Annual Collective Effective Dose Research Articles

Assessment of Occupational Radiation Exposures at Ghana Research Reactor-1 Facility.

The annual occupational doses for workers at the Ghana Research Reactor-1 facility were assessed for the period 2018-2021. The dose records of monitored staff were retrieved and analysis done for dose distribution and collective effective doses. Thermoluminiscent dosimeters were used to monitor the occupational exposures. The dosimeters were evaluated for the cumulative radiation dose levels using the Harshaw 6600 TLD reader system. Annual dose of 1.52 mSv/year was the maximum acquired by an individual. An annual average effective dose range of 0.20-1.36 mSv was determined for all workers. The annual total collective effective dose was established to be in the range of 0.40-10.08 man-Sv. The 20 mSv annual limit for occupational exposure was not exceeded for monitored workers. The assessment shows that the GHARR-1 facility, in terms of radiation health effects, is a favorable environment for workers since exposures are mostly below occupational exposure limit.

Collective Effective Dose from Medical Radiation Use in Indonesia: Si-INTAN Data Study Period 2018-2021

Until now, there has been no information regarding the value of the collective dose per procedure using the X-ray modality in Indonesia. As in the ICRP 103 publication (2007), it is stated that the collective effective dose is an instrument for optimizing protection by comparing radiological technology and the protection procedures that will be taken. This article aims to raise awareness and optimize the use of diagnostic X-ray modalities by providing an estimate of the proportion of Indonesia's total population compared to the number of radiation examinations carried out, the collective annual effective dose, and the potential risks. The information provided is based on a data reported to the Patient Dose Data Information System (Si-INTAN) application from 2018 to 2021. The data is in the form of the number of patient examinations per modality and the national Diagnostic Reference Level (DRL) value for each type of procedure. From the results of the analysis, it was found that the proportion of patient examinations per modality in the sequence was conventional radiology (79.19%), CT Scan (17.56%), dental radiology (1.75%), interventional fluoroscopy (0.70%), medical diagnostic nuclear (0.62%), and mammography (0.18%). The majority of the annual collective effective dose in Indonesia comes from CT Scan (97.45%), interventional fluoroscopy (1.30%), conventional radiology (0.86%), diagnostic nuclear medicine (0.38%), and a small percentage from mammography and dental radiology. It is estimated that around 116.6 million Indonesians receive radiation exposure for medical needs with a collective annual effective dose of 860,000 man-Sv. This collective effective dose provides an estimate of the incidence of cancer in the Indonesian population of around 0.016% of the entire population in 2021. This information can be used as a baseline to evaluate trends in using and monitoring ionizing radiation sources for medical imaging needs in Indonesia. Keywords: effective dose, collective effective dose, diagnostic reference level (DRL), radiation imaging, diagnostic X-rays, radiation protection

Whole body occupational exposure in industrial radiography in Cameroon (2012–2022)

Whole body doses records of industrial radiography workers in Cameroon were analyzed in this study. Average annual effective dose and collective effective dose were estimated from dose records of 2012 to 2022. The average annual effective dose for monitored workers in the periods 2012–2022 and 2020–2022 were respectively equal to 1.28 mSv and 0.41mSv, and the average annual effective dose for measurably exposed workers in the periods 2012–2022 and 2020–2022 were respectively equal to 1.61 mSv and 0.66 mSv. The average annual effective dose for monitored workers in the period 2020–2022 is lower than the global value of 1.10 reported by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR 2020/2021 Report). The highest collective effective doses were obtained in 2013 and 2014 and were equal to 0.131 man.Sv and 0.126 man.Sv respectively. Many cases of high exposures and one case of effective dose limit exceeded were recorded during the period 2012–2022. Investigations carried out showed that high exposures were mainly caused by high workloads, working in elevated levels, failure to follow operational procedures, equipment malfunction or defect.

Automated Workflow for Calculating the Collective and Average Effective Doses of Galactic Cosmic Radiation Received by Pilots in Taiwan from 2006 to 2021.

