Measurement of Radiation Dose on Medical Workers in Selected Hospitals in Dhaka Bangladesh

Ashiru Garba Abdullahi¹, Fazlul Haque, A. K. M.¹, Musa Garba Abdullahi^2*, Mutari Ali hajara³ & Saratu Garba Abdullahi⁴

¹Department of Electronics and Telecommunication Engineering, Daffodil International University of Dhaka Bangladesh
²Department of Physics, Faculty of Science, Yusuf Maitama Sule University Kano, Nigeria
³Department Physics, Faculty of Science, Bayero University Kano, Nigeria
⁴Nursing Department Bayero University Kano, Nigeria

*Correspondence to: Musa Garba Abdullahi, Department of Physics, Faculty of Science, Yusuf Maitama Sule University Kano, Nigeria.

Copyright © 2018 Musa Garba Abdullahi, et al., This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Introduction
Recently, radioactive sources are using in most of the applications, such as medicine, industry, research, agriculture, and education, for a wide variety of beneficial purposes. The purposes of improved health services and an aging population have resulted in a combination of high application to increase the use of radiation and radionuclides in diagnosis and treatment [1]. All medical workers and occupational exposure to ionizing radiation represent the significant part of exposure to low radiation doses. The researchers estimated that cancer risk incidence directly increases with the increases in the absorbed dose. It is essential to establish a model to examine the carcinogenic impacts forth slow radiation dose [2]. The aims of the International Commission on Radiological Protection (ICRP) is to come off with a system, and useful standards for radiation protection consist of medical, environmental, occupational, and exposure controls against radiological misfortunes without excessively limiting the valuable Practices giving rise to radiation exposure [3,4]. The term “occupational exposures” means the exposure of environmental, as well as the exposure controls against radiological accidents without excessively limiting Practices produces to the radiation exposure [3,4]. The term “occupational exposures” defined as the exposure of people at work to ionizing radiation from natural and human-made sources as a result of operations within a place of work, except for exposures excluded from the standards and exposures from practices or sources exempted by measures [5-12].

Therefore, we considered exposure to radiation as one of the hazards of working in a department of diagnostic radiology (DR) or radiography due to the possibility of long-term exposure to low-level radiation. And any associated biological effects. Evidence of reversible and irreversible genotoxic impacts during periods of Radiation exposure has been reported [14]. Even though biological effects caused by moderate and highlevel doses (>100mGy) are evident; hence, there is still considerable debate regarding this biological effects due to low-dose exposures (100mGy) [14-17]. During the last decade, the number of Peoples who work in departments of radiography and DR has increased [15,18]. Due to the introduction of advanced imaging technologies, such as multislice computed tomography (MSCT), tomography, and positron emission (PET), the number of workers in the departments of radiography and Diagnostic Radiation, as well as the different types of imaging examinations performed. Also, the relative number of patients undergoing imaging procedure and hence the amount of radiation used have all increased [15,19]. Nonetheless, historical evidence of the radiation exposure of workers indicates that the doses have decreased with time due to improved radiation protection practices since the discovery of X-rays [17].

Many kinds of literature estimated the radiation dose of workers in these departments as mentioned earlier in which they had been reported the radiation doses vary between 1 and 50mSv/year in many parts of the world [20-26]. The United Nations Scientific Committee on the Effects of Atomic Radiations (UNSCEAR) has reported that the worldwide mean annual occupational dose in NM and DR is below 2mSv [27]. The substantial variation in exposure among staff working with radiation in departments of radiography and DR has attributed to the nature of the work that individual carries out.

This research deals with the analysis of Radiation level in occupational workers and effects that might cause when exposes to high doses. The point in this research work are essentially based on the data analysis and the research findings we recommended for workers exposed to medical radiation sources to follow and apply all the Safety rules established in the International Basic Safety Standards to Protect themselves against Ionizing Radiation and the Safety of Radiation Sources. Dose estimation for radiation workers is an essential factor for government and organizations to evaluate radiation risks and establish protective measures as recommended by [6,7,10,13].

Materials and Methods
The research used thermo luminescent dosimeters (TLD) and questionnaires in collecting the data. The TLDs comprise the cards with holders containing a Harshaw detector crystal of LiF: Ti, Mg (TLD-100) to give measurements of both skin and deep doses. The data was collected from five departments in different hospital in Dhaka city Bangladesh which includes Radiology department, CT scan department, Cardiology department, Radiotherapy department, and Nuclear medicine department. All workers are advised to wear the badge in proper position throughout their work. We recommended the upper-left side of the chest because is the most essential area to wear the dosimeter outside the lead apron as the maximum radiation exposure is anticipated in this part of the body. The target people for this investigation is all of the diagnostic medical radiation workers who carry out or assist in interventional radiation procedures and are presently registered in the five selected hospitals in Dhaka Bangladesh which works as a lifetime management system of occupational radiation doses.

