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As part of secret chemical weapons experiments during World War II, the U.S. military exposed thousands of troops to mustard gas. It's a story NPR has been investigating this year. As we've learned, the experiments also continued after World War II, and thousands of troops were tested with other chemical and biological agents. Many of those veterans still don't know exactly what they were exposed to. As NPR's Caitlin Dickerson reports, now they're fighting to find out.
CAITLIN DICKERSON, BYLINE: As one Army scientist put it at the time, the American military wanted to learn how to induce symptoms such as fear, panic, hysteria and hallucinations in enemy soldiers. The testing was top-secret. Young troops were recruited right out of boot camp.
BILL BLAZINSKI: There would be a guaranteed three-day pass every weekend unless you had a test. There would be no KP - kitchen police duties, no guard duties. And it sounded like a pretty good duty.
DICKERSON: Bill Blazinski signed up in 1968. He was 20 years old. Blazinski said that what sounded more like a vacation than military duty quickly changed. In one test, doctors said they would inject him with an agent and its antidote back to back.
BLAZINSKI: There were three troops, including myself, taking the test. We were placed in individual padded cells. You know, the nurse left, and I'm looking at this padded wall. And I know it was solid, but all of a sudden it starts fluttering like a flag does, like the wind was blowing it. And I said, no, that can't be.
DICKERSON: The researchers never told Blazinski what caused him to hallucinate. In fact, they routinely withheld information from test subjects about what substances they were given. Today, he's part of a class-action lawsuit that would require the Army to tell anyone was used in testing exactly what they were exposed to. Ben Patterson from the law firm Morrison and Foerster is representing the veterans in the case.
BEN PATTERSON: They don't know what they were exposed to. You know, some of these substances were only referred to by codenames.
DICKERSON: Codenames like CAR 302668 - that's one of the experimental agents that researchers injected into Frank Rochelle when he was 20 years old, according to records from the testing.
FRANK ROCHELLE: When I was young, I'd never experienced any kind of drugs at all. You know, I drank some wine, and that's about it.
DICKERSON: During one test, Rochelle remembers looking down at his arms and legs. He says his freckles looked like they were moving, and he thought bugs had crawled under his skin.
ROCHELLE: And I went in the bathroom, went in there and closed the door. And I had my shaving kit - I had a razor blade, the old type. And there was a couple places that was on my leg - it's where I tried to cut the bug out because to me it was all real.
DICKERSON: In 1975, the Army's chief of medical research admitted to Congress that he didn't have the funding to monitor test subjects' health after they went through experiments. Since then, the military says it has ended all chemical and biological testing. But Frank Rochelle says that's not enough.
ROCHELLE: We were assured that everything that went on inside the clinic - we were going to be under 100 percent observation, they were going to do nothing to harm us, and also, we were assured that we would be taken care of afterwards if anything happened. Instead, we were left to hang out to dry.
DICKERSON: The law firm representing the veterans estimates upwards of 70,000 servicemen were used in military testing. Most of them have died, but those who are still alive would also get access to health care from the Army if they win their case. Part of the reason they're suing is because many have come down with illnesses they believe were caused by the tests they were in. Attorney Ben Patterson.
PATTERSON: It's just crazy and kind of disturbing. I mean, these are 18-, 19-year-olds and you could see people being enticed to want to take this risk but not really understanding what the risk was.
DICKERSON: The Department of Justice is representing the Army in the case and declined to comment for this story. In June, an appeals court ruled in favor of the veterans. Yesterday, the Army filed for a rehearing.
Caitlin Dickerson, NPR News.