They were told depleted uranium was not hazardous. Now, 23 years after a US arms plant closed, workers and residents have cancer - and experts say their suffering shows the use of such weapons may be a war crime

Professor Randall Parrish's research, which found depleted uranium (DU) in the urine of people exposed at the former Colonie, New York weapons factory, was funded by the UK Natural Environment Research Council, not the UK Ministry of Defence, as we said in the article below. His facility has participated in other DU tests for the MoD, but these are not directly linked to the New York study. A fact box accompanying the piece called depleted uranium 'the densest naturally occurring metal' but as a by-product of the production of enriched uranium it does not occur in nature. Neither is it the densest when compared with, for example, tungsten, gold or platinum. This has been corrected.

It is 50 years since Tony Ciarfello and his friends used the yard of a depleted uranium weapons factory as their playground in Colonie, a suburb of Albany in upstate New York state. 'There wasn't no fence at the back of the plant,' remembers Ciarfello. 'Inside was a big open ground and nobody would chase us away. We used to play baseball and hang by the stream running through it. We even used to fish in it - though we noticed the fish had big pink lumps on them.'

Today there are lumps on Ciarfello's chest - strange, round tumours that protrude about an inch. 'No one seems to know what they are,' he says. 'I've also had a brain aneurysm caused by a suspected tumour. I'm constantly fatigued and for years I've had terrible pains, deep inside my leg bones. I fall over without warning and I've got a heart condition.' Ciarfello's illnesses have rendered him unable to work for years. Aged 57 and a father of five, he looks much older.

The US federal government and the firm that ran the factory, National Lead (NL) Industries, have been assuring former workers and residents around the 18-acre site for decades that, although it is true that the plant used to produce unacceptable levels of radioactive pollution, it was not a serious health hazard.

Now, in a development with potentially devastating implications not only for Colonie but also for the future use of some of the West's most powerful weapon systems, that claim is being challenged. In a paper to be published in the next issue of the scientific journal Science of the Total Environment, a team led by Professor Randall Parrish of Leicester University reports the results of a three-year study of Colonie, funded by the UK Natural Environment Research Council.

Parrish's team has found that DU contamination, which remains radioactive for millions of years, is in effect impossible to eradicate, not only from the environment but also from the bodies of humans. Twenty-three years after production ceased they tested the urine of five former workers. All are still contaminated with DU. So were 20 per cent of people tested who had spent at least 10 years living near the factory when it was still working, including Ciarfello.

The small sample size precludes the drawing of statistical conclusions, the journal paper says. But to find DU at all after so long a period is 'significant, since no previous study has documented evidence of DU exposure more than 20 years prior... [this] indicates that the body burden of uranium must still be significant, whether retained in lungs, lymphatic system, kidneys or bone'. The team is now testing more individuals.

In 1984, having bought the factory from NL for $10 in a deal that meant the firm was exempted from having to pay for its clean-up, the federal government began a massive decommissioning project, supervised by the Army Corps of Engineers. The clean-up did not finish until summer 2007, having cost some $190m. Contractors demolished the buildings and removed more than 150,000 tons of soil and other contaminated detritus, digging down to depths of up to 40ft and trucking it 2,000 miles by rail to underground radioactive waste sites in the Rockies. All that is now left of the NL plant is a huge, undulating field, ringed by razor wire.

Despite this colossal effort, Parrish and his colleagues found high concentrations of DU particles in soil, stream sediments and household dust in the vicinity of the site, deposited long ago when the factory burnt the shavings and chips produced by the weapons manufacturing process: the study estimates that, over the years, about 10 tons of uranium oxide dust wafted from the chimney into the surrounding environment.

The Army Corps clean-up team tested the soil from some of the gardens of houses backing on to the plant, and in cases where it was found to be emitting more than 35 pico curies of radiation per gram they removed it. The researchers discovered dust in and around buildings emitting up to 10 times as much. DU, inhaled in the form of tiny motes of oxide that lodge inside the lungs, emits alpha radiation, nuclei of helium. Unlike the gamma radiation produced by enriched, weapons-grade uranium, alpha particles will not penetrate the skin.

But inside the body DU travels around the bloodstream, accumulating not only in the lungs but also in other soft tissues such as the brain and bone marrow. There, each mote becomes an alpha particle hotspot, bombarding its locality and damaging cell DNA. Research has shown that DU has the potential to cause a wide range of cancers, kidney and thyroid problems, birth defects and disorders of the immune system.

When DU 'penetrators' - armour-piercing shells that form the standard armament of some of Britain's and America's most commonly deployed military aircraft and vehicles - strike their targets, 10 per cent or more of the heavy DU metal burns at high temperatures, producing oxide particles very similar to those at Colonie.

TV footage shot in Baghdad in 2003 shows children playing in the remains of tanks coated with thick, black DU oxide, while there have long been claims that the DU shells that destroyed Saddam Hussein's tanks in the 1991 Gulf war were responsible for high rates of cancer in places such as Basra.

Parrish's team includes David Carpenter, an environmental health expert from Albany University. 'DU burns, it releases particulates that can be breathed in, and it doesn't go away,' he says. 'The issue does not concern military personnel as much as civilian populations in theatres where they are used. Now we know that we can still find measurable levels of DU among the people of Colonie, we need a much bigger study to establish whether they have suffered disproportionate ill-effects such as cancers as a consequence. If they have, it would raise a serious ethical challenge to the use of these weapons. Arguably it could constitute a war crime.'

