scholarly journals Measurement of Environmental Radioactivity within Dangote Cement Escavation Site Gboko, Benue State.

2015 ◽  
Vol 6 ◽  
pp. 168-172
Author(s):  
A A Tyovenda ◽  
A A Akombor ◽  
S T Tamaugee
Keyword(s):  
Environmental Radioactivity ◽  
Radiological Protection ◽  
Limit Set ◽  
Exposure Rate ◽  
Dose Equivalent ◽  
Background Count ◽  
Equivalent Rate ◽  
The Mean ◽  
Excavation Site ◽  
Safety Limit

The radioactivity of rocks from Dangote Cement excavation site in Gboko, Benue State were monitored and measured using the radiation meter inspector 06250 and dose meter 6150AD 2/4/6. The meters measure the dose rate, exposure rate and the activity. The meters were held 1 meter above the surface of the soil at the excavation site. Each reading was taken 10 times at varying distances between zero and 100 meters from the excavation site after which the mean readings for each of the distance were then found. Finally, the background count was taken 200 meters away from the excavation point. The highest value of dose equivalent rate of 0.428±0.006 mSv/yr, exposure rate of 0.206±0.003 mR/hr and activity of 6.8±0.4kBq were measured at zero distance from the excavation point while the least value of dose equivalent rate of 0.212±0.002 mSv/yr, exposure rate of 0.081±0.001 mR/hr and activity of 3.2±0.8kBq were obtained at 100 meters away from the excavation point. The result shows that the excavation site is within the safety limit set by the international commission on Radiological protection (ICRP) (1990).

PRE-ANTHROPIC AND PRESENT OUTDOOR GAMMA EQUIVALENT DOSE RATE OF THE HISTORIC CENTER OF ROME (ITALY)

2019 ◽  
Vol 187 (4) ◽  
pp. 518-534
Author(s):  
Guglietta Daniela ◽  
Serena Carloni ◽  
Mario Voltaggio ◽  
Giuseppe Antonino Di Lisa
Keyword(s):  
Gamma Ray ◽  
Fine Particulate Matter ◽  
Radioactive Material ◽  
Radiological Protection ◽  
Dose Equivalent ◽  
Lifetime Cancer Risk ◽  
Equivalent Dose Rate ◽  
Gamma Background ◽  
Historic Center ◽  
Equivalent Rate

Abstract The outdoor gamma background of the historic center of Rome was studied by in situ measurements and average values of the outcropping geological formations. The survey resulted in two maps of dose equivalent rate, related to pre-anthropic and present conditions. Presently, the average of the dose equivalent rate from outdoor gamma-ray field is equal to 0.31 μSv h−1, corresponding to an outdoor annual effective dose equivalent of 0.548 mSv a−1 and to an outdoor excess lifetime cancer risk [International Commission on Radiological Protection (ICRP). Recommendations of the ICRP, 21, 1/3, Publication 60, 1990] of 2.56 × 10−3. The originary radioactivity was enhanced by anthropic action up to a level of health risk comparable to that one deriving by fine particulate matter. The assessment of the evolution and dispersion of the outdoor gamma background offers a new perspective to study the urban architectural evolution. Such a mapping allows us to individuate mitigation actions and neighborhoods in which the monitoring of illicit trafficking of radioactive material can be efficiently tested.

scholarly journals Occupational exposure to Am-Be neutron calibration source mounted in OB26 shielding container

Nukleonika ◽  
2014 ◽  
Vol 59 (3) ◽  
pp. 97-103 ◽  
Author(s):  
Kamil Szewczak ◽  
Slawomir Jednorog
Keyword(s):  
Occupational Exposure ◽  
Reference Points ◽  
Radiological Protection ◽  
Individual Dose ◽  
Control Room ◽  
Dose Equivalent ◽  
Calibration Source ◽  
Equivalent Rate ◽  
Ambient Dose Equivalent ◽  
Ambient Dose

