Keywords
OSL - TLD - lithium fluoride
Introduction
Radiation was discovered by Wilhelm Conrad Roentgen on November 8, 1895. It is possible
to say today that radiation is one of the causes of illnesses. Radiation is more damaging
on the molecular, cellular, and organ systems, which are known health stress agents.[1] Personnel radiation monitoring equipment monitors the level of exposure to radiation
and personnel will have to wear a personnel radiation detection device while dealing
with radiation. A personnel monitoring equipment detects and records a radiation dose
over a set period of time. The personnel monitoring equipment is usually worn by a
worker for 3 months. The measured dosage by the personnel monitoring equipment is
registered to the employer and then it is sent to the dosimetry service provider for
review.[2] According to AERB (Atomic Energy Regulatory Board) guidelines, the occupational
exposure of any worker will be so controlled that the effective dose of the whole
body is 20 mSv/year on average for 5 years, 30 mSv in any 1 year or public performance
for 1 mSv/year dose equal to the eye lens is 20 mSv in 1 year, spread over a given
5 year period; or public exposure 15 mSv a year; 500 mSv a year or an equivalent dose
of skin 50 mSv/year in public exposure; equal dose of hands and feet at per year 500
mSv. The fetus should not be exposed to greater than 1 mSv for pregnant radiation
workers following pregnancy declarations. AERB's mission consists of ensuring the
use of radioactive and ionizing radiation in India does not pose a health and environmental
danger.[3] The purpose of the measurement is to identify undesirable practices and unexpected
sources of high risk to provide information about occupational exposure, directing
long-term controls necessary to limit exposure and reduce exposure.[4] A variety of personnel radiation monitoring devices are used to measure radiation
exposure dose rates of radiation workers, such as film badge, thermoluminescent dosimeter
(TLD), pocket dosimeter, and optionally stimulated luminescence (OSL) dosimeters.[5]
Film Badge
Personnel dosimeter film badges are widely used for X-rays, gamma-rays, and β particles
for measuring and recording radiation exposure. The detector is a photographic film,
as the name implies, which is sensitive and must be produced on a monthly basis. The
film is sealed in a light- and vapor-resistant envelope to avoid any effects of illumination,
moisture, or chemical vapor on the film. The higher the radiation exposure, the darker
the film becomes. The film's blackness is linearly proportional to the dosage and
doses can be tested up to around 10 Gy. Dosimeters for film badges are used once only
and cannot be reused. A dosimeter is a film tag, which is worn by a person for monitoring
the surface of the body, and it records the received exposure dose. Film dosimeters,
aluminum oxide-based dosimeters, and electronic personal dosimeters are commonly replaced
by TLDs.[6]
[7]
Thermoluminescent Dosimeter
Thermoluminescent Dosimeter
TLD is an inert radiation detector device for monitoring personal exposures and for
measurement of patient exposure. The dosage can be as low as 1 millirem for a long
duration (normally 3 months or less), but the low dose capacity is almost identical
to that of a film badge under daily conditions. TLD badge parts are fitted with plastic,
nickel-plated TLD aluminum cards, discs of thermoluminescent content, and normally
doped with dysprosium-activated calcium sulfide (CaSO4:Dy) or lithium fluoride (LiF).
The discs are 0.8 mm in thickness and 1.35 cm in diameter. Each disc has three filters;
top: copper and aluminum, center: perspex, bottom: free. Electrons are excited as
radiation enters into the TLD and store energy. If you have a lead apron, you should
wear the TLD badge inside the apron (to reflect body supplements). TLD can measure
doses from 0.01 mGy to 10 Gy.[8]
[9]
Pocket Dosimeters
These are used to protect the wearer from X-rays and-gamma rays. They are normally
worn in the pocket as the name indicates. There are mainly two types, direct read
pocket dosimeters and digital electronic dosimeters, widely used in industrial radiography.[10]
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Direct read pocket dosimeter: It is usually of the size and shape of a fountain pen.
