Types of Radiation

Most radiation can be considered as part of the electro-magnetic spectrum. This comprises, in order of decreasing wavelength, radio waves, microwaves, infrared radiation, visible light, ultra-violet (UV) radiation, X-rays and gamma rays, which have the shortest wavelength. There is also 'particulate radiation' produced during the radioactive decay of radioactive elements (alpha and beta particles).

Broadly speaking there are two types of radiation, non-ionising and ionising. The longer wavelength parts of the electromagnetic spectrum, radio waves to the 'near UV', represent the non-ionising radiation . The shorter wavelength parts of the spectrum, 'far UV' or UVC to gamma rays, plus particulate radiation represent the ionising radiation. Most often when people refer to 'radiation' they mean ionising radiation. As an example we get sunburnt by short wavelength UV radiation because it ionises some of our skin molecules.

Ionising Radiation

Radiation can also be divided into 'natural' and 'man made' radiation. Natural radiation is produced from elements naturally present on the Earth and radiation arriving from outer space. Man made radiation is produced by processes such as medical X-rays, nuclear reactors and nuclear bomb test explosions. The effects of radiation depend on the type of radiation not its source.

An average person in the UK will receive approximately 10% of their annual dose of radiation from cosmic rays originating from the Sun, whilst another 50% is due to Radon (Rn) a radioactive gas generated during the radioactive decay of naturally occurring uranium and thorium present in the earth. Sources of man made radiation include medical treatments (approximately 15% of personal annual dose) and fall out from nuclear tests and accidents (approximately 1% of personal annual dose).

A person will be continually exposed to a low level of radiation throughout their life, this is perfectly normal and does not cause any health effects. Exposure to large amounts of radiation however can cause sterility, cataracts or even death. Lower amounts of exposure over a long period of time can cause cancer or hereditary defects in descendants. Radon exposure is thought to cause about 2,500 deaths per year in the UK.

Further information about radon

Radioactive Substances Register

A number of premises use small amounts of radioactive materials. Examples include americium 241 used in smoke detectors and Polonium 210 used in dust detection and anti-static devices.

All these premises are registered with the under the Radioactive Substances Act 1993. The Environment Agency is obliged to send a copy of the certificate for each premises to the relevant local authority.

Radiation from Mobile Phone Masts

Much concern has been raised in the last few years about radiation from mobile phone masts.

Mobile phone companies have a licence from the government to provide network installations throughout the country. They have to show some consideration in the location and the design of the installation.

Mobile phones work by using radio waves transmitted to and from base stations - both the phone and the base station emit radio frequency radiation when in use. This radiation is an electromagnetic transmission of energy, similar to that from televisions or radios.

If there is a large distance between a mobile phone and its connecting base a lot of energy is needed for a phone to operate. The more energy that is used by the phone, the higher the level of radiation is emitted from the phone to the soft tissues of the head, which is more pronounced in children due their softer head tissue. Aerial masts are unlikely to cause a heating effect beyond a few metres around their base area.

The actual power used by a transmitting mast to communicate with an individual phone is roughly the same as the power used by that individual phone to communicate with the mast. In fact if your head is seven times further away from a mobile phone mast than it is from your mobile phone then you are receiving a greater dose of radiation from your phone than from the mast. However, the nearest an ordinary member of the public can get to a transmitter mast is 30 metres or more, whereas we hold our mobile phones right against our heads. We must conclude that if there is any danger from mobile phone masts it is much less than from our mobile phones themselves.

A great deal of research has been carried out worldwide and studies are continuing to assess if this radiation is a health risk. No evidence has been found to show any significant risk to health. However, as this technology is new and with unknown long term effects, the government requires that the emission of radiation does not exceed the levels set by the ICNIRP International Commission on Non-Ionising Radiation

Mobile phone companies must submit a certificate with each application for a mast to prove that the levels are not exceeded.

The most recent research (reviewed in New Scientist July 2007 shows that, unlike the unsubstantiated claims raised by some people, there is no evidence that cellphone masts cause fatigue, anxiety or headaches.

The report, Mobile phone radiation sensitivity study (PDF, 306KB) shows that mobile phone radiation does not produce any symptoms in people and strongly suggests that "electromagnetic hypersensitivity" (EHS), a condition where sufferers claim to feel ill in the vicinity of mobile phones, masts, and appliances like microwave ovens, could be all in the mind, being psychological in origin and not due to 'toxic effects' from radio waves.

Schools who are concerned about the radiation levels within the school grounds can request measurements to be carried out by the Office of Communications (Ofcom) Ofcom

Radiation levels measured by Ofcom at schools and other areas, have found only a very small percentage of the maximum levels prescribed by ICNIRP.

Last Updated: 26 May 2020