This document summarizes occupational radiation safety in hospitals. It covers typical medical uses of radiation like radiotherapy, diagnostic imaging, and nuclear medicine. It discusses the regulatory framework in India, categories of radiation exposures, and issues related to excessive exposures. The conclusion emphasizes that while occupational doses are usually low, there are concerns about reported excessive exposures in diagnostic radiology and nuclear medicine. Improving safety culture and proper use of dosimeters is important to ensure doses remain below limits.

1. Overview of
Occupational Radiation Safety in
Hospital
Dr. Avinash U. Sonawane
Head, Radiological Safety Division
Atomic Energy Regulatory Board

2. Topics covered in presentation
• Applications of radiation
• Regulatory framework
• Regulatory requirements in respect of
occupational workers
• Categories of exposures
• Issues relating to excessive exposures
• Conclusion
18 November 2015 2

3. Typical Usage of Radiation in Medicine
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Treatment of Cancer
through Radiotherapy
Medical Diagnosis and
Cardiological
Procedures Using X-rays
Nuclear Medicine for
diagnosis, PET
examination and
treatment
Blood
irradiation to
prevent
Transfusion-
Associated
Disease

4.  An estimated 5.1 million courses of radiotherapy treatment were
administered annually between 1997 and 2007.
UNSCEAR 2008 Report
 Every year, 1 million new cancer cases are detected in India of which
40,000 cancer cases occur in children.
TMH,Mumbai Report
 Over the last three decades, at least 3000 patients have been
affected by radiotherapy incidents and accidents.
 These accidents do not affect patients directly (e.g. harm and
death), but might also undermine the public’s confidence in the
treatment.
 Preventable medical errors overall also cost countries billions of
dollars each year.
IAEA
Radiotherapy

5.  An estimated 3.6 billion (3.1 medical and 0.5 dental) x-ray examinations
were undertaken annually in the world between 1997 and 2007.
 Total annual collective effective dose to the global population (6,446
millions) from diagnostic medical exposures was estimated to be 4000
x103 manSv .
 Annual per caput effective dose is 0.62 mSv.
 CT scanning accounts 43% of the total collective effective dose due to
diagnostic medical radiology.
UNSCEAR 2008 Report
Diagnostic Radiology

6. Nuclear Medicine
• Nuclear medicine includes all uses of unsealed radioactive sources
for diagnostic and therapeutic purposes.
• An estimated 33 million diagnostic nuclear medicine examinations
performed annually worldwide.
• Annual collective effective dose to the world population due to
diagnostic nuclear medicine examinations is estimated to be 202
x103 manSv.
• For diagnostic nuclear medicine, the main contribution to the
collective effective dose arise from Tc-99m bone scans, Tl-201
cardiovascular studies and iodine thyroid scans.
UNSCEAR 2008 Report

7. The UN Classes of Dangerous Goods
1. Explosive Substances
2. Gases
3. Flammable liquids
4. Flammable solids
5. Oxidizing substances
6. Toxic substances
7. Radioactive material
8. Corrosive substances
9. Miscellaneous dangerous substances and articles
7

8. Direct
effects
Indirect
effects
Cell death
Primary
damage
Modified
cell
Damage
to organ
Somatic
cells
Germ
cells
Hereditary
effects
Cancer
Leukemia
Death of
organism
Repair
Deterministic
effects
Stochastic
effects
Biological effects of ionizing radiation

9. Regulatory Framework
18 November 2015
System of Regulatory Control
Issued by Central Government
Act
[Atomic Energy Act, 1962]
Rules
[Atomic Energy (Radiation Protection)
Rules, 2004]
Notifications
Published by AERB
Safety Codes
Safety Standards
Safety Guides
Safety Manuals

10. • Atomic Energy Regulatory Board
(AERB) – the National Regulatory
Authority for radiation protection
• AERB constituted in 1983.
• The mission of the Board is to
ensure that the use of ionizing
radiation and nuclear energy in
India does not cause undue risk to
health and the environment.
• Chairman, AERB is the
Competent Authority for radiation
protection in India.
10
Atomic Energy
Regulatory Board (AERB)

