Fig. 2: O3 levels and associated mortality according to O3 emission sources in 35 European countries, 2015–2017.
From: Geographic sources of ozone air pollution and mortality burden in Europe

a, Average daily mean 8-h maximum O3 (µg m−3). b, Mortality attributable to O3 (annual deaths per 1 million population). Horizontal bars represent 95% eCI of overall O3-attributable mortality (that is, the sum of the five contribution sources).