What is Radiation?
Radiation is a natural part of our living environment, and is commonly described as energy travelling as waves or particles. Radiation sources can be natural or artificial (man-made).
All electromagnetic radiation can be broadly grouped into two categories:
Ionising radiation (e.g. x-rays, cosmic rays and naturally occurring radioactive materials in soil and food) – ionising radiation possesses enough energy to knock electrons out of atoms and poses a health risk as it can potentially damage tissue and DNA in genes. Long-term exposure to ionising radiation at high levels can harm people’s health.
- Non-ionising radiation (e.g. visible light, radio waves and microwaves) – non-ionising radiation moves atoms in a molecule around or causes them to vibrate (which would generate heat) but does not have enough energy to remove electrons from atoms and break chemical bonds in our cells.
In general, ionising electromagnetic radiation travel at high frequency/short wavelength and has high energy. On the other hand, non-ionising radiation travels at a low frequency/long wavelength and has low energy. The different kinds of non-ionising radiation as they fall on the electromagnetic spectrum is depicted below.
Source: UK Ofcom - 5G Mobile Technology: A Guide