2. Radiation Safety Program
The objective of the Radiation Safety
Program is to provide a place of
employment as free as possible from any
radiation hazards
3. What is Radiation ?
Radiation:
Energy in the form of
particles or
electromagnetic waves
6. Radiation protection
The aim of radiation protection is to ensure that radiation
is used safely.
The system of radiation protection was proposed by
International Commission of Radiological Protection(ICRP)
Radiation protection is based on the following principles:
A: Justification
B: Optimization
C: Dose limit
7. •JUSTIFICATION
•All exposure either diagnostic or therapeutic shall be
under taken only if the benefit gained out of the
detriment.
•No practice shall be adopted unless it produces a net
positive benefit.
•OPTIMIZATION
•All exposures which are justified shall be under taken
with a minimum possible dose.
8. •Every effort shall be taken to reduce the dose to As Low
As Reasonable Achievable (ALARA), taking into
account the economic and social considerations.
• Dose limit
•Exposure of radiation worker and individuals of public
must not exceed dose limit.
10. Factors which influence radiation exposure:
. Time
. Lower the time of exposure, lower the dose to patient
and radiation worker.
. For a given shielding and distance from the source,
exposure is directly proportional to time.
11. Distance
Effective & Easy
Inverse Square Law
Doubling distance from source,
decreases dose by factor of four
Tripling it decreases dose nine-fold
More Distance = Less Radiation
Exposure
13. Public dose limits
.Whole body : 1mSv/yr averaged over any 5 year period.
. Lens of the eye : 15mSv/yr
. Skin : 50mSv/yr
. Hands & feet : no limit specified
14. Occupational dose limits
.Whole body : 20mSv/yr averaged over any 5 year period.
(for pregnant radiation worker it is 5mSv/yr .)
. Lens of the eye : 150mSv/yr.
. Skin : 500mSv/yr.
. Hands & feet : 500 mSv/yr.
15. Radiation and Pregnancy
The pregnant woman who is a radiation worker can
be considered as an occupationally exposed
individual, but the foetus cannot. The total dose
equivalent limit to an embryo-foetus is 5mSv,
with the added recommendation that exposure to
the foetus should not exceed 0.5 mSv in any one
month.
Pregnant radiation worker should wear a second
badge at the waist level (under the lead apron)
16. Biological effects
generally a threshold level exist (1Gy)
greater the dose, greater the effect.
e.g. : cataract, sterility.
generally without a threshold level of dose.
higher the dose, higher risk of the effect.
Genetic (damage in DNA/genes)
Somatic (damage in cells/body/cancer)
Teratogenic (damage in fetus)
Deterministic
Effects:
Stochastic
Effects
17. Relative penetrating ability of
ionizing radiation in tissue
Alpha
Beta
Gamma
Neutron
(Several layers of skin)
102-12
18. Low energy gamma or x-ray
High energy gamma or x-ray
Shielding for gamma emitting material
19. External Exposure
1. Cosmic radiation
Extremely energetic particles (protons)
On interaction in atmosphere produces low energy particles
Mainly muons, gamma, neutrons, electrons at sea level
Range is 0.3 to 1 mSv (0.4 mSv)
2. Terrestrial gamma radiation
K-40, U-238, Th-232 are available in earth’s crust
These nuclides and daughter products found in soil, building materials
Range is 0.3 to 0.6 mSv (0.5)
High in some areas (1.0 mSv)
NATURAL RADIATION EXPOSURES
20. 1. Fluoroscopy
2. Computed Tomography (CT)
3. Chest Examinations
4. Mammography
Important Radiological Examinations
Medical radiation exposures
Diagnostic Radiology
Radiotherapy
Nuclear Medicine
Interventional Radiology
23. Types of Radiation use at Batra Hospital
Radiation is used for diagnosis and therapeutic
treatment
OT & Dental X-Ray , CT Machines, Fluoroscopy-
Diagnostic, Deptt ….
Radioactive Materials imaging – Nuclear Medicine
Therapeutic – Radiation Oncology
• Large quantities are used for patient therapy.
• Smaller quantities are used for diagnostic procedures
and medical research
• Special training and monitoring are required in areas
where personnel use radiation.
24. Protection from External Radiation Exposure
Protective Devices
Lead Apron
Lead collar
Lead Gonad Shield
Lead gloves,
proper monitoring
25. 0.25 mm lead
60 kV; 100% 2 - 3 %
100 kV; 100% 8 - 15 %
Attenuation measured with lead
aprons
X ray beam filtration has a great influence!!
Measurements at San Carlos Hospital, Madrid
26. 0.50 mm lead
60 kV; 100% < 1 %
100 kV; 100% 3 - 7 %
Attenuation measured with lead
aprons
X ray beam filtration has a great influence!!
Measurements at San Carlos Hospital, Madrid
27. Examination Dose to patient
CT Head 2mSv
CT Abdomen 9mSv
CXR 0.05mSv
Dental X-ray 0.005mSv
Lumber spine 2mSv
Dose from X-ray Procedures:-
28. Responsibilities of X-ray Technologist
. Repeat X-ray must be avoided in order to reduce patient
dose.
. Records of all radiological examination should be
maintained.
. Personnel monitoring devices shall be used by all
radiation worker.
. Each equipment must have separate log book which
provide information about equipment manufacturer,
model, serial no., max kV & max mA.
29. Radiation safety in Diagnostic Radiology
The radiation safety of radiatin worker :
. Use of protective clothing, lead aprons, lead lined
viewing windows, protective barriers, organ shields.
. Use of suitable imaging parameter(kV & mA) so
that repeat of same examination for a patient can be
avoided.
. Use of radiation monitoring and survey instruments.
. Training of operator.
30. Radiation safety in Diagnostic Radiology
The radiation safety of patient :
. Justification of the practice.
. Use of standard procedure and imaging parameter.
. Use of screen-film combinations, use of fast film.
. Limiting the field size to region of interest.
. Use of organ shield.
. Proper communication with patient.
32. Guidelines for Using TLD Badge:-
1.TLD badges are to be used only by persons directly
working in the radiation. Administrators, dark room
assistant , sweepers etc., need not be provided with
TLD badges .
2. TLD badge is used to measure the radiation dose it
does not protect the user from the radiation .
3. The name, personnel number, period of use, location
on the body ( chest or wrist ) etc, should be written in
the block letters on the front side of the badge.
33. 4. A TLD badge once issued to a person should not be
used by another person.
5. TLD badge should be worn compulsorily at the chest
level. It represent the whole body dose equivalent. If
lead apron is used, TLD badge should be worn under
the lead apron.
6. A badge without filter or damaged filter should not
be used . It is replaced by a new holder.
34. 7. Every radiation worker must ensure that the badge is
not left in the radiation field or near hot plates, ovens,
burners etc.
8.Loss or accidental exposure to the TLD badges
should immediately reported to the RSO.
9. Every new radiation worker has to fill up the
personnel data form, and should be sent to
Radiological safety officer of their respective
department.
35. Radiation Safety
-Laboratory Rules-
1. Smoking, eating, and drinking are not permitted in
radionuclide laboratories.
2. Food and food containers are not permitted in the
laboratory.
- Do not use refrigerators for common storage
of food and radioactive materials.
- Do not heat food or beverages in microwaves
used to conduct research.
