London, Nov 14 (IANS): The longer someone talks over the phone - in terms of hours and years - the more likely is he/she to develop glioma, a deadly form of brain cancer, says a new study.

Brain tumour rates were three times more among people, who spoke on cell or cordless phones after more than 25 years than those who did not use them, the findings showed.

"The risk is three times higher after 25 years of use. We can see this clearly," Lennart Hardell, lead researcher and oncologist from University Hospital in Orebro in Sweden was quoted by Daily Mail as saying.

Swedes who talked on cell phones for over 25 years had three times the risk of one type of brain cancer, compared with people who used those phones for under a year.

For the study, Lennart Hardell and his colleague Michael Carlberg matched 1,380 patients with malignant brain tumours to people without such tumours.

They also compared their phone use.

People who reported using cordless or mobile phones for 20 to 25 years had higher risk of being diagnosed with glioma as compared with those who reported using them for less than a year, the study found.

However, no link was found between wireless phones and malignant brain tumours besides glioma, pointed out the study.

A World Health Organization (WHO) panel of 31 scientists from 14 countries classified mobile phones as 'possibly carcinogenic' in 2011.

The study appeared in the journal Pathophysiology.