Air pollution history is littered with early warnings that were not heeded. November 2018 marks the 70th anniversary of one of these. On Friday 26 November 1948, a dense fog developed in London. It lasted six days. Football matches were cancelled and transport disrupted. Traffic convoys were formed to follow trams, each guided by a conductor with a torch. Initially, conductors walked alongside buses but this became impossible as they ran into lamp-posts. There were train accidents too, but the greatest death toll came from breathing the smog. Five weeks later the medical statistician William Logan reported an estimated 300 extra deaths.

The warning was ignored. Four years and one week later 12,000 Londoners died in the so-called great smog of 1952. The pattern of ignoring warnings continues. In 2000, researchers at London’s King’s and Imperial Colleges warned of difficulties in controlling nitrogen dioxide from traffic. The UK is still failing to meet legal limits for this pollutant. This month, 21 researchers published a nine-year study. It concluded that air pollution in London was stunting children’s lung growth and this may be storing up problems for their long-term health.