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That's a crude description of the hazards that a combination of architecture and inadequate ventilation can have on children. The result is an increased exposure to indoor air pollution, which can affect children's health and learning abilities.
Researchers at the Georgia Tech Research Institute (GTRI) have found that schools without advanced climate control systems – which regulate humidity, while bringing in fresh air – have higher levels of airborne pollutants than schools that use such sophisticated systems. The differences are statistically significant, the researchers say.
"Bad air and susceptible kids can lead to sick buildings, ill children and a less effective learning environment," says Charlene Bayer, the GTRI principal research scientist who headed the study.
Her study is one of the few that attempts to statistically quantify exactly what is and isn't floating in the air of school buildings. The study's database of indoor air pollutants found in schools may give scientists new insight into the association between indoor air quality and childhood respiratory problems, such as asthma, she says. This association has been noted in previous research published by the American Society of Heating, Refrigeration, and Air Conditioning Engineers.
It's a big issue. The U.S. General Accounting Office reports that one in five U.S. schools have indoor air quality problems. And asthma is the top chronic illness of childhood. Of the 26 million Americans who have been diagnosed with asthma, 8.6 million are younger than 18, according to the American Lung Association.
Schools are far more susceptible to air quality problems than most other buildings for several factors, including low budgets, deferred maintenance and high population density, Bayer says. And children – with their developing immune systems – are more significantly affected than adults, she adds.
"We don't know the precise causal link between pollutants and asthma, but we strongly suspect that one is associated with the other," she adds.
To control space humidity, most schools limit the amount of outdoor air that is brought into a building. Conventional packaged cooling units, the kind often used in schools, dehumidify air only when the unit runs to cool the air. The resultant high humidity and reduced ventilation can breed a proliferation of microbes – fungi, mold, mildew and other pollutants.
Newer "desiccant-based outdoor air pre-conditioning systems" can deliver the desired ventilation rates on a continuous basis and control space humidity levels. This is not possible with conventional packaged equipment.
"The desiccant systems may cost more to install than conventional systems, but their increased energy efficiency offers a quick payback in addition to an improved indoor environment," Bayer says.
To find out whether there is a measurable difference in air quality between the two systems, the U.S. Department of Energy funded Bayer's study via a grant to SEMCO Inc., a Missouri-based manufacturer of desiccant systems. The study matched five schools with active humidity control systems with five conventional schools. All are newly constructed and are scattered throughout three cities in different regions of Georgia. None of the schools had previously reported problems with air quality at the time the study began in mid-1998.
Bayer's research team consisted of GTRI scientists, as well as those from the Georgia State University Department of Biology, and John Fischer, a technology consultant for SEMCO.
Four times during a yearlong period, they visited each school to measure numerous air-quality indicators – volatile organic compounds, particles and aerosols, bioaerosols, aldehydes and ketones, carbon dioxide, carbon monoxide, temperature, humidity and air change rate. The researchers' equipment also continuously monitored one room in each school for carbon dioxide, temperature and humidity.
They found that schools with conventional systems had humidity levels above the 50 percent norm that desiccant-based systems provide. Most reached "the breakpoint of 70 percent humidity, above which you have a high probability of microbiological contamination," Bayer says.
As a result, researchers found fungi levels were generally higher in schools without active humidity control. Researchers were surprised that all schools – even the ones with the desiccant-based systems – tested above the national guideline level of 1,000 parts per million (ppm) of carbon dioxide in the air, at some point during the study.
Carbon dioxide levels indicate whether there is sufficient ventilation to remove generated pollutants. When the carbon dioxide level rises above 1,000 ppm, other pollutants are not being removed sufficiently, Bayer explains.
The investigation also revealed that as air filters age in conventional systems, the amount of outdoor air delivered to a building reduces significantly. Because routine climate control system maintenance is lacking in most schools, researchers suggest that system designers should consider the impact of aging filters. Then designers should select minimum outdoor air quantities based upon filters that need replacement, not new clean filters.
"None of the schools we studied operated their systems correctly all the time," Bayer says. "Facility staff members don't understand them and sometimes turn them off when they should remain on."
Only three of the 10 schools investigated provided outdoor air quantities in accordance with national guidelines set by the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE). This finding emphasizes the risk associated with the proposed reduction by ASHRAE of its current recommended minimum ventilation rates, Fischer says.
There were other sources of air pollution. Chemicals often seeped out from markers and other art supplies, and "plug-in" air fresheners were commonly found in the schools; one room had four of them, Bayer reports. "Teachers love plug-ins, but they are a constant emission source, masking one odor with another. And if you have an odor, you have a contaminant in the air."
Bayer is finishing her analysis and expects to present and publish in the conference proceedings of the ASHRAE Indoor Air Quality 2001 meeting scheduled for November. Researchers plan to submit additional papers on various aspects of the study to peer-reviewed journals.
