In efforts to locate hidden explosives, humans have had few allies as valuable as the explosives-detecting canine. The unrivaled sensitivity and selectivity of the canine nose have combined to make these animals an attractive choice for law enforcement, military, and private security applications.
Although the efficacy of trained detector dogs is well-established, the question of which chemical compounds are responsible for causing a dog to recognize a particular odor and alert to it remains a subject of debate for several explosive formulations--including, perhaps most notably, Composition C Previous studies have indicated that cyclohexanone, 2,3-dimethyl-2,3-dinitrobutane, and 2-ethylhexanol are the chemicals that may cause canines to alert to C This has led to the suggestion that these substances could be used as a substitute for genuine C-4 in the training, testing, and maintenance of explosives-detecting canines.
When the phone rang one morning in at Trans World Airlines' New York City headquarters, the caller on the other end delivered a bomb threat. Not sure which planes were in danger, the airline began grounding all of its flights to search them. Flight 7 had been in the air only 15 minutes when the pilot got the message.
He turned the aircraft back to New York and rushed 45 passengers and seven crew members off the plane. Taxing to the far end of the runway, the plane stopped for its search, and Brandy, a German shepherd led by New York City Police, trotted on. In the cockpit, she sniffed a black briefcase and sat down next to it. The briefcase, marked "Crew," was a normal sight on planes. Pilots kept their manuals in such briefcases back then. But Brandy's instinct was correct.
Inside, police found enough of the explosive C-4 to destroy the plane. A detective from the New York City Police Department whisked the bomb off the plane and disarmed it five minutes before it was set to explode [source: Witkin]. No other flights had bombs. The crisis was averted. This twist of this story is its heroine, Brandy. Few police forces, and no airports, had bomb-sniffing dogs at that time. Brandy's training occurred in a university psychology laboratory, and her funding sprang from an Army research lab that has long since dissolved.
She was in JFK airport by coincidence, as part of a demonstration of dogs' ability to find bombs [source: New York Times]. On her first real job, Brandy stopped an extortion plot. For context, extortion hijackings outnumbered winter holidays in , with five occurring in January alone [source: Witkin]. It's no wonder that President Richard Nixon gave the Federal Aviation Administration its own bomb-sniffing canine unit in the same year. In this article, we'll explore the odoriferous world of bomb-sniffing dogs.
Keep reading to find out how Brandy's nose saved the day. Dogs smell bombs like they smell everything else. First, Brandy sniffed.
Her sniff reshaped her nose so that air, including odors from the bomb, hit her odor receptors. The signal traveled from her nose to her somatosensory cortex , an area of the canine and human brain that processes sensations, including smells.
Brandy then interpreted the smell; she decided she'd smelled an explosive. She did that by the bomb's odor signature, says Lawrence Myers, an associate professor of anatomy, physiology and pharmacology at Auburn University's College of Veterinary Medicine.
C-4's signature includes which odors are in it, their ratios and, possibly, whether C-4 tickled a nerve in her nose called the trigeminal. Because Brandy smelled C-4 many times, she remembered its signature, and she knew to sit when she smelled it. Could another animal have smelled the bomb better than Brandy -- a raccoon, a rat or … you?
We don't know which animal has the best sense of smell because no good studies have directly compared animals, says professor Myers. Although humans smell using most of the same equipment as dogs, differences exist. Dogs are better than us at sucking in odors. Their noses are longer and roomier than ours, so they can inhale more air per sniff. Dogs also have more odor receptors in their noses than we do -- 20 to 40 times more, according to Myers.
Despite these two advantages for dogs, whose nose is more sensitive -- meaning, who can smell an odor with fewer molecules of it in the air -- depends on the chemical being smelled. For example, dogs can detect eugenol, an oil in cloves, at one-millionth the concentration that humans can [source: Myers]. However, Myers, in informal experiments, found that humans can smell acetone at lesser concentrations than dogs can. While dogs largely interpret the world through smell, and we do not, it's not a true advantage for dogs.
With training, we can pay attention and discriminate smells as well as dogs can -- wine tasters and perfumers are evidence of that. All of this leads to an answer scientists often give: "Dogs almost certainly are better than humans at smelling for explosives , but as a scientist, I can't state that," says Myers. In some indisputable ways, dogs are better. Dogs can sniff closer to explosives on the ground.
We'd look suspicious on all fours. Practically speaking, it comes down to whose face we want to put closer to the bomb. As part of U. That includes:. Militaries often use bomb-sniffing dogs in war.
Every branch of the U. The dogs help find an enemy through its artillery and make sure an area is safe for troops to pass. In the shrouded world of bomb dog education, MSA is one of the elite academies. It currently fields teams working mostly in New York, Washington, D.
It deconstructs an odor into its components, picking out just the culprit chemicals it has been trained to detect. Roberts likes to use the spaghetti sauce analogy. Instinctively, it says tomatoes, garlic, rosemary, onion, oregano.
Ingredients from the basic chemical families of explosives—such as powders, commercial dynamite, TNT, water gel and RDX, a component of the plastic explosives C4 and Semtex—are placed in random cans. In addition, urea nitrate and hydrogen peroxide—primary components of improvised explosive devices—have joined the training regimen.
Merry is working quickly and eagerly down the row of cans, wagging her tail briskly and pulling slightly on the leash. There are perhaps five other teams working the cans along with Merry, and none of them seems remotely interested in checking out the others. Snort, snort, sniff, snort, snort, sniff, snort, snort, sniff. Suddenly Merry sits down. No one wants a dog pawing and scratching at something that could blow sky-high. It sounds pretty silly, and new trainers often have a hard time bringing themselves to talk to dogs this way.
Women handlers have a much easier time with it. Almost all of the dogs here arrived when they were a year to a year and a half old. Before that, they all attended an unusual canine kindergarten called Puppies Behind Bars. Gloria Gilbert Stoga founded the nonprofit program in as a way to train guide dogs for the blind, but the idea was for the prison inmates to learn as much as the puppies they live with.
It is sad I had to come to prison to learn this lesson. MSA stepped up shortly after. Since then, the prison program has graduated working dogs, most explosive detective canines.
It would be tough to conceive of a better smelling machine than a dog. Dogs have some million olfactory receptor cells; humans have six million. A human brain assigns only 5 percent of its cellular resources to smelling, and given the low esteem in which we hold our noses, even that sounds like an overinvestment. Even better, it allows dogs to smell continuously over many breathing cycles—one Norwegian study found a hunting dog that could smell in an unbroken airstream for 40 seconds over 30 respiratory cycles.
Remember the kid in school who could wiggle his nose without touching it? Well, dogs can wiggle each nostril independently. This is not just a party trick.
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