Which Cities and Countries Have the Unhealthiest Air?

How healthy is the air in your country or city? 

Chances are, it’s not healthy enough. Swiss air quality technology company IQAir released its fifth annual assessment of particulate matter (PM) 2.5 pollution in cities, nations and regions around the world and found that only six countries met the World Health Organization’s (WHO) updated safe levels of the deadly air pollutant. 

“Too many people around the world don’t know that they are breathing polluted air,” Senior Air Quality Scientist at Greenpeace International Aidan Farrow said in a press release announcing the data. “Air pollution monitors provide hard data that can inspire communities to demand change and hold polluters to account, but when monitoring is patchy or unequal, vulnerable communities can be left with no data to act on. Everyone deserves to have their health protected from air pollution.”

The 2022 World Air Quality Report used data from more than 30,000 air quality monitors in 7,323 cities and 131 countries, regions and territories. The data recorded whether or not levels of PM2.5 were above or below the safe level lowered from 10 to five micrograms per cubic meter (µg/m3) by the WHO in 2021, based on growing scientific evidence of the health risk of this type of pollution, which is small enough to enter the bloodstream from the lungs and damage the heart and other organs. It’s estimated that air pollution exposure causes around seven million early deaths each year.

According to IQAir, the countries with the worst particulate matter air pollution were:

1. Chad, at 89.7 µg/m3
2. Iraq at 80.1 µg/m3
3. Pakistan at 70.9 µg/m3
4. Bahrain at 66.6 µg/m3
5. Bangladesh at 65.8 µg/m3

For cities, the most polluted in 2022 were

1. Lahore, Pakistan, at 97.4 µg/m3
2. Hotan, China, at 94.3 µg/m3
3. Bhiwadi, India, at 92.7 µg/m3
4. Delhi, India, at 92.6 µg/m3
5. Peshawar, Pakistan, at 91.8 µg/m3

Overall, eight of the 10 most polluted cities were in Central or South Asia, and a total of 118 countries and regions–or 90 percent of those with sufficient data–surpassed the WHO’s new health limits. 

The six countries with healthy air according to WHO guidelines were Australia, Estonia, Finland, Grenada, Iceland and New Zealand. They were joined by seven territories in the Pacific and Caribbean, as CNN reported. 

The data comes about a week after another study found that more than 99 percent of the world’s population was breathing unhealthy air. However, that study added machine learning to fill in the gaps from on-the-ground monitoring. IQAir noted that gaps in monitoring remain, which is a major environmental justice issue, since more than 90 percent of air pollution deaths happen in low or middle income countries. For example, while monitoring in Africa increased by seven countries from 2021 to 2022, that still meant only 19 of the continent’s 54 countries were covered. Further, only 156 stations produced readings on the continent. 

“With the only real-time, publicly available source of air quality data for the entire country of Chad being provided by a single air quality monitor in the city of N’Djamena, this year the spotlight on global air quality data coverage disparities shines bright on the continent of Africa,” IQAir wrote in an executive summary. 

In the U.S., the most polluted city was Coffeyville, Kansas, and the largest most polluted city was Columbus, Ohio. However, 10 of the nation’s 15 most polluted cities were in California. Air pollution in the U.S. was down in 2022 compared to 2021, largely because it was a less extreme year for wildfires, CNN reported. In general, air pollution was caused either directly by fossil fuels via vehicle and energy emissions or indirectly by smoke from wildfires made more intense by the climate crisis. 

“This is literally about how we as a planet are continuing this unhealthy relationship with fossil fuels,” IQAir North America CEO Glory Dolphin Hammes told CNN. “We are still dependent on fossil fuels and fossil fuels are responsible for the majority of air pollution that we encounter on this planet.”