On September 11th 2001, the World Trade Center (WTC) collapse created an enormous urban disaster site with high levels of “WTC-Dust” (respirable particulates and combustion by-products). Rescue workers and residents have since developed respiratory symptoms and pulmonary function abnormalities. We investigated whether WTC-Dust exposure affected spirometric decline rates (forced expiratory volume in one second [FEV1], forced vital capacity [FVC]) in the New York City Fire Department (FDNY) workforce.
Longitudinal cohort study of pulmonary function before and after 09/11/2001 in 12,079 FDNY rescue workers employed on/before 09/11/2001. Declines were computed separately for pre- and post-9/11 periods and analyzed for differences according to WTC-Dust exposure intensity. Exposure intensity was assessed with (1) initial arrival time at the WTC site (early arrival before/during WTC collapse, intermediate after collapse during 09/11/2001-09/12/2001, late after 09/12/2001; non-exposed never present) and (2) work assignment (Special Operations Command [SOC] vs. non-SOC).
FEV1 decline after 09/11/2001 correlated linearly (p for trend<0.001) with arrival time-based WTC-Dust exposure intensity and was fastest for those with early, high exposure, reaching more than twice the magnitude for the non-exposed group (-845cc/yr for early vs. -405cc/yr for non-exposed, p<0.001; figure 1A&2A). The intermediate exposure group had a decline between that of early and late groups. The late group had a decline 50% above the non-exposed. In addition, SOC workers experienced 50% faster decline than non-SOC workers (-926cc/yr for SOC vs. -615cc/yr for non-SOC; p=0.007; figure 1B&2B).
WTC-Dust exposure produced accelerated declines in spirometric measures of lung function in 12,079 WTC exposed FDNY rescue workers during the first year following 09/11/2001.
Findings are of potential relevance for less exposed populations. The long-term time course of spirometric decline is not certain. For these reasons, WTC-exposed occupational and community cohorts merit continued close medical monitoring.
Gisela Banauch, None.