Loni Is Now the World’s Most Polluted City — And Delhi, Noida & Ghaziabad Aren’t Far Behind

Forget what you thought you knew about India's air pollution map. While Delhi has long hogged the headlines, it's a lesser-known city in Uttar Pradesh that has quietly become the…

By Reetam Bodhak

March 27, 2026

3 min read

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Forget what you thought you knew about India’s air pollution map. While Delhi has long hogged the headlines, it’s a lesser-known city in Uttar Pradesh that has quietly become the most toxic place on the planet to breathe.

India’s Most Polluted Cities — IQAir 2025 Report

Rank (Global)	City	PM2.5 (µg/m³)	Times Above WHO Limit
#1	Loni, UP	112.5	22x
#3	Byrnihat, Meghalaya	101.1	20x
#4	Delhi	99.6	19x
#7	Ghaziabad	89.2	17x
#18	Noida	80.5	16x
#21	Greater Noida	77.2	15x

Source: IQAir World Air Quality Report 2025

Loni: The Name You Should Know

Loni, a city in Ghaziabad district bordering Delhi, recorded an annual average PM2.5 concentration of 112.5 µg/m³ in 2025 — more than 22 times the WHO permissible guideline — making it the world’s most polluted city. Wikipedia

What drove this? Extreme pollution events in March, April, and December pushed Loni’s annual average up nearly 23% compared to 2024. Wikipedia Add industrial clusters, brick kilns, vehicular overflow from Delhi, and geographic “bowl effect” trapping pollutants — and you have a slow-burning crisis.

🔗 Also Read: Top Gadgets & Air Purifiers to Beat India’s Toxic Air — Technosports

Delhi Still the World’s Most Polluted Capital

Among capital cities globally, New Delhi ranked as the most polluted capital in 2025, with an annual average PM2.5 concentration of 82.2 µg/m³. Wikipedia That’s a city of 33 million people breathing air that is nearly 16x beyond safe limits — every single day.

Vehicular emissions, industrial output, crop residue burning, and construction dust remained the dominant sources of PM2.5 pollution across India. Wikipedia

India’s Bigger Picture

Five of the ten most polluted cities globally are Indian — Loni, Byrnihat, Delhi, Ghaziabad, and Ula — and all 25 of the world’s most polluted cities are located in India, Pakistan, and China. Telugu Library

Despite this, India’s national average PM2.5 dropped slightly from 50.6 µg/m³ in 2024 to 48.9 µg/m³ in 2025 — though scientists caution this is likely due to weather patterns, not permanent improvement. Wikipedia

🔗 Read More: EV Adoption in India: Can Electric Vehicles Fix Our Air? — Technosports

For deeper context on particulate matter and its health impact, visit the Wikipedia article on PM2.5.

FAQs

Q1. Which is India’s most polluted city in 2025?

Loni in Ghaziabad, Uttar Pradesh — with PM2.5 at 112.5 µg/m³, it surpassed Delhi to become both India’s and the world’s most polluted city.

Q2. Is Delhi still the most polluted capital city in the world?

Yes. Despite Loni topping the overall city rankings, New Delhi retained its title as the world’s most polluted capital city in 2025 with an average PM2.5 of 82.2 µg/m³.