The U.S. Army is conducting medical tests on a handful of GIs who complained of illnesses after reported exposure to depleted uranium (searchin Iraq.

Up to six soldiers from a National Guard unit based in Orangeburg, N.Y., have undergone exams at Fort Dix (search), and three of them remain there under observation, Fort Dix spokeswoman Carolee Nisbet said Monday.

"We are following up on this. We are on top of it. It's not something that has fallen by the wayside," she said.

Of nine members of the unit examined by a doctor at the request of the New York Daily News, four had "almost certainly" inhaled radioactive dust (searchfrom spent U.S. artillery shells containing depleted uranium, the newspaper reported Monday.

Six of the nine contacted the newspaper after unsuccessfully appealing to the Army for testing because of unexplained illnesses, the Daily News reported.

The soldiers complained of headaches, fatigue, shortness of breath, nausea, dizziness, joint pain and unusually frequent urination.

The exposures apparently occurred last summer when the 442nd Military Police Co. served in Samawah, Iraq. Most members of the unit, which includes many New York police officers, firefighters and prison guards, remain in Iraq.

Military medical officials from Walter Reed Army Medical Center in Washington and the Army's Center for Health Promotion and Preventive Medicine conducted testing at Fort Dix, Nisbet said.

The Army would not identify the soldiers or say whether testing revealed contamination or illness.

All National Guard and Reserve soldiers mobilized through Fort Dix receive physical exams upon their return from overseas, Nisbet said. The soldiers who complained of ailments asked for and received a second round of evaluations, she said.

Depleted uranium, which is left over from the process of enriching uranium for use as nuclear fuel, is an extremely dense material that the U.S. and British militaries use for tank armor and armor-piercing weapons. It is far less radioactive than natural uranium.

According to a Depleted Uranium Information Web page posted by the Army, depleted uranium recently provided to the Pentagon by the U.S. Department of Energy contained trace amounts of contaminants like neptunium, plutonium, americium, technitium-99 and uranium-236.

"These contaminants in (depleted uranium) add less than one percent to the radioactivity of (depleted uranium) itself," the Web page said.

"Medical scientists consider this insignificant."

Army spokeswoman Cynthia O. Smith would not comment Monday on whether other troops have complained of similar ailments or whether the Pentagon would take precautions aimed at preventing future exposure.