Hazards of nuclear radiation

Radioactive materials are hazardous. Nuclear radiation can ionise chemicals within a body, which changes the way the cells behave. It can also deposit large amounts of energy into the body, which can damage or destroy cells completely.

Some of the effects that radiation has on a human body are shown below.

EyesHigh doses can cause cataracts.
ThyroidRadioactive iodine can build up and cause cancer, particularly during growth.
LungsBreathing in radioisotopes can damage DNA.
StomachRadioactive isotopes can sit in the stomach and irradiate it for a long time.
Reproductive organsHigh doses can cause sterility or mutations.
SkinRadiation can burn skin or cause cancer.
Bone marrowRadiation can cause leukaemia and other diseases of the blood.

Managing the risks

The risk associated with radioactive materials depends on the amount of exposure. Being exposed to highly radioactive materials or being exposed to radioactive materials for long periods of time or on a regular basis increases the dose received which, in turn increases the risk.

Risk is the likelihood of cell damage occurring.

Given that radioactive materials are hazardous, certain precautions can be taken to reduce the risk of using radioactive sources. These include:

  • keep radioactive sources like technetium-99 shielded (preferably in a lead-lined box) when not in use
  • wear protective clothing to prevent the body becoming contaminated should radioactive isotopes leak out
  • avoid contact with bare skin and do not attempt to taste the sources
  • wear face masks to avoid breathing in materials
  • limit exposure time so less time is spent around radioactive materials
  • handle radioactive materials with tongs in order to keep a safer distance from sources
  • monitor exposure using detector badges, etc

The risk also depends on the type of radiation to which a person has been exposed and whether that exposure is internal or external.

If the radioactive source is inside the body, after being swallowed or breathed in:

  • alpha radiation is the most dangerous because it is easily absorbed by cells
  • beta and gamma radiation are not as dangerous because they are more likely to pass through a cell than to be absorbed

If the radioactive source is outside the body:

  • alpha radiation is not very dangerous because it is absorbed by the skin and is unlikely to reach living cells inside the body
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