A former US military researcher tells Gay Alcorn of his crusade to expose the health risks of depleted-uranium weapons used in the Gulf wars.

Doug Rokke sits on the edge of his chair in a beige, could-be-anywhere hotel room in Carlton. He stares at you with an almost embarrassing intensity and is close to tears.

"It's lonely," he says slowly. "It's very lonely. I made a decision. I was given a job. I did my job. I learned something. I gave them an answer they didn't want. I became persona non grata. And the better parts of my life ended."

What remains is an obsession with proving he is right about the dangers of depleted uranium (DU) weapons. A waste produced from the uranium enrichment process, depleted uranium has become increasingly contentious since American and British militaries first used it in the 1991 Gulf War and, since then, in the Balkans, Afghanistan and Iraq.

Rokke, a health physicist who became the Pentagon's most senior DU expert during the first Gulf War, became convinced it had contaminated the battlefield and could be a factor in Gulf War Syndrome, the mysterious mix of illnesses that have afflicted returning soldiers. Rokke acknowledges DU's brilliance as a weapon - because it is an extremely dense metal that sharpens and burns as it hits its target, it is used on the ends of tank shells and missiles to penetrate steel and concrete much more easily than conventional weapons. But he also believes that he and the research team became contaminated. "Everybody is sick," he says. "We've all got rashes, respiratory and kidney problems. It's there; there are no two ways about it."

Rokke is a military veteran. He joined the US Air Force in 1967 and bombed Vietnam targets "before I could shave". Years later, with a master of science and expertise in environmental health, he was ordered to the Gulf to help protect American soldiers if chemical and biological weapons were used and, later, to oversee DU clean-up. He became convinced DU was causing illnesses such as cancer, and that the Pentagon was downplaying its dangers. When he went public with his views, he was sacked

He is still campaigning, and this week urged the Australian Government, which doesn't allow weapons to be made with DU, to test returning troops for contamination and to campaign for it to be banned globally.

DU is only slightly radioactive - far less than uranium itself - but it is also chemically toxic, and scientists are divided about whether the combination poses a serious or remote health risk to soldiers and civilians who come in contact with it or inhale its dust. Little rigorous research has been done, and Rokke's theories remain unproven.

The official American position is that it is safe. In March, US Army Colonel James Naughton dismissed Iraqi claims that DU weapons caused cancers and leukaemia in children who played around bombed-out tanks and buildings during the first Gulf War. He claimed the real reason Iraq complained about DU weapons was because they were so effective. "Why do they (the then Iraqi government) want it to go away?" Naughton asked. "They want it to go away because we kicked the crap out of them. There is no doubt DU gave us a huge advantage over their tanks."

In the first Gulf War, most American deaths were from friendly-fire DU weapons. Rokke was ordered to decontaminate shot-up vehicles and tanks and to investigate health effects on troops. Dressed in protective gear and masks, he and his team crawled over tanks and other vehicles, sending some back to the US. Those considered too dangerous to move were buried in a giant hole in the ground.

In the mid-1990s, he was recalled from an academic job to head the Depleted Uranium Project in Nevada, which test-fired weapons into targets to analyse the health risks and to work out how to clean up safely.

Rokke, now 54, is convinced that he and other members of his team in Iraq were contaminated and that the tests he undertook showed that significant amounts of the DU vaporised on impact, making it extremely dangerous when inhaled. He pulls up his trouser leg to reveal the red rash he says appeared within hours of his contact with DU. He holds up his hand and moves fingers clumsily to show that his fine motor skills have gone. He has respiratory problems and cataracts and has medical reports showing that the amount of uranium in his urine is way above acceptable limits.

He has become a campaigner, not just for better clean-up and treatment, but for the weapons to be banned. "After everything I've seen, everything I've done, it became very clear to me that you just can't take radioactive wastes from one nation and just throw it into another nation. It's wrong. It's simply wrong."

Depleted uranium is so cheap and effective - 350 tonnes was used in weapons in the first Gulf War and possibly 500 tonnes in this year's Iraq conflict - that Rokke says the US is reluctant to do proper studies of veterans or Iraqi civilians. "It's the arrogance. Once they acknowledge that there are actual health effects of depleted uranium munitions, then they can't use them any more; the house of cards falls apart."

Rokke, brought to Melbourne by the Victorian Peace Network, has the single-mindedness of a whistleblower. He says he has lost friends, had his house ransacked, had his taxes audited and been publicly vilified for his outspokenness.

Concerns about DU have found some political acceptance - the British Government has announced it will test returning troops for DU contamination. But neither it, nor Washington, plan decontamination in Iraq. In the Australian Senate this week, Democrat Lynn Allison urged the Government to campaign internationally against DU in the same way it does against cluster bombs. Defence Minister Robert Hill said Australian troops in Iraq were not in areas where DU was used, and "there is no conclusive evidence to indicate that ammunition containing depleted uranium poses a significant adverse health risk to (Australian) personnel operating in Iraq".

The scientific evidence is cloudy because there has been so little research. It is broadly accepted that DU does little harm outside the body. But it may cause serious damage if it is inhaled. That means that people near where it is used could be contaminated, and it is possible it could seep into water tables.

Professor Brian Spratt, chairman of the British Royal Society's DU working group, this week told Radio National he welcomed the testing of British troops, because it meant the government "was at least taking the issue seriously, which is a very different attitude to the American military, who seem not to be interested in having any tests for their soldiers".

Spratt acknowledged that the issue was deeply political: the military have reasons for downplaying DU's health effects, and the anti-nuclear lobby have an interest in inflating them.

Rokke has faith he is doing what is right, and he clings to the belief that he is still doing the job the Pentagon ordered him to do. "I didn't ask for this job," he says. "I was given the job, and I'm going to finish the job."

Gay Alcorn is a senior writer and former Washington correspondent for The Age.