When it hits you, the first thing you notice is the smell-a little like mustard or horseradish. If you get enough of it, your skin, eyes and lungs begin to blister, eventually causing respiratory failure and death.
More than a million soldiers were exposed to the painful and deadly mustard gas during the First World War after Germany used it as a weapon, releasing it in grenades and shells over the trenches. It's a story that brought home the horror of 20th-century warfare and helped upend the notion that it was glorious to die for one's country.
Gas attacks were famously depicted in the poem Dulce et Decorum Est by Wilfred Owen, who described soldiers as "knock-kneed, coughing like hags … at every jolt, the blood gargling from the froth-corrupted lungs, obscene as cancer, bitter as the cud."
It's been 100 years since mustard gas first appeared as a weapon in the world, but its legacy is anything but ancient history. According to the Organization for the Prohibition of Chemical Weapons, there is evidence ISIS has been using the gas recently on Syrian citizens, contrary to international prohibitions on chemical warfare.
It is perhaps not a huge stretch to imagine terrorists or dictators resorting to such cruel weaponry. Harder to accept are the mustard gas tests inflicted by Allied forces on their own soldiers during the Second World War-as many as 60,000 (likely more) in the United States, 7,000 in Britain and 2,500 in Canada. Many of those Canadian tests were conducted in Alberta, at Experimental Station Suffield.
Shedding light on a toxic history
When medical historian Susan Smith first heard about the human experiments on CBC Radio in 2000, you might say it left her burning to investigate further. The result is a new book, Toxic Exposures, that sheds light on the whole noxious affair, accounting for the human and environmental costs of chemical warfare.
"It's quite appalling to consider the atrocities committed by Nazis in World War II (who conducted mustard gas experiments of their own)," said Smith. "It's considered evil science. But I was so struck by how this was a story of the good guys-the Allies. It was ethically astonishing and done on a huge scale."
After lessons learned in the Great War, everyone expected the next global conflict to be a chemical war, said Smith, so huge quantities of mustard and chlorine gas were manufactured and moved around the globe by nations on both sides of the conflict.
For the most part, that war never happened. But in pursuit of better defences against the agent, soldiers were sprayed with it in fields and gas chambers in Australia, Britain, the U.S. and Canada to observe its effects under different conditions. Nurses at Suffield described watching blisters form, break, then form again underneath.
"It was the pain that just kept coming," said Smith. "The soldiers would be hospitalized for weeks or even months.
"A lot of those veterans said they believed in the war, felt it was a good war and wanted to do their part," said Smith. Participation was technically voluntary, but soldiers felt a huge pressure to contribute to the war effort in any way they could-and were likely not informed of the full extent of the risk.
"Many did not object to the fact their bodies were on the line, only that they didn't get recognition or compensation for it," said Smith.
From chemical weapon to chemotherapy
One great irony of those tests, however, was they resulted in an unanticipated medical discovery, one not widely known because of the secrecy around the whole research program. Military scientists, many of whom studied cancer in civilian life, couldn't help but notice what the gas was doing to the immune system, specifically to white blood cells. They wondered: what if the destructive power of this compound could be directed at cancer cells without killing the patient?
"The researchers found it couldn't cure cancer, but could control it," said Smith. "They were able to extend the lives of certain patients and identify types of cancer, such as Hodgkin disease, that benefited most from the treatment."
Those benefits were temporary at first, overshadowed by problems with chemoresistance and chemotoxicity. But derivatives of the sulphur mustard agent are still used in some forms of chemotherapy to this day, said Smith.
A shameful legacy
On balance, however, the legacy of mustard gas has been far more damaging than positive, its destructive fallout anything but over. Outlawed first by the Geneva Protocol of 1925 and more expansively by the Chemical Weapons Convention in 1993, it is nonetheless still used today by ISIS because it is relatively cheap and easy to produce.
Despite the numbers of veterans affected by the gas experiments, their story didn't surface until the 1980s, when they began suffering from skin, lung and eye ailments related to exposure. Seeking compensation, however, was anything but easy, said Smith.
"When they go to the doctor, they're told, 'You're mistaken, you have the wrong war. Mustard gas was used in World War I. They go to the government to get help, and the government denies it ever happened."
The Canadian veterans did eventually settle a class-action suit in 2004, receiving about $24,000 each-"a pittance," said Smith-if they promised not to take the matter any further.
"In Canada, we're still content to push it under the rug," she said. "People argue it's one of those cases where people will just die off before we have to deal with it. It's an embarrassment."
The environmental consequences are equally staggering. It's estimated the American military amassed 187,000 tons of mustard gas between 1940 and 1945, but the war department refused to fund either storage or disposal of the barrels and gas bombs. After the war, huge stockpiles were simply buried or dumped in the ocean, including at sites off Tofino and Halifax.
Because dumping was imprecise and lacked proper records, and because barrels drifted with currents, many of them cannot now be found. To make matters worse, they have begun corroding, the agent oozing out and forming a crust on the surface of the water, where fishermen catch it in their nets and get burned. The American military is still at work destroying 26,000 tonnes of remaining mustard gas stockpiles in Colorado.
Smith has recently gathered yet more evidence suggesting the number of soldiers subjected to mustard gas experiments in the U.S. was far higher than the accepted figure of 60,000. She will present those findings at a history of medicine conference in May.
"It just goes to show the legacies of war are ubiquitous and never-ending," she said. "And now children in Syria are being burned in the same way as those soldiers 70 years ago."
Susan Smith will present her findings on the origins of chemotherapy in chemical warfare March 15 at a free public lecture.