This analysis used BioSense 2.0 frontend data to evaluate the impact of air quality indeces on emergency department visits for respiratory syndromes and subsyndromes during wintertime inversions in Salt Lake County, UT. Most syndromes and subsyndromes occurred more frequently on days with higher AQI and aberration alarms were more likely to be triggered on days with higher AQI for ILI, pleurisy, and respiratory failure. After adjusting for seasonality, the AQI was significantly associated with the proportion of emergency room visits for RSV, ILI, and the respiratory syndrome. These results suggest frontend data may be useful for ecological air quality analyses.