On the basis of statistical data obtained from publicly available annual civil aviation reports, we developed an automated workflow for estimating the overall radiation exposure of aircraft pilots caused by galactic cosmic radiation. The workflow comprises several data-processing scripts that work with the batch analysis capability built in the NTHU Flight Dose Calculator . This method can quickly provide best possible estimates of the annual collective and average effective doses received by pilots of various airlines because all passenger, cargo, and charter flights operated that year were considered rather than some selected flights. The workflow and its implementation as well as analysis of results for the period of 2006-2021 are discussed herein. The results revealed that in 2019, six airlines in Taiwan operated 479 separate flight segments with 226 aircraft. The collective effective dose received by all 2,986 pilots was approximately 5,536 person-mSv; hence, the average individual effective dose was 1.85 mSv. During the COVID-19 pandemic, the doses decreased by more than half. In 2020, the collective effective dose received by all 2,936 pilots decreased sharply to 2,527 person-mSv, corresponding to an average effective dose per pilot of only 0.86 mSv. During 2006-2019, the annual average effective dose per pilot in Taiwan was between 1.65 and 2.71 mSv, and the average effective dose rate per flight hour was 3.15 μSv h. -1.

Occupational radiation exposure for dental radiation workers and diagnostic radiology workers in Albania

The development of dental radiology in Albania has been over a century. Medical imaging isessential to dental practice. X-rays examinations help dentists to diagnose, plan treatments and monitorboth treatments and lesion development. This study explored mainly the profile of dental radiation workerscomparing it with the diagnostic radiology workers and their occupational radiation exposure in Albaniafor the period 2016 to 2020. The assessment and analysis procedures of this study were carried out at thepersonal dosimetry laboratory, Institute of Applied Nuclear Physics. The total number of monitored dentalradiation workers increased from 39 in 2016 to 82 in 2020. The annual collective effective exposure dosefluctuated from 26.84man-Sv to 70.14man-Sv, and it showed an increasing trend. In addition, the averageannual effective exposure dose of total monitored dental radiation workers varied from 0.73mSv to0.87mSv. The total number of monitored diagnostic radiology workers increased from 196 in 2016 to 332in 2020. The annual collective effective exposure dose fluctuated from 240.99man-Sv to 358.03man-Sv,and it has showed an increasing trend. The average annual effective exposure dose of total monitoreddiagnostic radiology workers varied from 1.08 mSv to 1.40 mSv. The results of the measured annual dosewere well below the international recommended dose limit of 20 mSv.

OCCUPATIONAL EXPOSURE IN RADIATION APPLICATIONS IN INDIA: TRENDS AND DISTRIBUTION ANALYSIS.

Occupational exposure data in radiation applications provide a good insight on the radiation risks to workers from occupational hazards, the safe practices adopted and in deriving methods to prevent possible radiation exposures. The analysis of occupational exposure may be used to provide regulatory guidance and more focused attention to improve the safety systems, thus improving the personnel and environment safety. In this study, occupational exposure from radiation applications during 2004-18 amounting to a total number of 1951486 occupational dose data are collected and analysed using the statistical software package, SPSS. As recommended by the United Nations Scientific Committee on the Effects of Atomic Radiation, four critical parameters viz., annual collective effective dose, average annual effective dose, individual dose distribution ratio and the annual collective dose distribution ratio for each practice are estimated. Using the trend observed for these parameters, it is predicted that occupational exposure in diagnostic radiology in the year 2023 would increase by 80% in total number of monitored with 76% increase in average collective dose and no significant change in average annual effective dose. In the same manner, nuclear medicine would see 28% of increase in radiation workers with the increase of 24% in collective dose with no significant change in average annual effective dose. Further, the reasons and area of regulatory focus for the different practices are discussed.

Analysis on monitoring results of individual dose of occupational external radiation among radiation workers in Lanzhou in 2019

