Question

As per the Central Pollution Control Board's National Air Quality Index (AQI) of India 2014, which of the following statement(s) is/are true?

• A. AQI is computed considering 8-hourly value of CO
• B. AQI is computed considering 2-hourly value of PM2.5
• C. AQI considers the O\textsubscript{3} concentrations
• D. AQI considers the CO\textsubscript{2} concentrations

Hint:

AQI includes only health-critical pollutants—CO₂ is not one of them. Remember: CO uses an 8-hour average; particulate matter uses a 24-hour average.

Answer 1

The Correct Option is A, C

The National AQI (2014) of India uses eight pollutants: PM₁₀, PM_2.5, NO₂, SO₂, CO, O₃, NH₃, and Pb.
Carbon dioxide (CO₂) is not included, since it is a greenhouse gas rather than a toxic pollutant impacting daily air quality. CO is measured using its maximum 8-hour moving average concentration due to its short-term exposure impacts on human health. Ozone (O₃) is also included because it is a secondary pollutant formed through photochemical reactions and has strong respiratory effects.
However, PM_2.5 is measured using a 24-hour average for AQI purposes, not a 2-hour average. Hence only statements (A) and (C) are correct.