The Chinese government is striving to respond. Following last year’s public furore over urban air quality, it revised its pollution standards, introducing new indices for PM2.5 and ozone, among other changes. But getting vast and rapidly urbanising China to meet higher standards is no easy task.
In the early days of industrialisation and urbanisation, the US and Europe experienced severe air pollution. The great smog of London, which may have killed as many as 12,000 people in a single week in 1952, was symptomatic of a dirtier era.