Since 1991 the U.S. military has admitted to using depleted uranium in armor and ammunition on a large scale. But since then, a debate has raged about its long-term health effects on soldiers and their families.

Could one of the most effective military tools in their arsenal actually be harming soldiers?

Jerry Wheat is one of the hundreds of thousands of American men and women who have enlisted in the U.S. Armed Forces.

"I was in the army for 4 years and 10 months. I joined in 1989 as a 19 Delta, which is a cavalry scout," said Wheat. "My job was to go out and look for the enemy."

Wheat was awarded the Purple Heart and the Bronze Star after his 1991 deployment in Gulf War I.

Wheat said his unit was in Iraq, heading toward Basra, when it got caught up in a firefight.

"My Bradley was hit again with another tank round, and that tank round knocked me unconscious," said Wheat.

In an instant flash of fire, smoke and shrapnel, Wheat became a casualty of war. But without knowing it, his battle was just beginning.

"I took shrapnel in the back of my head. I had some second- and third-degree burns, and there was about 25 pieces of shrapnel from my head all the way down my back," said Wheat.

The military initially denied it, but Wheat ultimately learned that the pieces of shrapnel embedded in his head and back were shards from "friendly fire" and some of the fragments contained depleted uranium.

"As a soldier, you know, most of us didn't know what DU was or made aware of to stay away from it," said Wheat.

When uranium is enriched for use as nuclear fuel or for nuclear weapons, a by-product called depleted uranium -- DU, for short -- is made. It is a form of uranium minus the most radioactive isotope.

The military discarded DU until it discovered that its properties as a heavy metal made it perfect to protect U.S. troops as armor and was very effective as ammunition.

Col. Mark Melanson, head of radiation safety at Walter Reed Army Medical Center in Washington, D.C., is the military's foremost expert on depleted uranium and its combat applications.

"When it encounters armor, it actually sharpens to a fine point as it penetrates into the armor," said Melanson. "DU has been well studied and the health effects are well understood. There are overwhelming international and national consensus in the scientific community of what the risks are."

But many critics aren't convinced.

Dan Fahey, a Navy veteran, has been studying DU and its effects for more than a decade. He points out that the Department of Defense and the Veterans Administration have thousands of studies and reams of test data on rats.

"Well, it's clear the military has done a lot of studies on DU, but the question is: are they doing the right studies?" said Fahey. "It's really time that the government does an adequate health study of veterans, and because the rat studies have shown that DU is carcinogenic, it can cause a variety of health problems."

Only 77 soldiers from Gulf War I and just four from Operation Iraqi Freedom are being tracked clinically. Jerry Wheat is one of them.

"I had a tumor removed in the 90s from my left arm that was in the bone, and DU stores in the bone," said Wheat.

Wheat said he has endured a series of health problems.

"I come back from the Gulf and have these abdominal problems and just not feeling well in general, and then my wife miscarriages," said Wheat.

Every two years, Wheat takes part in clinical surveillance headed by Dr. Melissa McDiarmid.

Since 1996, McDiarmid has been Medical Director of the DU Program at the Baltimore VA, responsible for studying and tracking the health effects on exposed soldiers.

"Your health risk is not only determined by your dose but by your duration of exposure. So those two things are working together," said McDiarmid. "It might be surprising for people to know that even the highest in the group that I follow who have retained fragments ... are just approaching what used to be allowable occupational limits for uranium exposure among workers 40 and 50 years ago."

Fahey criticizes the testing methods, characterizing the results as a case of "don't look, don't find."

"So, they have structured their studies, in my opinion, to come out with conclusions that validate their spin, which is that DU is completely harmless," said Fahey.

Fahey suggested that because DU continues to be a critical tactical advantage on the battlefield, the military has a vested interest in keeping it there.

"So, the thing about DU is that it's not always safe and not always dangerous," said Melanson. "As a scientist, my duty is to take a look at what the science says and assess the risks for the Army on what the risks from DU are. I am not an advocate for DU. I am not opposed to DU. I am neutral."

As experts debate the safety and toxicity of DU and the current testing methods for detecting it, Wheat said he lives with it every day and is proof of its effects.

"Prior to being exposed to DU I didn't have this and the tumor, and it's one thing after another," said Wheat.

So, does the government really have a handle on what DU's health effects are on the soldiers exposed to it?

