News

American Forces Press Service

Defending Against Invisible Killers -- Biological Agents

 

 By Linda D. Kozaryn
 
American Forces Press Service


 [For the full web version (with graphics and related sites), go 
 to www.defenselink.mil/specials/chembio/.]
 
 WASHINGTON -- You can't see, smell or taste them, so how do you 
 fight biological agents?
 
 The military has geared up defenses against these invisible 
 killers since the threat of biological weapons became a reality 
 during Operation Desert Storm. Since then, the military has 
 fielded new protection equipment and detection systems, and more 
 counter measures are in the works.
 
 Still, many people don't understand the nature of biological 
 agents, how they would be deployed or how to protect themselves, 
 according to Col. John V. Wade, an Army medical department 
 officer who has specialized in the chemical-biological warfare 
 field for the past 16 years. 
 
 During Desert Storm, Wade served as Army Gen. Norman 
 Schwarzkopf's medical chemical-biological warfare adviser. On 
 Oct. 1, 1998, he became deputy for counterproliferation and 
 chemical and biological defense to the director of defense 
 research and engineering and the undersecretary of defense for 
 acquisition and technology. 
 
 Biological warfare encompasses a mixed bag of bacterial agents, 
 viruses and toxins, Wade explained. Lumping all biological 
 warfare agents together as a class is almost as dangerous as 
 comparing biological and chemical agents directly, because they 
 can be very different, he said. Depending on the situation, some 
 are contagious, others are not.
 
 "If you and I in this room are exposed to these agents, 
 unprotected, we're in trouble," Wade said. "But when we leave 
 the room, we may not necessarily 'spread it' in a contagious 
 sense, unless some of the agent remains on our clothing and is 
 physically transferred to someone else." 
 
 Usually, people think of biological agents as an aerosol threat, 
 according to the Pentagon expert. 
 
 "Think of that as taking a liquid in an atomizer and putting it 
 out in very, very small microdroplets. Aerosols behave a lot 
 like chemical vapors. There's a lot of water vapor in a room, 
 but we can't see it, or feel it, or taste it, or touch it. 
 That's really what we'd have in a biological event."
 
 These deadly "bugs" do have some natural enemies, Wade said. 
 "Most biological agents don't weather well. There are lots of 
 things that make it difficult for these biological agents to 
 exist," he said. "You put them out in ultraviolet light and they 
 die. They don't like drying out. The same environmental factors 
 that keep us from having one cold after another will help us out 
 to some extent in the case of a biological attack."
 
 Wade said biological agents can be dispersed either by what's 
 known as a "line source" or by a "point source." 
 
 Imagine your platoon is dug in at a forward location. Miles 
 away, an enemy boat sailing along a river or coastline, or 
 possibly a train traveling a rail line, releases a spray. The 
 enemy has determined the prevailing wind will carry the disease-
 laden aerosol in your direction. This "line source," Wade 
 pointed out, can cover a sizable piece of geography.
 
 A more commonly envisioned scenario involves a point source, he 
 said. This is where the enemy launches a missile or other 
 munition that detonates and spews biological agent directly on 
 you -- the target.
 
 "Either way, what the enemy is trying to do is take the organism 
 or the toxin and disperse it into the atmosphere so that the 
 target troops then inhale it," he said. "That's really the 
 threat of most of these agents. Just like the common cold, we 
 get them via inhalation.
 
 "Because the agents are very small particles, they can make it 
 through our nasal passages -- evading all of the normal 
 protective measures we have to filter things out -- and get down 
 to the deep lung area where they then cause disease." 
 
 Unlike a chemical agent attack, which would cause an almost 
 immediate reaction, a biological attack would not cause a 
 reaction until after an incubation period. "Generally it takes 
 24, 36, 48 hours before our troops would start showing what 
 oftentimes are nondescript, flu-like symptoms which then 
 progress to whatever symptoms the specific agent would normally 
 cause," Wade said. 
 
 So, how do you defend yourself against an attack you don't even 
 know has happened? 
 
 Wade said the best defense comes from using a combination of 
 immunization and physical protective measures. He pointed to the 
 anthrax vaccine as a key countermeasure against a biological 
 warfare attack. Wade, who has already had the entire series of 
 anthrax shots as well as several annual boosters, said DoD is 
 working to develop a number of vaccines to protect against other 
 biological-threat agents.
 
