The findings of a new report issued by the Health Effects Institute, an independent research organization, are not entirely unexpected: the world’s biggest cities and urban areas face some of the worst air quality on the planet.

The detailed analysis of air pollution and global health impacts for more than 7,000 cities around the world focuses on fine particulate matter (PM2.5) and nitrogen dioxide (NO2), based on data for the 2010 to 2019 period. In 2019, 1.7 million deaths linked to PM2.5 occurred in the 7,239 cities included in the analysis. Cities in Asia, Africa, and Eastern and Central Europe saw the greatest health impacts from particulate exposures.

In 2019, 86% of the cities included in the study exceeded the World Health Organization‘s 10 µg/m3 guideline for annual NO2 exposure, impacting about 2.6 billion people. While PM2.5 pollution tends to get more attention in known hotspots around the world, less data has been available for NO2 at this global scale.

Global patterns for exposures to these two key air pollutants are strikingly different. While exposures to PM2.5 pollution tend to be higher in cities located in low- and middle-income countries, exposure to NO2 is high across cities in high-income as well as low- and middle-income countries.

Explore interactive maps to learn more about air quality in a given city, how it is changing and the disease burdens associated with air pollution.

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