The recently published sixth Annual World Air Quality Report has revealed troubling details of the world’s most polluted countries, territories, and regions in 2023. For this year’s report, data from more than 30,000 air quality monitoring stations across 7,812 locations in 134 countries, territories, and regions were analysed by IQAir’s air quality scientists.
According to the report, only seven countries met the WHO annual PM2.5 guideline (annual average of 5 µg/m3 or less): Australia, Estonia, Finland, Grenada, Iceland, Mauritius, and New Zealand.
The top five most polluted countries in 2023 were: Bangladesh (79.9 µg/m3) more than 15 times higher than the WHO PM2.5 annual guideline; Pakistan (73.7 µg/m3) more than 14 times higher than the WHO PM2.5 annual guideline; India (54.4 µg/m3) more than 10 times higher than the WHO PM2.5 annual guideline; Tajikistan (49.0 µg/m3) more than 9 times higher than the WHO PM2.5 annual guideline; and Burkina Faso (46.6 µg/m3) more than 9 times higher than the WHO PM2.5 annual guideline.
A total of 124 (92.5%) out of 134 countries and regions exceeded the WHO annual PM2.5 guideline value of 5 µg/m3. Africa remains the most underrepresented continent, with a third of the population still lacking access to air quality data. Climate conditions and transboundary haze were major factors in Southeast Asia, where PM2.5 concentrations rose in nearly every country. The region of Central & South Asia was home to the top ten most polluted cities in the world.
