American farmers are vulnerable to biological warfare attacks by enemy agents or airplanes carrying disease-laden mists and destructive chemicals. This may sound like a message from the Department of Homeland Security, but the warning is more than 50 years old. It came from the Civil Defense Administration in 1954.

“What the Farmer Should Know About Biological Warfare” was the name of a civil defense booklet distributed by Farm Bureau and other organizations. The agency reminded farmers to be alert and report any signs of unusual crop or animal diseases.

Fast forward to today. The enemy has changed but the warning is still valid. Large U.S. cities have an early-warning system known as BioWatch – a program of the Department of Homeland Security, Environmental Protection Agency and U.S. Centers for Disease Control and Prevention.

BioWatch uses sensors to monitor the air outdoors and indoors where crowds might gather, such as at airports or subways. There may be dozens or even hundreds of these sensors in strategic places. Scientists monitor the data to make sure deadly biological agents are not released into the air.

The American Farm Bureau Federation has called on federal and state governments to strengthen their existing capabilities to prevent and respond to acts of bioterrorism. But as was the case during the Cold War, farmers are still an important part of the defense network in rural areas.

Farmers are cognizant of the fact that the U.S. agricultural industry could be a target for several reasons. For one thing, an attack might not be discovered right away, or it could be misconstrued as a naturally-occurring disease outbreak. This would give perpetrators a good chance to get away. Secondly, a disruption of the nation’s food supply would alarm consumers and harm the economy.

In 1942, the British experimented with anthrax bombs on a small island near Scotland. One idea was to put a little bit of anthrax in cattle cakes and drop them over Germany to kill livestock herds. The cakes were manufactured but never used and later destroyed.

Bacteria, viruses and fungi could be used in an intentional attack against crops. This is not alarming news. Farmers have known for years that crops are vulnerable to disease. However, the intentional spreading of a disease to a crop such as wheat, barely, oats or rye could result in losses of up to 90 percent.

Terrorists also could tamper with food items after they leave the farm. In 1979, an extremist group injected liquid mercury into Israeli oranges sold on European markets. A dozen people suffered poisoning, and Israeli orange exports were sharply curtailed.

Numerous biological warfare agents have been identified over the years, but detection methods and countermeasures are rapidly advancing. By early next year, the Department of Homeland Security will announce the site of the National Bio and Agro-Defense Facility. The name is a good indicator of its work – the facility will address biological and agricultural security risks.

Agriculture needs to remain on alert. Guarding the nation’s food supply is a top priority and an important part of national security.