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AQI Explained: Air Quality Index in India and What the Numbers Mean
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AQI Explained: Air Quality Index in India and What Do the Numbers Actually Mean?

Have you ever checked the air quality on your phone and wondered what the numbers actually mean?

The Air Quality Index (AQI) makes air pollution data easier to understand. It helps you assess outdoor air quality and make more informed decisions about your daily activities.

What Is the Air Quality Index (AQI)?

The Air Quality Index is a system used to communicate how polluted the air is. India's National AQI considers eight pollutants, including PM2.5, PM10, nitrogen dioxide, ozone and carbon monoxide.

In simple terms, understanding the AQI helps you interpret air-quality readings instead of relying only on whether the sky looks clear.

Reference: Central Pollution Control Board (CPCB)

AQI Levels in India: What Do the Numbers Mean?

India uses six AQI categories:

Good (0–50): Minimal impact.

Satisfactory (51–100): Minor breathing discomfort may occur in sensitive people.

Moderate (101–200): Breathing discomfort may occur in people with lung or heart conditions, including asthma.

Poor (201–300): Breathing discomfort may occur in many people on prolonged exposure.

Very Poor (301–400): Prolonged exposure may be associated with respiratory illness.

Severe (401–500): Health effects may affect healthy people, with more serious effects for those with existing conditions.

These categories communicate potential health concerns; individual responses to air pollution can vary.

How Does Air Pollution Affect Health?

Air pollution is more than visible smoke or haze. Fine particulate matter, known as PM2.5, consists of tiny particles that can penetrate deep into the lungs.

The World Health Organization's 2021 Global Air Quality Guidelines review scientific evidence on particulate matter and several major air pollutants and their effects on health.

Checking air-quality readings can help you understand potential exposure and follow appropriate public-health advice.

Reference: World Health Organization, Global Air Quality Guidelines, 2021.

How Can You Use AQI to Plan Your Day?

Checking AQI is a simple way to become more aware of your surroundings.

  • Check local readings: Look at the latest available AQI before planning outdoor activities.
  • Pay attention to high readings: Follow official health advisories and adjust strenuous outdoor activities when recommended.
  • Consider vulnerable groups: Children, older adults and people with heart or lung conditions may need additional precautions.
  • Think about indoor air too: Cooking fumes, smoke and other indoor sources can affect the air inside homes and offices.

Remember, an outdoor AQI reading does not directly measure the air quality inside your home or workplace.

Why Does Delhi Air Quality Change Throughout the Day?

Delhi air quality can vary because of traffic, construction, industrial emissions, weather conditions and the movement of pollutants.

Readings can also differ between monitoring stations and neighbourhoods. Always check the location and timestamp rather than assuming one reading represents the entire city.

Where Can You Find Reliable AQI Updates?

For India, consult official sources:

Check the monitoring station, date and time when interpreting a reading.

The Takeaway

AQI is more than a number on your screen. It is a useful starting point for understanding air pollution and making informed everyday choices.

At AirRight, we believe better awareness is the first step towards more conscious decisions about the air around us.

Breathe Right | Live Better

Follow AirRight for simple, science-backed insights into air quality and everyday living.

References

Central Pollution Control Board. National Air Quality Index.https://www.airquality.cpcb.gov.in/ccr_docs/About_AQI.pdf

World Health Organization (2021). WHO Global Air Quality Guidelines.https://www.who.int/publications/i/item/9789240034228
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