China has made initial progress, beginning to achieve air pollution declines.
For the first time, 2019's report includes worldwide estimates of the effect of air pollution on how long people live, or life expectancy.
Worldwide, air pollution reduced life expectancy by an average 20 months in 2017, a global impact rivalling that of smoking; this means a child born today will die 20 months sooner, on average, than would be expected without air pollution.
The report also highlighted that nearly half of the world's population -- a total of 3.6 billion people -- were exposed to household air pollution in 2017.