London pollution: 'Very high' air pollution warning alert
24 January 2017 Last updated at 22:28 GMT
Pollution alert warnings are being issued to the public at bus stops, tube stations and on roadside signs, under the new system set up by London Mayor Sadiq Khan.
Many Londoners, however, are going about their daily business undeterred.
Produced by Alexi Peristianis and Greg Brosnan