France, Sept. 30 -- Some 34 percent of people worldwide faced "extremely poor" air quality between 1 January and 15 September, the EU's Copernicus Atmosphere Monitoring Service (CAMS) found in its first Atmosphere Watch review.

CAMS tracks air pollution and wildfires using satellite data and computer models. An "extremely poor" rating means ozone concentrations were well above the World Health Organization (WHO) guideline of 100 micrograms per cubic metre, averaged over eight hours.

Another 17 percent of the world's population breathed "very poor" air, while just 5 percent enjoyed "good" conditions.

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