scholarly journals Assessment of Internal Radiation Dose in Gastro Intestinal Tract for Acute Ingestion of Ra-226 of the People of Bangladesh

2018 ◽  
Vol 19 (1) ◽  
pp. 38-42
Author(s):  
AHMR Quddus ◽  
MMA Zaman ◽  
AS Mollah ◽  
MM Zaman

To design appropriate method for treatment planning it is necessary to know the precise radiation dose absorbed by any internal organ in human body. This paper will provide a method for calculating retention, absorbed dose, committed equivalent dose and committed effective doses due to acute ingestion of 1 Bq of Ra-226 in the gastro intestinal (GI) tract of Bangladeshi people for different age groups. Calculations are done by using “Internal Radiation Dose Assessment (IRDA)” software which has been developed in Visual Basic language. GI tract consists of four tissue compartments, e.g. stomach (ST), small intestine (SI), upper large intestine (ULI) and lower large intestine (LLI). One hour after the ingestion, the retention and absorbed dose show the trend ST > SI > ULI > LLI. For tissue compartments the variation of the committed equivalent dose pattern is LLI > ULI > ST > SI for the radionuclide. The variation of absorbed dose, committed equivalent dose and committed effective dose with respect to age follow the pattern: 1 year> 10years > adult female > adult male. The highest committed effective dose is found in the GI tract of 1 year old child. For other age groups these values are slightly less than those for 1 year old child.Bangladesh J. Nuclear Med. 19(1): 38-42, January 2016

2013 ◽  
Vol 4 (1) ◽  
pp. 135-143
Author(s):  
AHMR Quddus ◽  
M Moksed Ali ◽  
MMA Zaman ◽  
AS Mollah

Retention, absorbed dose, committed equivalent dose and committed effective doses have been assessed due to acute ingestion of 1 Bq of 60Co in human body. Calculations are done using “Internal Radiation Dose Assessment (IRDA)” software which has been developed based on the biokinetic model. Due to ingestion maximum radiation dose is deposited in the gastro intestinal (GI) tract, assumed to consist of four tissue compartments, e.g. stomach (ST), small intestine (SI), upper large intestine (ULI) and lower large intestine (LLI). In this work actual tissue masses of GI Tract of Bangladeshi people have been considered to calculate the above mentioned quantities for different age groups, such as 1 yr, 10 yrs and adult (female and male). One hour after the ingestion, the retention and absorbed dose show the trend ST > SI > ULI > LLI. Regarding tissue compartments the variation of the committed equivalent dose pattern is LLI > ULI > ST > SI for the radionuclide. The variation of absorbed dose, committed equivalent dose and committed effective dose with respect to age follow the pattern: 1 yr > 10yrs > adult female > adult male. The highest committed effective dose for ingestion of 1 Bq of the radionuclide under the study is found in the GI tract of 1 yr old child. This value is 6.56 x 10-6 mSv. For other age groups these values are slightly less. DOI: http://dx.doi.org/10.3329/bjmp.v4i1.14703 Bangladesh Journal of Medical Physics Vol.4 No.1 2011 135-143


2021 ◽  
Vol 8 (3) ◽  
pp. 155-160
Author(s):  
Asogwa Chijioke Obiora ◽  
Hyacienth Uche Chiegwu ◽  
Akintayo Daniel Omojola ◽  
Ebube Mmeli Onwughalu

Objective: Radiation dose to pediatric patients have been widely reported, it is however necessary that imaging expert keep doses as low as possible to forestall stall long term cancer risk. This study is aimed at determining pediatric entrance surface dose (ESD), 75th percentile ESD, absorbed dose (D) and effective dose (E) for 0-15 years. Material and Methods: The study used a digital radiography (DR) unit with a grid system for each chest X-ray. The thermoluminescent dosimeter (TLD) used was encapsulated in transparent nylon, it was then attached to the patient skin (chest wall) and the second was placed directly at the posterior end of it. Results: The mean ESDs for the 4 age groups were as follows: 0- < 1 (1.54±0.74mGy), 1- < 5 (1.53±0.83mGy), 5- < 10 (0.55±0.39mGy) and 10- ≤15 (1.30±0.57mGy), with an overall mean of 1.23mGy. The 75th percentile ESD for each age group above 10 patients (excluding 5- < 10yrs) was 2.18, 2.19 and 1.75mGy respectively. The absorbed dose (D) ranged from 0.03-2.39mGy. The mean effective dose (E) for the 4 age groups was 0.18±0.03mSv. There was a good correlation between ESD and D (P = 0.001). A One-Way ANOVA shows that the field size and focus to film distance (FFD) affected the ESD and D (P < 0.001) respectively. The risk of childhood cancer from a single radiograph was of the order of (1.54-23.4) ×10-6. Conclusion: The 75th percentile ESD, E and childhood risk of cancer was higher than most studies it was compared with. The study reveals that machine parameters such as the field size and FFD played a major role in dose increase. Protocol optimization is currently needed for pediatric patients in the studied facility.


