Mobile phones: is there a health hazard?

What kind of radiation do mobile phones use?

Mobile phones produce radiofrequency (RF) radiation that is part of the electromagnetic radiation spectrum. Most mobile phones transmit and receive RF radiation at frequencies of between 825 and 915 megahertz (MHz).

Known effects

Scientists have known for a long time about the ability of RF radiation to cause heating, which can lead to severe health effects on the body such as fatigue, reduced mental concentration and cataracts if exposed to very high levels. These effects are known as thermal effects, some of which can be created by subjecting a person to a warm environment.

RF exposure levels



The Radiation Protection Standard for Maximum Exposure Levels to Radiofrequency Fields - 3 kHz to 300 GHz (2002) specifies limits on exposure to RF radiation from various sources, including mobile phones. The level at which these limits are set is much lower than the levels at which any thermal (heating) effects can occur.

If the mobile phone is installed in a vehicle with a vehicle mounted antenna, the Standard allows the RF levels to be higher than the levels near a handheld mobile phone. This is because the vehicle mounted antenna is further away from the user than the antenna of a hand held mobile phone.

Hands free kits allow people to make phone calls without having to hold the mobile phone next to their head. The user is then free to use both hands to perform other tasks. Due to the increased separation between the antenna and the user’s head, RF exposure to the head is reduced by about 100 times when compared to normal mobile phone use.


Can mobile phones cause headaches?



Some users of mobile phones complain of sensations of heating, headaches and nausea when using their mobile phone. However, whether these effects can result from the RF levels associated with mobile phones has not been verified by scientific studies.

Some research has shown that RF radiation levels below the limits specified in the Standard can cause certain biological effects but has not established that these biological effects can adversely affect health. It is important to know the difference between biological and health effects, for example, moving from near sea level to somewhere in the mountains causes more blood cells to be made - a biological effect but not a health effect.


What about cancer?

In recent years attention has been focussed on the possibility that long term exposure to RF radiation may be responsible for serious health effects, such as cancer. Research continues to be undertaken on several fronts including the study of human populations and laboratory experiments on cells and tissues, and on rats and mice. While some studies have found effects associated with exposure to RF radiation, other studies have not shown such effects. To date, this research has not provided substantive evidence that exposure to RF radiation typical of the levels around mobile phones can cause cancer in humans.

Other risks

RF radiation from mobile phones can affect the operation of sensitive electronic equipment such as aircraft navigation systems and medical equipment. This may indirectly endanger the lives of people through the failure of these electronic systems and warnings to turn mobile phones off are given in aircraft and hospitals.

Conclusion

Although more research into the effects of RF radiation is being undertaken to answer unresolved questions, there is no convincing evidence that prolonged exposure to very low levels of RF radiation causes any adverse health effects.