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Fighting terrorism with clothes
By Marsha Walton
(CNN) -- Fabrics and clothing are a vital line of defense for firefighters, police officers and emergency medical workers responding to domestic terrorism calls. That's why North Carolina State's College of Textiles is hard at work developing gear to keep first responders safe from biological hazards, from anthrax to smallpox to other blood-borne pathogens. The college is trying to create a "smart suit" capable of adapting to its environment. It will incorporate electronics into the fibers, for communication and location, and for sensing body changes or environmental hazards. "What we're looking at now is a full range of threats, not only fire but biological, chemical, dust, everything that can come from an event of mass destruction," said Roger Barker, director of the college's Center for Research on Textile Protection and Comfort. Researcher Tushar Ghosh is perfecting a project that is best described as "spray-on clothes." In a demonstration, small polymer capsules are melted and the fibers blown onto a mannequin. It looks and feels like cotton candy. The lightweight garment has no seams that would be vulnerable to liquids or toxins. Ghosh says eventually a soldier could carry this high-strength, head-to-toe barrier in a pocket, and put it over a standard uniform in the event of a chemical or biological threat. Pyro-Man goes through the fireWhile chemical and biological weapons can be tested on him, the college's Pyro-Man dummy is key to testing clothes that could protect emergency workers from fire and heat.
This complex mannequin is set up in a small, glass-enclosed room. In a demonstration, a technician counts down, and suddenly blue flames appear from several pipes. Soon Pyro-Man is engulfed in flames from several angles. Spectators can even feel the heat from outside Pyro-Man's chamber. One hundred twenty-two heat sensors are distributed across the surface of the mannequin. "We collect data for 30 seconds, even after the flame has been extinguished," said researcher Shawn Deaton. "We measure the amount of heat that has been absorbed, so we can predict where on the body a person would receive different levels of burns." A computer soon displays a checkerboard of colors on outlines of the front and back of the mannequin. Yellow means no burn. Red means second degree. And purple means third-degree burns. Sweaty-Man to the rescueSweaty-Man is another hard-working mannequin. It's used to simulate how much a certain piece of protective equipment will make a human sweat. "This mannequin has very sophisticated skin," Barker said. "Water is delivered to 187 simulated sweat glands at a very controlled rate, so what we measure is very accurate, we know exactly how much sweat is coming in, and how much is leaving the mannequin." Heat stress can be especially dangerous in situations that are lengthy, such as the rescue and recovery efforts at the World Trade Center, which took months to complete. Different types of fabric testingThe North Carolina State scientists looking for better protection from chemical and biological threats must rely on very different types of fabric testing. Materials are sometimes tested for their protective qualities using synthetic blood. Fabrics also are tested to see if tiny aerosol particles can penetrate. "We know that viruses can come through; sometimes liquids can penetrate the fabric in such minute amounts that we can't detect it visually," said McCord. "If they pass the synthetic blood test, we'll take it a step further and look for whether or not we'll have viral penetration." Researchers say the comfort level of a protective suit is just as important as its safety qualities. "Protective clothing is not going to do anyone any good hanging on a hanger in somebody's closet, it has to be worn," said Marian McCord, associate professor of textile engineering. "You can go overkill with the protection, and some will unzip it in the field ... and that is going to cause problems." Front-line workers provide 'reality checks'People in the field provide "reality checks" about why a particular piece of equipment will or will not be an asset in the heat of battle. The quality of gear can make the difference between life and death for firefighters. And few people know just how complex and cumbersome a hazardous materials suit is for a firefighter heading to an unknown toxic danger. In a demonstration at an Atlanta firehouse, it took two colleagues to help suit up firefighter Earl Powell in a "Class A" protective suit. An oxygen tank and facemask have to be attached, wrists and ankles taped, heavy boots secured. And he did more than just wear all of that equipment. He performed hard, unforeseen work at the scene, tasks like covering barrels, turning off valves, trying to neutralize toxic materials. "A lot of the chemicals that we deal with are like chlorine, sulfuric acid, nitric acid, they react to the moisture in your skin," said firefighter Matt Moseley. "So anywhere there is moisture on your skin it turns to acid. One of the reasons we wear this is because you know the burn may not be lethal, but you don't want that kind of injury." It may be years before Moseley and his coworkers can simply don a lightweight, super-strong miracle suit that will shield them from heat, chemicals, or biological threats. Textile engineers are anxious to make it happen as soon as possible, perhaps with fibers that don't even exist yet. "We're interested in looking at novel materials, novel combinations of existing materials, and we're also interested in evaluating just whatever is out there," said McCord.
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