This dosimeter has a small ionization chamber with a volume of about two cubic milliliters.
There is a central wire anode inside the ionization chamber, and a metal connected
to this wire anode is the quartz fiber. When the anode is charged to a positive potential,
the charge is stocked between the anode and the quartz fiber.[10]
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Digital electronic dosimeter: This wireless electronic dosimeter is another kind of
pocket dosimeter. This dosimeter records the dosage and dose information. The radiation
detector output is collected and the recovered charge is unloaded to activate the
electronic counter when there is a predetermined danger. The counter then shows the
risk and dosage rate accrued in the digital form. An audible warning, which releases
an audible signal or chirp each time the emission is increased, is used in some wireless
electronic dosimeters.[10] The advantage of a pocket dosimeter is to permit the staff to check his and her
risk, a significant benefit to high-radiation workers at all times.[11]
Optically Stimulated Luminescence Dosimeters
Optically Stimulated Luminescence Dosimeters
OSL dosimeters are designed to provide a very high level of sensitivity to X-rays
or gamma-ray photon energy from 5 kV to greater than 40 MeV, giving accurate readings
as low as 1 millirem. OSL technologies are mainly using for x-ray, gamma-ray, β-ray,
neutron and radiation detections are planned to be supplied by OSL dosimeters. The
dynamic component of the OSL locator is a meager shot in a lace containing carbon-doped
aluminum oxide powder. This powder is then covered with a fastener between two portions
of a polyester film, then combined consequently framing a lace. OSL dosimeters have
properties that clarify why they are generally utilized: nondamaging perusing; an
expansive estimating range from 0.01 mSv to 10 Sv; and preferred affectability to
all energies over photographic film and TLDs.[12]
Materials and Methods
This study was a prospective, comparative, questionnaire-based study and designed
and performed among paramedical students of College of Paramedical Sciences, Teerthanker
Mahaveer University, Delhi–Moradabad Road, Uttar Pradesh. Knowledge about personnel
monitoring devices and their use by postgraduate and undergraduate students, from
the Department of Radiological Imaging Techniques, was compared. A total of 140 paramedical
radiology students pursuing both bachelor's and master's degree programs were selected.
The study was composed of a self-structured survey partitioned into two segments.
The first section of the questionnaire consisted of demographic data including name,
age, gender, program, department, and year. The second section of the questionnaire
consisted of 20 basic questions regarding assessing adequate theoretical and practical
knowledge of the participants for personnel radiation monitoring devices based on
AERB 2017 guidelines. The randomized study control consisted of all students including
both males and females of College of Paramedical Sciences who were physically and
mentally sound and aged between 17 and 30 years, excluding the candidates who fell
under the exclusion criteria.
Inclusion Criteria
Radiology students pursuing bachelor's (second year and third year) and master's degree
programs (first year and second year).
Exclusion Criteria
Students of B.Sc. in Radiology and Imaging Technology (BRIT) first year, all except
radiology students and diploma holders.
Procedure
For this study 140 participants who were willing to participate were taken from the
College of Paramedical Sciences, Teerthanker Mahaveer University, Moradabad as per
the inclusion and exclusion criteria. The questionnaire used in the study consists
of 20 questions that comprise the knowledge of personnel monitoring devices and their
use. The data collection was done by an online source (Google form) and the link of
the form was shared in the classrooms under the inclusion criteria, by which all the
responses were obtained in MS Office (2013) files and the data were subjected to mean
value.
The project setting was done in the College of Paramedical Sciences, Teerthanker Mahaveer
University, located in the area of Moradabad district of Uttar Pradesh, India. This
University is well established with various paramedical courses with various programs
required for this study including radiological imaging techniques.
Statistical Analysis
The data collected were compiled, tabulated, presented in graphs, and analyzed. Analysis
was done using the mean value.
Result
This study questionnaire was filled by a total of 140 students who were students of
bachelor's and master's programs, including 61% (86) males and 39% (54) females from
the radiology department.
[Fig. 1] shows a pie chart of the total number of students, males and females.
