Bio-terrorists present a real risk to crops

12 November 1999

Bio-terrorists present a real risk to crops

Surely poor prices, food

scares, battles over GM

crops and dwindling

government support

give crop farmers

enough to worry

about? In North

America bio-terrorism

is the latest worry.

Stephen Leahy reports

ANTI-CROP bio-weapons and terrorists were the unlikely subjects at a recent conference in North America, where close to 500 delegates heard that farmers should have real concerns for the future.

A panel of experts in plant diseases and terrorism revealed how vulnerable agriculture is to bio-terrorism – the use of pathogens to cause a food crop epidemic or contaminate the food supply.

The risks are very real, according to plant pathologists, the FBI and the international intelligence community gathered at the American and Canadian Phyto-pathological Society symposium in Montreals Palais des Congres.

Belgiums dioxin scandal may not have been accidental, suggested panellist Tom Frazier, president of GenCon a Virginia-based scientific and educational organisation focused on terrorism and biotechnology. It did enormous damage to that countrys economy and even threatened the structure of the EU.

The incident has probably given some people ideas, Mr Frazier added. GenCon is studying the potential for contaminating animal feed with dioxins and other toxins for the US Department of Agriculture.

Introducing toxins or diseases like foot and mouth or anthrax into animal feed would be relatively easy. "All it would take is one case of foot and mouth disease to do an enormous amount of damage to the beef industry," he noted.

While that is hypothetical, he offered the real example of the disease outbreak in Taiwans pig industry coupled with a devastating soybean fungus in the last two years. Whether or not those were acts of bio-terrorism, their cause remained mysterious and they cost Taiwan billions of $s, he said.

Iraq is believed to have used wheat smut as an anti-crop weapon against Iran in the 1980s. And after the Gulf War, UN investigators found 2200 litres of a toxic mycotoxin and seven bombs containing the toxin.

Although never used, contamination of crops in the US or UK with the mycotoxin would have made them worthless, potentially causing an economic crisis, some believe.

Specific anti-crop weapons have their roots in World War Two. Germany, the USSR, the US and France all stockpiled plant diseases and developed ways to infect an enemys crops, the conference heard.

The subsequent Cold War and advances in the biological sciences led to the creation of biological weapons engineered to infect people with virulent forms of smallpox, plague and other diseases. The 1972 Biological Weapons Convention was supposed to end the race to develop ever nastier bio-weapons.

But in 1992, a senior Soviet Union biomedical research scientist Kanatjian Alibekov, now known as Ken Alibek, defected. He told a stunning tale about his career in the Biopreparat, his former nations massive biological weapons programme.

Now documented in his book Biohazard, it makes clear the USSRs military production of large quantities of advanced bio-weapons, including anti-crop bio-weapons, right into this decade.

Although now disbanded, the question remains as to where have the thousands of Biopreparat scientists and technicians gone and what they are doing, Christopher Davis, a former British intelligence officer wrote in the May 29 issue of New Scientist.

Anti-crop bio-weapons can destroy a countys economy without directly killing its people, panellist Robert Hickson, a US Air Force Academy strategist, said. That would have a certain appeal to some trans-national criminal syndicates or terrorists, he suggested.

It is not just yield losses from a deliberate infection by something like soybean rust that would have an impact. Concerns about a bacterial or fungal infection producing toxins would mean intensive crop screening or even destruction. That could easily lead to a loss of confidence in the food supply, even if the contamination was isolated.

Contamination with a quarantined organism would end any exports as well, said USDA plant pathologist Norm Shaad, whose job is to detect new pathogens. There is little to stop someone from deliberately introducing a pathogen, he continued.

Keeping up with accidental introductions by tourists toting food, seeds and plant materials from one country to another is hard enough, Mr Shaad said. Ever-increasing global trade creates a myriad of further opportunities.

Should a US farmer spot an unusual disease in his field, he is not going to get much help, Mr Shaad continued. No Foreign Pathogen Emergency Team springs into action. There are no detection or analysis systems in place. "It could take one to two years to detect and identify a pathogen." &#42


&#8226 Disease spread on purpose.

&#8226 Immediate trade impact.

&#8226 Difficult to trace.

&#8226 Examples known.

&#8226 Global monitoring needed.

Weapon of choice

When it comes to deliberately infecting crops, fungi are the most likely weapon, says Anne Vidmar of the University of Nebraska. Fungal spores could be distributed onto crops like maize, wheat or rice by any number of ways from aerial spraying to bombs to contaminated bird feathers.

Establishing an infection needs a high concentrations of spores, the right environmental conditions – moisture and warm temperatures – and a good storm. The latter creates plant wounds to provide entry points for the spores.

But the biggest threat is soil disease. Introduced pathogens with some effect on soil could cause very serious problems and would be extremely difficult to detect because so little is known about soil micro-organisms. However, terrorists would have to do their homework, she said.

Bio-engineered pathogens pose fewer worries because they are easier to detect, harder to make and do not survive as well as natural pathogens. "Mother Nature does a better job designing nastier and fitter plant disease organisms."

Who would strike?

Who would even threaten such bio-terrorism? A 1992 US Congressional Office of Technology Assessment report on bio-terrorism lists some candidate organisations: Japanese Red Army, Red Army Faction, US white supremacist groups such as the Aryan Nations, Hizbollah, and the Abu Nidal Organisation.

Tom Frazier, president of Virginia-based scientific and educational organisation GenCon added extremists in animal rights and environmental organisations to the list. He also envisioned a near future of professional bio-terrorists with advanced degrees, hired to attack particular companies or countries.

Whether such attacks have already occurred is difficult to know. Companies will not comment and government reports are classified.

Moreover, it is very hard to differentiate a naturally occurring pathogen from a deliberate introduction, noted Anne Vidmar, a plant pathologist at the University of Nebraska. That is why detection technology and rapid diagnosis capability are needed.

Plant disease monitoring and surveillance systems are also needed world-wide, she said. Equally important is an openness between countries about disease problems. Currently, to avoid trade restrictions, countries are reluctant to announce the discovery of a new disease problem. That reluctance extends to funding. While the FBI wants to work with the American Phytopathological Society on crop bio-terrorism, their interest has yet to be translated into $s, she said.

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