A recent study suggests that the mere act of breathing deeply may stretch lung tissue and cause the release of a protective chemical that keeps the airways open.
Clothing turns out not to be all that important a part of the kit, since the protective chemical suits have to be worn 24 hours a day.
The temperature was just below 100 degrees, and everyone traveling with the military wore protective chemical and biological suits that enclosed the body from head to toe, plus body armor and a helmet.
I lost my gas mask on that flight, but not the rest of my protective chemical outfit, because like everyone else, I wore it night and day, despite being highly skeptical about the likelihood of a toxic attack.
As they spoke, firefighters in protective chemical suits milled through the scene, a supposed street corner, where overturned buses, police cars and fire engines could be seen, fake victims wandered in a daze, car fires smoldered and a few news helicopters flew overhead.
His troops are being sent with relief supplies into the city's now quiet streets without flak jackets, wearing berets instead of helmets and accompanied by Arabic-speaking interpreters, in contrast to the Americans in their full combat gear and protective chemical warfare suits.