11. Atomic Energy Regulatory Board
18 November 2015 11
“Licence in accordance with Atomic Energy (Radiation Protection)Rules,
2004 from AERB is mandatory requirement for the procurement and use
of radiation sources in India”.
AERB, Anushaktinagar, Mumbai
Radiological Safety Division (RSD) of AERB is responsible for enforcement of
regulations to ensure safe handling of ionizing radiation sources

12. Principles of Radiation Protection
• Justification- whether benefit of
use of radiation outweighs the
risk
• Optimisation- If exposure
justified, then keep it as low as
reasonably achievable (ALARA)
• Dose Limits- exposures should
be within the prescribed dose
limits

13. 13
Principles of Radiological Protection
Justification
– Includes risk, cost and radiation detriment
– Depends upon availability of alternate techniques
– Sometimes beyond the scope of radiological protection alone
– In planned situation by controlling the source
– In emergency situation by modifying the pathway to avert further
exposure
– Responsibility for justification generally lies with the Government or
National authority
– For medical exposure justification often lies with professionals
– Professionals need to be specifically trained in Radiological Protection
Unjustified Practices
– Introducing radiations in consumer products-toys, jewellery, foods etc.
– Radiological examination without clinical indication
– Mass screening

14. 14
Optimisation
• Likelihood of incurring exposure
• Number of people exposed
• Magnitude of individual dose
• Socio-economical factors
• ALARA – Time…Distance…..Shielding
Level of benefit should be high maximizing
the margin over harm.

15. Basis of Dose Limits
• Risk based approach:
• For radiation workers: The death rate probability is 1 out of 1000. This
death rate probability is equal to the death rate probability of the workers
working in high risk areas in a safe industry.
• For the public the risk is considered to be 1/10th of the workers
• The average dose received by a radiation worker is below 1 mSv/annum
i.e. below 1/20th of the prescribed limit
Note:
• The risk is estimated on the basis of Linear No Threshold (LNT) Model.
• The deleterious effects of ionising radiation is yet to established at low
doses.
• The genetic effects w.r.t. radiation exposure in human beings is yet to be
established.

16. 16
System of Radiological Protection
• Type of exposure situations
– Planned exposures
– Emergency exposures
– Existing exposure situations
• Categories of exposures
– Occupational exposure
– Public exposure
– Medical exposure
• Identification of exposed individuals
– Workers
– Members of public
– Patients and comforters

17. Categories of Exposure…
• Occupational Exposure: Rradiation exposure
of workers incurred as a result of their work
during use of radiation sources (radioactive
material and radiation generating equipment).
Dose Limit: As per AERB Directive 01/2011

18. Adult Occupational Dose Limits
Whole Body (everything except extremities)
30 mSv maximum per year
20 mSv averaged over 5 years
Extremities
500 mSv per year
Skin of the Whole Body
500 mSv per year
Lens
150 mSv
(New limit 20
mSv/y)

19. Categories of Exposure…
• Public Exposure:
Public exposure encompasses all exposures of
the public other than occupational exposures
and medical exposures of patients.

20. Public Dose Limits
Whole Body (everything except extremities)
1 mSv per year
Extremities
50 mSv per year
Skin of the Whole Body
50 mSv per year
Lens
15 mSv

21. Annual average exposures (mSv) for the year 2014 in
India
Source/Practice Average
annual
effective dose
(mSv)
Diagnostic X-rays 0.8
Radiation therapy 0.55
Nuclear Medicine 0.9
Industrial Radiography and Radiation processing 1.41
Research 0.37

22. Categories of Exposure…
• Medical Exposure: As per RPR 2004
"medical exposure" means exposure incurred by -
(i) patients as part of their own medical diagnosis
or treatment;
(ii) persons, other than occupationally exposed,
while knowingly and willingly helping in the
support and comfort of patients; and
(iii) volunteers in biomedical research.

