17. ALARA: THE GOLD STANDARD OF RADIATION PROTECTION Flashcards
1
Q
- What does ALARA stand for?
A
- As Low As Reasonably Achievable
- this helps to limit the dosages of Radiation Exposure
2
Q
- What are the 3 Principles for Reducing Radiation Exposure?
A
- TIME
- an decrease in time = a decrease in radiation - DISTANCE
- an increase in time= a decrease in radiation
- the relation is squared
- this is the most effective method - SHIELDING
- an increase in shielding = a decrease in radiation
3
Q
- What does the Principle of Optimisation apply to?
A
- it applies to all circumstances
- it includes soft and hard restrictions
IT ADDRESSES THE CONSIDERATIONS OF:
- fairness
- restrictions
- doses
- risks
- to all individuals
4
Q
- What are 2 examples of soft restrictions?
A
- dose
- risk constraints
5
Q
- What is 1 example of hard restrictions?
A
- dose limits
6
Q
- What is Dose Limitation?
A
- these limits do not apply to patients
during their procedures - this means that there are no private
limits - this is because doctor’s have justified this
exposure - doctors have ensured that the benefit
has outweighed the harm and risk - there are limits for public and
professional bodies - these limits cannot be breached
7
Q
- Where are Dose Limits typically introduced?
A
- they are introduced into radiological protection
legislation - they have penalties that are associated with causing an
individual to exceed these limits - dose limits do not apply to all circumstances
8
Q
- What is the Effective Dose Limit in:
8.1. Occupational (mSv)
8.2. Public (mSv)
A
8.1: 20 mSv per year
: this is the averaged over the defined period of 5
years
8.2: 1 mSv in a year
9
Q
- What is the Annual Equivalent Dose Limit for for Lens
of the eye in:
9.1. Occupational (mSv)
9.2. Public (mSv)
A
9.1: 20 mSv
9.2: 15 mSv
10
Q
- What is the Annual Equivalent Dose Limit for for
Skin in:
10.1. Occupational (mSv)
10.2. Public (mSv)
A
10.1: 500 mSv
10.2: 50 mSv
11
Q
- What is the Annual Equivalent Dose Limit for for
Hands and feet in:
11.1. Occupational (mSv)
11.2. Public (mSv)
A
11.1: 500 mSv
11.2: n.a mSv
12
Q
- What are the two different ways that the system of Radiological Protection organises exposures to individuals?
A
- BY THE EXPOSURE SITUATION:
- planned
- existing
- emergency
NB: these address all conceivable circumstances - BY THE CATEGORY OF EXPOSURE:
- occupational
- medical
- public
13
Q
- What are Planned Exposure Situations according to ICRP Report 103?
A
- this is where radiological protection can be planned in
advance - this can be planned before exposures occur
- the magnitude and the extent of the exposures can be
reasonably predicted
EXAMPLE:
- when you send a patient for an X-Ray
14
Q
- What are Existing Exposure Situations according to ICRP Report 103?
A
- these are the situations that already exist when a
decision on control has to be taken - there are many types of existing exposure situations
that may cause exposures - these exposures are high enough to warrant
radiological protective actions or at least their
considerations
EXAMPLES:
- Radon in dwellings
- Radon in the workplace
- Naturally Occurring Radioactive Materials (NORM)
15
Q
- What are Emergency Exposure Situations according to ICRP Report 103?
A
- they are unexpected situations that may require
urgent protective actions - they can also be longer-term protective actions that
are to be implemented
EXAMPLES:
- Chernobyl
- Hiroshima
- Nagasaki