History of Air Pollution Time Chart
| Date |
Comment |
| Background | There has always been air pollution from many natural sources: volcanos, fumaroles, dust storms, forest fires, pollen, etc. |
| c. 1273 | British King Edward I banned burning of "sea coal," an impure, dirty-burning form of British coal |
| 17th century | Air pollution became a major and often noted problem in London |
| mid 1850s | London's "pea soup" fogs began |
| 1911 | The word "smog," for smoky fog was coined |
| 1930 | 63 died in a pollution siege in Belgium's Meuse Valley |
| 1940s | Los Angeles became notorious for its smog |
| 1948 | >20 died, thousands became ill during a 5-day pollution episode in Pennsylvania's Monongahela River Valley |
| December 1952 | A 5-day siege of "pea-soup" fog claimed ~4000 lives in London |
| 1956 | UK parliament passed Clean Air Act |
| 1970, -77, -90 | US Clean Air Act & revisions became law |
| 2001 | US Supreme court ruled that monetary cost need not be taken into account when setting clean air standards |