23. Categories of Exposure…
• Medical Exposure:
• Dose limits do not apply to medical exposures.
• Diagnostic reference levels
• Dose constraints for comforters and carers???

24. • Dose constraints for comforters and visitors of patients:
5 mSv for adults and 1 mSv for children.
• Diagnostic Reference levels / Guidance Levels
(Radiography, Fluoroscopy, CT & Cardiology
procedures, Nuclear Medicine)

26. Personnel monitoring requirements (Rule 27b)
• The workers shall be subjected to personnel
monitoring and health surveillance and
appropriate records shall be maintained.

27. Records of workers (Rule 24)
(1) Every licensee shall maintain complete and up-to-date
records of -
(a) personnel monitoring
(b) the health surveillance
(2) Such records shall be preserved during the working
life of each worker, and afterwards until the worker
attains or would have attained the age of Seventy five
years, or not less than thirty years after the
termination of the work involving occupational
exposure whichever is later.
(3) A worker shall have access to his personnel
monitoring and the health surveillance records.

28. Classified worker (Rule 18)
The employer shall designate as classified
workers, those of his employees, who are
likely to receive an effective dose in excess of
three tenths of the average annual dose limits
notified by the competent authority and shall
forthwith inform those employees that they
have been so designated.

29. Health surveillance of workers (Rule 25)…
(1) Every employer shall provide the services of
a physician with appropriate qualifications to
undertake occupational health surveillance of
classified workers.

30. Health surveillance of workers
(2) Every worker, initially on employment, and
classified worker, thereafter at least once in three
years as long as the individual is employed, shall
be subjected to the health surveillance such as -
(a) special tests or medical examinations as
specified by order by the competent authority,
for workers who have received dose in excess of
regulatory constraints; and
(b) counselling of pregnant workers.

31. Directives in the cases of exposures in excess of
regulatory constraints (Rule 28)…
(1) When, in the opinion of the competent
authority, any worker has exceeded the dose
constraints, the competent authority may,
without prejudice to other course of action
available, issue appropriate directives for
controlling further exposure and the employer
shall comply with the directives.

32. Directives in the cases of exposures in excess of
regulatory constraints…
(2) If a worker discontinues radiation work under
the directives of the competent authority issued
under this rule, the employer shall assign
alternative work not involving exposure to
radiation, until the competent authority is
satisfied about the fitness of the worker to
resume radiation work.
(3) The employer shall comply with restrictions, if
any, that the competent authority may impose in
this regard.

33. Reporting of suspected excessive exposure (EE)
If in a reporting period, the dose received
exceeds 10 mSv, the same needs to be
reported and investigation is required.

34. Issues while dealing with EEs
→ Delays in receipt of TLD badges from user institutions (especially
Oct-Dec quarter)
→ time required in processing of TLDs
→ time required in reporting excessive exposures to
Excessive Exposure Investigation Committee (EEIC)
→ time required in establishing dose,
owing to information collection (CA
Test, explanation from individual etc;)
→ time required for information to
be updated into National Occupational
Dose Registry Section (NODRS),
RP&AD, BARC
→ Reporting to AERB.

35. Steps initiated for a speedier mechanism
A) Faster Information gathering from NODRS
B) Graded approach in dealing with excessive
exposures.
– 10-20mSv
– 20-30mSv
– 30-100mSv
– >100mSv

36. Graded approach adopted
• 10-20mSv:
– Issue letter by AERB cautioning the institution.
– Await explanation for lead correction ( 15 days)
– Check for TLD pattern (genuine/non-genuine)
– Assign the dose as per AERB Guidelines
• 20-30mSv:
– Review by RSD internal committee
– Issue a warning letter.
– Await explanation ( 1 month) before assigning dose.
• 30-100mSv: Review by RSD, AERB committee
• >100mSv:
– Priority review by present >50mSv committee
– Inspection of the facility on priority or in the annual schedule by RSD members
– Requirement of CA test can be decided based on Committee review and/or
inspection.

