India 6th most polluted country in the world: World Air Quality Report

India’s particulate matter (PM2.5) concentrations were at a three-year low, though it still is the sixth most polluted country in the world, according to the World Air Quality Report, a yearly global compilation of air quality by IQAir, a Swiss company that makes air filtration devices.

India’s population-weighted annual average PM2.5 concentration in 2025 was 48.9 µg/m³, a 3% decrease from 2024 (50.6 µg/m³) and a 10% decrease from 2023 (54.4 µg/m³). The 2025 numbers were part of a report—now in its eighth edition—made public on Tuesday (March 24, 2026).

The population-weighted numbers that IQAir calculates give more weight to the particulate matter numbers from cities with higher population—a metric meant to underline the quality of air that the majority of a country’s population are exposed to.

In 2023, India ranked 3rd globally, behind only Bangladesh and Pakistan. In 2024, it slipped to 5th as Chad and the Democratic Republic of Congo entered the rankings with higher concentrations. In the 2025 report, India stands at 6th, now also behind Tajikistan. In the 2025 edition, more countries with high pollution loads and hitherto unmonitored entered the IQAir compilation. There were 143 countries (spanning 9,446 cities) in 2025, up from 134 countries (spanning 7,812 cities) in 2023.

New Delhi’s annual PM2.5 concentration has moved from 92.7 µg/m³ in 2023 to 108.3 µg/m³ in 2024 (a 6% rise, its highest since 2019), and then back down to 82.2 µg/m³ in 2025—a three-year low and 8% drop from the previous year. Yet, New Delhi remains the top most-polluted capital city in the world.

In 2023, Begusarai in Bihar was the most polluted metropolitan area in India and the world. In 2024, it was Byrnihat on the Assam-Meghalaya border (128.2 µg/m³). In 2025, the pole position was captured by Loni in Uttar Pradesh’s Ghaziabad district at 112.5 µg/m³. “Only PM10 concentrations have been targeted, rather than the more harmful PM2.5. Weak enforcement of vehicular and industrial emission norms, combined with relaxed sulfur rules for coal plants, likely impacted air quality,” the report said in a section on India. For their analysis, the report relies on publicly reported data from the countries’ monitoring networks. These are highly variable, and poorer cities and countries have fewer monitors per unit of population, often failing to give a representative picture of their air quality.

The 2025 report notes that India’s National Clean Air Programme has directed 64% of its funding toward road dust reduction, which primarily comprises watering and sweeping roads, while only 15% went to biomass burning, 13% to vehicle emissions, and a mere 1% to industrial pollution. It also noted the public protests at India Gate, New Delhi in November 2025 following spikes in air pollution.

In 2024, 74 of the 100 most polluted cities globally were in India, a slight improvement from 83 in 2023. The 2025 report notes that 17 of the world’s 20 most polluted cities are in the Central & South Asia region, with the “majority” in India and Pakistan.

Globally, only thirteen countries/territories met the WHO annual average PM2.5 guideline: French Polynesia, Puerto Rico, U.S. Virgin Islands, Barbados, New Caledonia, Iceland, Bermuda, Réunion, Andorra, Australia, Grenada, Panama and Estonia.