Good news for Delhiites ahead of 2025, a data released by the Commission for Air Quality Management (CAQM) shows that the National Capital recorded 209 'good to moderate' air quality days in 2024, the highest since 2018. However, 2020's record is an exception as pollution was dropped sharply that year due to the COVID-19 lockdown. February, December and August recorded the best average Air Quality Index (AQI) in six years.
Delhi records highest 'good to moderate' air quality days since 2018
As per the CAQM data, the number of 'good to moderate' air quality days was 159 in 2018, 182 in 2019, 227 in 2020, 197 in 2021, 163 in 2022 and 206 in 2023. This year, Delhi witnessed 157 'poor to severe' days this year, the lowest since 2018 when the number stood at 206, excluding 2020 (139 days).
Dry spells and high-speed winds from April to June, especially in May, brought heavy dust and pollution, making it the worst May AQI since 2018. Despite this, 2024 tied with 2021 and 2022 for the second-best annual average AQI of 209, the CAQM said.
What is the Air Quality Index (AQI)
The air quality index (AQI) is an index for reporting air quality daily. It is a measure of how air pollution affects one's health within a short span. The purpose of the AQI is to help people know how the local air quality impacts their health. The Environmental Protection Agency (EPA) calculates the AQI for five major air pollutants, for which national air quality standards have been established to safeguard public health.
How is air quality measured?
To measure the air quality, everyday concentrations of the major pollutants are recorded and these measurements are converted into a separate AQI value for each pollutant (ground-level ozone, particle pollution, carbon monoxide, and sulfur dioxide) using standard formulae developed by EPA.
AQI in India
India follows 500 point scale to measure air quality, wherein rating between 0 and 50 is considered good. Rating between 301 to 500 range is deemed hazardous.
- Good (0–50) - Minimal Impact
- Satisfactory (51–100) - May cause minor breathing difficulties in sensitive people.
- Moderately polluted (101–200) - May cause breathing difficulties in people with lung disease like asthma, and discomfort to people with heart disease, children and older adults.
- Poor (201–300) - May cause breathing difficulties in people on prolonged exposure, and discomfort to people with heart disease
- Very Poor (301–400) - May cause respiratory illness in people on prolonged exposure. Effect may be more pronounced in people with lung and heart diseases.
- Severe (401-500) - May cause respiratory issues in healthy people, and serious health issues in people with lung/heart disease. Difficulties may be experienced even during light physical activity.
(With PTI inputs)
