 mSv for the reservoir water and 1.052 mSv for the tap water.

scholarly journals Specific Activities of Natural Radionuclides and Annual Effective Dose Due to the Intake of Some Types of Children Powdered Milk Available in Baghdad Markets

2017 ◽  
Vol 14 (3) ◽  
pp. 619-624
Author(s):  
Baghdad Science Journal
Keyword(s):  
Effective Dose ◽  
Sodium Iodide ◽  
Specific Activity ◽  
Annual Effective Dose ◽  
Natural Radionuclides ◽  
Mean Value ◽  
Powdered Milk ◽  
Effective Doses ◽  
The Mean ◽  
Specific Activities

In this research the specific activity of natural radionuclides 226Ra, 232Th and 40K were determined by sodium iodide enhanced by thallium NaI(TI) detector and assessed the annual effective dose in Dielac 1 and 2 and Nactalia 1 and 2 for children of less than 1 year which are available in Baghdad markets. The specific activity of 40K has the greater value in all the types which is in the range of allowed levels globally that suggested by UNSCEAR. The mean value of annual effective doses were 2.92, 4.005 and 1.6325 mSv/y for 226Ra, 232Th and 40K respectively.

scholarly journals Annual Effective Dose and Lifetime Cancer Risks Due to Natural Radioactivity in Hand –Dug Well Water of Tai Rivers State, Nigeria

2019 ◽  
pp. 1-10
Author(s):  
C. P. Ononugbo ◽  
N. N. Ndodo
Keyword(s):  
Effective Dose ◽  
Natural Radioactivity ◽  
Specific Activity ◽  
Annual Effective Dose ◽  
Gamma Spectroscopy ◽  
Adult Population ◽  
Well Water ◽  
Yearly Average ◽  
Rivers State ◽  
Dug Well

The presence of radionuclide in water poses a number of health hazards, especially when the radionuclide is deposited in the human body through drinking water. The aim of this study was to evaluate natural radioactivity and its associated health risk in hand dug well water of Tai Local Government Area of Rivers State, Nigeria by means of gamma spectroscopy techniques and radiation models. The well water was collected from five selected coastal communities of Tai and chemically treated by adding nitric acid and then pre-concentrated further by evaporating to certain levels and kept in marineli beaker properly sealed for 28 days, after which was counted with NaI(Ti) detector. The mean values of specific activity concentration of 40K, 226Ra and 228Ra(232Th) were  25.90, 19.21 and 18.50 Bql-1 respectively. The annual effective doses for different age categories were estimated taking into consideration the ingested dose conversion factors as well as their yearly average water consumption. The average annual effective dose estimated for infants, children, teenagers and adult population were 0.115, 0.027, 0.071 and 0.013 Svy-1 respectively. The annual effective dose due to ingestion of the sampled water were above the recommended values by WHO, IAEA and UNSCEAR for the age brackets. The paper presents the overview of the techniques used and the summary of the findings. The result of this study gives the radiological baseline data for effective monitoring of the study area.

Evaluation of Gross Alpha and Beta Activity Concentrations and Annual Effective Dose in Drinking Waters of Misan Province-Iraq Using Low Background Gas Flow Proportional Counter (LB- 4110)

2021 ◽  
Vol 19 (11) ◽  
pp. 22-31
Author(s):  
Sawsan Sh. Fleifil ◽  
Zahraa A. Ismail AL-Sudani
Keyword(s):  
Drinking Water ◽  
Effective Dose ◽  
Water Samples ◽  
Proportional Counter ◽  
Gas Flow ◽  
Annual Effective Dose ◽  
Tap Water ◽  
Beta Activity ◽  
Low Background ◽  
Background Gas

In this study, assessment of levels natural radioactivity in drinking water samples of Misan Province of Iraq was carried out. A total of 33 (Tigris river, station and Tap) water samples collected from eleven places in Misan Province of Iraq. The beta and alpha gross radioactivity of the samples water was measured and an average annual effective dose derived of drinking-water ingestion was estimation utilizing new model a LB-4110 low background gas flow proportional counter. The data indicated that the Beta and Alpha gross activities and annual effective dose in samples did not exceed WHO recommended levels (0.5 Bq/L of Alpha gross, 1.0 Bq/L of Beta gross and 0.1 mSv/y for annual effective dose).