– Renee Twombly, freelance writer
For more information, contact Charlene Bayer, Georgia Tech Research Institute, Atlanta, GA 30332-0820. (Telephone: 404-894-5361) (E-mail: charlene.bayer@gtri.gatech.edu); or John Fischer, SEMCO Inc., 737 Terrell Crossing, Marietta, GA 30067 (Telephone: 770-952-6962) (E-mail: johnfischer@worldnet.att.com)
New Help for Repairing Injured Nerves
Biomaterial developed at Georgia Tech is the basis for new nerve cuff.
A device for repairing damaged or severed peripheral nerves recently received clearance from the U.S. Food and Drug Administration for sales in the United States, and it is expected to hit the market this summer.
The SaluMedica™ Nerve Cuff will help repair damaged or severed peripheral nerves. Made from the biomaterial Salubria developed by Dr. David Ku at Georgia Tech, the device recently received clearance from the U.S. Food and Drug Administration for sales in the United States.
(300-dpi JPEG version - 1.12MB)
The device, called the SaluMedica™ Nerve Cuff, is made from Salubria ™, a moldable, elastic biomaterial developed at the Georgia Institute of Technology. It is being marketed by SaluMedica LLC, an Atlanta company founded and headed by David Ku, the Georgia Tech professor of mechanical engineering who developed the biomaterial. Ku also holds the Lawrence P. Huang Chair of Engineering Entrepreneurship at Georgia Tech and is a professor of surgery at Emory University.
"A typical patient for the Salubria Nerve Cuff is a 3-year-old who has cut her hand badly in a serious accident," Ku explains. "The nerve cuff lets the surgeon repair the nerve so the girl regains feeling and function in her fingertips so she can write."
The cuff – a flexible tube about 2 1/2-inches long and available in 2-, 5- and 10-millimeter inner diameters – provides a protective environment to help peripheral nerves grow back together after an injury. Its range of sizes enables the nerve cuff to fit peripheral nerves from about 1 to 8 millimeters in diameter, allowing its use for peripheral nerve trauma in the finger, arm, leg or face.
Before the introduction of the SaluMedica Nerve Cuff, surgeons used a vein or nerve from another part of the patient's body to help bridge the repair. "Our device offers surgeons the ability to repair nerves without a second surgery," says Xavier Sarabia, vice president of SaluMedica. "Eliminating the need for this second surgery reduces the associated costs and the likelihood of medical complications, such as infection."
Surgeons perform about 220,000 nerve repairs in the United States each year, comprising an annual nerve cuff market of an estimated $80 million. SaluMedica is establishing international sales partnerships to market the nerve cuff in Europe and elsewhere.
The nerve cuff is the first Salubria-based product manufactured by SaluMedica, which Ku founded in 1998 with assistance from Georgia Tech's Advanced Technology Development Center. The nerve cuff obtained U.S. market clearance from the FDA through its 510(k) pathway, a method that compares the new product to a previously or currently marketed product. Unlike predicate silicone nerve cuffs that are no longer used in the United States, the SaluMedica Nerve Cuff is made from Salubria, a hydrogel that contains water in similar proportions to human tissue. It is stronger than typical hydrogels used for contact lenses and can withstand millions of load cycles.
Its strength as well as its ability to be molded into anatomical shapes and sterilized makes Salubria a good candidate for medical devices that replace soft tissue in the body, Sarabia says.
"We are excited about the potential applications of Salubria," he adds. "In the near future, we hope to offer patients suffering from knee arthritis a less invasive, more cost-effective alternative to total knee replacement."
The market for applications of Salubria in treatment of knee arthritis is estimated conservatively at $2 billion a year. Other applications for the biomaterial include wound dressings, drug delivery and a spinal disc implant.
– Jane M. Sanders
The Georgia Institute of Technology has won a five-year, multimillion-dollar contract to run NASA's Southeastern Regional Technology Transfer Center (SERTTC).
Advanced sensors, inspection systems, new composite materials and alloys, unique motors and specialized software are among the technologies essential to NASA's space and earth sciences missions. But beyond NASA's highly specialized uses, these innovations often have broader commercial application.
One of six such centers nationwide and housed in Tech's Economic Development Institute (EDI), SERTTC serves Georgia and eight neighboring states. In each, SERTTC has an affiliate organization to identify and contact local industries with potential to use technologies developed by the space agency.
The goal is to get marketable NASA technologies licensed to private firms and demonstrate a public good from NASA research. "We want to brand NASA as a product resource," says EDI's David Bridges, who manages SERTTC.
SERTTC is seeking industries that can use measuring and detection instruments, gaskets and fasteners, remote sensors and advanced materials, Bridges says. Others include companies that make communications devices, software and energy-related products. Among widely used items stemming from space research are radiation-blocking sunglasses, microcomputers, weather forecasting gear, water purification systems, ultrasound scanners, heart monitors, dry-film machinery lubricants and high-density batteries.
The center can benefit companies in several ways, Bridges explains, by: (1) augmenting product development activities, (2) offering a resource for new product development, (3) reducing time from innovation to market and (4) providing grant money to small firms with promising innovations.
For SERTTC, the process entails NASA field centers in Florida, Alabama and Mississippi sending viable technologies and recommendations to SERTTC for industry matching and outreach.
In Georgia, John Mills, head of Tech's Columbus regional office, will assist SERTTC by contacting manufacturers and serving as the program's technology expert.
