"What makes me angry is that they continue to sell these phones without making sure that they are safe." The evidence is mounting. Brain tumors are on the increase - even neurosurgeons are concerned. The industry stands firm, however, not all of them. David was just 30 years old when he underwent three operations to remove the tumor as big as a golf ball, around his acoustic nerve.

During the surgery, the nerve was removed and another was accidentally damaged, causing David to lose muscular control in his face. "I believe mobile phones gave me this tumor and I blame the mobile phone companies," David said."I was angry at the mobile phone companies and at the telecommunication companies because they've put this product on the market without the proper research to what it does, I guess they've used us as guinea pigs." The tumor was situated just behind his right ear.

"I used to use my right ear as my phone ear, but I don't do that anymore because I can't hear out of it," David said. "I used to use the mobile phone maybe one or two hours a day for the 10 years or so before I was diagnosed."

David's tumor is one that studies have linked to mobile phone use. Professor Bruce Armstrong is head of Sydney University's Public Health Dept. He's spent 10 years looking at the research between mobile phones and brain tumors.

There was evidence of a twofold increase in risk of tumors. While David is trying to piece his life back together, he worries for the millions who constantly use their mobile. "You see 10 year olds running around the street using mobile phones, I wonder how they'll affect the development of their brains," said David.

Enrico Grani too blames his brain tumor on heavy mobile phone use over 10 years. "I had an analogue phone it was like a toy, you know what I mean, you get a new toy you talk on the phone," said Enrico. He was diagnosed with a meninglioma in the right parietal globe.

After the operation, he was in a coma for three days and suffered a stroke. "I blame the cell phone industry blinded by greed, they've known about this for many, many years but they still deny it," said Enrico.

None of this surprises those in the business of brain surgery.

One prominent Canberra Neurologist has written a research paper on the link between mobile phones and brain tumors. He believes mobile phones will be the next great public health issue and he compares their effects with those of smoking and asbestos.

He's calling on government and industry to take immediate steps to reduce exposure of consumers to mobile phones. As a Neurosurgeon Richard Bit-tar has seen a rise in brain tumors in the last 15 years, but says its hard to point the finger solely at mobile phone use. Yet Richard tries to use his mobile phone only on loudspeaker or uses a nearby land line when possible.

"There is certainly an element of concern not only from myself but from a lot of my colleagues. A lot of my neurosurgery colleagues go even further and really try and minimize the amount of mobile phone use they engage in, that reflects an underlying concern that there may well be a relationship," said Richard.

His warning to consumers? "Minimize the amount of time you spend with your mobile phone up against your ear. "We asked the Australian Mobile Telecommunications Association's Chris Althaus if he was worried about getting a tumor: "No."

Does he use his phone every day? "I use it every day and I use it a lot every day, I'm very comfortable personally with the way the research effort conveys to markets like Australia and globally the level of safety you can enjoy when using a mobile phone," said Chris. But David had a different view.

"It's ruined the life I had previously had, all these plans and ideas and so much hope for the future and now that's all changed. I've had to reevaluate everything," said David.