We developed a questionnaire by reviewing previous studies among radiation workers and adjusting the questionnaire items used of earlier studies of diagnostic radiological medical workers we also conducted a pilot study between interventional medical radiation workers [28]. The enrolment questionnaire contains items on work practices, demographics, work history, the experience of high-dose exposure, and radiation exposure by personal medical examination, health-related behaviors and medical history. The demographic data comprise the date of birth, gender, name and workplace address.

The data where cumulatively collected and analyzed using charts and graphs to determine the absorb dose from each afore-mentioned categories that deal with radiation in the above departments where the equipment and the questionnaires was used. This study tried to entails the details of the distribution and trends of doses from occupational radiation exposure among radiation workers from these five selected hospitals in Dhaka Bangladesh. We used two-month dose measurements collected for a period of six months (April to September 2015); using a transportable environment radiation monitor (thermo luminescent dosimeters) to compute the total radiation in places of work in the mentioned departments. A total of 80 medical occupational workers were monitored, comprising 48 persons Diagnostics radiology department, 12 persons CT scan department, 5 people’s cardiologist, 10 personnel Radiologist and 5 people’s Nuclear medicine department.

Results and Discussion
The study used the introduction stage of more comprehensive and regular monitoring of occupational radiation exposures and compared the long-term investigations into its accumulation patterns. Hence, this could form the basis of future records on the detrimental effects of the radiation characteristic of workers in the medical field, because the ionizing radiation has dangerous health effects upon human exposure.

The dose dissemination of radiation workers is used to evaluate the minimum level of exposure in the medical field given by ALARA principles. In the Dhaka hospital, we monitored approximately 80 occupational radiation workers. Their percentage is as follows: nuclear medicine 4%, general radiography 38.4%, CT scan, and catheterization laboratory 9.6%, radiotherapy 8%, and Cardiology 4%. However, this percentage is part of 80. Table 1 explained the total number of radiation workers monitored for all the occupational categories of medical departments as well as their position during 2017 exercise. Also, Fig. 1 gives the percentage contribution yields for each type of medical radiation worker to the total monitored worker.

Where DR is the Diagnostics Radiation, RT is the Radiotherapy Dept. CD stand for Cardiology Department, NM is the Nuclear Medicine and CT is CT scan department.

The study obtained the average of the estimated dose for all departments ranged from 0.01 to 2.42mSv. Among these workers, workers in radiology department received the largest estimated dose. It was obtained by the use of a simple equation to compute the estimated dose received per person per year as:

In this regards we used the equation 1 and obtained the results in Table 2 as:

Where X stand for estimated dose per year in a unit mSv.

This method was applied to all the remaining departments. As for purpose of an article, due to the limitation we cannot present all the tables as it might sound boring and bulky. We summarized the results as in the Table 3.

All the results obtained are well below recommended dose for the international dose limit which is 20mSv. It is significant to comment that completely radiation workers were wearing a protective lead aprons and thyroid shields throughout when performing examinations, in agreeing to the radiation protection policy at the country hospitals. The annual estimated dose distribution for the entire radiation workers in the medical department is shown in Table 3 and Fig. 2. The highest recorded is far below the recommended dose limit 20mSv as adopted from the ICRP. As seen in Table 3, the highest annual dose obtained as recorded was 2.42mSv, recorded by the chest TLD that worn by one of the Nurse radiologists in the department, which represents 12.1% of the annual recommended dose limit.

This percentage was obtained using the relation given by the international commission for radiation protection (ICRP). Hence, the maximum permissible exposure limit for occupational workers by the international commission for radiation protection (ICRP) allowed standard maximum exposure is 20mSv for workers in radiation environment. From the estimated dose of exposure per year shows in this study, the maximum estimated dose exposure per year among all the workers in all departments is 2.42mSv, and minimum is 0.01. Their percentage is given as:

Then the minimum estimated dose exposure per year is 0.01mSv. The percentage is given as:

So, the average estimated dose exposure per year is

This yields the percentage average of

The percentage as calculated above for the occupational workers that work with radiation in selected hospitals in the hospital in Dhaka city will not exceed the estimated dose for the international commission on radiological protection (ICRP). It implies that the workers under these departments based on this research can maintain the daily continue record by keeping safety measures and rules.

Conclusion
The measured annual effective doses for diagnostic radiology, nuclear medicine radiotherapy, Cardiology and CT scan workers at Dhaka Bangladesh hospital were found to range from, 0.01 and 2.42mSv, respectively. The radiation protection program carried out at Dhaka Bangladesh hospital was effective due to correctly uses the international recommended rules and regulations. However, we found the occupational radiation to workers at five different medical departments received well below the recommended dose limit as compared it with the accepted international or global occupation radiation exposure level is 20mvs.

Acknowledgements
The author will like to thank the Head of Department ETE Daffodil International University and Directors and staff of Ibn Sina Hospital, Dhaka medical, and Square Hospital whose guidance yielded much for the completion of this research.

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