Abstract Laboratory for Dosimetric and Radon Instruments Calibration which is a part of Central Laboratory for Radiological Protection (CLRP) in Warsaw is equipped with 241Am-Be neutron calibration source with activity of 185 GBq since 1999. The capsule was mounted in the OB26 type shielding container. The control room is separated from the above source by a concrete wall of 0.5 m in thickness. The calibration hall is adjacent to one side of the offi ce room. To comply with the requirements of the radiological protection system, the occupational exposure of persons that are working both in the offi ce and control room needs to be assessed. Two methods were involved for ambient dose equivalent rate determination. The active instrument measurements (AIMs) performed with the Berthold LB6411 neutron probe and the Monte Carlo simulation method (MCS) based on MCNP5 code. These estimations were completed for fi ve reference points. Additionally the γ radiation component was measured by RSS131 ionisation chamber. An increased value of the ambient dose equivalent rate from neutrons was observed in two reference positions. The fi rst observation was done in the control room while the second one in the offi ce room. Expected individual dose equivalents were evaluated based on the results of the AIM and on the expected working time in particular reference points. The annual individual dose equivalent associated with calibration activities using mentioned neutron source was estimated at maximum 0.8 mSv.

scholarly journals Determination of Calibration Factors and Uncertainties Associated with the Irradiation of MTS-N (LiF: Mg, Ti) Chips with Cesium-137 and X-ray Sources Under Low Doses for Personal Dosimetry in Diagnostic Radiology

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Akintayo Daniel Omojola ◽  
Michael Onoriode Akpochafor ◽  
Samuel Olaolu Adeneye ◽  
Moses Adebayo Aweda
Keyword(s):  
Line Graph ◽  
Coefficient Of Determination ◽  
Radiological Protection ◽  
Dose Equivalent ◽  
X Ray ◽  
Calculated Dose ◽  
Cesium 137 ◽  
Personal Dosimetry ◽  
The Mean

Purpose: The purpose of this study was to compare calibration factors for deep dose equivalent Hp (10) and shallow dose equivalent Hp (0.07) between Cesium (Cs)-137 and X-ray sources when they are exposed to same dose and to determine uncertainties with MTS-N (LiF: Mg, Ti) chips when they are exposed to low dose ≤ 2mGy. Material and Methods: Thermoluminescent (TL) chips were annealed at 400oC for one hour and allowed to cool and were subjected to a temperature of 100oC for another two hours using a TLD Furnace Type LAB-01/400. They were then taken to a Secondary Standard Dosimetry Laboratory (SSDL) for irradiation using a Cs-137 source at known doses (0.2-2mGy). A RadPro Cube 400 manual TLD Reader was used to determine corresponding TL signal. The above process was replicated but with a calibrated X-ray unit as the source for calibration. Results: The calibration factors (CF) from the line graph of dose (mGy) against TL signal (count) for Cs-137 source with Hp (10) and Hp (0.07) were 3.72 x 10-6 and 5.97x10-6 mGy/count respectively. Those with X-ray source for Hp (10) and Hp (0.07) were 3.44x10-6 and 4.05x10-6 mGy/count respectively with an overall coefficient of determination (R2) = 0.99. The adjusted maximum percentage deviation between the actual and calculated dose for both sources was -2.74%. The percent (%) deviation of the mean with both sources for Hp (10) and Hp (0.07) was 3.9% and 19% respectively. Conclusion: Adjusted percent deviation from both sources were within the recommended dose limit of ±30% by the Radiological Protection Institute of Ireland (RPII) and within the International Commission on Radiological Protection (ICRP) limit respectively. Better accuracy was seen for Hp (10) with both sources compared to Hp (0.07). Calibration of the MTS-N chips using both sources was successful and can be used for personal dosimetry.

scholarly journals Radiation eye dose to medical staff during respiratory endoscopy under X-ray fluoroscopy

2020 ◽  
Vol 61 (5) ◽  
pp. 691-696
Author(s):  
Yoshihiro Haga ◽  
Koichi Chida ◽  
Yuichiro Kimura ◽  
Shinsuke Yamanda ◽  
Masahiro Sota ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Medical Staff ◽  
International Commission ◽  
Radiological Protection ◽  
Dose Equivalent ◽  
Dose Limit ◽  
Clinical Value ◽  
Correct Evaluation ◽  
X Ray ◽  
The Mean

