Lecture 2 Flashcards
What is the justification of a practice?
No practice shall be adopted unless it produces significant benefit to the exposed individuals outweighing the detriment the radiation causes
What should also be included in the justification of a practice?
Clinical evaluation, check required information regarding treatment
What are three considerations of the optimisation of a practice?
The magnitude of doses
The number of people exposed
Likelihood that the potential exposures will be kept ALARA
What is a constraint?
A source related restriction on the dose from an individual source for planned exposures- an upper bound on the predicted dose
Must not exceed 1/3 of limit
What is a reference level?
A benchmark dose for a particular procedure to indicate whether under routine procedures a dose is unusually high or low
Only applies to MI
What is a limitation?
Places limits on the risk to individuals so that
Risks do not exceed a value which s considered unacceptable
Involves all IR practices
Types of exposure
Planned- deliberate introduction involves normal exposures and potential exposures!!
Emergency-may occur in a planned situation or malicious act require urgent action to avoid
Existing- exist when a decision or control has to be taken including prolonged exposure after emergencies
Categories of exposure?
Occupational
Medical
Public
Radiation protection in occupational and public exposure involves?
Justification, optimisation and limitation and recommended dose limits
Radiation protection in medical exposure involves?
Justification, optimisation not limitation
effective dose for occupational and public exposure?
O-20mSv per year over a period of 5 consecutive years
P-1mSv
Equivalent dose for lens of the eye, skin and hands and feet?
O- lens:150 mSv
Skin:500 mSv
Hands and feet 500 mSv
P-lens:15 mSv
Skin:50 mSv
What are the dose limits?
- Limits shall apply to the sum of the relevant doses in specified period and 50 ur committed dose up to age 70
- shall not exceed 50mSv in a single year
- Should not average 20mSv for 10 consecutive years
- for public a higher value of effective dose can be allowed as long as over 5 years does not exceed 1mSv
- equivalent dose to the skin applies to the dose averaged over any 1cm^2 of skin
What is the age limit for occupational exposure
Must be older than 16
Pregnant women and foetus exposure?
Total effective dose 1mSv