Assessment of Natural Radionuclides in Local and Imported Cements in Erbil Governorate, Kurdistan Region- Iraq

2020 ◽  
Vol 13 (1) ◽  
pp. 73-77
Keyword(s):  
Sodium Iodide ◽  
Specific Activity ◽  
Annual Effective Dose ◽  
Natural Radionuclides ◽  
Absorbed Dose ◽  
Dose Equivalent ◽  
Hazard Indices ◽  
Spectrometry Analysis ◽  
Radium Equivalent ◽  
Radiological Hazard Indices

A total of 10 cement samples were collected from the manufactures and markets. Spectrometry analysis of Sodium Iodide NaI (Tl) detector was used for measuring the samples' specific activity. The obtained specific activities of (226Ra, 232Th and40 K) were (35, 30 and 400) Bq/kg, respectively, which are below the critical values suggested by UNSCEAR2000. The radiological hazard indices of radium equivalent activities (Raeq), the indoor absorbed dose , the internal annual effective dose equivalent (Ein) and the internal index (Hin) were calculated. All of the obtained values were below the world wide recommendation values. Fortunately, from the analyzed results, it was concluded that the local and imported cements in Erbil governorate will make no risk when used in building constructions.

Radiation Safety Standards and Basic Health Rules for Radiation Safety: Proposal on the Development of New Versions

2019 ◽  
Vol 64 (5) ◽  
pp. 15-19
Author(s):  
А. Симаков ◽  
A. Simakov ◽  
Ю. Абрамов ◽  
Yu. Abramov
Keyword(s):  
Effective Dose ◽  
Radiation Safety ◽  
Specific Activity ◽  
Annual Effective Dose ◽  
Uranium Isotopes ◽  
Time Interval ◽  
Solid Materials ◽  
Safety Standards ◽  
Basic Health ◽  
One Year

The objective of this work is to enhance national Radiation safety standards (NRB) and Basic Health Rules for Radiation Safety (OSPORB).  This article discusses proposals how to amend new versions of the fundamental regulatory documents – national NRB and OSPORB as regards the interpretation of the term “limit of the annual effective dose of manmade individual exposure” and the health physics limiting the content of artificial radionuclides in solid materials for their unrestricted use. In current Radiation Safety Standards, NRB-99/2009 (paragraph 3.1.5.), in contrast to the Federal Law of 09.01.1996 No 3-FZ “On the Public Radiation Protection” and provisions of draft International Basic Safety Standards, annual effective dose means gross effective dose of external and internal exposure, received for the calendar year. The article describes the situation where the doses of a conditional worker do not exceed the dose limits in a single calendar year, i.e. < 50 mSv, however, for any arbitrarily taken time interval equal to one year, the annual dose limit of 50 mSv is repeatedly exceeded. Therefore, the following amendment is proposed to be made in new version of the NRB: “Annual effective dose means the sum of the effective external dose received for any arbitrarily taken time interval equal to one year and the ambient effective internal dose due to the intake of radionuclides in the body over the same period”. In current Basic Health Rules for Radiation Safety, OSPORB 99/2010, Annex 3 “The Specific Activities of Artificial Radionuclides, at which Unrestricted Use of Materials is Permitted” does not include the uranium isotopes 234U, 235U and 238U; this contradicts paragraph 5.2.10 of OSPORB-99/2010, according to which these isotopes should be attributed to manmade radiation sources.  The article justifies the expediency of establishing the upper value of the specific activity of 1 Bq/g for the main uranium radionuclides in solid materials in case of their unlimited use. The supplement of Appendix 3 is proposed to the new version of the OSPORB with uranium isotopes 234U, 235U, 238U, setting the standard for their specific activity of 1 Bq/g in solid materials for unlimited use.

INDOOR RADON CONCENTRATION AND RISK ASSESSMENT IN SOME DWELLINGS OF OBUASI, MINING TOWN

2019 ◽  
Vol 188 (1) ◽  
pp. 30-37
Author(s):  
Irene Opoku-Ntim ◽  
Aba Bentil Andam ◽  
Vicenzo Roca ◽  
J J Fletcher ◽  
T T Akiti
Keyword(s):  
Effective Dose ◽  
Radon Concentration ◽  
Rainy Season ◽  
Building Materials ◽  
Indoor Radon ◽  
Dry Season ◽  
Indoor Radon Concentration ◽  
Mining Town ◽  
222Rn Concentration ◽  
Materials Used

