where IAQIp is the index for pollutant p; Cp is the rounded concentration of pollutant p; BPHi is the breakpoint that is greater than or equal to Cp; BPLo is the breakpoint that is less than or equal to Cp; IAQIHi is the AQI value corresponding to BPHi; IAQILo is the AQI value corresponding to BPLo. IAQI and corresponding thresholds of each pollutant is displayed in Table 1. The overall AQI is the maximum of the individual AQIs as shown in Eq.