Jim Bunker, president of the National Gulf War Resource Center headquartered in Kansas City, Kan., said it was an honor to be among the thousands who served in the first Gulf War. But now he says, that same service has left him with unanswered questions about his health.

"I went into the service because it was a family tradition. It's something I always wanted to do. My dad was in the service, my uncles were in the service, my grandpa was in the service," said Bunker. "It was something that started over time -- having a hard time breathing, muscle twitches and later on muscle cramps. And nauseousness."

He was prescribed an assortment of medications, but military doctors were not able to immediately pinpoint the cause of Bunker's symptoms, and he wasn't alone.

Numerous returning veterans were also reporting weakness, dizziness or overall changes in health.

"What were your symptoms?" KCTV5's Ash-har Quraishi asked Wheat.

"Just really bad abdominal cramps and couldn't keep any food down. It was pretty severe at the time," said Wheat.

That is a common thread in the complaints among many of the soldiers like Wheat, who had been struck with fragments containing DU.

"We set up in positions that were blown up by coalition forces, so you had a lot of tanks and stuff around that had a lot of DU dust around," said Bunker.

"Because DU is radioactive, we assume that there is a radiation risk associated with the exposure," said Melanson. "All of the studies done where individuals received exposure to uranium or DU have have not shown any adverse health effects."

"It's virtually the same script as the Agent Orange saga that happened where you had people exposed to Agent Orange returning home, reporting health problems, and the government denying that, first of all, that Agent Orange was dangerous at all, and then entering this debate of who was exposed and how much they were exposed to," said Fahey.

"When soldiers come back from theater, we have a very aggressive screening program to make sure that we catch people with valid potentials for exposure and address soldiers concerns," said Melanson.

Part of the screening program includes filling out a Post Deployment Health Assessment questionnaire.

KCTV5 News obtained five years of data for nearly 2 million soldiers, and found that 54,567 soldiers said they had been exposed to DU "sometimes" or "often."

Compared with the 1.9 million soldiers who reported "no" exposure to DU, those exposed to DU were twice as likely to report concerns with symptoms like vomiting, difficulty breathing and weakness.

And in general, those exposed to DU were twice as likely to characterize their health as "poor."

McDiarmid said the data she has collected suggests little to be concerned about.

"Unless you have an on-going elevated urine/uranium concentration, there are not going to be health effects seen down the road," McDiarmid said.

While tests for exposure to DU are available, solid scientific data on what it does to the body have not been conclusively determined.

The VA admits that "research on the human health effects of DU exposure in military occupations is limited." While also citing that "chronic exposure by inhalation presents a potential radiologic hazard to the lung."

Perhaps even more hazardous than the low levels of radiation DU emits is that it is a highly toxic metal.

Dr. Diane Stearns is a metal toxicologist and biochemist at Northern Arizona University. For the last seven years she has been studying DU's ability to damage DNA. She found that DU actually binds to DNA and causes cell deaths and mutations.

"We understand how its radioactivity can damage DNA and lead to cancer, but no one had ever explored uranium as a chemical," said Stearns. "If we know how it damages DNA, then we know how to protect ourselves and protect the soldiers against harm."

"Do we know that yet?" asked Quraishi.

"We don't know that yet," said Stearns. "There is a lot more research that needs to be done."

According to a mandated Congressional report by the Institute of Medicine last year, "it would be difficult to design a study to assess the health outcomes of DU exposure in military and veteran populations with currently available data."

"I think, unfortunately, in the field of toxicology, usually we're sure something is harmful when people are clearly and quickly harmed. And something like depleted uranium, that may cause cancer, that's something that's going to happen decades down the road," said Stearns.

Still, the Army maintains that the health risks associated with DU exposure are minimal.

"Can you say that you are very comfortable with the use of DU in its current form?" Quraishi asked Melanson.

"Absolutely," replied Melanson.

"They don't understand the long-term effects of DU, but there is nothing better for them to use at this point in time, so they are not going to give up that magic bullet they have," said Bunker.

Wheat is scheduled to travel the Baltimore VA hospital next week for its eighth evaluation of exposed veterans.

According to The National Academy of Sciences, more than 300 tons of large caliber DU munitions were used in the first Gulf War. U.S. forces continue to use DU on the battlefield today.