In 2023, the world’s air pollution crisis hit a new high, with New Delhi, India’s capital, ranking as the most polluted capital city. According to the World Air Quality Report from IQAir, New Delhi’s air had an average PM2.5 concentration of 92.7 micrograms per cubic meter, which is over 17 times the limit recommended by the World Health Organization (WHO). PM2.5 particles, the most harmful pollutants in the air, are so tiny—less than 2.5 micrometers across—that they can easily enter the lungs, posing severe health risks.
What makes New Delhi’s situation so alarming is how far it exceeds other cities. Only one other capital comes close to New Delhi’s pollution level: Dhaka, Bangladesh, with an average PM2.5 level of 80.2 micrograms per cubic meter. After Dhaka, the list features capitals like Ouagadougou in Burkina Faso (46.6 micrograms), Dushanbe in Tajikistan (46.0 micrograms), and Baghdad in Iraq (45.8 micrograms), all with high pollution levels, but none nearly as severe as New Delhi’s.
Interestingly, Sarajevo, in Bosnia and Herzegovina, is the first non-Asian or non-African city on the list, with an average PM2.5 concentration of 28.6 micrograms. While still high, Sarajevo’s pollution levels are relatively low compared to New Delhi’s and even Dhaka’s.
The World Air Quality Report by IQAir pulled its data from 7,812 air monitoring stations and sensors worldwide, and for this year’s report, it added new data from countries in Africa and Latin America. This update helps provide a more complete picture of the pollution crisis across different regions.
So what exactly is behind these dangerous PM2.5 levels? According to experts, most of these particles come from human activities. The largest sources are road transport and energy production, as well as the burning of agricultural waste, especially in countries still heavily reliant on these practices.
IQAir’s report highlights the urgent need for action to reduce air pollution worldwide, especially in cities where people are exposed to alarmingly high levels of pollutants daily. Without significant changes, millions will continue to breathe unsafe air—putting them at risk of health problems now and in the future.
