Question

The Air Quality Index is measured using the Criteria Pollutants. Which one of the following is not a Criteria Pollutant?

• A. Sulfur Dioxide
• B. Lead
• C. Carbon dioxide
• D. Ozone

Hint:

Be careful to distinguish between direct air pollutants and greenhouse gases. The AQI measures pollutants that cause immediate health effects like asthma (Ozone, SO\(_2\), PM). Carbon Dioxide (CO\(_2\)) is the primary driver of global warming but is not an AQI component. However, Carbon {Monoxide} (CO) \textbf{is} a criteria pollutant.

Answer 1

The Correct Option is C

Step 1: Definition of Criteria Air Pollutants:
Criteria air pollutants are a set of six common pollutants, initially defined by the US EPA and now recognized globally, known to harm public health and the environment. They form the basis of the Air Quality Index (AQI).

Step 2: Listing the Six Pollutants:
The six criteria air pollutants include:

Ground-level Ozone (O\(_3\))
Particulate Matter (PM\(_{2.5}\) and PM\(_{10}\))
Carbon Monoxide (CO)
Sulfur Dioxide (SO\(_2\))
Nitrogen Dioxide (NO\(_2\))
Lead (Pb)

Step 3: Evaluating the Options:
- (A) Sulfur Dioxide (SO\(_2\)): A criteria air pollutant.
- (B) Lead (Pb): A criteria air pollutant.
- (C) Carbon dioxide (CO\(_2\)): A major greenhouse gas linked to climate change, but not a criteria air pollutant because typical ambient levels aren't directly toxic to humans.
- (D) Ozone (O\(_3\)): Ground-level ozone is a criteria air pollutant.

Step 4: Conclusion:
Carbon dioxide (CO\(_2\)) is not a criteria pollutant used in the AQI calculation. Therefore, the correct answer is (C).