World Air Quality: Top 10 global cities with the cleanest and most polluted air

As per the World Air Quality report, Africa and Central and South Asia, grappling with worsening air quality exacerbated by climate change, bore the brunt of the world’s most severe air pollution, with population-weighted annual average PM2.5 concentrations reaching alarming levels.

Notably, the four most polluted countries globally are situated in the Southeast Asian region. India ranks among the worst, standing as the third-most polluted country globally, as it continues to grapple with alarming air quality levels. In 2023–24, the annual average PM2.5 concentrations in India increased to 54.4 µg/m3, up from 53.3 µg/m3 in 2022, as per the report.

India’s capital city, Delhi, experienced a 10% rise in PM2.5 levels, with peak levels reaching 255 µg/m3 in November, primarily due to factors such as crop burning, vehicle emissions, coal burning, and waste burning.

World Air Quality Report 2023-24: India (screenshot from the report)

About 11.5 per cent of deaths in Delhi every year can be attributed to air pollution. This is the highest for any city in the country, according to a first-of-its-kind multi-city study in India, published in the Lancet.

Conversely, Oceania maintained its status as the world’s cleanest region, with most of the top 10 countries from this region meeting the WHO annual PM2.5 guideline. However, there is a slight increase in average PM2.5 concentrations for Australia and French Polynesia.

According to the PM2.5 data collected from ground-level air quality monitoring stations, countries have been ranked and assigned Air Quality Index (AQI) scores. The report has compiled the data on ground measurements of annual mean concentrations of particulate matter of a diameter equal to or smaller than 2.5 μm (PM2.5).

The World Air Quality Report encompassed data from 7,812 locations in 134 countries, regions, and territories, identifying concerning trends in 2023–24.  So, with air pollution becoming a significant global concern, here are the top 10 polluted and cleanest cities in the world.

Air Quality Index (AQI) Scale

The top 10 most polluted cities in the world:

Delhi pollution levels registered a steep climb. (Express Photo: Praveen Khanna)

Rank	City	Country	AQI
1	Kinshasa	Democratic Republic of the Congo	169
2	Beijing	China	160
3	Lahore	Pakistan	159
4	New York City	USA	152
5	Jakarta	Indonesia	137
6	Delhi	India	133
7	Sao Paulo	Brazil	128
8	Chicago	USA	125
9	Ho Chi Minh City	Vietnam	123
10	Santiago	Chile	114

The top 10 cities with the cleanest air in the world:

Sydney, Australia, has the world’s cleanest air, with an AQI of 9. (Source: Britannica)

Rank	City	Country	AQI
1	Sydney	Australia	10
2	Auckland	New Zealand	12
3	Bratislava	Slovakia	14
4	Stockholm	Sweden	17
5	Oslo	Norway	17
6	San Francisco	USA	20
7	Berlin	Germany	21
8	Budapest	Hungary	22
9	Vancouver BC	Canada	22
10	Dublin	Ireland	22

Source: World Air Quality Report