Heathrow and Fog

MQT on 2007-01-30
Session date: 
January 30, 2007
Question By: 
Darren Johnson
City Hall Greens
Asked Of: 
The Mayor


On the days in December when Heathrow was largely shut down because of fog has any assessment been taken of the impact such a reduction in flights and traffic had on air quality on those days?


Answer for Heathrow and Fog

Answer for Heathrow and Fog

Answered By: 
The Mayor

The meteorological conditions which caused the fog which led to reduced flights from Heathrow, and associated transport, would also have affected air quality. This fog occurred under still, cold weather conditions. Such conditions would also inhibit the dispersion of air pollution, leading to a build up of pollution and a reduction of air quality. Emissions from Heathrow and traffic are likely to have been considerably lower than normal, due to the fog and the reduced traffic in London in the few days (and weekend) before Christmas. However it is not currently feasible to distinguish the specific contribution of aircraft and traffic emissions due to fog, from other influences on emission and the impact of meteorology on air quality. Therefore, while monitoring data is available from www.londonair.org.uk (which is supported by the Mayor), no detailed apportionment of air pollutants has been carried out for this period.GLA officers continue to assess the impact of traffic and aircraft on air quality, through the use of the London Atmospheric Emissions Inventory, and associated air quality modelling.