November 26, 2025
11:45 a.m. – 12:45 p.m.
Building 9, Level 2, Lecture Hall 1
London’s air pollution story: from pea soup smog to an ultra-low emission city
By Frank Kelly, Imperial College London
Abstract
London has a long history of air pollution challenges. In this presentation I will guide you through the various steps taken and initiatives launched to address this important environment and health issue.
The devastating health effects brought about by air pollution became all too evident in December 1952, when a toxic combination of London’s cold, motionless smoggy air brought about the worst pollution disaster in history. This great killer smog episode claimed an estimated 4,000-12,000 premature deaths and increased morbidity from cardiorespiratory causes. It was also the impetus for the 1956 Clean Air Act, the major focus of which curtailed domestic coal burning. However, as one air pollutant was being solved another was developing in London and indeed in many cities around the world – traffic.
Working with successive Mayors in London policies were developed to move towards the point where air pollution no longer poses a significant risk to human health. A reduction in London’s road traffic emissions was achieved in two ways. First, through a decrease in the number of vehicles on the road (congestion charging), and second through reduced emissions from individual vehicles (low emission zones). Understanding that public transport emissions needed to decrease as well, a number of schemes have been introduced to achieve this as well. All buses in central London now meet or exceed the cleanest Euro 6 standards. Since January 2018 all newly registered taxis in London have been required to be Zero Emission Capable (ZEC).
Finally, The Mayor is also keen that we improve public knowledge about air pollution and thus we have developed a sophisticated alert system such that if an air pollution episode is forecast alerts are sent out to all schools, doctor’s surgeries, hospitals and are shown on the public transport digital signs such as at bus stops and on the London Underground system.