The effects of radiation on the human body

Radioactive materials are hazardous. Nuclear radiation can ionise atoms and molecules in the body, which may change the way cells behave. It can also transfer large amounts of energy into the body which can damage or destroy cells.

Effects that radiation has on a human body include:

  • eye cataracts
  • cancer
  • skin burns
  • leukaemia and other blood disorders

Managing the risks

The risk associated with radioactive materials depends on the amount and type of radiation. For example, alpha radiation is more ionising than gamma radiation but does not penetrate as far. In general, the dose received and the risk of ill-effects increases by being exposed:

  • to highly radioactive materials
  • to radioactive materials for long periods of time or on a regular basis

Precautions are taken to reduce the risk of harm when using radioactive sources. These include:

  • keeping radioactive sources shielded when not in use, for example in a lead-lined box
  • wearing protective clothing to prevent the body becoming contaminated
  • limiting exposure time so less time is spent with radioactive materials
  • handling radioactive materials with tongs to increase the distance from them
  • monitoring exposure using detector badges

Background radiation

Radioactive materials occur naturally. As a result, everyone is exposed to low levels of radiation every day. This exposure comes from a mixture of natural and man-made sources.

Pie chart looking at sources of background radiation, these are from: Radon gas, Buildings, cosmic rays, food and drink and man-made. Man-made is broken down in another pie chart.

The actual amount of radiation that a person is exposed to depends on where they live, what job they do and many other things.

Scientists must always take into consideration the amount of background radiation when working or experimenting with radioactive sources and discount it from their results.