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40% of World Faces Dangerous Ozone Exposure; Delhi Among Worst-Hit Cities
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Firstpost•30-09-2026, 18:27
40% of World Faces Dangerous Ozone Exposure; Delhi Among Worst-Hit Cities
- •Almost 40% of the global population, and 60% in Asia, experienced extremely high ground-level ozone exposure in 2026.
- •Delhi, Rio de Janeiro, Mexico City, Milan, and Cairo are among major cities with the highest ozone exposures on their respective continents.
- •Only 5% of the global population was exposed to "good" long-term ozone levels, with half experiencing very or extremely poor air quality.
- •The Northern Hemisphere is particularly vulnerable due to more land, higher population density, and greater precursor emissions.
- •Climate change, with increasing heatwaves, could intensify ozone pollution, making precursor emission control crucial for reducing long-term exposure.
Key Questions Answered
Almost 40 per cent of the global population has been exposed to extremely high levels of ground-level ozone so far in 2026, with Asia recording an even higher figure of around 60%.
Major cities recording some of the highest ozone exposures include Rio de Janeiro in South America, Mexico City in North America, Milan in Europe, Delhi in Asia, and Cairo in Africa.
Climate change is expected to influence ground-level ozone concentrations through frequent or intense heatwaves, where warm temperatures and strong sunlight drive chemical reactions involving precursor pollutants and increase local ozone concentrations.
