Spatial relationships among asthma prevalence, health care utilization, and pollution sources in neighborhoods of Buffalo, New York.

In this retrospective study, the authors investigate the spatial distributions of asthma cases in relation to major traffic corridors and the Peace Bridge Complex in Buffalo, New York, and assess possible contributions of other U.S. Environmental Protection Agency (U.S. EPA)--identified pollution release sources. Multiple data sources, including emergency room visits, outpatient visits, and hospital discharge databases are utilized to evaluate whether an association exists between the addresses of diagnosed asthma cases and release sources. Using a two-factor multilevel model, this study finds a statistically significant association between proximity to source and diagnosed asthma (p < .025). The authors further observe that two-thirds of the asthmatic sufferers resided between 204 and 700 meters from pollution sources and that over 40 percent who utilized health care lived within walking distance of the health care facility they patronized. Using Turnbull's method, the authors detect notable geographic asthma clusters in areas within the city of Buffalo, in North Tonawanda, along major roadways, and in the communities adjoining the Peace Bridge Complex. The authors also find local clusters in Buffalo's west side using Turnbull's method, and a significant global cluster using Besag and Newell's method. One-quarter of the case address locations were within 700 meters of identified clusters. The Score Test methods of Lawson and Waller and of Bithell also find statistically significant associations between three previously identified U.S. EPA focus sites and increased risk of asthma. Correlation of these findings with air quality assessments, especially with respect to traffic-related pollution, however, would be required for a definitive link to be made between an increased risk of asthma and identified pollution sources.