Objective: To analyze the individual dose level of occupational external radiation of radiation workers in Lanzhou in 2019, so as to provide reference for radiation protection and occupational health management. Methods: In April 2020, a total of 1460 radiation workers in Gansu Provincial Center for Disease Control and Prevention in 2019 were selected as the research objects. The unit nature, hospital level and occupational category of the monitored workers were collected, and the monitoring results of external radiation personal dose in 2019 were analyzed and compared. Results: In the occupational external radiation monitoring of radiation workers in Lanzhou in 2019, the effective dose of 48 persons was 1.0~<5.0 mSv, the effective dose of 2 persons was 5.0~<10.0 mSv, the annual collective effective dose was 308.21 people·mSv, and the average annual effective dose of monitored persons was 0.21 mSv/a. There was significant difference in the distribution of annual effective dose per capita among different occupational groups (H=34.43, P<0.05) . The annual effective dose per capita of nuclear medicine personnel was higher (0.56 mSv/a) , followed by interventional radiology (0.33 mSv/a) . The ratio of annual collective dose to total annual collective dose with annual individual dose more than 5 mSv (SR(5)) and the ratio of the number of staff with annual individual dose more than 1mSv to the total number of monitored personnel (NR(1)) were higher in nuclear medicine and interventional radiology personnel. The average annual effective dose distribution of diagnostic radiologists in different level hospitals was statistically significant (H=16.46, P<0.05) . The average annual effective dose in private hospitals, community hospitals and health centers was higher (0.32 mSv) , followed by county hospitals (0.23 mSv) . Conclusion: The individual dose of occupational external radiation of radiation workers in Lanzhou is generally low, and the annual effective dose of nuclear medicine and interventional radiology workers is high. The management of radiation protection should be emphasis on this people. And it is suggested to strengthen the supervision of private hospitals and update and maintain the equipment of community health centers.

Status and Trend of Occupational Radiation Exposure in Radiotherapy and Diagnostic X-ray Practices in Bangladesh

Introduction: The evaluation of occupational exposure and related trends due to external ionizing radiation in diagnostic and therapeutic purposes has become crucial to understand the implementation of regulatory acts and technological advancement. This study describes the status of occupational radiation exposure in radiotherapy (RADT) and diagnostic X-ray (DRA) sector and the comparison with related research.Materials and Methods: Overall, 12141 number of radiation workers were monitored using thermoluminescent dosimeters (TLDs) which read-out by Harshaw TLD Reader (Model 4500) on a quarterly basis. Several parameters such as annual collective effective dose, average annual effective dose, collective and individual dose distribution, and the probability of cancer risk were analyzed.Results: The number of monitored workers increased by around 35%, whereas the number of radiation workers received a measurable amount of doses decreased by around 37% during 2014-2018. The annual average effective doses in RADT and DRA were in the range of 0.017-0.1112 and 0.076-0.1702 mSv, respectively. The results indicate that more than 94% of the total collective dose was for the non-physician group. Among exposed radiation workers, almost 78% received doses below 1mSv and

OVERVIEW OF AIRCREW EXPOSURE TO COSMIC RADIATION IN THE CZECH REPUBLIC.

Monitoring of exposures of aircrew members of airline operators registered in the Czech Republic has been performed since 1998. The individual effective doses are calculated using the computer code CARI annually. The calculations are based on information about participation of aircrew members on the specific flights and on the parameters describing the typical flight profiles of the flights; the latter is regularly verified with control measurements performed onboard aircraft. The results show that (1) the average annual effective doses in the period from 1998 to 2017 range from 1.3 to 2.1mSv, (2) the maximum effective dose of a crew member is 5.7mSv and (3) the annual collective effective doses range from 1.3 to 4.1 manSv. Combined relative uncertainty of the results is ~25%.

Doğu Karadeniz Bölgesinde kozmik ışın kaynaklı yıllık etkin doz dağılımının belirlenmesi

In this study, annual effective dose rate distribution due to cosmic radiation, which constitutes an important part of natural radiation, was mapped in spatial pixels for three provinces in the Eastern Black Sea region (Artvin, Rize and Trabzon). Cosmic ray-induced annual effective dose calculations were performed based on latitude and altitude changes with EXPACS, an excel-based program. Besides, the effect of cosmic radiation on the population living in the study area was determined. For the entire study area, it was calculated the average effective dose rate from Cosmic radiation as 0.65 mSv y-1 and range as (0.33-1.72) mSv y-1. The average annual collective effective dose rate was determined approximately 508 person-Sv y-1. Besides, the population-weighted average annual effective dose rates were obtained as 449, 376 and 370 for Artvin, Rize and Trabzon provinces, respectively.

OCCUPATIONAL EXPOSURE TO EXTERNAL IONISING RADIATION IN TANZANIA (2011-17).

