Air pollutant concentrations

MQT on 2011-03-23
Session date: 
March 23, 2011
Question By: 
Mike Tuffrey
Liberal Democrats
Asked Of: 
The Mayor


Your final Air Quality Strategy projects reductions in emissions of dangerous airborne particles and oxides of nitrogen between 2008 and 2011 and between 2008 and 2015. What are the corresponding projected reductions in concentrations of these pollutants in the same time timeframes?


Answer for Air pollutant concentrations

Answer for Air pollutant concentrations

Answered By: 
The Mayor

Officers are drafting a response which will be sent shortly.

Written response received on 7 April 2011:

It is not possible to be as precise about concentrations as it is about emissions because concentrations of air pollutants at a particular location will vary depending on the weather, geography and distance from the source.

Modelling shows that the reduction in London-wide average concentrations of PM10 are 0.9ug/m3 from 2008 to 2011 and 1.9ug/m3 from 2008 to 2015. For NO2, the reductions are 7.8ug/m3 and 19ug/m3 for 2008 to 2011 and 2008 to 2015 respectively.

Locations near emissions sources (e.g. roadside sites) could experience higher reductions, as many policies are designed to reduce emissions from road transport.