Planes' recirculated air didn't circulate colds By Dan Vergano, USA TODAY Recirculated air on short airline flights doesn't appear to lead to more colds among passengers, researchers say. In a study in Wednesday's Journal of the American Medical Association, medical researchers checked up on the runny noses, sneezing, sore throats and other cold symptoms among 1,100 travelers flying from San Francisco and Oakland to Denver. Researchers questioned them about cold symptoms in boarding areas before flights, then talked to them by telephone a few days after the two-hour trip. Among the passengers, 70% believed cabins ventilated with recirculated air, instead of completely fresh air, led to more colds. So did the researchers. But, "to our surprise, there wasn't any difference," says lead reseacher John Balmes, a lung ailment specialist at the University of California-San Francisco. About 20% of passengers reported cold symptoms after a flight, regardless of what plane they flew. Using a more strict definition of a cold that requires eight symptoms, about 3% of both recirculated-air and fresh-air passengers had colds. Half of the passengers traveled on older 727s and DC-10s, which are ventilated with 100% fresh air. The rest traveled on newer 737s and DC-10s that recirculate half of their ventilated air. Newer planes recirculate the cabin air through filters as a cost-cutting measure. Total air ventilation raises fuel costs. Diverting air from the engine reduces the jet's efficiency. Working with United Airlines, which did not sponsor the study, the researchers checked out what type of flight ventilation was used on each passenger's flight, after collecting data on the individuals. "All this does, more or less, is reassure us the air is clean in aircraft," says aerospace medicine specialist Russell Rayman of the Aerospace Medical Association in Alexandria, Va. Proper maintenance of filters and ventilation systems should greatly reduce the chance of getting a cold, he says, adding that the biggest risk is the passenger next to you having one. Balmes said the study cannot rule out the chance that colds may spread on long-distance flights, as filters work less efficiently after screening the air for more time. A National Academy of Sciences report last year called on the Federal Aviation Administration to begin monitoring air quality in airplanes. An FAA spokesman says plans for such monitoring have begun. The agency banned smoking on domestic flights more than a decade ago, citing health concerns. About 1.5 billion passengers fly every year, inside cabins whose low-humidity, low-pressure air has long raised fears of spreading colds. Given current airport security concerns, Balmes doubts his team's study could be attempted again. The findings don't rule out the possibility that travel itself leads to colds, either from stress, sleep loss or simply confinement with others. "The best advice I would tell people is to wash their hands if they are worried about colds," Balmes says. The owner of Roger's Trinbago Site: Roj (Roger James) *************************************************** escape email mailto:ejames@escape.ca Trinbago site: http://www.tntisland.com CBC Website http://www.tntisland.com/caribbeanbrassconnection/ The Trinbago Site of the Week: (Queen's Hall) http://queenshall.org/ (Queen'sHall) courtesy of Roj Trinbago Website & TnT Web Directory Roj's Trinbago Website: http://www.tntisland.com TnT Web Directory: http://search.co.tt *********************************************************