Most polluted cities based on PM2.5 concentration in Mexico 2024
Ajaplan was the most polluted city in Mexico in 2024, based on fine air particulate matter concentration (PM2.5). Throughout the year, the city had an average particulate matter concentration of 24.3 micrograms per cubic meter. The average particulate matter pollution in the national capital Mexico City stood at 19.5 micrograms per cubic meter that year.
How bad is fine air pollution in Mexico?
Fine air particulate pollution (PM2.5) refers to particles with a diameter smaller than 2.5 micrometers. Due to their small size, once inhaled they can penetrate body tissue, and trigger respiratory issues such as asthma and allergies, in addition to being associated with an increase in mortality from cardiovascular and respiratory diseases. The World Health Organization's air quality standards recommend a maximum annual average concentration of 10 µg/m³. Nevertheless, Mexico's PM2.5 levels in 2024 averaged over 17 µg/m³. This positioned Mexico in 55th place amongst the countries with the highest PM2.5 concentration that year, far below Chad, which ranked first in the list with pollution levels reaching over 90 µg/m³. Mexico also had some of the cities with the highest air pollution across Latin America, together with Chile and Peru.
Where are the world’s most polluted cities?
Despite pollution levels above those recommended by the World Health Organization, Mexico City didn’t even make it to the top 25 most polluted capital cities in 2024. That year, the ranking was topped by Indian capital New Delhi, with an average PM2.5 concentration of nearly 108.3 µg/m³. In fact, the majority of the most air polluted cities worldwide in 2024 were located in India, with the average PM2.5 concentration reaching as high as 128.2 µg/m³. Pakistan also had some of the world’s most polluted cities.
