One day we're told all is OK, and the next, it seems, chatting on our mobiles is bad for us after all.

A study from Israel suggests that heavy mobile phone use may be linked to an increased risk of cancer of the salivary gland.

Researchers looked at 500 Israelis and found that those who had used the phone against one side of the head for several hours a day were 50% more likely to have developed a salivary gland tumour.

Dr Siegal Sadetzki of Tel Aviv University said that this report may show what could happen long-term elsewhere: "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".

However, the report isn't completely conclusive but Sadetzki suggested precautions such as curbing children's use of mobiles.

The BBC reports that cancer of the salivary gland is a very rare condition. Of the 230,000 cases of cancer diagnosed in the UK annually, for instance, only 550 relate to this area.