Detection Is the Best Prevention
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KNOWING ABOUT A THREAT BEFORE IT CAN CAUSE HARM IS THE BEST DEFENSE IN THE WAR AGAINST CHEM/BIO AGENTS.
In the area of chemical and biological detectors, as in some other areas of military and security technologies, there is the constant drive to make devices smaller, cheaper and more automated. Cheaper, of course, to save on scarce resources. Smaller, in order to be easier deployed on vehicles in forward areas and to save on equally precious space. More, automated, in order to save on the time and expense of manual processes.
Detection devices designed to be deployed with forward troops are not necessarily designed to be the most sensitive or accurate, however. Reducing size and costs enable more extensive deployment of such detection devices with forward units but also involves a tradeoff with performance. Low-cost tactical biological detectors now being developed at Army facilities, for example, are not meant to analyze dangerous materials but merely to detect their presence, so that troops can take countermeasures.
The granddaddy of biological detection programs is Biowatch, a Department of Homeland Security initiative and its Department of Defense counterpart, Guardian. Biowatch had its genesis following the Salt Lake City Olympic games in 2002, where a prototype was tested and demonstrated, according to Penny Hitchcock, a senior associate at the University of Pittsburgh Center for Biosecurity. Hitchcock worked on guidelines for the use of Biowatch data when she was employed at the Los Alamos National Laboratory.
“Biowatch consists primarily of a series of aerosol collection devices coupled with laboratory analysis,” Hitchcock explained. “It is a continuous monitoring system for a select group of agents with a history of weaponization.”
Biowatch was initially deployed in 30 metropolitan areas around the United States and has since been expanded. “The locations were chosen based on an analysis of the geography of the urban areas, prevailing winds, and weather patterns,” said Hitchcock. “The units were sited where they were most likely to collect air that had been contaminated.” The specific locations of the Biowatch sites are classified information.
The program has disclosed the detection of a number of environmental contaminants, none of any public health significance, according to Hitchcock. But some of Biowatch’s findings have been of interest to environmental biologists, while others have been useful in making clinical diagnoses of illnesses.
A chemical biological mass spectrometer currently being developed at the Oak Ridge National Laboratory in partnership with Hamilton Sundstrand of Pomona, Calif., MSP Corp. of Shoreview, Minn., and the University of Colorado, could be considered the next iteration of Biowatch.
“Biowatch collects air from various locations on a filter,” explained Kevin Hart, an Oak Ridge analytical chemist. “You need collectors to change out the filters and bring them to the lab. Then the samples are cultured and other analyses are performed to determine the content of the samples. It is a pretty manual and labor-intensive process.”
The CBMS is being developed with the welfare of forward troops in mind, according to Hart. “It is being designed as a realtime monitoring device to be put on the NBC platform of reconnaissance vehicles assigned to monitor for biological attacks,” he said. “The unit is being designed to be small enough to get into a variation of the Stryker vehicle where space and power are at a premium.”
Real-time monitoring means that it takes only a few minutes to get results, Hart added. “It can take 24 hours to 48 hours it to get Biowatch results,” he said. “The idea here is to sense an attack and get everyone into protective gear or ready for treatment.”
The CBMS bioaerosol module pulls in air at the rate of 300 liters to 600 liters per minute. “The unit looks for particles in the size range that are respirable,” Hart explained. “In other words, they are small enough to breath in, get into the lungs, and cause infection. It also has the ability to do chemical agent monitoring on the same sensor.”
The chemical sensor has undergone testing and is currently in an initial low-rate rate-production phase. The biological sensor is being tested and evaluated at this point, according to Hart.
The biological sensor uses a pyrolysis process, which collects air in a tube and heats it to very high temperatures. The mass spectrometer identifies the composition of the volatized product by looking at the distribution of cellular fatty acids for bacteria from which it develops a biological signature. The chemical sensor uses a similar process to volatilize and analyze the sample.
Idaho Technology, a biotech company based in Salt Lake City, Utah, is also responding to the call for developing smaller and more portable bioagent analysis units that can be easily deployed with troops in the field. Its new Razor environmental air sampler has slimmed down a 50-pound unit to a lightweight nine pounds, according to company spokesperson Matt Scullion.
“Front line troops are able to test suspicious materials on the spot with a DNA analysis,” Scullion explained. “There is no need to send the sample to a lab to be cultured.”
But Razor has fewer capabilities than the heavier unit. “It is limited to air samples and powders that are relatively clean,” Scullion said. The older unit is able to perform seventeen different tests on blood, sputum, stool and soil, as well as air.
U.S. special operations forces have bought Razor units as have military agencies in Australia, Canada, the Czech Republic, Singapore and Japan.
A product Idaho has on the drawing boards, and which it expects to release within the next two years, will be able to test and identify 50 different bioagents on the spot, Scullion said.
The idea of slimming down detection units—as well as their capabilities—also pervades efforts at the U.S. Army’s Edgewood Chemical Biological Center to develop a tactical biological (TAC-BIO) detector. The goal is to develop a unit that drastically reduces the cost, size and power requirements of the bioagent detection units currently available. The project recently emerged from the test bed to the prototype stage, according to Aime Poldmae, an engineer at ECBC and one of the developers of the TAC-BIO system.
The science behind the system is “the detection of biological aerosols based on their fluorescent properties when excited with an ultraviolet light source,” she explained. “Historically, the requirements for this kind of system have been to use lasers to analyze the fluorescence of bioagents and have been outside the boundaries for low cost, low power, lightweight detectors.”
The TAC-BIO detector capitalized on the solid-state ultraviolet optical source (SUVOS) program of the Defense Advanced Research Projects Agency, according to Poldmae. “The low power, low cost optical sources being produced under that program offer the excitation energy and wavelengths needed for the detection of biological aerosol,” she said. “This unit uses light emitting diodes in the ultraviolet range. This has proved to be a significant step in the research.”
A network of TAC-BIO detectors offers the potential for an early warning capability against biological aerosol attacks, Poldmae contended. “By deploying an array of detectors upwind from protected assets, an effective network with prior-notice capabilities can be created,” she said. “This would include longer warning times.” Poldmae expects the TAC-BIO detector prototype to undergo testing at ECBC and other military facilities, a well as in urban and natural environments to see how it stands up.
Current biological detectors use lasers to identify bioagents, Poldmae explained. “They are highly sensitive but very expensive,” she said. “TAC-BIO is a meant to be a trigger. It tells you a bioagent is out there but not what it is. It is meant to be more of an early warning detector that is put a kilometer or two away from forward platoons.”
With the reduction of size and power, there has been a tradeoff with the sensitivity of the equipment, Poldmae acknowledged. “We were tasked to make an inexpensive and lightweight sensor that uses less power,” she explained.” The current prototype uses four watts while the goal is to get power consumption down to two watts.
But TAC-BIO is also much smaller and less expensive than units currently available to U.S. troops. ECBC’s work has reduced the size of laser-powered units from nearly 150 cubic feet to a little more than three cubic feet. And the cost has also been dramatically reduced, from $100,000 per unit to a mere $1,000. ♦