Context

• Air quality was recorded "severe" at many places in the national capital, while the city's AQI remained in the "very poor" category, according to data from the Central Pollution Control Board.

Air Quality Index (AQI)

• The Air Quality Index (AQI) is a scale that tells us how clean or polluted the air we breathe is.
• This index measures the concentration of various pollutants and converts it into an easily understandable number.

The AQI level is divided into six categories:

Good: 0-50

• Air quality is good, no health impacts expected.

Satisfactory: 51-100

• Air quality is satisfactory but may cause mild health effects to sensitive groups.

Moderate: 101-150

• Air quality is moderate, may cause health effects to sensitive groups.

Poor: 151-200

• When air quality is poor, everyone can feel health effects, especially sensitive groups.

Very Poor: 201-300

• The air quality is very poor, everyone can feel the health effects, especially sensitive groups.

Severe: 301-500

• The air quality is severe, everyone can feel serious health effects.

Pollutants affecting AQI:

• PM2.5: These fine particles can penetrate deep into the lungs and cause health problems.
• PM10: These particles can also be harmful to health, especially for lung and heart patients.
• Ozone (O3): It is a gas that can cause breathing difficulties and inflammation in the lungs.
• Nitrogen dioxide (NO2): It is a pollutant emitted from vehicles and industrial plants that can cause respiratory problems.
• Sulfur dioxide (SO2): It is a gas emitted by burning coal that can cause respiratory problems and acid rain.
• Carbon monoxide (CO): It is a colorless, odorless gas that can disrupt the transport of oxygen in the blood.