What's Your AQI? - Air Pollution: What's the Solution?

1. Obtain copies of the AQI Equation (.PDF) and Breakpoints Table (.PDF).
2. Review the following examples to learn how to convert ozone ppm readings into an AQI value:
   1. 8-hour Ozone example
      Suppose you have an 8-hour ozone concentration of 0.0874125 ppm.  First you round off the concentration to 0.087 ppm.  Then look in the Breakpoints Table (.PDF) under the 8-hour ozone for the range of concentrations that contain this concentration (0.085 - 0.104 ppm). This range in the table for the 8-hour ozone corresponds to index values of 101 to 150. Now you have all the numbers needed to use the AQI equation:

      
      
      Where I_P = the index for pollutant _P  
      C_P = the rounded concentration of pollutant _P        
      BP_Hi = the breakpoint that is greater than or equal to C_P 
      BP_Lo = the breakpoint that is less than or equal to C_P       
      I_Hi = the AQI value corresponding to BP_Hi   
      I_Lo = the AQI value corresponding to BP_Lo

      
      
      So, an 8-hour concentration of 0.0874125 ppm corresponds to an AQI value of 106.

   2. Multiple Pollutants example
      Suppose you have an 8-hour ozone value of 0.077 ppm, a PM_2.5 value of 54.4μg/m³, and a CO value of 8.4 ppm.  You apply the equation 3 times:

      - For Ozone (O3):
      - For Particulate Matter (PM2.5):
      - For Carbon Monoxide (CO):
      The AQI is 128 with PM2.5 as the responsible pollutant.

3. Complete the problems on the Student Worksheet.

EPA | NESCAUM | CIESE | Stevens Institute of Technology