A recent study put out by the American Thoracic Society reports that "Biomarkers may provide early warning of lung problems in 9/11 firefighters." The study found that the increased loss of lung function could lead to higher rates of airway obstruction and diagnosis' of COPD.

ScienceDaily reported that the 15 year long study which followed 9,434 New York City firefighters and rescue workers ran from September 11, 2001 through September 10, 2016. In the year after 9/11 there were high rates of loss of lung function among the group of firefighters and rescue workers exposed to the dust cloud. In 2002 lung function stabilized for many of those affected while others continued to experience a decline in lung function.

“We have previously observed some of our patients were doing worse than others and performed this study because we wanted to understand factors that increased the risk for excessive lung function loss,”

— senior study author Michael D. Weiden, MS, MD, associate professor of medicine and environmental medicine at New York University and a New York City Fire Department medical officer.

The objective of the study was to discover if the discrepancy in lung function for the exposed firefighters correlated with “blood concentrations of eosinophils and neutrophils" which are two kinds of immune cells that are regularly measured during respiratory medical checkups. Following 9/11, it was determined that around 1 of 8 firefighters who worked at Ground Zero suffered from decreased lung function over the 15 year period.

The study is hoped to promote continued research to discover other treatments for the firefighters and rescue workers who continue to suffer from diminished lung function.