French scientists have found, that people who use cellular phones intensively have a higher risk of  brain cancer.

The findings, Newsmax Health reports with reference to Medical Xpress, are based on a new study showing individuals who used a cellphone for more than 15 hours each month over five years on average had between two and three times greater risk of developing glioma and meningioma tumors compared with those rarely used such devices.

Over the last 15 years, most research has failed to turn up conclusive evidence of a risk, but several have suggested a link between gliomas and intensive, long-term use.

The new study looked at 253 cases of glioma and 194 cases of meningioma reported in four French counties between 2004 and 2006. These patients were compared to 892 healthy individuals.

The comparison found a higher risk among those who used their phone intensively, especially among those who used it for their work. But study also found several inconsistencies with other investigations that have suggested a link between heavy phone use and brain cancer.

For instance, it found that cancer occurred on the opposite side of the brain, rather than on the same side, of where the phone was customarily used.

"It is difficult to define a level of risk, if any, especially as mobile phone technology is constantly evolving," the study acknowledged.