Fig. 1 A pie chart representing the total number of students, male and female.
BRIT second year students comprised 41% (58), BRIT third year participants comprised
35% (49), M.Sc. in Radiology and Imaging Technology (MRIT) first year participants
comprised 10% (14), and master's final year students comprised 14% (19) of the total
participants.
[Fig. 2] shows a pie chart of the total number of students.
Fig. 2 A pie chart representing the total number of students.
[Fig. 3] shows a graph of the overall average %.
Fig. 3 A graph representing the overall average %.
The graph shows that from the students of the BRIT second year, 66% responded with
the right answer and the rest 34% responded with the wrong answer. Among participants
from BRIT third year, 65% responded with the right answer and the rest 35% with the
wrong answer. Among participants from MRIT first year, 80% responded with the right
answer and the rest 20% with the wrong answer, and among MRIT final year participants
81% responded with the right answer and the rest 19% with the wrong answer.
Discussion
In this study to obtain the response of the first question about personnel monitoring
device, 49 out of 58 (84%) responded with the right answer and the rest 9 (16%) with
the wrong answer from BRIT second year; from BRIT third year 45 out of 49 (92%) responded
with the right answer and the rest 4 (8%) with the wrong answer; from MRIT first year
13 out of 14 (93%) responded with the right answer and the rest 1 (7%) with the wrong
answer; and from MRIT final year participants 19 out of 19 (100%) responded with the
right answer.
For the second question about what type of material is used in the TLD badge, from
BRIT second year participants, 40 out of 58 (69%) responded with the right answer
and the rest 18 (31%) with the wrong answer; from BRIT third year participants, 28
out of 49 (57%) responded with the right answer and rest 21 (43%) with the wrong answer;
from MRIT first year students, 11 out of 14 (79%) responded with the right answer
and rest 13 (21%) with the wrong answer; and from MRIT final year participants, 15
out of 19 (79%) responded with the right answer and the rest 4 (21%) with the wrong
answer.
For the third question about which type of monitoring device replaces the film badge,
53 out of 58 (91%) responded with the right answer and the rest 5 (7%) with the wrong
answer from BRIT second year; from BRIT third year 43 out of 49 (88%) responded with
the right answer and the rest 6 (12%) with the wrong answer; from MRIT first year
12 out of 14 (86%) responded with the right answer and the rest 2 (14%) with the wrong
answer; and from MRIT final year participants 16 out of 19 (84%) responded with the
right answer and the rest 3 (16%) with the wrong answer.
For the fourth question about whether TLD uses lithium fluoride, 41 out of 58 (71%)
responded with the right answer and the rest 17 (29%) with the wrong answer from BRIT
second year; from BRIT third year 44 out of 49 (90%) responded with the right answer
and the rest 5 (10%) with the wrong answer; from MRIT first year 14 out of 14 (100%)
responded with the right answer; and from MRIT final year participants 17 out of 19
(89%) responded with the right answer and the rest 2 (11%) with the wrong answer.
For the fifth question about which device gives instant reading when exposed to radiation,
38 out of 58 (66%) responded with the right answer and the rest 20 (34%) with the
wrong answer from BRIT second year, from BRIT third year 35 out of 49 (71%) responded
with the right answer and rest 14 (29%) with the wrong answer, from MRIT first year
13 out of 14 (93%) responded with the right answer and rest 1 (7%) with the wrong
answer and from MRIT final year 15 out of 19 (79%) responded with the right answer
and rest 4 (21%) with the wrong answer.
For the sixth question about which monitoring device was easily affected by heat,
water, and humidity, 38 out of 58 (66%) responded with the right answer and the rest
20 (34%) with the wrong answer from BRIT second year; from BRIT third year 29 out
of 49 (59%) responded with the right answer and the rest 20 (41%) with the wrong answer;
from MRIT first year 10 out of 14 (71%) responded with the right answer and the rest
4 (29%) with the wrong answer; and from MRIT final year 13 out of 19 (68%) responded
with the right answer and the rest 6 (32%) with the wrong answer.
