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Dogs May Help 'Sniff Out' Pollution - 2004-06-12

Dogs have an incredible sense of smell and because of it they have become a valuable resource alongside police and military officers and in search and rescue missions. Now, a research laboratory in Athens, Georgia is exploring the use of dogs to detect pollution in homes and commercial buildings. VOA's Rosanne Skirble observed this low-tech canine technology at a recent science meeting in Washington, sponsored by the U.S. Environmental Protection Agency.

Sammy is small for a four-year-old, with short gray hair. Right now he is curled up on the carpet of a Washington Hotel ballroom, sound asleep.

Sammy is a Swedish Valhund, a breed with a great nose, according to Environmental Protection Agency researcher Sandra Bird. She has trained the dog to identify indoor pollutants that can leak through cracks in buildings from contaminated groundwater. In scientific lingo this is called vapor intrusion.

"In some areas it is fairly common," said Ms. Bird. "It is associated with gas stations where they have had leaking storage tanks."

It's also found in contaminated fluids used in dry cleaning operations. Ms. Bird says dogs are trained to distinguish between common pollutants like cigarette smoke, degreasers and paint strippers and the dangerous unwanted vapor intrusion. A dog can then be sent in to a building to find a suspected contaminant and where it is coming from.

"What we would do is to take the dog into the house and see where they are responding and then use chemical analytical samplings to confirm what they have found," Ms. Bird said. "This would cut down on the sampling cost tremendously. So instead of having to take 100 samples to characterize the house, you might only have to take four or five to find the source."

Sammy has focus. He is a fanatic ball player with in-bred herding instincts. But, Sandra Bird says his best trait for the job is a trained nose.

"If you look at a dog, the dog actually has an extra organ in its nose that is a scent detection organ," she said. "It has thousands more scent receptors than we do. If you look at just the size [length] of their nose, inside, it's lined with olfactory receptors. When they are sampling [a scent] they don't just breathe in and out, they actually have a sampling burst: sniff, sniff, sniff, sniff and they take it into their nose cavity. And, then they also have a purge breath where they clean their nose out. So they clear it back out so they can sample again."

Sandra Bird, who trains dogs in her free time, brought Sammy into her work at the National Exposure Research laboratory in Athens, Georgia about a year ago. At a scientific meeting in Washington, she puts the dog through his paces: she fills glass jars with either water or a very weak solution of rubbing alcohol and places the jars into three separate wooden boxes. Sammy is charged with finding the jar that has the diluted chemical.

"I put him on a 'down' [command]. 'Sammy down!' It's a signal for him that we are about to go to work," Ms. Bird said. "Then I have a command. I just point to where to look and tell him to find it. 'Sammy, find it!' You see, he sat on that one. That is his signal that there is something there. Now to confirm that he's found something, especially in a real situation, I do, 'Show me!' a show me command, and he goes right to the source and then sits again."

Sammy makes the task look easy. EPA engineer Sandra Bird says if trained properly, dogs have the right stuff to sniff out pollution.

"I believe the most important aspects in developing it as a working tool are to develop standard quality assurance methods for testing and quality assurance standards for using them," she said.

The EPA's Sandra Bird says with proper standards in place, dogs like Sammy have a great future. In other environmental applications, dogs have proven that they can find mercury bits from broken thermometers in schools, uncover mold in old buildings and screen equipment used in contaminated waste sites.