Mobile phone towers are not making people sick - but the belief that they are dangerous is.

A meta-analysis by a New Zealand researcher has looked at studies into whether cell tower radiation is making people sick.

Some people feel that many symptoms - such as fatigue, sleep problems, anxiety, headache and others - can be caused by radiofrequency (RF) electromagnetic fields from cell phones or transmitters.

A recent study examined the scientific evidence assessing this.

There is a lot. Many studies are very simple—just asking if people have symptoms and if they are exposed to RF. Many of these show associations, but they tended to be weaker studies.

The best studies (tests of immediate effects in ‘double blind’ experimental conditions) tend to show that actual RF exposure does not cause symptoms, but the belief that there is RF exposure and that it is harmful can cause symptoms.

For longer term effects, much more extensive studies taking several years are being undertaken; these are now giving results and so far show no real effects.

The symptoms are real, and people may be quite ill, but the cause seems not to be RF exposure.