PEOPLE living on an island used as an American bombing range are suing the United States Navy for $100 million in damages, claiming that radiation from depleted-uranium (DU) shells has caused widespread cancer.

Known throughout the Caribbean as the "Enchanted Island" because of its beautiful beaches, Vieques is now called "Cancer Island" by many locals because of a big rise in incidence of the illness. More than a third of the 9,000 inhabitants have been found to be suffering serious health problems which could be linked to DU, says the law firm handling the case. The class-action lawsuit so far involves 3,600 islanders.

Eva Torres, a 52-year-old school administrator who recently underwent a hysterectomy after the discovery of a tumour, said: "Everyone here knows many people who have cancer. Nowadays I always seem to be going to funerals."

The little island is 19 miles long and four miles wide. It is part of the United States dependency of Puerto Rico and has long captured the imagination of film-makers and naturalists. The original version of William Golding's Lord of the Flies was filmed here, while marine scientists like to study a bay full of bioluminescent plankton that make the fish glow at night.

The dominating presence in Vieques, however, is the US Navy, which took over two-thirds of the island in 1941 and uses it for live weapons fire. Every big US military action of the past 50 years, from Korea to Kosovo, has been practised there, and Vieques has been a valuable testing ground for new types of arms. These include the DU shells used in the Balkans, over which an outcry has erupted after the deaths from cancer of 32 soldiers who served there.

US Navy officials insist that there is no evidence to link the use of DU in weaponry to ill-health on Vieques. Commander John Correra said: "Stories of cancers and illness are just part of a campaign of misinformation by those opposed to our presence on the island, We are talking about very small amounts of depleted uranium and we have done our utmost to make sure it is cleared away."

The incidence of breast, uterus and lymphatic cancers among islanders, however, has increased by 300 per cent over the past 20 years, according to Puerto Rican government figures. The island's health service, consisting of a handful of general practitioners, is struggling to cope.

The case has been taken up by a Mississippi-based law firm, John Arthur Eaves, which specialises in class-action suits involving industrial pollution. John Arthur Eaves Jnr said: "I think $100 million [£68 million] may turn out to be at the lower end of what we might get from the navy. His firm has already begun interviewing potential clients in Europe regarding DU contamination. "We're very interested in what's happening there," he added.

One of their clients on the island is Rolando Garcia, 32, a father of two. Test results show him to be contaminated with a range of heavy metals, including uranium. He said: "I'd never heard of uranium before. Now it looks like it might kill me." Every hair on his body has fallen out and he has difficulty in walking. He thinks that he might have been exposed to DU when he worked on the bombing range, maintaining military buildings.

Other islanders showing high levels of uranium in their bodies have never been on the range. They are thought to have picked up heavy metals blown over the island by strong local winds. Campaigners used the US Freedom of Information Act to force the navy to admit that it had fired DU shells onto a range on the eastern tip of Vieques in 1999.

Navy officials said this was done by mistake after the wrong shells were loaded onto a jet, and that they made efforts to recover the shell casings afterwards, although they managed to find only about 50 of them.

Although the navy maintains that several hundred DU shells would not be enough to constitute a health hazard, scientists claim to have found signs of far greater use. Dr Jorge Fernandez, an environmental scientist said: "The Navy say the shells were used on target tanks on one particular spot on the bombing range, but when we made soil samples we found nine separate spots, all over the bombing range, which showed significant levels of uranium."

The navy spent several months test-bombing before the Gulf and Kosovo conflicts. Robert Rabin, of the Committee for the Rescue and Development of Vieques said: "I find it hard to believe that they didn't try DU shells out here first. After all, they tried everything else out here first, including napalm during the Vietnam War."

Matthew Chapman is the producer of Shell Shocked to be broadcast on Radio 5 Live at noon today.