National Ambient Air Quality Standards
Also called: NAAQS · Topic: Geographical Issues: Pollution, Urban Waste, Slums and Land Degradation · NCERT: Beyond NCERT
Meaning
The National Ambient Air Quality Standards (NAAQS) are the legal limits for how much of each pollutant the outdoor air may hold. "Ambient" means the open air around us. The Central Pollution Control Board set them in 2009 for 12 pollutants. For PM2.5 (very fine dust and smoke particles), the limit is 60 µg/m³ (micrograms per cubic metre) over 24 hours and 40 µg/m³ as a yearly average. These are much looser than the World Health Organization's 2021 guidelines of 15 and 5 µg/m³.
Example
A city that failed the NAAQS for PM10 or NO₂ for five years in a row (2011–15) became a non-attainment city. Many cities of the Indo-Gangetic plain, such as Delhi, fall in this group.
Don't confuse with
- National Air Quality Index: this is the public scale launched in 2015. It turns eight pollutants into one number with six bands. NAAQS are the legal limits themselves.
- WHO guidelines: these are advice, not Indian law, and they are much stricter.
Related concepts
- National Air Quality Index
- Non-attainment city
- National Clean Air Programme
- Graded Response Action Plan
- Commission for Air Quality Management