Air Quality Alerts

MQT on 2009-07-15
Session date: 
July 15, 2009
Question By: 
Mike Tuffrey
Liberal Democrats
Asked Of: 
The Mayor


Do you accept that the government's current low, medium and high bandings for air quality alerts, which are then used on the London Air Quality Network website and to send out airTEXT warnings, are out-of-date and potentially misleading in representing the actual health risks from air pollution?


Answer for Air Quality Alerts

Answer for Air Quality Alerts

Answered By: 
The Mayor

The Government's current air quality system uses a numerical index grouped into four bands to describe pollution as low (1-3), moderate (4-6), high (7-9) and very high (10). The four bands describe levels of concentrations over time for the pollutants sulphur dioxide, nitrogen dioxide, ozone, carbon monoxide and fine particulate matter - these differ depending on the pollutant and the bandings relate to the estimated health effects of each. The Government's system is an effective way of telling people about the daily changes in air pollution and conveys an easily understandable message to the general public to take action.

I am, however, aware that other systems are used in other European countries to inform the public that use a different pollution rating system that provides detailed information. These systems produce pollution indices on an hourly, daily and annual basis for both background and traffic dominated conditions and are derived from the EU Directives (annual air quality standards and objective values. These systems are used in some 50 cities within Europe to inform their public of air quality conditions and I would like to investigate further whether these are more effective in raising public awareness. This, however, is not an action that I can take alone and will require central Government assistance to reform their national pollution index. I have asked my officials to raise this with Defra.