Air Quality Index Calculator

Formula

The formula to calculate the Air Quality Index (AQI) is:

\[ \text{AQI} = \frac{\text{I_high} - \text{I_low}}{\text{C_high} - \text{C_low}} \times (\text{C} - \text{C_low}) + \text{I_low} \]

Where:

\(\text{AQI}\) is the Air Quality Index
\(\text{I_high}\) is the AQI value corresponding to the higher concentration breakpoint that encompasses \(C\)
\(\text{I_low}\) is the AQI value corresponding to the lower concentration breakpoint that encompasses \(C\)
\(\text{C_high}\) is the higher concentration breakpoint that encompasses \(C\)
\(\text{C_low}\) is the lower concentration breakpoint that encompasses \(C\)
\(\text{C}\) is the pollutant concentration

What is the Air Quality Index?

The Air Quality Index (AQI) is a system used to measure and report the daily air quality in a specific area. It focuses on health effects that may be experienced within a few hours or days after breathing polluted air. The AQI scale ranges from 0 to 500, where a higher AQI value represents a higher level of air pollution and a greater risk to health. It considers five major air pollutants regulated by the Clean Air Act: ground-level ozone, particle pollution, carbon monoxide, sulfur dioxide, and nitrogen dioxide.

Example Calculation

Let's assume the following values:

AQI value corresponding to higher concentration breakpoint (I_high) = 150
AQI value corresponding to lower concentration breakpoint (I_low) = 100
Higher concentration breakpoint (C_high) = 0.125
Lower concentration breakpoint (C_low) = 0.065
Pollutant concentration (C) = 0.080

Using the formula:

\[ \text{AQI} = \frac{150 - 100}{0.125 - 0.065} \times (0.080 - 0.065) + 100 = \frac{50}{0.06} \times 0.015 + 100 = 12.5 + 100 = 112.5 \]

The Air Quality Index (AQI) is 112.5.