A review backed by the World Health Organization into brain cancer and cellphone usage has found no connection between the two.

There have been concerns about radiation emitted from mobile devices for decades and the WHO's cancer agency declared it a potential carcinogen to people in 2011.

But the new review, based on dozens of studies dating back to 1994, found no association between cellphone use and cancer, even among people who spend all day making calls or using their smartphones.

Ken Karipidis, a lead author of the review, said the results 'are very assuring', especially given cellphone use has 'skyrocketed'.

Karipidis, who works for Australia’s radiation and nuclear protection authority, added: 'There has been no rise in the incidence of brain cancers.'

The panel of experts looked into whether there was any link between cancers in the brain and saliva glands and leukemia, and exposure to radio waves commonly used by wireless tech such as cellphones, TV and baby monitors.

The final analysis included 63 studies from 1994-2022, assessed by 11 investigators from 10 countries, including the Australian government's radiation protection authority. 

Despite the huge rise in the use of wireless technology, there has not been a similarly large increase in the incidence of cancers, the review found.

That was true even among people who make often make long phone calls or those who have used mobile phones for more than a decade.

Co-author Mark Elwood, professor of cancer epidemiology at the University of Auckland, New Zealand, said: 'None of the major questions studied showed increased risks,' he said. 

The review follows other similar work. The WHO and other international health bodies have said previously there is no definitive evidence of adverse health effects from the radiation used by mobile phones, but called for more research.

It is currently classified as 'possibly carcinogenic', or class 2B, by the WHO's cancer agency, the International Agency for Research on Cancer (IARC).

The category used when the agency cannot rule out a potential link, and includes other common goods such as talcum powder and aloe vera.

The WHO's advisory group has called for the classification of wireless radiation to be re-evaluated as soon as possible given the new data since its last assessment in 2011.

WHO's evaluation will be released in the first quarter of next year.

Previous research has linked cellphone radiation to brain cancers, but Karipidis said those early studies were flawed.

For example, some relied case-control studies that compared the responses of people with brain cancer against those without the disease.

This can introduce bias because people with brain tumors 'tend to overreport their exposure,' Karipidis said.