37. Actions of AERB for expeditious investigation and to
avoid recurrences of EE
• Constitution of regional committees at two RRCs of AERB
• Advised RP&AD to take up CA examination on fast track
• Circular issued by AERB to each institution where EE has
occurred in regard to prevent misuse of TLDs
• Guidelines issued to all Radiation facilities for proper use of
TLDs to avoid non-genuine OEs
• Inspection/Investigations carried out at many facilities by
making visit to the radiation facility
• A working group being constituted within RSD to investigate
all EE cases and consolidated report to be submitted for
review.
• Emails sent to more than 14000 individuals in diagnostic
radiology practice guiding for proper use of TLD badges till
date.

38. Genuine radiation exposures expected to be received in
diagnostic procedures
• Fluoroscopy ( Cath-lab/ C-arm/R&F):
– 0.05mSv/cardiac procedure translates to 15mSv/ 3 months. Highly likely to exceed the
annual dose limit.
– Cardiac procedures has the highest radiation generation as compared to other
procedures.
– This is assuming lead apron has been worn at all times, which is normally the case.
• Radiography: Without protection and working at 1 m distance, operator
could receive nearly 80-100mSv/ year, for a busy centre.
• CT: Similar situations as a patient facilitator/ employee for CT. This
might specifically occur in Operation Theatres.
• Dental: Design fault possible, leading to high leakage radiation levels
owing to extensive manufacturing of tube housing for shielding in local
industries.
• Manufacturer: Not having proper work culture

39. Reasons for non-genuine exposures in diagnostic radiology
-Improper use of TLD
- Instances of TLD placed on equipment
- Use of TLD without filter
- Leaving the TLD near x-ray primary beam.
-Positive on CA test could mean
• Exposures for individual’s medical exam
• High level of uncertainty involved near 100mSv ( as
per discussions with bio-dosimetry group, BARC)

40. Issues under review….
• e-LORA module presently limited applicability - few
registered institutes -Hence, both paper and electronic
processing will have to be present.
• Very difficult to lay-off medical practitioners
>100mSv/qtr.
• Institutions where there was an excessive exposure to
be included as part of inspection schedule of AERB.
• Rationale in issuance of TLD badges in medical
practice to be firmed up . ( practice already followed in
Industry)

41. Exposure during emergency
Reference level
• Normally it should not be more than 100 mSv
• For life saving activities: 500 mSv

42. Exposure during emergency
• Response organizations and employers shall
ensure that emergency workers who
undertake actions in which the doses received
might exceed 50 mSv do so voluntarily (BSS).

43. Exposure during emergency
• Workers who receive doses in an emergency
exposure situation shall not normally be
precluded from incurring further occupational
exposure. However, qualified medical advice
shall be obtained before any further
occupational exposure if such a worker has
received a dose exceeding 200 mSv or at the
request of the worker (BSS).

44. Training programme for RSOs
44
Name of the
course
Conducted by No. of
courses
No.
Candidates
per course
duration
No. of
Person
Trained per
year
RSO Certification
* for Radiotherapy
Applications
RP&AD, BARC 16 5-30 1-2 years ~70
RSO Certification
# for Nuclear
Medicine
Applications
RP&AD, BARC 16 2-12 1-3 ~80
RSO
Certification in
Diagnostic
Radiology (Only
for Service
Engineers)
RP&AD, BARC 5 15-30 Two wks 45-100

45. Conclusion
• Overall occupational doses in medical applications of radiation are
found to be much below the prescribed annual effective dose
limits.
• However, the concern is that number of excessive exposure
incidents to workers in the monitoring period are being reported
in medical practices such as diagnostic radiology and nuclear
medicine.
• The Safety Culture need to be established in the institution and
further maintained all the times to ensure that dose constraints are
not exceeded and importantly PMS badges are properly used.
• The Licensee is solely responsible for ensuring enforcement of
safe procedures for handling of radiation sources and their secure
storage when not in use.

46. 30th June 2015 46