Context: New York City firefighters responding to the World Trade Center (WTC) disaster on September 11, 2001, were exposed to numerous hazards. A medical screening program was conducted 3 weeks after the disaster on a sample of firefighters.
Objectives: To determine whether arrival time at the WTC and other exposure variables (including respirator use) were associated with symptoms and changes in pulmonary function (after exposure - before exposure).
Design: A cross-sectional comparison of firefighters representing the following groups: (1) firefighters who arrived before/during the WTC collapse, (2) firefighters who arrived 1 to 2 days after the collapse, (3) firefighters who arrived 3 to 7 days after the collapse, and (4) unexposed firefighters.
Setting: Fire Department of New York City (FDNY) Bureau of Health Services on October 1 to 5, 2001.
Population: A stratified random sample of 362 of 398 recruited working firefighters (91%). Of these, 149 firefighters (41%) were present at the WTC collapse, 142 firefighters (39%) arrived after the collapse but within 48 h, 28 firefighters (8%) arrived 3 to 7 days after the collapse, and 43 firefighters (12%) were unexposed.
Main outcome measures: New/worsening symptoms involving the eyes, skin, respiratory system, and nose and throat (NT), and changes in spirometry from before to after exposure.
Results: During the first 2 weeks at the WTC site, 19% of study firefighters reported not using a respirator; 50% reported using a respirator but only rarely. Prevalence ratios (PRs) for skin, eye, respiratory, and NT symptoms showed a dose-response pattern between exposure groups based on time of arrival at the WTC site, with PRs between 2.6 and 11.4 with 95% confidence intervals (CIs) excluding 1.0 for all but skin symptoms. For those spending > 7 days at the site, the PR for respiratory symptoms was 1.32 (95% CI, 1.13 to 1.55), compared with those who were exposed for < 7 days. Mean spirometry results before and after exposure were within normal limits. The change in spirometry findings (after exposure - before exposure) showed near-equal reductions for FVC and FEV(1). These reductions were greater than the annual reductions measured in a referent population of incumbent FDNY firefighters prior to September 11 (p <or= 0.05). There was a 60% increased risk of a decline of >or= 450 mL in FEV(1) in those arriving during the first 48 h compared to the referent (p <or= 0.05).
Conclusions: The symptoms and pulmonary function changes following exposure at the WTC demonstrate the need for improvements in respirators and their use, as well as long-term medical monitoring of rescue workers.