Mobile phones and your health

Mobile phone use is now so widespread (it was estimated in 2011 that there were around five billion users) that public concern about possible health effects receives a lot of media coverage. Because so many people use mobile phones, researchers are mindful that even a small associated health risk could add up to a significant public health problem. It is worth understanding the possible effects so you can make your own decisions about how you use your phone.

Radiation and mobile phones#

Mobile phones communicate with base stations using radio frequency (RF) radiation. At high enough levels, RF radiation has a “thermal” effect, meaning it raises temperature. There have been concerns that the low levels emitted by mobile phones might cause problems such as headaches or brain tumours.

Intensive research around the world has found no conclusive or convincing evidence that mobile phones damage health in the short or long term. However, in May 2011 the World Health Organization (WHO) classified RF radiation as “possibly carcinogenic to humans, based on an increased risk for glioma, a type of brain cancer”. This statement prompted many people to call for a “precautionary approach” to mobile phone use. Research is ongoing.

Understanding radiation#

Radiation is a combination of electrical and magnetic energy that travels through space at the speed of light, and is also called electromagnetic radiation (EMR). It falls into two broad groups:

• Ionising radiation (IR) can cause changes in atoms or molecules in the body that may result in tissue damage such as cancer. Examples include x-rays and gamma rays.
• Non-ionising radiation (NIR) does not cause these changes, but can make molecules vibrate, which can raise temperature and have other effects. Examples include ultraviolet radiation in sunlight, visible light, light bulbs, infrared radiation, microwave energy and radiofrequency energy.

How the mobile phone system works#

The mobile phone system works like a two-way radio, made up of individual handsets and base stations. Base station antennae are mounted high off the ground, on a tower or roof, to give the widest coverage. A handset contains both a radio receiver and a transmitter.

When you make a call, your phone uses RF radiation through its antenna to “talk” to a nearby base station, and the call is then directed through the wider phone network. Base stations emit relatively constant levels of RF radiation, while handsets emit levels that vary depending on how close you are to a base station, how long you use the phone, and how close you hold it to your body. If the link to the base station is weak, the handset increases its radiation level to compensate.

The RF radiation reaching your head from a handset is around 100 to 1,000 times more intense than exposure from base stations. Even so, it is estimated that a phone held against your ear heats a localised area of your face, and to a lesser extent your brain, by only a fraction of a degree. This is less than the heating caused by, for example, exercise. High levels of RF radiation can overheat body tissues and cause damage, so exposure limits for mobile phones are set far below the level at which any meaningful heating occurs, and handsets are required to meet recognised safety standards.

Mobile phones and cancer#

Many studies around the world have looked at RF radiation and its effects on the body. There is an important difference between a biological effect (an effect on the body) and a health effect. For example, RF radiation from a mobile phone has the biological effect of raising the temperature of a small area of the brain by a fraction of a degree, but this does not automatically carry any health risk. The human body copes with very wide variations in temperature without harm.

Because RF radiation is a form of non-ionising radiation, it cannot cause cancer, and there is no other known biological way it could be carcinogenic. Research continues into whether mobile phone use causes health problems other than cancer, but so far none has been found.

Other possible health effects#

Mobile phone use can have indirect health effects, for example:

• Electronic equipment: RF radiation can interfere with medical electronic equipment if that equipment is vulnerable to the field. For this reason, handsets should be switched off in hospital buildings where required.
• Road accidents: studies show that using a mobile phone while driving greatly increases the risk of a crash. Using a hand-held mobile phone while driving is illegal in many places.

Reducing your exposure#

Evidence so far suggests mobile phones are not harmful, but long-term risks have not been fully clarified. If you are concerned, you can reduce your exposure to RF radiation by:

• choosing a phone with a low specific absorption rate (SAR), which is the amount of RF radiation absorbed by body tissues
• using a landline phone when one is available
• keeping your calls short
• using a hands-free kit
• not carrying your phone close to your body when it is switched on
• being wary of claims that protective devices or “shields” reduce exposure; there is no evidence they work, and they can actually increase RF radiation, because the phone raises its output to overcome the shield and maintain a good connection

Key points#

• The heating from a phone held to the ear is less than the heating caused by, for example, exercise.
• High levels of RF radiation can overheat body tissues and cause damage.
• A small biological effect such as slight localised heating does not automatically carry a health risk.
• Because RF radiation is a form of non-ionising radiation, it cannot cause cancer.
• Studies show that using a mobile phone while driving greatly increases the risk of road accidents.

Where to get help#