For the seventh question about whether the statement was true that film badge records
whole-body radiation over a long period the time, 38 out of 58 (66%) responded with
the right answer and the rest 20 (34%) with the wrong answer from BRIT second year;
from BRIT third year 5 out of 58 (10%) responded with the right answer and the rest
44 (90%) with the wrong answer; from MRIT first year 7 out of 14 (50%) responded with
the right answer and the rest 7 (50%) with the wrong answer; and from MRIT final year
8 out of 19 (42%) responded with the right answer and the rest 11 (58%) with the wrong
answer.
For the eighth question about the maximum period time TLD should be worn, 40 out of
58 (69%) responded with the right answer and the rest 18 (31%) with the wrong answer
from BRIT second year, from BRIT third year 36 out of 49 (73%) responded with the
right answer and the rest 13 (27%) with the wrong answer; from MRIT first year 11
out of 14 (79%) responded with the right answer and rest 3 (21%) with the wrong answer;
and from MRIT final year 19 out 19 (100%) responded with the right answer.
For the ninth the question about the things film badge, OSL, a pocket dosimeter, and
TLD have in common, 48 out of 58 (83%) responded with the right answer and the rest
10 (17%) with the wrong answer from BRIT second year; from BRIT third year 48 out
of 49 (98%) responded with the right answer and the rest 1 (2%) with the wrong answer;
from MRIT first year 14 out of 14 (100%) responded with the right answer; and from
MRIT final year 19 out of 19 (100%) responded with the right answer.
For the 10th question about which device uses an aluminum oxide detector, 38 out of
58 (66%) responded with the right answer and the rest 20 (34%) with the wrong answer
from BRIT second year; from BRIT third year 38 out of 49 (78%) responded with the
right answer and the rest 11 (22%) with the wrong answer; from MRIT first year 12
out of 14 (86%) responded with the right answer and the rest 2 (14%) 38 with the wrong
answer; and from MRIT final year 15 out of 19 (79%) responded with the right answer
and the rest 4 (21%) with the wrong answer.
For the 11th question about which dose limit is specified for, 36 out of 58 (62%)
responded with the right answer and the rest 22 (38%) with the wrong answer from BRIT
second year; from BRIT third year 25 out of 49 (51%) responded with the right answer
and the rest 24 (49%) with the wrong answer; from MRIT first year 12 out of 14 (86%)
responded with the right answer and the rest 2 (14%) with the wrong answer; and from
MRIT final year 18 out of 19 (95%) responded with the right answer and the rest 1
(5%) with the wrong answer.
For the 12th question about the annual effective dose limit of students which should
not be exceeded, 36 out of 58 (62%) responded with the right answer and the rest 22
(38%) with the wrong answer from BRIT second year; from BRIT third year 25 out of
49 (51%) responded with the right answer and the rest 24 (49%) with the wrong answer;
from MRIT first year 11 out of 14 (79%) responded with the right answer and the rest
3 (21%) with the wrong answer; and from MRIT final year 16 out of 19 (84%) responded
with the right answer and the rest 3 (16%) with the wrong answer.
For the 13th question about which compound is used in OSL, 28 out of 58 (48%) responded
with the right answer and the rest 30 (52%) with the wrong answer from BRIT second
year; from BRIT third year 23 out of 49 (47%) responded with the right answer and
the rest 26 (53%) with the wrong answer; from MRIT first year 10 out of 14 (71%) responded
with the right answer and the rest 4 (29%) with the wrong answer; and from MRIT final
year 13 out of 19 (68%) responded with the right answer and the rest 6 (32%) with
the wrong answer.
For the 14th question about OSL stimulation, 32 out of 58 (55%) responded with the
right answer and the rest 26 (45%) with the wrong answer from BRIT second year; from
BRIT third year 28 out of 49 (57%) responded with the right answer and the rest 21
(43%) with the wrong answer; from MRIT first year 10 out of 14 (71%) responded with
the right answer and the rest 4 (29%) with the wrong answer; and from MRIT final year
15 out of 19 (79%) responded with the right answer and the rest 4 (21%) with the wrong
answer.
