Some U.S. soldiers returning from the Middle East have acquired constrictive bronchiolitis, a kind of lung damage virtually unknown in young adults, according to U.S. News & World Report. \"Respiratory disorders are emerging as a major consequence of service in southwest Asia,\" said study author Dr. Matthew S. King, an assistant professor of pulmonary and critical care at Meharry Medical College in Nashville, Tenn. \"In addition to our study, there have been studies showing increases in asthma, obstructive lung disease, allergic rhinitis and a general increase in reports of respiratory symptoms,\" he added. \"Most of the patients say they can’t seem to catch their breath when exerting themselves.\" On the other hand, Anthony Szema, a physician and engineer at Stony Brook University in New York, has examined a soldier and found tiny complexes of titanium and iron in the man’s lungs, where metals can cause severe damage. Mined separately, the two metals could have gotten together only through a manufacturing process, Szema reported. While the metals’ origin is unclear, he presents a new case study, suspecting garbage-burning pits or exploding devices sent them airborne. While the cases in the study represent only a few dozen people of the hundreds of thousands serving in the Middle East, there is no estimate of how many more might have bronchiolitis. it is recommended that soldiers exercise caution in the field until more is known. Soldiers are now told to wear a mask when burning garbage.