Vol. 51, No. 8 April 23, 1999

Bees go on hundreds of chemical sampling missions a day

By John German

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Bees dutifully going about their daily business -- gathering nectar and pollen and taking it back to the hive -- may soon help protect the lives and limbs of people, literally, if a demonstration project at Sandia is successful.

MINE BEES -- Beekeeper Gary Bender (a contractor in Dept. 7577) holds a ³frame² of honeybees from a hive in Area 3. Gary, a hobbyist beekeeper, is part-time tender of the honeybees and bumblebees being used in landmine-detection experiments at Sandia. In the foreground are two unfuzed antitank mines used in Sandiaıs demonstration minefield. (Photo by Randy Montoya) Download 150dpi JPEG image, 'bees_pix.jpg', 1.4 Mb

Sandia is lending its explosives-detection and chemical-analysis skills, as well as a mock minefield in Area 3, to a longtime bee researcher at the University of Montana to see if foraging bees can safely and reliably detect buried landmines and help return hundreds of thousands of acres of uncharted land back to productive use.

Landmines have been called the worst form of pollution on earth. Some 60 people are maimed or killed by buried mines every day. The Red Cross estimates that 80-120 million landmines currently are deployed in 70 countries worldwide, with an average 40,000 new mines deployed each

Although a variety of high-tech and brute-force methods of detecting and clearing mines are available to the worldıs militaries, the people in developing nations where most of the worldıs landmines are deployed typically have few options when the fighting stops. Many thousands of acres of land lie unused because farmers are afraid to work their fields. Streams and other sources of badly needed water are littered with mines. In some countries professional mine prodders are paid a few dollars a day to carefully poke the soil every several inches with a metal probe checking for buried mines.

³The landmine issue is a serious problem in many countries,² says project leader Susan Bender (1831). ³By attacking the landmine problem from several angles, we think we can make a difference.²

Bees are like flying dust mops

In the landmine project, Sandia is working with Jerry Bromenshenk at the University of Montana­Missoula to see if bees can be trained to find residues of TNT, the primary ingredient of most landmines, and bring the evidence home.

The demonstration builds on three decades of explosives-detection work at Sandia and 25 years of biosystems research at the University of Montana. The work is funded by the Defense Advanced Research Projects Agencyıs (DARPA) Controlled Biological Systems Program.

Bromenshenk and his colleagues have shown that as bees forage, they attract particles of dust, soil, and pollen to their fuzzy, statically charged bodies and bring the samples back to the hive. In doing so they provide a chemical survey of an area extending a mile or more from the hive in all directions.

³Bees are like flying dust mops,² says Bromenshenk. ³Wherever they go, they pick up dust, airborne chemicals, and other samples. If itıs out there, theyıll find it and bring it back.²

All landmines leak small amounts of explosives into nearby soil or water. Sandiaıs mine-detection research has focused on predicting what happens to mine-leaked vapors and residues and their chemical byproducts in the environment as they are adsorbed on soil particles, permeated or leached through soil, dissolved in water, and consumed by animals and plants.

By modeling the ³fate and transport² of explosives and understanding where they concentrate in the environment, the researchers are better able to detect their presence at lower levels and determine optimum conditions for detection.

Based on this work, Sandia is developing a number of mine-detection systems, including handheld chemical ³sniffers,² soil-penetrating vapor extractors, and methods to enhance the chemical signature of landmines. Many of these systems can detect plastic (nonmetal) landmines, which most conventional metal-detector-based systems cannot.

Increasing beesı odds

The bee demonstration in Albuquerque makes use of an Area 3 testbed laden with unfused antitank mines, specifically created for Sandiaıs landmine-detection work. Last fall, the Sandia team established two small honeybee hives in the landmine field. They also established two control hives a few miles away, from which theyıll gather baseline data.

Several varieties of plants are being grown in an enclosed greenhouse near the test site. The plantsı soil is tainted with varying levels of TNT so the researchers can study how efficiently the plants uptake the TNT.

³There is very little written in the scientific literature about plant uptake of explosive contaminants,² says Susan. ³We are conducting new studies to see if plants rooted in TNT-tainted soil will uptake the residues into their roots, stems, and flowers, and even incorporate them into their pollens.²

If a plant that readily accumulated the TNT could be identified, a suspected minefield could be seeded with that plant (by air) to maximize the beesı chances of finding the mines, she says.

