Using your mobile phone for several hours every day puts you at more risk of developing cancer of the salivary gland.
That's according to a new study which looked at 500 Israelis suffering from cancer of the salivary gland and compared their mobile phone use with that of 1,300 healthy people. Those who had used a handset against the same side of their head for hours on end were especially at high risk.
They were 50 per cent more likely to develop a salivary gland tumour, BBC News reports.
Researchers at Tel Aviv University said that mobile phone use in Israel is heavier than in most other countries. The study could therefore be viewed as an insight into potential future problems relating to mobile phone use..
"Compared to other studies, the amount of exposure to radiofrequency radiation we saw here was much higher. If you like, you're seeing what could happen elsewhere 'speeded-up' in Israel," Dr Siegal Sadetzki, who led the research, told BBC News.
Using mobile phones in rural areas pushes the risk up even more, presumably from the stronger signals and therefore higher radiation needed to get reception.
Sadetzki said that children in particular should have limited use of mobile phones, taking a "precautionary approach".
Ed Yong, of Cancer Research UK, agreed. "Mobile phones are a relatively recent invention and new research into any possible health risks is welcome.
"However, it's important to remember that the vast majority of studies so far have found that mobile phones do not increase the risk of any type of cancer."
The Tel Aviv research team will continue the study to see if there are further links between mobile phone usage and cancer.