Concepts of Risk

Risks relative to other occupations

  • Relative Risks 1
  • Relative Risks 2

From data given above a whole body effective dose of 1mSv gives rise to a probability of 40 in a million (4 x 10-5) of developing a fatal cancer.  This risk estimate can be compared to the risks of death associated with other occupations, and with the probability of dying from other causes:

Table: Average annual risk of death in the UK
SOURCE RISK OF DEATH
(PER YEAR)
Natural causes, 40 years old
1 in 700
Modern Life (Unavoidable):
 
        Accidents on the road
1 in 10,000
        Accidents in the home
1 in 25,000
        Nuclear Discharges (max.)
1 in 70,000
Occupational Hazards*:
 
        Sea Fishing Industry
1 in 500
        Clothing and Footwear
1 in 300,000
        Radiation Worker (Medical - 0.1mSv))
1 in 250,000
        Accidents at work (all workers)
1 in 50,000
Medical Investigations:
 
        Chest X-Ray (ave. 0.05mSv)
1 in 500,000
        Barium Enema (ave. 7.7mSv)
1 in 3,250
        Bone Scan (ave. 4mSv)
1 in 6,250
Voluntary Acts:
 
        Smoking 20 cigarettes per day
1 in 100
        Rock climbing for 5 hours
1 in 5,000
        Canoeing for 10 hours
1 in 10,000
TOTAL (ALL CAUSES)
1 in 80

* - Source for Occupational Hazards - HSE 1982.

It should be noted:

  • the average annual risk of death from 0.1mSv is much less than that from all accidents at work averaged together.
  • the probability of developing a fatal cancer from 0.1mSv per year is only approximately 1/10th the risk of dying from an accident in the home.

Other risks that may be quoted, in terms of "one in a million" include:

  • smoking 1 cigarette (in a lifetime)
  • travelling 50 miles by car
  • travelling 250 miles by air
  • rock climbing for 1.5 minutes
  • canoeing for 6 minutes
  • being aged 60 for 20 minutes
  • being aged 30 for 9 hours

 

Conversely a positron may be created when the nucleus has too many protons to be stable and it is the changing of a proton into a neutron with the subsequent release of a positron particle that accounts for the genesis positrons.

Click on an option.

Which type of radiation is most easiest to shield?
Alpha
Beta
Beta +
Gamma