The Killer Fog Of 1952

From Friday December 5 to Tuesday December 9, 1952, a toxic mix of dense fog and black coal smoke killed thousands of Londoners in four days. It remains the deadliest environmental episode in recorded history.

The so-called killer fog is not an especially well-remembered event, even though it changed the way the world looks at pollution.

Early in December 1952, a cold fog descended upon London. Because of the cold, Londoners began to burn more coal than usual. The resulting air pollution was trapped by the inversion layer formed by the dense mass of cold air. Concentrations of pollutants, coal smoke in particular, built up dramatically. The fog was so thick that driving became difficult or impossible.

Officials believe that as many as 12,000 people may have died. Many of those killed were elderly people or those who were already weak or ill. According to medical staff who treated patients at the time, few people realised the extent of the impact.