Explained: How India handles pollution and what WHO air guidelines say

The government says India sets its own air quality standards and does not follow WHO guidelines; cities are ranked under NCAP, with top performers rewarded annually

The government on Thursday told Parliament that widely cited global air quality rankings are not conducted by any official authority. Indices such as IQAir's World Air Quality Ranking, WHO Global Air Quality Database, the Environmental Performance Index (EPI), and Global Burden of Disease (GBD) metrics are advisory and not legally binding.

 

In a written statement, Minister of State for Environment Kirti Vardhan Singh said, "The World Health Organisation's air quality guidelines serve only as guidance and are recommended values to help countries achieve good air quality. However, countries prepare their own air quality standards based on geography, environmental factors, background levels, socio-economic status and national circumstances.”

 

 

What are India’s official air quality standards?

 

India has its own National Ambient Air Quality Standards (NAAQS) for 12 pollutants, notified in 2009, to protect public health and the environment. These standards are designed to fit India’s unique geography, environmental conditions and socio-economic factors.

 

While no global authority officially ranks countries by pollution levels, India carries out the Swachh Vayu Survekshan annually under the National Clean Air Programme (NCAP). This survey evaluates 130 cities based on their implementation of air-quality improvement measures. The best-performing cities are felicitated every year on National Swachh Vayu Diwas (September 7).

 

Although the WHO updated its air quality guidelines in 2021, setting stricter limits for PM2.5 (15 micrograms per cubic metre for 24 hours and 5 annually), India still follows its 2009 National Ambient Air Quality Standards (NAAQS), which allow 60 micrograms per cubic metre in 24 hours and 40 annually. The government says these limits suit the country’s conditions.   

 

What are WHO air quality guidelines?

 

The World Health Organisation (WHO) sets Air Quality Guidelines (AQG) to help countries reduce pollution and protect health. These guidelines are advisory, not laws and aim to inform governments about safe levels of air pollutants.

 

According to WHO, clean air is a basic human right. Yet air pollution remains one of the leading causes of early deaths globally, responsible for around 7 million premature deaths every year due to diseases such as heart attacks, strokes and lung illnesses, mostly in developing countries.

 

How has Delhi’s air quality changed in recent years?

 

Environment Minister Bhupender Yadav highlighted improvements in the national capital:

• “Good to moderate” air quality days (AQI ≤ 200) increased from 110 in 2016 to 200 in 2025 (till date)

• Average AQI from January to November improved from 213 in 2018 to 187 in 2025

• No day in 2025 has recorded “Severe Plus” air quality (AQI > 450)

• Farm fire incidents in Punjab and Haryana dropped by around 90 per cent in the 2025 paddy harvesting season compared to 2022

 

What is air pollution, and why is it harmful?

 

Air pollution consists of tiny particles and gases from sources like:

• Smoke from burning fuels in homes

• Vehicle exhaust from cars and trucks

• Factory and power plant emissions

• Burning waste

• Dust from land and farming

 

The most dangerous particles are PM2.5, which can penetrate deep into the lungs and enter the bloodstream, causing severe heart and lung diseases over time.

 

How are WHO guidelines determined?

 

WHO updates its guidelines based on global scientific evidence. Experts review research and recommend pollution levels that are safest for human health. Major updates were made in 2005 and 2021, reflecting studies that show even lower pollution levels than previously thought can harm health.

 

How do countries use these guidelines?

 

Governments can adopt the WHO recommendations into local laws or use them as targets to guide pollution reduction policies. While not legally binding, the guidelines help countries make better decisions on energy, transport, waste management and urban planning to improve air quality and protect public health.