![The first smog alert in the area the towns Essen and Dortmund were completely blocked in the inner city area for traffic about 28 years ago | Stock Photo - Alamy The first smog alert in the area the towns Essen and Dortmund were completely blocked in the inner city area for traffic about 28 years ago | Stock Photo - Alamy](https://c8.alamy.com/zooms/6/cb736e3f778640ddb1e96f47573425bc/dfknh6.jpg)
The first smog alert in the area the towns Essen and Dortmund were completely blocked in the inner city area for traffic about 28 years ago | Stock Photo - Alamy
![The first smog alert in the area the towns Essen and Dortmund were completely blocked in the inner city area for traffic about 28 years ago | Stock Photo - Alamy The first smog alert in the area the towns Essen and Dortmund were completely blocked in the inner city area for traffic about 28 years ago | Stock Photo - Alamy](https://l450v.alamy.com/450v/dfkmk5/the-first-smog-alert-in-the-area-the-towns-essen-and-dortmund-were-dfkmk5.jpg)
The first smog alert in the area the towns Essen and Dortmund were completely blocked in the inner city area for traffic about 28 years ago | Stock Photo - Alamy
Slg. Helmut Orwat: Das Ruhrgebiet und Westfalen in den 1950er bis 1990er Jahren - Bildarchiv / Bilddatenbank LWL-Medienzentrum für Westfalen
![The first smog alert in the area the towns Essen and Dortmund were completely blocked in the inner city area for traffic about 28 years ago | Stock Photo - Alamy The first smog alert in the area the towns Essen and Dortmund were completely blocked in the inner city area for traffic about 28 years ago | Stock Photo - Alamy](https://c8.alamy.com/comp/DFKMJF/the-first-smog-alert-in-the-area-the-towns-essen-and-dortmund-were-DFKMJF.jpg)
The first smog alert in the area the towns Essen and Dortmund were completely blocked in the inner city area for traffic about 28 years ago | Stock Photo - Alamy
![The first smog alert in the area the towns Essen and Dortmund were completely blocked in the inner city area for traffic about 28 years ago | Stock Photo - Alamy The first smog alert in the area the towns Essen and Dortmund were completely blocked in the inner city area for traffic about 28 years ago | Stock Photo - Alamy](https://c8.alamy.com/comp/DFKMH3/the-first-smog-alert-in-the-area-the-towns-essen-and-dortmund-were-DFKMH3.jpg)
The first smog alert in the area the towns Essen and Dortmund were completely blocked in the inner city area for traffic about 28 years ago | Stock Photo - Alamy
![Dortmund, Germany, January 18th 1985. Smog alarm in the Ruhr area. Sign prohibits the exit on the B1 in the city center of Dortmund. In the Federal Republic of Germany for the Dortmund, Germany, January 18th 1985. Smog alarm in the Ruhr area. Sign prohibits the exit on the B1 in the city center of Dortmund. In the Federal Republic of Germany for the](https://c8.alamy.com/comp/T7DDX0/dortmund-germany-january-18th-1985-smog-alarm-in-the-ruhr-area-sign-prohibits-the-exit-on-the-b1-in-the-city-center-of-dortmund-in-the-federal-republic-of-germany-for-the-first-time-smog-alarm-level-iii-is-called-above-all-the-western-ruhr-area-is-affected-stage-iii-of-the-smog-regulation-imposed-an-absolute-ban-on-driving-private-cars-dortmund-18-januar-1985-smog-alarm-im-ruhrgebiet-schild-verbietet-die-ausfahrt-an-der-b1-in-die-innenstadt-von-dortmund-in-der-bundesrepublik-wird-erstmals-smog-alarm-der-stufe-iii-ausgerufen-betroffen-ist-vor-allem-das-westliche-ruhrgebie-T7DDX0.jpg)