Inside the greenhouse a small colony of bumblebees has been established to measure how efficiently the bees carry TNT-tainted pollen and soil back to the hive.

³The greenhouse, plant uptake experiments, and control hives are designed to help us increase our chances of success when we begin testing the bees in the landmine field,² says Phil Rodacy of Explosives Materials and Subsystems Dept. 1552. ³Weıll compare the results we get in the controlled environments with the results we get in the field to see how well the bees are doing.²

High-tech Œhoneybee condosı

In May Bromenshenk and a team of University of Montana colleagues and students plan to come to work at Sandia. New colonies of honeybees will be introduced at the test minefield.

The Montana team will use highly instrumented ³honeybee condos,² which automatically count the number of times bees fly in and out of the hive, to track the beesı flight activity. Bromenshenkıs team has shown that subtle changes in flight activity and other bee behaviors can signal that the bees are being exposed to environmental contaminants.

For the experiments, Tom Hund of Photovoltaic Systems Application Dept. 6218 is providing solar panels for the minefield that will generate the power necessary to drive the hivesı electronics, including fans, computerized bee counters, and data analysis cards. Researchers from Pacific Northwest and Oak Ridge national labs are helping the Montana team upgrade the high-tech beehives for the experiments, as well. Steve Reber of Explosives Materials and Subsystems Dept. 1552 is managing the minefield and hive electronics, power, and data acquisition systems for the tests.

Training bees for success

Pollen, dust, air, and other samples collected by the bees and brought to the hive will be analyzed for trace amounts of explosives by Susan, Phil, and Ted Borek of Materials Characterization Dept. 1822 using gas chromatography, mass spectroscopy, and ion mobility spectroscopy. The chemical analyses will help determine whether the bees can reliably indicate the presence of landmines in an area over time.

One goal of ongoing tests at Montana is to determine which explosives bees can smell and then train them to seek those chemicals. If bees can be trained to associate the odor of explosives (such as TNT) with food (sugar syrup, for instance), says Bromenshenk, the bees may spend more time near plants and surface soils contaminated with TNT, increasing the odds that they would bring back TNT residues from an area that contains buried mines.

Bromenshenk has demonstrated that by providing a new bee colony with feeders tainted with a marker chemical, then gradually moving the feeders farther from the hive and eventually removing them, bees can be trained to forage wherever they smell the chemical.

If the bees can be trained to seek TNT, the Montana team may attach small diodes onto the backs of several hundred TNT-trained bees. Then, using a handheld radar tracking device, they will chart where those bees go to determine whether they tend to forage near the locations of known landmines.

Feel-good humanitarian work

The ultimate goal of the project, says Susan, is to determine whether buried mines are present in large areas by establishing beehives near the suspected mines, monitoring beesı flight activity, and analyzing hive samples.

³If this approach works and itıs reliable, you could foresee giving people the green light to re-enter or farm large areas based on bee sampling,² she says.

Susan and her husband Gary Bender (a contractor in 7577) are hobbyist beekeepers and own a 25-hive honey business in Tijeras, N.M. Susan saw mention of Bromenshenkıs research in a magazine last spring and contacted him about working with Sandia on the landmine problem. Bromenshenk e-mailed Susan right back, asking her to put together a proposal to DARPA to fund the landmine demonstration.

DARPAıs Controlled Biological Systems Program supports research of sentinel species (such as bees, wasps, caterpillars, and moths), biohybrids (robotic systems that make use of animal features), and robotic systems for detection of contaminants and other environmental variables.

Gary Bender tends the bee colonies used for the project and may be Sandiaıs first and only professional beekeeper. ³The beauty of this approach is that bees are indigenous to every climate on earth, there are beekeepers everywhere, and you wouldnıt need a million-dollar piece of equipment and extensive training to use it,² says Susan. ³The countries where landmines are a problem typically donıt have those kinds of resources.

³This is the kind of humanitarian work that makes you feel good when you go to bed at night,² she adds.

Last modified: April 26, 1999

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