The objectives of this paper were to evaluate the occupational radiation exposure data from 2011 to 2017 and to compare the results with status in 1996-2010 periods. The evaluation was performed in terms of annual collective effective dose, the average annual effective dose, the individual dose distribution ratio and the annual collective effective dose distribution ratio. Irrespective of work category, the results indicate that the average effective dose ranged from 0.64 to 1.55 mSv and broadly comparable to data in the previous analysis. Over seven year period, the maximum annual individual dose was 4 mSv and therefore below the dose limit of 20 mSv y-1. The impact of radiological practice on the exposed population was <1.1 person.Sv. The results demonstrate satisfactory radiation protection conditions at workplaces, a situation which is mainly explained by the existing effective regulatory enforcement and improved workers' awareness.

Level of Practical Skills in Personnel Dosimetry Monitoring and the Laboratory Experience with Different Types of TLD Readers

This study was carried out to analyze individual annual dose records of diagnostic radiology staff at forty-eight (48) different medical facilities in urban and rural Region of Ghana for the period of 2011-2015. The monitored dose data were extracted from the Radiation Protection Institute of the Ghana Atomic Energy Commission’s database called the Dose Management System (DMS). The doses of these OEWs analyzed, are divided into four subgroups namely; general radiographers, radiologists, computed tomography (CT) technologists, fluoroscopy technologists. The dose distribution, collective dose and mean annual dose were determined. A total of 1574 OEWs were monitored comprising of 56% radiographers, 15% radiologist, 21% computed tomography (CT) technologists and 8% fluoroscopy technologists. The average annual effective dose ranged from 0.36 to 1.70 mSv with radiographers receiving the largest. Fluoroscopy technologist recorded the least annual total collective effective dose value of 0.1 person-Sv. The study contributes to the existing works to promote a more comprehensive personal monitoring service for OEWs. Continued analysis of occupational doses should be an integral component of institutional radiation safety programs in Ghana.

94. Evaluation of the effective dose due to medical radiation exposures in Tuscany: Methods and operational issues

Purpose Medical exposures are the main source of artificial exposure to ionizing radiation for developed countries. In recent years there has been a significant improvement in imaging techniques but also a substantial increase of patient exposures. The harmful effects of radiations used for diagnostic purposes are essentially stochastic. Exposure to ionizing radiation is known to increase the future incidence of cancer (solid tumors and leukemias). The latest EU radiation protection recommendations of the Directive 2013/59/EURATOM layied down basic safety standards for exposure to ionizing radiation. The region of Tuscany (through resolution No 994/2014) has planned a project aimed to assess the annual per-capita and collective effective doses due to medical exposures. Methods The total number of examinations was evaluated by data recorded on the Radiological Information System (RIS) of each regional hospital and by the regional database for Outpatient services (SPA) and Hospitalized Patients (SDO). Relevant exposure parameters for effective dose estimation were collected by a questionnaire that allowed a sampling of dosimetry aspects of radiological and nuclear medicine practices throughout the region. These data were used to evaluate the effective dose associated with each examination by simulations with dedicated software. A different approach has been used for interventional radiology. Due to the intrinsic variability characterizing this kind of procedures, the exposure and dosimetric parameters of each exam were extracted from databases implemented by commercially available dose monitoring software packages and then processed with specific simulation software for effective dose estimate. Results We derived per-capita and collective effective dose for the Tuscany Region population due to radiology (computed tomography, conventional radiology, interventional radiology and mammography) and nuclear medicine procedures. Conclusions We compared the current data with those of previous surveys to outline any statistically significant trend.

Analysis of individual dose monitoring results among radiation workers in a first-class hospital at Grade 3 from 2010 to 2017

Objective: To understand the occupational external exposure dose among radiation workers in a first-class hospital at Grade 3 of Suzhou, and to provide reference for radiological protection. Methods: The individual dose of 1156 radiation workers in the hospital from 2010 to 2017 were detected, the annual collective effective dose and per capita annual effective dose were analyzed for different years, different occupations (diagnostic radiology, radiotherapy, nuclear medicine, interventional radiology) , gender, and age. Results: From 2010 to 2017, the total annual collective effective dose was 351.40 person·mSv, the per capita annual dose was 0.30 mSv/a, and radiation workers whose annual effective dose was less than 1 mSv accounted for 94.98%. There were 5 interventional radiology workers and 1 nuclear medicine worker with annual effective dose between 2 and 4 mSv. There was no worker with annual effective dose over 4 mSv. The per capita annual effective dose of nuclear medicine workers was the highest (0.40 mSv/a) . The per capita annual effective dose was not significantly different between radiation workers with different genders and ages (P>0.05) . Conclusion: Most of radiation workers have low individual dose level in the hospital. It is important to focus on nuclear medicine workers and interventional radiology workers.

