Abnormalities on Chest Computed Tomography and Lung Function Following an Intense Dust Exposure: A 17-Year Longitudinal Study.

Charles Liu,Mayris P Webber,David J Prezant,Theresa Schwartz,Melissa J Fazzari,Ankura Singh,Rachel Zeig-Owens,Hillel W Cohen,Charles B Hall,Michael D Weiden,Barbara Putman

doi:10.3390/ijerph16091655

Abstract

Fire Department of the City of New York (FDNY) firefighters experienced intense dust exposure working at the World Trade Center (WTC) site on and after 11/9/2001 (9/11). We hypothesized that high-intensity WTC exposure caused abnormalities found on chest computed tomography (CT). Between 11/9/2001–10/9/2018, 4277 firefighters underwent a clinically-indicated chest CT. Spirometric measurements and symptoms were recorded during routine medical examinations. High-intensity exposure, defined as initial arrival at the WTC on the morning of 9/11, increased the risk of bronchial wall thickening, emphysema, and air trapping. Early post-9/11 symptoms of wheeze and shortness of breath were associated with bronchial wall thickening, emphysema, and air trapping. The risk of accelerated forced expiratory volume at one second (FEV1) decline (>64 mL/year decline) increased with bronchial wall thickening and emphysema, but decreased with air trapping. The risk of airflow obstruction also increased with bronchial wall thickening and emphysema but decreased with air trapping. In a previously healthy occupational cohort, high-intensity WTC exposure increased the risk for CT abnormalities. Bronchial wall thickening and emphysema were associated with respiratory symptoms, accelerated FEV1 decline, and airflow obstruction. Air trapping was associated with respiratory symptoms, although lung function was preserved. Physiologic differences between CT abnormalities suggest that distinct types of airway injury may result from a common exposure.

Highlights

The collapse of the World Trade Center (WTC) on the morning of 11 September 2001 (9/11)produced a caustic dust plume containing more than 10,000,000 tons of irritating alkaline dust with pH> 10 [1]
We examined the associations of emphysema, bronchial wall thickening and air trapping with early respiratory symptoms and longitudinal lung function in order to understand the clinical correlates of radiographic airway abnormalities in this population
We evaluated the associations of emphysema, bronchial wall thickening, and air trapping with lung volumes in the subgroup with complete pulmonary function tests11/9/2001–10/9/2018 (PFTs)

Summary

Introduction

The collapse of the World Trade Center (WTC) on the morning of 11 September 2001 (9/11)produced a caustic dust plume containing more than 10,000,000 tons of irritating alkaline dust with pH> 10 [1]. Fire Department of the City of New York (FDNY) rescue and recovery workers who arrived at the site the morning of 9/11, were exposed to an extremely high concentration of dust that produced airway injury. Those who arrived in the afternoon and following days received a lower intensity, but substantial exposure, as rescue and recovery work resuspended the dust. In the years following 9/11, WTC-exposed rescue/recovery workers had high rates of airway injury, including excessive loss of lung function [2], airflow obstruction [3], and airway hyper-reactivity [4]. A significant portion of the cohort experienced accelerated FEV1 decline, defined as greater than 64 mL/year FEV1 decline, a risk factor for chronic obstructive pulmonary disease (COPD) [5] and asthma/COPD overlap [6]

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