After decades of denying that anthrax was used on Canadian soil, the Defence Department has asked a university professor to re-examine its history of experimenting with the deadly spores.
The project will not be a purely academic exercise, according to contract documents published on a Web site Tuesday: The government needs to know what happened during secret experiments of the 1940s and 1950s by Canadian, U.S. and British researchers because any remaining bioweapons material could be dangerous.
"In light of the persistent nature of the anthrax spore, it is highly desirable that a concerted effort be made to determine the extent of Canadian participation in this project," the document states.
The Defence Department said that its records do not show that anthrax was used in weapons tests, but reports to the contrary have spurred it to action.
Donald Avery, a history professor at the University of Western Ontario, said the defence officials who approached him are particularly worried about recent reports that scientists performed live trials of anthrax weapons at Canadian Forces Base Suffield in southern Alberta. Live trials are tests that use the real substance, rather than a harmless substitute.
"They were very concerned about the allegations that have been made about the open-field testing of anthrax during the Second World War, and possibly afterwards," Mr. Avery said. "And for understandable reasons, because those anthrax spores could still be there."
Biological weapons were outlawed under the Geneva Protocol of 1925, and Canada kept its biological-weapons program secret for decades after the Second World War. The military has acknowledged that researchers grew anthrax spores in Canada and tested delivery systems at CFB Suffield, but the documents published Tuesday show that official records do not reveal whether live testing was done.
"Records indicate that ... the project was cancelled before any field trials with anthrax spores were carried out," the documents state.
The official version has been challenged repeatedly in recent years. Liberal MP John Bryden, who wrote a book about Canada's bioweapons program, said he found documents indicating that British scientists during the Second World War tested experimental anthrax munitions at Suffield without the knowledge of their Canadian hosts. British researchers were essentially running the facility at the time, Mr. Bryden said, and they did not always conduct their experiments safely because of an urgent request from British prime minister Winston Churchill to develop biological weapons.
"It's a darn good idea to figure out where these sites may be," Mr. Bryden said.
In September, researcher Brian Balmer published a book based on recently declassified British documents that detail Canada's collaboration on bioweapons projects starting in the early 1940s. One such project, code-named Red Admiral, aimed to build bombs with payloads of anthrax, brucellosis, tularemia or bubonic plague.
Grosse-Île, east of Quebec City, was used as an anthrax-manufacturing site, Mr. Balmer wrote, and researchers experimented with weapons packed with rinderpest, a cattle virus.
Most of the live experiments used substitutes for the pathogens, to simulate spreading a deadly powder or mist without using actual agents. Mr. Balmer found references to researchers exploding "baby four-pound bombs" using "non-pathogenic simulants" and trying out spraying devices at the Suffield test ranges in 1950 and 1951.
A key question for the researchers will be whether such simulation munitions were the only ones used, Mr. Avery said. No evidence of live tests emerged during the research for his 1998 book
"My gut feeling is that nothing happened, but it was definitely being considered," Mr. Avery said. "But if I find evidence that the charges by Bryden and others are accurate, then that's what I'll publish. No strings attached."
Anthrax is not the only weapon under historical review by the Canadian military. A five-year, $9-million program is under way to find environmental or health hazards left behind from weapons research dating to 1900.
It is admirable that the military is willing to risk embarrassment for the sake of finding the truth about these programs, Mr. Avery said. "With something like anthrax, you can't err on the side of uncertainty."
It takes only a few thousand bacterial-anthrax spores to kill a human, and they are so small that a fatal dose could be placed on the period at the end of this sentence. Not only are they deadly, said Don Woods, scientific director of the Canadian Bacterial Diseases Network, the anthrax spores are remarkably durable.
"These things can last 100, 200 years, maybe more," Mr. Woods said.
If any Canadian military range is contaminated with anthrax, it will take a monumental effort to clean it up, said Brian Ward, an infectious-diseases expert at McGill University. Typical measures such as blasting the spores with heat or gluing them together with fixatives will not work on open terrain, he said.
The best option would be to soak the area with the chemical formalin, but even that might not eradicate the threat.
"How would you get the chemical down into the fissures of a rock, for instance? You might just have to abandon the area."