Geological influence on the terrestrial gamma radiation dose rate in Jos Plateau, Nigeria

Natural environmental terrestrial gamma radiation dose (TGRD) rate measurements have been carried out across the geological formations of Jos Plateau, Nigeria. External gamma radiation dose rates ranged between 11 and 714 nGy h-1 with a mean value of 204 nGy h-1. Relationship between TGRD levels and geological type was determined. Statistical comparative method one way analysis of variance (ANOVA) was used to compare the TGRD means for the various types. The statistical results revealed in some instances, significant differences among the mean values of TGRD rates for the different underlying geological structures. Annual effective dose and collective effective dose for the general public due to exposure to terrestrial gamma radiation were estimated at 0.25 mSv y-1 and 1.20x102 mSv y-1, respectively. Isodose map for exposure rate due to TGRD wasplotted using ArcGIS software. The results will serve as database for natural background radiation for the country.Keywords: Natural radiation; Terrestrial gamma radiation dose (TGRD); geological type; Analysis of variance (ANOVA)

Assessment of Occupational Exposure to External Radiation among Workers at the Institute of Radiotherapy and Nuclear Medicine, Pakistan (2009-2016)

Introduction: Assessment of occupational exposure to external radiation and the analysis of associated trends are imperative to observe changes that have taken place over time due to regulatory operations or technological advancements. Herein, we describe the occupational radiation exposure to workers employed in Nuclear Medicine (NM), Radiotherapy (RT), and Diagnostic Radiology (DR) departments at the Institute of Radiotherapy and Nuclear Medicine, Peshawar, Pakistan, and to evaluate the related trends during 2009-2016. Materials and Methods: A retrospective analysis of the dose records of 4320 film dosimeters was performed during 2009-2016. The analyzed quantities included annual collective effective dose, annual average effective dose, distribution of workers, and their annual average effective doses in various effective dose intervals, as well as the maximum and minimum annual individual effective doses. Results: The annual average effective doses in RT, NM, and DR were within the ranges of 1.07-1.45, 1.25-1.55, and 1.03-1.60 mSv, respectively. The majority (90%) of the workers received effective doses in the interval of 1-4.99 mSv, while 10% of the workers received doses within the range of the minimum detectable level-0.99 mSv. The minimum and maximum annual individual effective doses were 0.30 mSv and 3.96 mSv as recorded in RT and NM, respectively. The annual average effective doses measured for NM, RT, and DR were 1.39, 1.23, and 1.30 mSv, respectively. These values are comparable with the worldwide annual average effective doses. Conclusion: All the workers received doses below the annual dose limit. The status and trends of doses showed that radiation protection conditions were adequate.

POPULATION RADIATION EXPOSURE FROM DIAGNOSTIC NUCLEAR MEDICINE PROCEDURES IN TEHRAN 2011-14; TRENDS IN THE LAST 3 DECADES.

This study represents an update of Tehran population exposure from the diagnostic nuclear medicine procedures and the annual collective effective dose during 2011-14. The diagnostic nuclear medicine procedures data were collected from 58 out of 60 nuclear medicine centers in Tehran and were composed of the type and frequency of diagnostic examinations, radiopharmaceuticals used, administered activities, and age distribution of the patients. The annual number of examinations per 1000 population increased from 13.73 in 2011 to 22.59 in 2014 with an increase of 64.53% during 4 years. Most frequent examinations were cardiac (71.05%), bone (9.80%) and thyroid (7.26%) averaged over the 5 years. The collective effective dose increased from 807.74 person-Sv in 2011 to 1413.81 person-Sv in 2014. The effective dose per capita increased from 44.06 μSv in 2011 to 120.91 μSv in 2014, could be because of 70% increase of examinations, but ~3.42% increase in the population of Tehran.

