Recently we published our new case-control study on use of mobile phones and cordless phones and the risk of malignant brain tumours, mostly glioma. The cases were diagnosed during 2007-2009 and population based persons were used as the reference entity. Exposures on a variety of agents were assessed by mailed questionnaires supplemented by telephone interviews. This was done without knowing if it was a case or a control that was interviewed.
For persons with more than 25 years latency period (time since first use until tumour diagnosis) a 3-fold increased risk was found. The risk increased further for tumours located in the most exposed area of the brain, the temporal lobe, to a 5-fold increased risk.
There was also a statistically significant trend for increasing risk with total number of hours for use. Further details can be found in the published study.