Residents of Manhattan were exposed to inhaled substances after the collapse of the World Trade Center. Exposure may lead to an increase in asthma severity, with residential distance from the disaster site (Ground Zero) predictive of the degree of change.

We retrospectively reviewed the charts of 205 established asthma patients from a community health center in lower Manhattan's Chinatown. Clinical data were obtained for the year before and the year after September 11, 2001. Measurements included: number of patient visits, asthma medication prescriptions, oral corticosteroid prescriptions, weekly doses of rescue inhaler, and peak expiratory flow rates (PEFR). Residential zip codes were used to compare the asthma severity of patients living within and beyond a 5 mile radius of Ground Zero.

After 9/11, all patients had significantly more asthma-related clinic visits (mean 3.79 pre-9/11 versus 4.69 post-9/11, p=0.002), and received significantly more prescriptions for asthma medications (mean 2.05 pre-9/11 versus 2.33 post-9/11, p=0.018). No significant differences in oral steroid or rescue inhaler use were noted. Those living within 5 miles had significantly more clinic visits post 9/11 (3.95 pre-9/11 versus 5.10 post-9/11, p=0.013); the increase in clinic visits for patients living greater than 5 miles from Ground Zero was not significant. Mean percent predicted PEFRs declined solely for those patients living within 5 miles of Ground Zero during the three months following 9/11.

Asthma severity worsened after 9/11/01 in pediatric asthmatics living near Ground Zero. Residential proximity was predictive of the degree of decline.