Bronchial Reactivity and Lung Function After World Trade Center Exposure

• Published in: Chest Vol. 150; no. 6; pp. 1333 - 1340
• Main Authors: Aldrich, Thomas K., MD, Weakley, Jessica, MPH, Dhar, Sean, MD, Hall, Charles B., PhD, Crosse, Tesha, MS, Banauch, Gisela I., MD, Weiden, Michael D., MD, Izbicki, Gabriel, MD, Cohen, Hillel W., DrPH, Gupta, Aanchal, MD, King, Camille, RRT, Christodoulou, Vasilios, BA, Webber, Mayris P., DrPH, Zeig-Owens, Rachel, DrPH, Moir, William, MPH, Nolan, Anna, MD, Kelly, Kerry J., MD, Prezant, David J., MD
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-12-2016; American College of Chest Physicians
• Subjects: Adult; airway disease; asthma; Bronchial Hyperreactivity - epidemiology; Bronchial Hyperreactivity - physiopathology; Bronchial Provocation Tests; Disaster Medicine; epidemiology; Female; firefighting; Humans; Inhalation Exposure - adverse effects; Male; Methacholine Chloride; occupational diseases; Occupational Diseases - epidemiology; Occupational Diseases - physiopathology; Occupational Exposure - adverse effects; Prevalence; Pulmonary/Respiratory; Respiratory Function Tests; September 11 Terrorist Attacks; Surveys and Questionnaires; provocative concentration of methacholine producing a 20% decline in FEV 1; airway disease; methacholine challenge test; occupational diseases; WTC; FDNY; asthma; firefighting; lower limit of normal; BHR; LLN; reactive airway dysfunction syndrome; epidemiology; PC20; World Trade Center; RADS; bronchial hyperreactivity; Fire Department of the City of New York; MCT
• ISSN: 0012-3692; 1931-3543
• DOI: 10.1016/j.chest.2016.07.005

Background World Trade Center (WTC)-exposed rescue/recovery workers endured massive respiratory insult from inhalation of particulate matter and gases, resulting in respiratory symptoms, loss of lung function, and, for many, bronchial hyperreactivity (BHR). The persistence of respiratory symptoms and lung function abnormalities has been well-documented, whereas persistence of BHR has not been investigated. Methods A total of 173 WTC-exposed firefighters with bronchial reactivity measured within 2 years after September 11, 2001 (9/11) (baseline methacholine challenge test), were reevaluated in 2013 and 2014 (follow-up methacholine challenge test). FEV1 measurements were obtained from the late pre-9/11, early post-9/11, and late post-9/11 periods. Respiratory symptoms and corticosteroid treatment were recorded. Results Bronchial reactivity remained stable (within 1 doubling dilution) for most (n = 101, 58%). Sixteen of 28 (57%) with BHR (provocative concentration of methacholine producing a 20% decline in FEV1  <8 mg/mL) at baseline had BHR at follow-up, and an additional 27 of the 145 (19%) without BHR at baseline had BHR at follow-up. In multivariable models, we found that BHR baseline was strongly associated with BHR follow-up (OR, 6.46) and that BHR at follow-up was associated with an estimated 15.4 mL/y greater FEV1 decline than experienced by those without BHR at follow-up. Annual FEV1 decline was moderated by corticosteroid use. Conclusions Persistent BHR and its deleterious influence on lung function suggest a role for airway inflammation in perpetuation of WTC-associated airway disease. In future massive occupational exposure to inorganic dust/gases, we recommend early and serial pulmonary function testing, including measurements of bronchial reactivity, when possible, and inhaled corticosteroid therapy for those with symptoms or pulmonary function tests consistent with airway disease.