Abstract Although the clinical value of fluoroscopically guided respiratory endoscopy (bronchoscopy) is clear, there have been very few studies on the radiation dose received by staff during fluoroscopically guided bronchoscopy. The International Commission on Radiological Protection (ICRP) is suggesting reducing the occupational lens dose limit markedly from 150 to 20 mSv/year, averaged over defined periods of five years. The purpose of this study was to clarify the current occupational eye dose of bronchoscopy staff conducting fluoroscopically guided procedures. We measured the occupational eye doses (3-mm-dose equivalent, Hp(3)) of bronchoscopy staff (physicians and nurses) over a 6-month period. The eye doses of eight physicians and three nurses were recorded using a direct eye dosimeter, the DOSIRIS. We also estimated eye doses using personal dosimeters worn at the neck. The mean ± SD radiation eye doses (DOSIRIS) to physicians and nurses were 7.68 ± 5.27 and 2.41 ± 1.94 mSv/6 months, respectively. The new lens dose limit, 20 mSv/year, may be exceeded among bronchoscopy staff, especially physicians. The eye dose of bronchoscopy staff (both physicians and nurses) was underestimated when measured using a neck dosimeter. Hence, the occupational eye dose of bronchoscopy staff should be monitored. To reduce the occupational eye dose, we recommend that staff performing fluoroscopically guided bronchoscopy wear Pb glasses. correct evaluation of the lens dose [Hp(3)] using an eye dosimeter such as the DOSIRIS is necessary for bronchoscopy staff.

scholarly journals Estimation of dose and cancer risk to newborn from chest X-ray in South-South Nigeria: a call for protocol optimization

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Akintayo Daniel Omojola ◽  
Michael Onoriode Akpochafor ◽  
Samuel Olaolu Adeneye ◽  
Isiaka Olusola Akala ◽  
Azuka Anthonio Agboje
Keyword(s):  
Cancer Risk ◽  
Age Groups ◽  
Field Size ◽  
Radiological Protection ◽  
International Studies ◽  
X Ray ◽  
Thermoluminescent Dosimeters ◽  
Chest X Ray ◽  
Neonatal Patient ◽  
The Mean

Abstract Background The use of X-ray as a diagnostic tool for complication and anomaly in the neonatal patient has been helpful, but the effect of radiation on newborn stands to increase their cancer risk. This study aims to determine the mean, 50th percentile (quartile 2 (Q2)), and 75th percentile (quartile 3 (Q3)) entrance surface dose (ESD) from anteroposterior (AP) chest X-ray and to compare our findings with other relevant studies. The study used calibrated thermoluminescent dosimeters (TLDs), which was positioned on the central axis of the patient. The encapsulated TLD chips were held to the patients’ body using paper tape. The mean kilovoltage peak (kVp) and milliampere seconds (mAs) used was 56.63(52–60) and 5.7 (5–6.3). The mean background TLD counts were subtracted from the exposed TLD counts and a calibration factor was applied to determine ESD. Results The mean ESDs of the newborn between 1 and 7, 8 and 14, 15 and 21, and 22 and 28 days were 1.09 ± 0.43, 1.15 ± 0.50, 1.19 ± 0.45, and 1.32 ± 0.47 mGy respectively. A one-way ANOVA test shows that there were no differences in the mean doses for the 4 age groups (P = 0.597). The 50th percentile for the 4 age groups was 1.07, 1.26, 1.09, and 1.29 mGy respectively, and 75th percentile were 1.41, 1.55, 1.55, and 1.69 mGy respectively. The mean effective dose (ED) in this study was 0.74 mSv, and the estimated cancer risk was 20.7 × 10−6. Conclusion ESD was primarily affected by the film-focus distance (FFD) and the patient field size. The ESD at 75th percentile and ED in this study was higher compared to other national and international studies. The estimated cancer risk to a newborn was below the International Commission on Radiological Protection (ICRP) limit for fatal childhood cancer (2.8 × 10−2Sv−1).

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