2021 ◽  
Vol 66 (6) ◽  
pp. 102-110
Author(s):  
A. Molokanov ◽  
B. Kukhta ◽  
E. Maksimova

Purpose: Harmonization and improvement of the system for regulating the internal radiation exposure of workers and the basic requirements for ensuring radiation safety with international requirements and recommendations. Material and methods: Issues related to the development of approaches to regulation and monitoring of workers for internal radiation exposure in the process of evolution of the ICRP recommendations and the national radiation safety standards, are considered. The subject of analysis is the standardized values: dose limits for workers and permissible levels as well as directly related methods of monitoring of workers for internal radiation exposure, whose purpose is to determine the degree of compliance with the principles of radiation safety and regulatory requirements, including non-exceeding the basic dose limits and permissible levels. The permissible levels of inhalation intake of insoluble compounds (dioxide) of plutonium-239 are considered as a numerical example. Results: Based on the analysis of approaches to the regulation and monitoring of workers for internal radiation exposure for the period from 1959 to 2019, it is shown that a qualitative change in the approach occurred in the 1990s. It was due to a decrease in the number of standardized values by introducing a single dose limit for all types of exposure: the effective dose E, which takes into account the different sensitivity of organs and tissues for stochastic radiation effects (WT), using the previously accepted concepts of the equivalent dose H and groups of critical organs. From the analysis it follows that the committed effective dose is a linear transformation of the intake, linking these two quantities by the dose coefficient, which does not depend on the time during which the intake occurred, and reflects certain exposure conditions of the radionuclide intake (intake routes, parameters of aerosols and type of radionuclide compounds). It was also shown that the reference value of the function z(t) linking the measured value of activity in an organ (tissue) or in excretion products with the committed effective dose for a reference person, which is introduced for the first time in the publications of the ICRP OIR 2015-2019, makes it possible to standardize the method of measuring the normalized value of the effective dose. Based on the comparison of the predicted values of the lung and daily urine excretion activities following constant chronic inhalation intake of insoluble plutonium compounds at a rate equal annual limit of intake (ALI) during the period of occupational activity 50 years it was shown that the modern biokinetic models give a slightly lower level (on average 2 times) of the lungs exposure compared to the models of the previous generation and a proportionally lower level (on average 1.4 times) of plutonium urine excretion for the standard type of insoluble plutonium compounds S. However, for the specially defined insoluble plutonium compound, PuO2, the level of plutonium urine excretion differs significantly downward (on average 11.5 times) compared to the models of the previous generation. Conclusion: With the practical implementation of new ICRP OIR models, in particular for PuO2 compounds, additional studies should be carried out on the behavior of insoluble industrial plutonium compounds in the human body. Besides, additional possibilities should be used to determine the intake of plutonium by measuring in the human body the radionuclide Am-241, which is the Pu-241 daughter. To determine the plutonium urine excretion, the most sensitive measurement techniques should be used, having a decision threshold about fractions of mBq in a daily urine for S-type compounds and an order of magnitude lower for PuO2 compounds. This may require the development and implementation in monitoring practice the plutonium-DTPA Biokinetic Model.


1989 ◽  
Vol 30 (2) ◽  
pp. 201-206 ◽  
Author(s):  
K. Geterud ◽  
A. Larsson ◽  
S. Mattsson

The radiation dose to patients and personnel was estimated during 11 percutaneous renal stone extractions. For the patients the energy imparted, the mean absorbed dose to various organs, and the effective dose equivalent were estimated. For different personnel categories some organ doses and the effective dose equivalent were also estimated. Large differences in the radiation dose between patients were observed. The mean effective dose equivalent to the patient was 4.2 (range 0.6–8.3) mSv, and the energy imparted 285 (range 50–500) mJ. These figures are comparable to those reported for routine colon examination and urography. For the personnel there were also large differences between individuals and categories. The highest radiation dose was received by the radiologist. It was estimated that a radiologist who performs 150 percutaneous renal stone extractions per year will receive a yearly contribution to his/her effective dose equivalent of 2.4 mSv. Even when the contribution from other diagnostic and interventional radiologic procedures is added, the total effective dose equivalent hardly exceeds 5 mSv or 1/10 of the present dose limit for persons engaged in radiologic work. For the hands of the radiologist there is a risk of doses closer to the present limit for single organs or tissues of 500 mSv/year.


Author(s):  
Aysenur Yilmaz ◽  
Sibel Yıldız ◽  
Ahmet Çelik ◽  
Uğur Çevik

In this study, radioactivity and heavy metals accumulations in Agaricus campestris mushroom collected from Kahramanmaraş and Erzurum provinces was determined. HPGe gamma detector was used for the determination of radioactivity concentrations. Heavy metal content was measured using a ICP-MS. As radioactive element; natural (238U, 232Th 40K) and artificial radionuclide (137Cs) concentrations were determined. The values of the committed effective dose were calculated. Same measurements were made in soils. Absorbed dose and excess lifetime cancer risk were calculated. Amount of Mg, Al, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Cd, Pb206, Pb207 and Pb208 as heavy metals of mushrooms were determined. 238U, 232Th, 40K activity concentrations of mushroom collected from Erzurum was determined as 12.1 ± 0.8, 11.7 ± 0.9, 497.7 ± 17.8 Bq/kg, respectively and 137Cs was not detected by system. 232Th and 40K activity concentrations of mushroom collected from Kahramanmaraş was determined as 13.4 ± 0.5, 134.9 ± 6.3 Bq/kg, respectively, 238U and 137Cs was not detected by system similarly. The value of the committed effective dose collected from Erzurum and Kahramanmaraş were calculated as 75 and 29 μSv respectively and these values were found lower than 290 μSv accepted as world average. Absorbed dose and risk of lifetime cancer for Erzurum was determined as 37.39 nGy/h, 16.5 x 10-5; absorbed dose and excess lifetime cancer risk for Kahramanmaraş was determined as 30.92 nGy/h, 13.3 x 10-5 respectively. Amount of daily intake for each heavy metal was calculated. Radionuclide activity concentrations and accumulations of heavy metal were not founded threaten level to healthy, except from arsenic As (0.025 and 0.039 mg/kg) in mushroom collected from both provinces. They were found a bit higher than upper limit (0.015 mg/kg) in report which is prepared World Health Organization (WHO) and Food and Agriculture Organization of the United Nations (FAO) jointly.


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