By a nose

Philadelphia research scientists sniff out the best way to make a stink bomb or sweeten the air at pig farms.

January 30, 2002|By Dan Fesperman | Dan Fesperman,SUN STAFF

PHILADELPHIA - Chemist George Preti learned a few years ago that taking work home from the office could get him in trouble with his wife. That's because his work stinks.

"My wife said I smelled like a bum," Preti said, which was doubly embarrassing because he'd just come home on a crowded commuter train, unaware of the stench. "I later found out I had splashed onto my sneakers the equivalent of about 600,000 smelly armpits. I had to throw the sneakers away."

Such are the occupational hazards of the Monell Chemical Senses Center, a nonprofit research center where office supplies include essence of hog farm, armpit smell and even something known as U.S. Government Standard Bathroom Malodor. Their clients include corporations hampered by a foul odor and industries in search of olfactory relief.

Monell's greatest claim to fame is the recent news that its scientists are working on a "stink bomb" for the U.S. Army. Why worry about shooting your way into the caves of Tora Bora, for example, if a few whiffs of bad air could make your enemies flee in panic and disgust?

Or so the thinking goes at the Pentagon.

The jokes and one-liners that followed the revelation were inevitable - "Stench warfare, "War is Smell," and, of course, good old "Stink Bomb," even though, as Monell cognitive psychologist Pam Dalton says, "There is no bomb, and there has never been any bomb. What we work with are the components of odor."

They work with quite a few others things, too, researching an intriguing array of matters regarding smell, taste and chemosensory irritation (think of a jalapeno pepper burning its way through your tongue), that have kept the researchers occupied since the center opened in 1968.

Preti, for example, who has been at Monell for the past 31 years, has just submitted a research paper to a scholarly journal on whether men's armpit secretions stimulate women's fertility cycles. It seems that they do, he says, but he doesn't want to say more until his paper is published.

But if it's true, would that mean we might soon see some sort of "pheromone spray" marketed to attract members of the opposite sex? Such products are already out there, Preti says.

"It's all a crock," he adds. "And oddly enough, if you look at a lot of the literature that these hideous Web sites [for such products] ballyhoo, a lot of it's mine. But there's no connection between my work and what they're doing."

Preti's other work at Monell includes recent efforts to try to keep places such as hog farms from smelling so terrible. As suburbs creep further into agricultural land, it's more than just an idle concern.

Swine slurry - a mush of pig excrement, pig urine and rotting feed - has been some of the smelliest stuff he's ever brought into a lab.

"I've dubbed it the mother of all malodors," he says, "and naturally it's bacterially rich. The interesting thing is, the literature on pig odors is extensive. People have been working on this a long time."

But no one has yet gone at it as methodically as the folks at Monell.

Every two weeks for six months, ending last December, Preti met at noon with about eight others at Gerald Funk's pig farm (pop. 110 swine), in Lancaster County, Pa. Most were neighbors of the farm and already quite familiar with its usual smell.

When they got together, they'd sniff, then sniff some more.

"The odor experience on a hot, humid day was particularly intense," he says.

Preti, meanwhile, analyzed the swine slurry with a chromatogram to determine the chemicals at work, then began trying various remedies to see which was most effective at holding down the smell.

Adding powdered activated charcoal to the slurry worked some. The best deodorant so far has been putting small amounts of copper chlorophyllin complex into the feed, knocking down the smell by about 90 percent. But he doesn't yet know if the remedy will be worth the cost.

He does, however, believe that hog slurry might be exactly what Monell needs for the aforementioned "stink bomb" project.

Pam Dalton isn't so sure. In fact, so far no one has yet discovered an odor that is certain to work on all people or within all cultures.

When the Pentagon's Non-Lethal Warfare program first approached Monell about the project three years ago, she says, "We were initially amused and interested. ... The military's interest in odors has been sporadic. There was even some interest in it in World War II."

The state-of-the-art in militarily offensive smells then was a liquid dubbed "Who Me?"

French Resistance fighters were supposed to find a way to spray some on German officers, who would be humiliated into non-action. Of course, the sprayer would also smell. And if he could get close enough to spray, he'd presumably also be close enough to shoot, so why bother with a mere odor?

Tear gas and pepper spray, which serve some of the same purposes that a "stink weapon" would - crowd dispersal, keeping warring factions apart, flushing out the enemy and so on - can have harmful side effects, and disperse quickly.

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