Long-term respiratory symptoms in World Trade Center responders.

BACKGROUND New York State (NYS) employees who responded to the World Trade Center (WTC) disaster on or after 11 September 2001 potentially experienced exposures that might have caused persistent respiratory effects. NYS responders represent a more moderately exposed population than typical first responders. AIMS To assess whether NYS employees who were WTC responders were more likely than controls to report lower respiratory symptoms (LRS) or a diagnosis of asthma 5 years post-9/11. Persistence and severity of symptoms were also evaluated. METHODS Participants were initially mailed self-administered questionnaires (initial, Year 1, Year 2) and then completed a telephone interview in Year 3. Data were analysed using Poisson's regression models. RESULTS WTC exposure was associated with LRS, including cough symptoms suggestive of chronic bronchitis, 5 years post-9/11. When exposure was characterized using an exposure assessment method, the magnitude of effect was greater in those with exposure scores above the mean. WTC exposure was associated with persistence of LRS over the 3 year study period. Results also suggest that participants with the highest exposures were more likely to experience increased severity of their asthma condition and/or LRS. CONCLUSIONS Our findings suggest that even in a moderately exposed responder population, lower respiratory effects were a persistent problem 5 years post-9/11, indicating that some WTC responders require ongoing monitoring.