Something in the air may cause lung damage in troops

Some soldiers serving in the Middle East who develop difficulty breathing — but whose chest X-rays show nothing out of the ordinary — have constrictive bronchiolitis, a kind of lung damage virtually unknown in young adults, a study shows.

Reporting in the July 21 New England Journal of Medicine, physician Robert Miller of Vanderbilt University in Nashville and his colleagues documented the condition in 38 of the 49 soldiers studied, who had served in Iraq or Afghanistan and came down with lung problems. Constrictive bronchiolitis, in which tiny airways become narrowed, has rendered some soldiers unfit for active duty.

“Most of them say they can’t seem to catch their breath when exerting themselves,” says study coauthor Matthew King, a pulmonologist at Meharry Medical College, also in Nashville. And while anti-inflammatory medicine and inhaled steroids can help symptoms, he says, the soldiers with bronchiolitis don’t improve. “We have seen no reversibility.”

The researchers discovered the condition by removing and analyzing small bits of lung tissue from the soldiers, who turned up ill between 2004 and 2009. All 49 of these biopsies showed abnormal tissue despite normal X-rays, and inflammation in 38 of the soldiers indicated constrictive bronchiolitis. Scarring and thickening of tissues was common in this group, and all but one soldier harbored grayish-black deposits in the lungs.

The origin and composition of the lung deposits remains unclear, King says. But the blackened nature of the deposits signals carbon, suggesting fires.

Evidence of bad air in Iraq and Afghanistan is accumulating. A 2009 study of medical records found higher rates of respiratory problems in personnel deployed there than in those stationed elsewhere. In March, researchers reported high levels of airborne aluminum and lead in dust storms in Iraq (SN: 4/23/11, p. 15).

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 scarring, inflammation and damage. Mined separately, the two metals could have gotten together only through a manufacturing process, Szema reported at a May meeting of the American Thoracic Society in Denver, where he presented the case study. While the metals’ origin is unclear, he suspects that garbage-burning pits or exploding devices sent them airborne.

In the new study, the researchers “have been very aggressive in figuring out what’s going on” in these soldiers’ lungs, says Andrew Shorr, a pulmonologist at Georgetown University in Washington, D.C. “Miller’s diligence in pushing this as an issue of concern is very legitimate,” says Shorr, formerly at the Walter Reed Army Medical Center.

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.

Shorr recommends soldiers exercise caution in the field until more is known. “If you’re burning garbage,” he says, “you wear a mask.”