AN INTERNATIONAL panel of experts says mobile phones are possibly carcinogenic to humans after reviewing details from dozens of published studies.

The statement was issued in Lyon, France, today by the International Agency for Research on Cancer after a weeklong meeting of experts. They reviewed possible links between cancer and the type of electromagnetic radiation found in,mobile phones, microwaves and radar.

The agency is the cancer-focused wing of the World Health Organisation and the assessment now goes to WHO and national health agencies for possible guidance on mobile phone use.

The group classified mobile phones in category 2B, meaning they are possibly carcinogenic to humans. Other substances in that category include the pesticide DDT and gasoline engine exhaust.

Last year, results of a large study found no clear link between mobile phones and cancer. But some advocacy groups contend the study raised serious concerns because it showed a hint of a possible connection between very heavy phone use and glioma, a rare but often deadly form of brain tumor. However, the numbers in that subgroup weren’t sufficient to make the case.

The study was controversial because it began with people who already had cancer and asked them to recall how often they used their mobile phones more than a decade ago.

In about 30 other studies done in Europe, New Zealand and the US, patients with brain tumors have not reported using their mobile phones more often than unaffected people.

Because mobile phones are so popular, it may be impossible for experts to compare mobile phone users who develop brain tumors with people who don’t use the devices. According to a survey last year, the number of mobile phone subscribers worldwide has hit 5 billion – nearly three-quarters of the global population.

People’s mobile phone habits have also changed dramatically since the first studies began years ago and it’s unclear if the results of previous research would still apply today.

Since many cancerous tumors take decades to develop, experts say it’s impossible to conclude mobile phones have no long-term health risks. The studies conducted so far haven’t tracked people for longer than about a decade.

Mobile phones send signals to nearby towers via radio frequency waves, a form of energy similar to FM radio waves and microwaves. But the radiation produced by mobile phones cannot directly damage DNA and is different from stronger types of radiation like X-rays or ultraviolet light. At very high levels, radio frequency waves from mobile phones can heat up body tissue, but that is not believed to damage human cells.

According to Cancer Research UK, the only health danger firmly connected to mobile phones is a higher risk of car accidents. The group recommends children under 16 only use mobile phones for essential calls because their brains and nervous systems are still developing.

Also, a recent US National Institutes of Health study found that mobile phone use can speed up brain activity, but it is unknown whether that has any dangerous health effects.

- AP