Did toxic chemical in Iraq cause GIs' illnesses?

KBR also points to Army tests of Indiana Guard soldiers that showed no medical problems that could be linked to exposure, as well as a military board review that found it unlikely anyone would suffer long-term medical consequences.

But Bayh and Doyle say those tests were done too late to be valid and note that soil tests were taken after the contaminated area was covered.

Doyle also disagrees with KBR's contention that workers weren't there long enough to have elevated cancer risks.

It can take a long time for symptoms of illness to surface — five to 10 years or more for cancer. But some of those who say they were exposed are already ill.

James Gentry, a retired lieutenant colonel in the Indiana Guard, is in the late stages of lung cancer and the disease has spread to his ribs and spine, according to his friend, Christopher Lee.

Gentry hasn't sued but in a December 2008 deposition he said it was "very disappointing" KBR managers didn't share information soldiers were around cancer-causing chemical.

"I'm dying because of it," he said.

While acknowledging he wasn't 100 percent certain that's why he has cancer, Gentry — who served a second tour in Iraq — said his doctor "believes the most probable cause was my exposure to this chemical."

The Indiana, West Virginia and Oregon National Guards have sent hundreds of letters to soldiers notifying them of possible contamination and urging them to seek medical attention.

Bayh has introduced a bill calling for a medical registry that would require the Department of Defense to notify all military members of exposure to potential toxins and ensure their medical care. A similar measure that only mandates notification was approved Thursday in the U.S. House as an amendment to the defense authorization bill.

All these steps come too late for 1st Sgt. David Moore.

When he returned from Iraq, his persistent cough escalated into breathing problems, nosebleeds and boil-like rashes, recalls his brother, Steve.

Even when doctors couldn't figure out what was wrong, Moore didn't give up, Steve Moore says.

"He was always upbeat," he recalls. "He said, 'They'll figure it out, they'll figure it out.' He thought that until the last time I talked to him."

Moore died in February 2008. The cause was lung disease. His death was ruled service related. His brother believes it was hexavalent chromium.

Larry Roberta, the former Oregon Guardsman who needed stomach surgery after his return, says he suffers from post-traumatic stress, mood swings, nose polyps, chest pains and debilitating migraines.

"I have 100 percent disability," he says. "I've got a long laundry list of things that happened to me while I was there. If you add it all up, I'd be almost 200 percent disabled."

Kimberling, the former Indiana Guardsman, struggles as well.

The father of two young children — he's a pharmaceutical salesman in Louisville, Ky. — says he hasn't been able to get life insurance because his possible exposure is mentioned on his medical records.

Sometimes, he says, it's hard to separate his ailments — sinus problems and joint pains — from his fears.

"I feel like I'm a 38-year-old in a 60-year-old's body," he says. ... "I'm not sure if it's the anxiety of finding out about it or not. I kind of know and feel it's just a matter of time before it catches up with me."