The report is required by the National Defense Authorization Act for Fiscal Year 2007, which President Bush signed into law last year.

The request for the study is an outgrowth of claims by Iraq war veterans that exposure to depleted uranium and other toxic substances there has negatively affected their health and that, therefore, their illnesses should be recognized as war-related and the treatment covered by the Veterans Administration.

Currently, the State Department’s Web site says fears about adverse health effects of depleted uranium, or DU, are “unwarranted,” and it lists worries about DU under a section called “identifying misinformation.”

The site says the American military uses the material in ammunition “to take advantage of its unsurpassed ability to penetrate armored vehicles,” and it cites four separate studies - by NATO, the Rand Corporation, the European Commission, and the World Health Organization - that found no evidence of adverse health effects from depleted uranium.

Even so, worries persist. According to Rep. Jim McDermott, a Democrat of Washington who pushed for the report from the Pentagon, “There are countless stories of mysterious illnesses, higher rates of serious illnesses, and even birth defects. We do not know what role, if any, DU plays in the medical tragedies in Iraq, but we must find out.”

Modern wars have produced a number of specific medical complaints, ranging from “Gulf War Syndrome” - a group of immune disorders and cancers whose connection to service in the 1991 Persian Gulf conflict is being studied - to the long-term effects of a defoliant, Agent Orange, for which some Vietnam veterans obtained a settlement in 1984.

While their causes can’t be pinpointed definitively, some soldiers who have avoided being killed or wounded in the current Iraq conflict are returning to America to find they have debilitating illnesses or cancers that they suspect are related to battlefield conditions, whether it is the depleted uranium used in projectiles, the remains of Saddam Hussein’s chemical weapons, or the smoke from burning oil wells.

An Army chaplain, Captain Fran Stuart of the 101st Airborne was based in Mosul, Iraq, where “Shock and Awe” bombings occurred, for a year beginning in March 2003. In March 2006, the 40-year-old chaplain - who is this reporter’s sister - was diagnosed with a rare condition only seen in teenage girls: Stage IV dysgerminoma, an ovarian germ cell cancer. She was flown from Germany to Walter Reed Army Medical Center in Washington, D.C., where doctors removed a volleyball-sized tumor from her abdomen and she faced daily battles with the side effects of an aggressive chemotherapy regimen - 35 rounds to date.

“My body isn’t mine anymore. I can feel the other tumors inside of me. I look like a monster,” Captain Stuart said last May as patches of her strawberry blond hair fell out.