Medical radiation exposure of the greek population

Introduction Medical exposures contribute the largest to the population man-made radiation exposure, mainly due to the high frequency of diagnostic examinations and the patient doses involved. Purpose A research project was carried out by the Greek Atomic Energy Commission (EEAE) to assess the collective dose and the average annual effective dose to the Greek population from x-ray and nuclear medicine procedures. This work was performed in the framework of ‘PRISMA’ project within GSRT’s KRIPIS action, funded by Greece and the European Regional Development Fund of the EU under the O.P. Competitiveness and Entrepreneurship, NSRF 2007–2013. Materials and methods For each type of diagnostic and interventional procedures, the estimation of the annual collective effective dose, S, (person-Sv) and per caput dose, E per-caput , (mSv/caput) required information on the frequency and the mean patient effective dose, E pat , (mSv). Results In 2014, approximately 6.7 million diagnostic and interventional procedures were performed in Greece. The estimated frequency, i.e. number of procedures per 1000 citizens was: 447 for plain radiographies, 135 for computed tomography scans, 7 for interventional procedures, 2 for fluoroscopic procedures and 20 for nuclear medicine procedures. The annual effective dose per caput was estimated to 1.7 mSv from diagnostic radiology and 0.1 mSv from NM procedures. Conclusion The main contribution to the collective dose due to x-ray procedures appeared from CT scans. The collective effective dose and the annual per caput dose from NM procedures have decreased in the last 5 years.

Chemical Toxicity of Surface-Based Drinking Water Sources Due to Natural Uranium Pollutant Around Princess Gold Mine Environs in Roodepoort, South Africa

The activity level of natural uranium pollutant in surface-based water around Princess Gold Mine in Roodepoort, South Africa was measured using inductively coupled plasma mass spectrometry. The highest activity level of 6.39E+04 mBq/L is reported in the reddish brown ochre surface water from tailing (SWA-RB) close to the houses, whereas the lowest value of 1.92E+03 mBq/L is reported in the flowing surface water (SRWA-5) 1 km away from the dump. Along the path high values of 1.56E+04, 1.07E+04, 1.57E+04 and 8.46E+03 mBq/L were reported at SRWA-2, SRWA-3 and SRWA-4, respectively. The inhabitants living around the tailings use the surface water for daily consumption. Based on the annual limit guideline for drinking water recommended by World Health Organization (731 L/year), this study revealed that, the community around this vicinity receives 2.10 mSv as the highest annual collective effective dose due to 238U in the drinking surface water. The radiological-health risks of 238U in the water samples analysed revealed the highest cancer mortality and morbidity values of 2.40E+03 and 3.67E+03, respectively. The mean chemical toxicity risk for the natural uranium over the lifetime consumption is 5.31E+05 μg/kg/day which shows that the main human risk may likely be due to the chemical toxicity of natural uranium.

RADIATION RISK ESTIMATION FROM OCCUPATIONAL MEDICAL IMAGING EXPOSURE IN MALAYSIA

Ionizing radiation has been increasingly applied in medicine and firmly established as an essential tool for diagnosis. There is high possibility for medical radiation workers to receive doses that are considerably higher than recorded by their dosimeters due to lack of knowledge about ionizing radiation, lack of training in radiation protection, and attitude of the workers themselves toward radiation protection. The purpose of this study is to estimate the radiation risk due to occupational exposure to ionizing radiation among medical diagnostic workers at hospitals in Malaysia. Also the objective is to determine the knowledge of occupational radiation exposure and radiation safety among the workers. The assessment was made based on the collective doses collected from film badge of the workers. The results of risk assessment show the mean annual collective effective dose based on type of X-ray procedure in this study was 5.445mSv, which is much lower compared to the whole body exposure dose limit, set by the ICRP Publication 60. A survey on knowledge of occupational radiation exposure and radiation safety was conducted using questionnaire and it was found that vast majority of respondents were aware of radiation safety with 91.3% answered the specific questions regarding radiation protection at workplace correctly. Unfortunately only 30.4% of the respondents fully understand the hazard they are exposed to. The study reveals that there is a critical need to educate not only medical radiation workers but also medical doctors and nurses to decrease unnecessary occupational exposure to radiation hazard.