Abstract

Background

Workers from the Fire Department of New York City were exposed to a variety of inhaled materials during and after the collapse of the World Trade Center. We evaluated clinical features in a series of 332 firefighters in whom severe cough developed after exposure and the prevalence and severity of bronchial hyperreactivity in firefighters without severe cough classified according to the level of exposure.

Methods

“World Trade Center cough” was defined as a persistent cough that developed after exposure to the site and was accompanied by respiratory symptoms severe enough to require medical leave for at least four weeks. Evaluation of exposed firefighters included completion of a standard questionnaire, spirometry, airway-responsiveness testing, and chest imaging.

Results

In the first six months after September 11, 2001, World Trade Center cough occurred in 128 of 1636 firefighters with a high level of exposure (8 percent), 187 of 6958 with a moderate level of exposure (3 percent), and 17 of 1320 with a low level of exposure (1 percent). In addition, 95 percent had symptoms of dyspnea, 87 percent had gastroesophageal reflux disease, and 54 percent had nasal congestion. Of those tested before treatment of World Trade Center cough, 63 percent of firefighters (149 of 237) had a response to a bronchodilator and 24 percent (9 of 37) had bronchial hyperreactivity. Chest radiographs were unchanged from precollapse findings in 319 of the 332 with World Trade Center cough. Among the cohort without severe cough, bronchial hyperreactivity was present in 77 firefighters with a high level of exposure (23 percent) and 26 with a moderate level of exposure (8 percent).

Conclusions

Intense, short-term exposure to materials generated during the collapse of the World Trade Center was associated with bronchial responsiveness and the development of cough. Clinical and physiological severity was related to the intensity of exposure.

Between October 1 and 14, 2001, 391 firefighters underwent medical screening examinations and 295 met the criteria for exposure, 102 of whom underwent methacholine or bronchodilator challenge. Clinical characteristics (sex, age, smoking status, and presence or absence of respiratory symptoms) did not differ significantly either between the subjects who were eligible for testing and the subjects who actually were tested or among the subjects in the two highest exposure groups (data not shown). In this cohort of 295 firefighters, the average age was 41±7 years, the mean tenure at the FDNY was 13±6 years, and 13 percent were exsmokers. All reported cough within 24 hours after exposure, and none were on medical leave. The mean FVC and FEV1 values were within normal limits in all groups. In the group of firefighters with a moderate level of exposure, the subjects who were eligible for testing had significantly higher FVC and FEV1 values than did subjects who were actually tested (FVC, 96 percent vs. 89 percent of the predicted value; P=0.04; and FEV1, 98 percent vs. 91 percent of the predicted value; P=0.003). Among tested subjects there were no significant differences between the mean spirometric values obtained before the collapse of the World Trade Center and those obtained afterward (FEV1, 103 percent and 95 percent of the predicted value, respectively; FVC, 98 percent and 92 percent of the predicted value). Among the four exposure groups, there were no significant differences in respirator use during the first week (fewer than 22 percent reported frequent use).

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