Types of Radiation

Ionising radiation: This refers to any form of radiation that has the capacity to remove electrons from atoms thereby creating ions. The main types are alpha, beta, and gamma radiation.
Alpha particles: These are positively charged. Made of 2 protons and 2 neutrons, they have a large mass. They don’t penetrate far into material and can be stopped by a sheet of paper or skin.
Beta particles: Beta radiation is a light, negatively charged particle (an electron). Beta particles penetrate further than alpha but can be stopped by a thin sheet of aluminium.
Gamma rays: These are electromagnetic waves of high energy. They have no mass and no charge. They can penetrate far into material, only stopped by several centimetres of lead or metres of concrete.

Effects of Radiation

Irradiation: This refers to the process of being exposed to radiation but not ingesting the radiation source. Removal from the source will stop the irradiation.
Contamination: This is when radioactive material is taken into the body (through inhaling, swallowing or through an open wound). The radioactive source continues to irradiate the body even when the person is removed from the source.
Radioactive decay: This is a random process. The rate at which a source of radiation decays is measured in Becquerels (Bq).

Medical: Tracers are used to check organ function, radiation therapy treats cancers. Gamma rays are used to sterilise medical equipment and food.
Industrial: Tracers are used to find leaks in pipe systems. Radiation is used in smoke detectors and to measure thickness of material during production.
Scientific: Carbon dating uses the ratio of carbon isotopes to estimate the age of organic matter. Radiotelescopes detect radiation from space to aid our understanding of the universe.

Exposure Risk: Too much exposure to radiation can lead to radiation sickness, or in extreme cases, death.
Ingestion Risk: If a person ingests a radioactive source, the radiation can repeatedly damage cells in your body, increasing the chance of cancer.
Exposure to Others: If a person has been contaminated with a radioactive source, that person can potentially expose others to that radiation.