The objective of this study was to assess the effects of air pollution on emergency room (ER) visits for respiratory problems and school absences over a period of 90 days.
Air Quality Index (AQI) is a simple aggregate measure of air quality used by the Michigan Department of Environmental Quality (DEQ) to document the quality of air. It measures Particulate Matter, Ozone, Sulfur Dioxide, Nitrogen Dioxide, and Carbon Monoxide. AQI levels range from 0-500, with 500 being the worst possible air quality. AQI levels, ER visits for respiratory problems, and school absences were recorded daily from October 2004 to January 2005.
Data was charted with no lag, with a one-day lag, two-day lag, and a three-day lag. A Pearson Coefficient of Correlation was performed and was best with a two-day lag for ER visits. The data from the two-day lag was separated into quartiles by AQI values. The AQI levels in the highest quartile ranged from 66-80, and in the lowest from 20-35. The average number of ER visits in the highest AQI quartile (poor air quality) was greater than in the lowest quartile(20.5 visits vs. 12.8 visits per day; p value of 0.09. School absences did not show a significant difference.
In conclusion there was a trend for the number of respiratory-related ER visits to be greater when the air quality was poor.
These results have implications for a small community in allocating resources for health care utilization based on real time simple air pollution measures. The results suggest a need for increased health care personnel in the emergency room two days subsequent to poor air quality.
Rachna Reddy, None.