26.4 The dangers of radioactivity

How does ionising radiation affect living cells?

1. destroys cell membranes causing cells to die

2. damages DNA causing rapid and uncontrollable cell division or mutations in future generations if sex cells are damaged

somatic effects

developed

genetic effects

passed down

What is the risk of high doses of ionising radiation? 

kills cells 

Is there a threshold level which cells are not damaged by ionising radiation?

no

How is radiation monitored?

film badge

What does a film badge contain? 

strip of photographic film in a light-proof wrapper 

different areas of film are covered by absorbers of different materials and thickness 

amount of exposure of each form of radiation can be estimated from blackening of film 

How is the dose of radiation measured?

energy absorbed per unit mass of matter from radiation

Background radiation

radiation which occurs naturally due to cosmic radiation and from radioactive materials

Sources of background radiation

Nuclear weapons tests

Air

Nuclear power

Cosmic rays 

Food and drink

Ground and buildings

Medical 

What must radioactive substances be stored in?

thick lead-lined containers

How should solid radioactive substances be transferred?

handling tools such as tongs and glove-boxes

How should liquid and gaseous radioactive substances be stored?

sealed containers

How long should radioactive substances be used? 

no longer than needed