The NL plant on Central Avenue, Colonie's main artery, opened in 1958 and became one of the Pentagon's main suppliers. DU - the material left in huge quantities by the process of refining enriched uranium for bombs and nuclear reactors - is extremely dense. A pointed rod fired at high velocity will penetrate not only armour but several feet of concrete. In 1979 a whistleblower from inside the plant told the local health department that it was releasing large amounts of DU from its 50ft chimney, which was not properly filtered. The state government carried out atmospheric tests and in 1981 ordered that main production cease. The factory shut three years later.

One of those who has now tested positive is Mike Aidala, 71, who worked at the plant for 22 years and became its health and safety director. 'When it started, the place was spotless,' he says. 'But over the years it got dirtier and dirtier. We burnt the chips produced by the lathes in a steel furnace.' He added: 'A lot of my co-workers died young. Whether the plant was the reason, I guess we'll never know.'

As concern in Colonie rose, a residents' group began to call for a publicly funded health study. For Anne Rabe, a founder member of a campaign that has now lasted for 25 years, the Parrish study represents overdue vindication. 'I do find it very ironic that the US government at state and federal level refused for so long to do anything, and now the UK comes along and has funded these tests,' Rabe says.

Repeatedly, US agencies have claimed that the Colonie plant was reasonably safe, despite the massive clean-up. Most recently, in 2003, the federal Agency for Toxic Substances and Disease Registry issued a report saying that, although the pollution produced when the plant was operating might have slightly increased the risks of kidney disease and lung cancer, there was now 'no apparent public health hazard'.

Rabe's campaign has conducted a health study of its own, assembling a dossier from personal contacts and by knocking on neighbours' doors. It found that among almost 400 people surveyed there were numerous cases of rare cancers, thyroid and kidney complaints and birth defects.

The main difficulty the campaigners faced in the past is that DU eventually dissolves and is passed in the urine. The US government claimed that the plant had been shut so long that it would be impossible to determine who had been contaminated - so rendering a full health survey pointless.

However, Parrish has developed new, more sensitive methods. At the same time, his impartiality is impeccable. Before his work in Colonie, Parrish tested more than 400 Gulf war veterans, failing to detect DU in any of them - so dealing a serious blow to those who claimed that DU is one of the causes of Gulf war syndrome. 'I did not expect to find it in Colonie,' he says.

Some of those who have tested positive display classic, common symptoms found in DU victims elsewhere. For example, Ciarfello says he was still in his twenties when his teeth 'just started to crumble: they ground down to nothing until they were just these little stumps and I pushed them out with my tongue'. Other members of his family are sick. His son developed a severe kidney condition, while his brother, Frank, can barely walk and also suffers chronic fatigue. A nephew was born with a disfiguring facial skin tumour that has required repeated surgery.

Tom Donnelly, 56, spent 34 years as a foreman at a garage door workshop next to the NL factory, where tests have found high concentrations of DU in dust samples from places such as shelves and light fittings. He has three auto-immune disorders: Crohn's disease, a chronic inflammation of the bowel, total alopecia, and cerebral vasculitis, an immune system-related narrowing of blood vessels in the brain.

'The new tests suggest I inhaled about 4,000 particles of DU,' Donnelly says. 'I used to come to work in the morning and see the chimney blowing its smoke in a thick black plume. Most of us had no idea that the plant was using uranium at all. After all, the sign outside said National Lead. The Army Corps removed all that soil, but they never looked at the dust at all. The effect on my life has been devastating, but how many others are already dead?' One is his late boss and friend Tom Murphy - who, like Donnelly, developed Crohn's and died of it at 61.

Ann Carusone lived in a house behind the plant from the time of her birth in 1966 until 1993. 'When I tested positive, my reaction was sheer disbelief,' she says. She has endured years of a chronic lung disease, sarcoidosis, an inflammation of the lymph nodes usually found in much older people, as well as a blood disorder that produced petecchiae - dots of blood beneath her skin, similar to those seen in some of those exposed to radiation at Hiroshima. In her twenties she had a pre-cancerous ovarian cyst that when removed was the size of a grapefruit.

'I knew many people from round here who died young, in their twenties and thirties,' she says. 'We used to play out in the creek that flowed out of the plant site. The water was sluggish, a weird yellow-green colour. We'd splash about in it. Now we know it was laden with depleted uranium.'

'It's very striking how many people in this small group have immune disorders like Tom Donnelly's,' says Carpenter. 'I can say with great confidence that people who inhaled DU are at greater risk of lung cancer, as well as leukaemia, other cancers and genetic damage of the type that causes birth defects. Previous responses by official bodies could be said to amount to a cover-up. People have been told that there's no problem, and that's very clearly not true.'

Yesterday NL failed to return calls requesting comment.

Deadly residue

Depleted uranium (DU) is the residue left in massive quantities when bomb-grade uranium is refined to make reactor fuel and nuclear weapons.

DU is used to make armour-penetrating shells, standard armament for some of the West's most widely deployed military aircraft and vehicles, such as Bradley armoured cars, Abrams tanks, and Jaguar A10 fighter planes.

Less intensely radioactive than bomb-grade uranium, DU emits alpha particles, known to cause cancers.

DU weapons that strike their targets produce clouds of tiny uranium oxide particles, which lodge in the lungs and other soft tissues such as the brain and bone marrow.

DU shells were widely used in the 1991 Gulf war; in Bosnia and Kosovo; and are being used now in Iraq and Afghanistan.