What’s Your AQI? – Air Pollution: What’s the Solution?
What’s Your AQI?
Procedure |
- Obtain copies of the AQI Equation (.PDF) and Breakpoints Table (.PDF).
- Review the following examples to learn how to convert ozone ppm readings into an AQI value:
- 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. - Multiple Pollutants example
Suppose you have an 8-hour ozone value of 0.077 ppm, a PM_{2.5} value of 54.4μg/m^{3}, and a CO value of 8.4 ppm. You apply the equation 3 times:– For Ozone (O_{3}): – For Particulate Matter (PM_{2.5}): – For Carbon Monoxide (CO): - The AQI is 128 with PM_{2.5 }as the responsible pollutant.
- 8-hour Ozone example
- Complete the problems on the Student Worksheet.
EPA | NESCAUM | CIESE | Stevens Institute of Technology