"Having SERTTC here will further raise the university's profile in the tech transfer community and enable Georgia Tech to provide additional services to state and regional industry," Bridges says.
– Lincoln Bates
Police officers serving a warrant or searching for a suspect hiding inside a building could soon have a new tool for protecting themselves and finding the "bad guy."
The RADAR Flashlight can detect a human's presence behind doors and walls up to 8 inches thick, says GTRI researcher Gene Greneker, who designed the device.
A prototype device called the RADAR Flashlight, developed at the Georgia Tech Research Institute (GTRI), can detect a human's presence through doors and walls up to 8 inches thick. The device uses a narrow 16-degree radar beam and specialized signal processor to discern respiration and/or movement up to three meters behind a wall. The device can penetrate even heavy clothing to detect respiration and movements of as little as a few millimeters.
"We believe the RADAR Flashlight potentially will be useful to police officers in ambush situations," says Gene Greneker, the GTRI principal research scientist who led the development of the device. ".... It is a force multiplier and a safety enhancement tool."
The RADAR Flashlight is undergoing further modification and testing for the next six months. The Georgia Institute of Technology has filed a provisional patent for the device, which could become commercially available to law enforcement officials within a couple of years if the university licenses the technology to a manufacturer.
With funding in 1998 from the National Institute of Justice (NIJ), a division of the U.S. Justice Department, Greneker and his team took the RADAR Flashlight from a bulky three-part prototype to a self-contained unit that weighs about 7 pounds. The NIJ tested the device last year at the National Law Enforcement Corrections Technology Center in Charleston, S.C., and suggested further modifications. Work on those changes is expected to begin this spring with additional funding from the NIJ.
"We will be modifying the RADAR Flashlight based on what law enforcement officials told us from the tests," Greneker says. "For one thing, they said it makes too much noise when it locks onto a wall (to scan). Also, for use by SWAT teams, the RADAR Flashlight needs to be operated by remote control. So we plan to put the RADAR Flashlight on a tripod at least 25 feet away from a wall and steer it by remote control to the part of the wall we're interested in scanning."
When these modifications are complete, the RADAR Flashlight will undergo more rigorous testing in various environmental conditions.
In its current form, the RADAR Flashlight operates in the following manner: The user holds the device with a pistol-grip handle, pulls a trigger, and the device runs a 3-second self-test to verify that it is properly functioning. The user sees the results as a bar graph on a small LED display built into the device. Then the user presses the device against a wall, pulls the trigger and within 3 seconds the system automatically spaces itself from the wall at a distance designed for best performance. The RADAR Flashlight's narrow radar beam sends out a pulse of electromagnetic energy, then detects the return signal, which is read by high-speed signal processing technology that quickly delivers bar-graph results to the user's display. As the person on the other side of the wall breathes, the bar-graph display rises and falls with a rhythmic response.
Research that evolved into the RADAR Flashlight began at GTRI in the mid-1980s with the patenting of a frequency-modulated radar for remotely checking vital signs of soldiers wounded on the battlefield before risking medics' lives to save the injured. This early technology also was tested for its ability to monitor vital signs of soldiers clothed in chemical or biological warfare suits, without requiring them to risk contamination by removing the protective gear.
Today, a technical challenge remains for researchers working on the RADAR Flashlight.
"We have one problem," Greneker says. "This instrument is so sensitive to motion that if you don't hold it still enough, it will detect its own self-motion. If we can overcome this, it would be the Holy Grail, and interestingly enough, we think we know how to solve this problem with additional research."
Bill Deck of the National Law Enforcement Corrections Technology Center says the RADAR Flashlight has potential, but adds that the device's stability and LED display are key issues to target before it is commercialized.
Greneker predicts the cost of the RADAR Flashlight to be between $1,000 and $1,500 to make it affordable to police departments.
– Jane M. Sanders
photo by Gary Meek
For more information, contact David Ku, School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0405. (Telephone: 404-894-6827) (E-mail: david.ku@me.gatech.edu); or Xavier Sarabia, SaluMedica 112 Krog St., Suite 4, Atlanta, GA 30307. (Telephone: 404-589-1727) (E-mail: Xavier.sarabia@salumedica.com)
Marketing NASA Technologies
Georgia Tech opens regional NASA center for technology transfer.
photo courtesy NASA
For more information, contact David Bridges, Economic Development Institute, Georgia Institute of Technology, Atlanta, GA 30332-0640. (Telephone: 404-894-6786)
(E-mail: david.bridges@edi.gatech.edu)
A Flash of Force
RADAR Flashlight could help police detect suspects hiding behind doors and 8-inch thick walls.
photo by Gary Meek
The full-text version of this article is posted at
gtresearchnews.gatech.edu/newsrelease/RADARFLASH.html.
For more information, you may contact Gene Greneker, Georgia Tech Research Institute, Atlanta, GA 30332-0856. (Telephone: 770-528-7744) (
E-mail: gene.greneker@gtri.gatech.edu).
Also see Research Links news stories.
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Last updated: July 14, 2001
