- Mobile use increases chance of brain cancer
- Conclusion based on wide review of evidence
- Aussie expert says 3G not as harmful
UPDATE: The latest 3G mobile devices like iPhones and other smart phones may deliver a lower dose of radiowaves to the brain than earlier models but frequent use could still cause cancer, a health expert says.
A report released by the World Health Organisation's cancer research wing says radio frequency electromagnetic fields generated by such devices are "possibly carcinogenic to humans".
The�International Agency for Research on Cancer said heavy usage could lead to an increased incidence of glioma, a malignant form of brain cancer. It advised people to text or use hands-free to reduce the risk.
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WHO had previously said that there were no ill-effects from mobile phone use.
An Australian researcher who worked on the report with 30 other experts says more research is needed before any real link can be made between mobile phone use and cancer.
"Really, what it's saying is there is an observed association between using a mobile phone and a higher risk of brain cancer," Professor Bruce Armstrong from the University of Sydney told the ABC.
"But it's also saying that there are perhaps biases in the study or ... other factors that could explain that association."
Brain tumours
Professor Armstrong said researchers studied radiowave activity on those who used phones the heaviest and for the longest period, and health risks for average users was "really quite small".
"In the general population, particularly in the younger population, there is just no evidence ... that brain tumours are increasing in a way that would suggest that they are related to the greater amount of radio-frequency energy in our environment," he said.
The WHO has put mobile phone radiation on a par with about 240 other agents for which evidence of harm is uncertain, including talcum powder, working in a dry cleaner's, pesticide DDT, petrol engine exhaust and coffee.
The 3G technology used by iPhones, Blackberry and other mobile phones also appeared to emit less harmful radiowaves, he said.
But research on these new technologies was still in its infancy.
"A very important observation, really, just based on the technology, is that the 3G phones in fact give a much lower dose to the brain than the previous generations," Professor Armstrong said.
Err on the side of caution
"Whether, for example, the 3G levels are sufficient to cause brain tumours, we don't know at this stage, because most of the research at this stage was done ... on the generation before."
The IARC had previously stated that there was no real health risks associated with long-term mobile phone use.
Professor Armstrong said while health agencies tended to err on the side of caution it was still important people avoided heavy mobile-phone use.
"I think that's a very common principal of public health, that in the face of uncertainty... it's good to take precautions," he said.
"I would say that the main message out of this study is to avoid exposing your brain to radiowaves from mobile phones."
He said using hands-free devices, texting or using a landline whenever possible would reduce any of the potentially negative health risks for phone users.
More research was needed across the board before any real conclusions could be drawn, he said.
The IARC report that radiofrequency electromagnetic fields generated by such devices are "possibly carcinogenic to humans" has resulted in a Group 2B classification.
The classification will now be assessed by the WHO, which can be expected to provide further advice in due course.