 When vaccines are not available as a biological countermeasure, 
 Wade said, the answer is "rapid detection, warning, reporting 
 and masking." He said it is important to note that the 
 protective mask is "effective against every known biological 
 agent, including those for which we don't yet have vaccines."
 
 Defense officials are developing and fielding smaller, lighter, 
 and simpler biological detectors, Wade said. "We have a number 
 of systems that can now be deployed on the battlefield." 
 
 One of these, he said, is the Biological Integrated Detection 
 System, or BIDS. It's a Humvee-mounted mobile lab suite that can 
 detect four different agents simultaneously and is manned by a 
 crew of four. The Army deploys BIDS companies as corps- or 
 theater-level assets to do bio-detection for all forces.
 
 BIDS are point detectors, Wade noted. "You have to wait for the 
 cloud to come to the BIDS. We have the same type of system 
 aboard ships called the Interim Biological Agent Detector, or 
 IBAD. After detecting what appears to be an unnatural agent, the 
 systems first provide a warning, then determine specifically 
 what the biological agent is. 
 
 "The individual doesn't need to know immediately whether it is 
 anthrax or plague," Wade said. "They simply need to put on 
 protective equipment. As a command, we'd need to know what agent 
 it was so that if there are specific medical countermeasures, we 
 can start immediately to protect those who didn't get their 
 masks on soon enough."
 
 Biological agents are considered "strategic weapons," Wade 
 noted. "They're not a good tactical weapon. So if someone is 
 going to use them, we want our detection arrayed out in front 
 of, or dispersed throughout, troop locations to give us early 
 warning."
 
 Defense officials also have developed (acquired) a long-range 
 biological detector, Wade said. It's a laser-scanning instrument 
 mounted on a Black Hawk helicopter that can look out about 50 
 kilometers. "It can't identify specific agents, but it's looking 
 for that telltale, cigar-shaped plume that comes from someone 
 laying down a line source," he said.
 
 "If we can see it 50 kilometers off, that gives us a tremendous 
 amount of time either to prepare for it coming our way, or to go 
 out and sample that cloud," Wade continued. "In the future, 
 we'll have detectors that are light enough and small enough to 
 go on an unmanned drone vehicle that will fly through the cloud, 
 find out what it is and report back."
 
 Wade calls the military's "Portal Shield" device one of its 
 biggest successes since the Gulf War. This system, deployed in 
 the Persian Gulf region in February 1998 during Operation Desert 
 Thunder, is about two-thirds the size of a typical office desk. 
 It's fully modular, self-contained and can detect eight 
 different agents. 
 
 "The beauty of this device is that it's a network sensor," Wade 
 said. Depending on the geography, as many as 18 sensors may be 
 arrayed around a port or an airfield. The sensors talk to one 
 another, he said, so you're not relying on just one of them 
 sounding an alarm.
 
 Using sensor arrays, the false positive rate very quickly gets 
 down to zero, Wade noted. In Bahrain, U.S. forces have run more 
 than 3,000 tests during round-the-clock monitoring by the Portal 
 Shield deployed there. The false positive rate was less than one 
 half of 1 percent, he said.
 
 Defense officials are also developing more user- and 
 environment-friendly decontaminates. "We're working on improved 
 technologies which are easier on us, as well as sensitive 
 equipment such as electronics, while still being effective in 
 eliminating the agents," Wade said.
 
 "The equipment and materials we have for decontamination right 
 now are pretty sturdy," he continued. "Super tropical bleach is 
 almost as hazardous in terms of being a caustic to human skin as 
 some of the biological agents themselves are. You sure want to 
 have your gloves and all your protective equipment on if you're 
 involved in using it."
 
 Defense officials are also evaluating what actually needs to be 
 decontaminated after a biological attack, Wade added. "When we 
 were maneuver-oriented, we always said we'd avoid contamination. 
 We'd go around it, or button up and go through it. We sure 
 weren't going to stop and live there." 
 
 But if you can't move because you're stationed at a port or 
 airport, Wade said, defense officials need to know what key 
 areas need to be decontaminated. 
 
 "We're doing studies to see if you take a plane up to 30,000 
 feet and fly it at 600 to 700 knots, is there anything left to 
 decontaminate?" he said. "Does the flight line have to be 
 decontaminated? What happens when a hazardous material oozes 
 into concrete? We're doing studies now to answer the questions, 
 'How clean is clean?' and 'What has to be cleaned for us to be 
 able to continue our mission?'"
 
 

http://www.defenselink.mil/news/Mar1999/n03101999_9903101.html