Question

Which of the following is not a criteria air pollutant under the National Ambient Air Quality Standards (NAAQS)?

• A. CO2
• B. CO
• C. O3
• D. Pb

Answer 1

The Correct Option is A

Under the National Ambient Air Quality Standards (NAAQS), specific criteria air pollutants are designated. These encompass:

• Carbon Monoxide (CO): A colorless, odorless gas originating from vehicle exhaust and industrial activities.
• Ozone (O₃): A reactive gas formed through the interaction of sunlight with pollutants like volatile organic compounds (VOCs) and nitrogen oxides (NOx).
• Lead (Pb): A metallic pollutant emitted from industrial sources and, historically, from leaded gasoline.

The inquiry concerns identifying which of the presented choices is not classified as a criteria air pollutant. From the options provided—CO₂ (Carbon Dioxide), CO, O₃, Pb—only Carbon Dioxide (CO₂) is not recognized as a criteria air pollutant by the NAAQS.

Correct Answer: CO₂