Top 20 Most Polluted Monitoring Stations of 2024 Located in Delhi-NCR

A new study has once again highlighted the severe air pollution crisis in Delhi-NCR. According to an analysis by the Health Effects Institute (HEI) all of the top 20 most polluted air quality monitoring stations in India in 2024 were located in Delhi and the National Capital Region (NCR). This assessment reviewed air quality trends after the launch of the National Clean Air Programme (NCAP) in 2019 and shows that while there are signs of improvement at some locations, absolute pollution levels in Delhi-NCR remain among the highest in the country.

Key Finding: Jahangirpuri the Most Polluted Station

The HEI report, titled “Assessment of Changes in Air Quality in Indian Cities Since the Launch of the National Clean Air Programme” found that Jahangirpuri in North Delhi was the most polluted monitoring station in India in 2024.

It recorded an annual average PM10 concentration of 276.1 µg/m³, far exceeding the National Ambient Air Quality Standards (NAAQS). PM10 refers to coarse particulate matter that can enter the lungs and cause serious respiratory and cardiovascular problems.

Out of the top 20 polluted stations,

• 19 were located within Delhi
• 1 was in the surrounding NCR region

Trends in Delhi

When long term data is examined, the trend picture for Delhi is mixed but cautiously improving.

Using raw PM10 data,

• 21 out of 27 monitoring stations in Delhi showed declining trends
• Reductions ranged from 0.3 to 9.7 µg/m³ per year
• However, most declines were not statistically significant
• Some areas, such as Punjabi Bagh and R.K. Puram, actually showed increasing PM10 levels, highlighting uneven progress across the city.

What Data Shows Clearer Progress?

When researchers removed seasonal and meteorological effects from the data,

• 19 stations showed statistically significant declines in PM10
• The steepest drop was recorded at Jawaharlal Nehru Stadium, with a reduction of about 7.5 µg/m³ per year

For PM2.5 (finer and more harmful particles),

• 22 stations showed declining trends after deseasonalisation
• 8 stations recorded increasing trends
• Again, Punjabi Bagh and R.K. Puram showed the strongest upward trends

Despite this progress, the report cautions that the rate of improvement is small compared to Delhi’s extremely high baseline pollution levels.

NCR Cities Show More Consistent Gains

• The study found better and more uniform improvements in some NCR cities outside Delhi.
• Ghaziabad and Noida: All long-term monitoring stations showed statistically significant declines in both PM10 and PM2.5
• These cities showed more consistent improvement compared to Delhi, where trends vary sharply by location
• This suggests that local factors and targeted interventions play a major role in pollution control outcomes.

National Picture Beyond Delhi-NCR

Across India, the picture is uneven but slightly more encouraging,

• Among stations with at least five years of data,
• 44 stations showed significant declines in PM10
• 24 stations showed significant increases

For PM2.5,

• 54 out of 89 stations recorded significant declines
• Cities like Mumbai, Kolkata, Hyderabad, Howrah, Noida and Ghaziabad showed consistent reductions
• Improvements were also seen in Amritsar, Chandigarh, Ludhiana, Thane and Chandrapur

However, cities with only one monitoring station face reliability issues in city-wide assessment.

NCAP and Monitoring Challenges

The National Clean Air Programme (NCAP) was launched in 2019 by the Ministry of Environment, Forest and Climate Change to reduce particulate pollution across Indian cities.

The HEI report stresses that,

• Delhi NCR remains India’s most persistent pollution hotspot
• Uneven and sparse monitoring networks weaken assessment accuracy
• There is a strong need for denser, more representative air quality monitoring stations under NCAP

Key Takeaways

• All top 20 most polluted stations in 2024 were located in Delhi-NCR
• Jahangirpuri (Delhi) was the most polluted station with PM10 at 276.1 µg/m³
• The study was conducted by the Health Effects Institute (HEI)
• It assessed air quality changes after the launch of NCAP in 2019
• PM10 and PM2.5 trends show gradual improvement but remain very high
• Ghaziabad and Noida showed more consistent pollution decline than Delhi
• Over 90% of stations still exceed National Ambient Air Quality Standards

Question

Q. According to the HEI study, all of the top 20 most polluted air quality monitoring stations in India (2024) were located in:

A. Indo-Gangetic Plain
B. Mumbai Metropolitan Region
C. Delhi and NCR
D. Eastern India