For the 15th question about in pocket dosimeter which unit is used to measure radiation,
16 out of 58 (28%) responded with the right answer and the rest 42 (72%) with the
wrong answer from BRIT second year; from BRIT third year 16 out of 49 (33%) responded
with the right answer and the rest 33 (67%) with the wrong answer; from MRIT first
year 5 out of 14 (36%) responded with the right answer and the rest 9 (64%) with the
wrong answer; and from MRIT final year 3 out of 19 (16%) responded with the right
answer and the rest 16 (84%) with the wrong answer.
For the 16th question about the three filters used in TLD, 22 out of 58 (38%) responded
with the right answer and the rest 36 (62%) with the wrong answer from BRIT second
year; from BRIT third year 21 out of 49 (43%) responded with the right answer and
the rest 28 (57%) with the wrong answer; from MRIT first year 10 out of 14 (71%) responded
with the right answer and the rest 4 (29%) with the wrong answer; and from MRIT final
year 18 out of 19 (95%) responded with the right answer and the rest 1 (5%) with the
wrong answer.
For the 17th question about the type of radiation measured by TLD, 54 out of 58 (93%)
responded with the right answer and the rest 4 (7%) with the wrong answer from BRIT
second year; from BRIT third year 46 out of 49 (94%) responded with the right answer
and the rest 3 (6%) with the wrong answer; from MRIT first year 14 out of 14 (100%)
responded with the right answer; and from MRIT final year 19 out of 19 (100%) responded
with the right answer.
For the 18th question about the level TLD should be worn at, 47 out of 58 (81%) responded
with the right answer and the rest 11 (19%) with the wrong answer from BRIT second
year; from BRIT third year 41 out of 49 (84%) responded with the right answer and
the rest 8 (16%) with the wrong answer; from MRIT first year 13 out of 14 (93%) responded
with the right answer and the rest 1 (7%) with the wrong answer; and from MRIT final
year 19 out of 19 (100%) responded with the right answer.
For the 19th question about the location of TLD inside the lead apron, 40 out of 58
(69%) responded with the right answer and the rest 18 (31%) with the wrong answer
from BRIT second year; from BRIT third year 36 out of 49 (73%) responded with the
right answer and the rest 13 (27%) with the wrong answer; from MRIT first year 8 out
of 14 (57%) responded with the right answer and the rest 6 (42%) with the wrong answer;
and from MRIT final year 16 out of 19 (84%) responded with the right answer and the
rest 3 (16%) with the wrong answer.
For the 20th question about whether technologists can use the same TLD, 33 out 58
(57%) responded with the right answer and the rest 25 (43%) from BRIT second year;
from BRIT third year 26 out of 49 (53%) responded with the right answer and the rest
23 (47%) with the wrong answer; from MRIT first year 13 out of 14 (93%) responded
with the right answer and the rest 1 (7%) with the wrong answer; and from MRIT final
year 15 out of 19 (79%) responded with the right answer and the rest 4 (21%) with
the wrong answer.
Conclusion
According to this study, it is concluded that there is good awareness about personnel
radiation monitoring systems. The level of knowledge of personnel radiation monitoring
devices among students remains at a medium level from the results of our students
as it has been concluded that master's degree students' knowledge level is greater
than that of bachelor's level. The level of knowledge of monitoring devices increases
with the age of the students and the year completed. Personnel monitoring's purpose
is to provide early notice if the exposure exceeds the thresholds and as low as reasonably
achievable (ALARA). Furthermore, the tracking device maintains a permanent record
of the radiation. For the knowledge about personnel radiation monitoring devices and
their use for further improvement, regular seminars, workshops, continuing medical
education should be organized. Enforcing personnel monitoring safety rules, as well
as any level of safety education and instruction, is important for wellbeing.
