Ionising Radiation and Living Things

Page
3

The quality factor, Q, allows the effects that different radiations have on living cells to be compared.

Slide 16

Quality Factor

The quality factor for each type of radiation is shown below:

From this it can be seen that alpha radiation is the most ionising radiation out of the three types.

Slide 17

Dose Equivalent

The DOSE EQUIVALENT is a measure of the biological effect of radiation and it takes account of the type and energy of the radiation as well as how the radiation is distributed.

REMEMBER, the biological effect of radiation depends on:

The type of radiation.

The type of body tissue or body organ that absorbs the radiation.

The total amount of energy absorbed.

Slide 18

Because 1 Sv is a very large dose of radiation which could only happen as a result of a very serious nuclear accident or explosion, doses are given in millisieverts (mSv) or microsieverts ( Sv).

The DOSE EQUIVALENT is measured in sieverts (Sv).

Slide 19

Suppose that 100 people all receive a dose equivalent of 1 Sv spread over the whole body. It is estimated that, of the 100 people on average 4 of them would eventually die as a result of the radiation.

But precisely who would die, or when they would die, or what illness they would die of, cannot be predicted.

Slide 20

Background Radiation

Radiation is all around us!

Background radiation is radiation that is naturally occurring.

Slide 21

Natural Sources of Radiation

Slide 22

Man-Made Sources of Radiation

Slide 23

Death Risk - Cause