Sniffing explosives among the flowers

Defense researchers track bees to detect buried land mines

May 27, 1999|By Frank D. Roylance | Frank D. Roylance,SUN STAFF

Pigeons once carried military dispatches. Dolphins trained for secret underwater missions. Dogs alerted combat patrols to snipers and booby traps.

Now the Defense Department wants to know whether honeybees can be drafted to help find land mines, including some of the 110 million buried mines that threaten innocent lives in 70 countries around the world.

The research is part of the Pentagon's Controlled Biological Systems program. Program scientists are spending about $10 million a year investigating whether insects can be used -- perhaps even trained -- to gather battlefield intelligence or to degrade the enemy's ability to fight back.

The bees have been shown to pick up minute traces of explosives while foraging among the flowers in mine fields. They carry the chemicals back to their hives, where sophisticated scanners can sniff them out.

"The bees do the sampling for us, so we don't have to go into the field," said Phil Rodacy, a chemist at Sandia National Laboratory in Albuquerque, N.M.

Scientists at the Pacific Northwest National Laboratory, in Richland, Wash., equipped their bees last week with backpacks -- radio-frequency tag slighter than a grain of rice and painstakingly glued on while the bees are chilled to sedate them. The tags will help scientists identify the bees as they come and go, and track the direction of their flight.

Next, researchers at Sandia will launch the bees into test mine fields, and use instrument-studded hives to scan for the chemicals they bring back. There is hope that bees, or wasps, can be trained to seek out the mines and bring the evidence back to their keepers.

Bees, parasitic wasps, caterpillars and other living "arthropod systems" are being studied for many potential contributions to future warfare.

Biologists and engineers funded under the year-old Controlled Biological Systems program are investigating ways to use sex attractants to move nuisance insects around a battlefield. Others are wiring up disembodied antennas to gather signals of chemical agents far too faint for man-made detectors.

Other teams are studying insect behavior and locomotion for clues to better designs for unmanned military weaponry.

The military payoff is uncertain, said Alan Rudolph, who directs the program, funded by the Defense Advanced Research Projects Agency. But it is that agency's job to take scientific risks. It was DARPA research that launched the Internet and many advances in microelectronics.

If the bee research bears fruit, honeybees could provide poor countries with a cheap and efficient means for detecting land mines.

"Bees are pretty much universal. They're indigenous to every country in the world," Rodacy said. "If you find a natural beehive in the woods, you can use that." The equipment needed to scan the bees for traces of explosives can be purchased for about $5,000, and one such detector is enough to serve hundreds of hives.

When mines are found, residents can be warned, Rodacy said. And "if we can come up with a good way to certify that a piece of land has been cleared of mines, it's a pretty good way of putting a lot of arable land back in the hands of the local population."

Abandoned mines remain dangerous decades after their military usefulness has ended. They kill or maim an estimated 2,000 people a month and constrict economic development, according to the United Nations.

Traditional detection methods are tedious, expensive and dangerous. Plastic mines can be invisible to magnetic or electronic detectors. Metallic shrapnel and trash produce thousands of false alarms, which induce tedium and carelessness among mine hunters.

"You get careless, you get killed," Rodacy said. The United Nations has estimated that one hunter is killed or injured for every 1,000 to 2,000 mines cleared.

Researchers are experimenting with ground-penetrating radar, synthetic aperture radar, neutron activation and X-ray technologies.

"But all these require a [tractor-trailer] truck full of equipment," he said. "A lot of countries can't afford it."

Sandia is testing a variety of chemical-sensing technologies that rely on absorbent materials to which traces of explosives will adhere.

"But you still have to have somebody go into the field," Rodacy said. "And if you can do that, you're pretty confident there are no mines."

So why not send in bees?

Biologist Jerry Bromenshenk of the University of Montana has found that foraging bees will pick up traces of chemicals in the environment and concentrate them at their hive. He has used them to map heavy-metal fallout from a Puget Sound lead smelter.

With almost no expense or danger, a hive of 25,000 bees can extend a search over two miles.

"Jerry monitored up to 250,000 entrances and exits [by bees] on one day. That's a phenomenal amount of sampling," said Susan Bender, a Sandia chemist working on the bee project.

"We figured, why not try it with explosives?" Rodacy said.

Land mines may lie hidden from sight, but they all reveal themselves chemically.

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