Interstitial lung disease potential occupational threat for firefighters

Firefighters may have increased risk for interstitial lung disease and autoimmunity as a result of inhalation exposure over years of service.

“The prevalence of pulmonary fibrosis among World Trade Center (WTC) first responders was recently described, and sarcoidosis has also been associated with firefighters responding to this disaster,” Cathryn T. Lee, MD, with the section of pulmonary and critical care medicine at University of Chicago, and colleagues wrote in an abstract scheduled for presentation at the American Thoracic Society International Conference. “The prevalence of interstitial lung disease among firefighters not associated with WTC cleanup is unknown. Autoimmune disease in first responders related to exposures has been suspected but not fully elucidated.”

Lee and colleagues evaluated electronic medical records of patients who visited the University of Chicago ILD clinic from 2007 to 2019 and were included in an ILD registry. Eighteen (1%) of the 1,634 patients in the registry were firefighters. Of those, the majority were career firefighters.

Nearly three-quarters of firefighters in this cohort had a history of smoking (mean duration, 21 pack-years). One-quarter reported secondhand smoke exposure.

Forty-four percent of firefighters had additional occupational exposures such as construction and metal work. Others reported participating in hobbies that involve inhalation exposures (29%) and a history of exposure to mold or birds (35%), according to the abstract.

Most patients had evidence of autoimmunity, with autoantibodies in 56% of firefighters in this cohort. Twenty-two percent had diagnoses for connective tissue disease and multidisciplinary ILD diagnoses of connective tissue disease-associated ILD, according to the abstract.

The researchers reported that, at the time of censoring, three deaths and two lung transplantations for ILD had occurred.

“While firefighters represent 0.2% of the national workforce, they comprised 1% of patients presenting to our tertiary care ILD center. A substantial number of patients had serologies consistent with autoimmunity, and 22% had a diagnosis of a connective tissue disease, which is generally recognized in 2% to 3% of the general male population,” Lee and colleagues wrote.

The researchers concluded that further study of this population using comparator groups is warranted to determine whether firefighters have an increased risk overall for ILD.