Figure 5.8: Seasonal average population-weighted O3 by country
concentration in 2016 for season with maximum ozone levels
Ozone µg/m3 77 - 117
66 - 76 55 - 65 43 - 54 26 - 42 0 - 25
Source: HEI (2018).
Urban areas, which are home to over half of the world’s population, have higher overall levels of air pollution. A review of published PM2.5
observations for 71 megacities (over 5
million people) for 2013 found that, of the 45 megacities with available observations, only 4 attained the WHO guideline for annual average concentrations (Cheng et al. 2016) (Figure 5.9).
period 2011-2015 250
Figure 5.9: Annual average PM10
Cities with the highest levels were clustered in east-central China and the Indo-Gangetic Plain. Many cities in low- and middle-income countries lack available measurements, but where data is available, 98 per cent of cities exceed the WHO guidelines for PM2.5
, compared with the 56 per cent of cities in high-income countries with available data (WHO 2016b). levels for megacities of more than 14 million inhabitants with available data for the
5 Megacities Source: WHO (2016b).
Delhi Shanghai Sao Paulo Mumbai Mexico City Beijing Cairo Dhaka Buenos Aires Kolkata Istanbul