Abstract 222Rn concentration indoors was measured in 40 dwellings in the Obuasi municipality, a gold-mining town in the Ashanti Region of Ghana using the LR 115 type II strippable detectors for the two major seasons in Ghana, rainy and dry. The detectors were placed in the bed rooms of dwellers for 6 months each. Average indoor radon concentration varied from 63.9 to 364.9 Bqm−3 with a mean of 152.2 ± 10.9 Bqm−3 in the rainy season and 26.1–119.0 Bqm−3 with a mean of 50.5 ± 3.9 Bqm−3 in the dry season. The effective dose of 3.90 ± 0.3 mSvy−1 for the rainy season and for the dry season, effective dose of 0.6 mSvy−1 were recorded. The seasonal variation of 222Rn concentration indoors showed higher values in the rainy season than the dry season. A dependence was observed between the type of building materials used in building and the indoor radon level.

Natural Radioactivity of Topsoil in Two Granite Areas of Guangzhou, South China

2014 ◽  
Vol 955-959 ◽  
pp. 3691-3695
Author(s):  
Gang Song ◽  
Min Xing Lu ◽  
Qiu Ping Zhu ◽  
Di Yun Chen ◽  
Yong Heng Chen
Keyword(s):  
Effective Dose ◽  
Annual Effective Dose ◽  
Natural Radionuclides ◽  
Hazard Index ◽  
Natural Radionuclide ◽  
Soil Samples ◽  
Absorbed Dose Rate ◽  
Radium Equivalent Activity ◽  
External Hazard Index ◽  
Radium Equivalent

The natural radionuclide (238U, 226Ra, 232Th and 40K) concentrations in 152 soil samples were determined from two major granite areas in Guangzhou, using high resolution γ-ray spectroscopic system based on the characteristic spectral peaks. The mean activity values for 238U, 226Ra, 232Th and 40K were found to be 156.6±98.8, 160.9±96.5, 184.8±101.5 and 832.5±493.1 Bq kg–1 dry mass, respectively. The absorbed dose rate (D) calculated from activity concentration of 226Ra, 232Th and 40K ranged from 53.2 to 497.1 nGy h–1 with a mean of 220.7 nGy h–1. The Radium equivalent activity (Raeq), the outdoor annual effective dose and the external hazard index (Ir), which resulted from the natural radionuclides in soil, were also calculated and found to vary from 119.7 to 1117.2 Bq kg–1, from 0.07 to 0.61 mSv and from 0.33 to 3.07, respectively. The radium equivalent activities and the external hazard index in all the soil samples were same as 64.5% higher than the limit of 370 Bq kg–1 and 1.0, respectively. The outdoor annual effective dose was higher than the worldwide mean value of 0.07 mSv.

scholarly journals Natural Radionuclide (Gamma and Alpha Emitters) in Grain Samples Collected from Kerbala Governorate, Iraq

2021 ◽  
Author(s):  
Zahraa Saad Hamzah ◽  
Abdalsattar Hashim ◽  
Ali Abojassim
Keyword(s):  
Effective Dose ◽  
Specific Activity ◽  
Annual Effective Dose ◽  
Natural Radionuclide ◽  
Human Consumption ◽  
Alpha Emitters ◽  
Average Value ◽  
The World ◽  
Specific Activities ◽  
Cr 39 Detectors

Abstract The aim of this research is to detect nature radioactivity for gamma emitters (specific activity 238U, 232Th, and 40K) using NaI(Tl) detectors and alpha emitters (concentrations of 222Rn, 226Ra, and 238U) using CR-39 detectors in selected samples of grain that are collected from Kerbala governorate. Also, annual effective dose and some radiological parameters due to gamma and alpha emitters to assess the health risk were calculated. Results have been shown that the average value of specific activities for 238U, 232Th and 40K were 6.61±0.91 Bq/kg, 3.07±0.22 Bq/kg and 227.59±32.34 Bq/kg respectively, while the average value of alpha emitters concentrations for 222Rn, 226Ra, and 238U were 3.99±1.13 Bq/m3, 4.69±1.28 mBq/kg and 0.072±0.019 Bq/kg respectively. The results of average total of annual effective dose associated with the exposure due to gamma and alpha emitted from ingestion grain samples in the present study were 0.139±0.013 mSv/y and 0.172±0.047 µSv/y, respectively. The results of natural Radionuclide and radiological parameter hazard based on gamma and alpha emitters from grain samples were discovered to be within the world acceptable levels. Finally, natural radioactivity from the grain samples that collected from Kerbala governorate were safety for the human consumption.

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