"What we can say is that this disorder is linked to service in the Middle East. But we haven't been able to definitively link what the cause is for the black lacy pigment. It's something that's inhaled that shouldn't be there."
Last month the New England Journal of Medicine published a study by Dr Miller and colleagues which documented the condition of soldiers who had served in Iraq and Afghanistan and were diagnosed with constrictive bronchiolitis.
However, their analysis doesn't reveal how common the condition is in troops or positively identify the cause of constrictive bronchiolitis in troops.
A civilian physician who has diagnosed more than 50 soldiers with constrictive bronchiolitis says the life-altering disease is linked to service in Iraq and Afghanistan.
Dr Robert Miller, of Vanderbilt University, says: "This scarring of the small airways in the lungs is common in people who have had bone marrow transplants or lung transplant rejection not people who have passed military fitness exams. Read More