
Where IP
= the index for pollutant
P
CP
= the rounded concentration of pollutant
P
BPHi
= the breakpoint that is greater than or equal to CP
BPLo
= the breakpoint that is less than or equal to CP
IHi
= the AQI value corresponding to BPHi
ILo
= the AQI value corresponding to BPLo

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