HL Deb 15 November 2001 vol 628 cc97-8WA
Baroness Ludford

asked Her Majesty's Government:

How air quality in London is monitored. [HL1263]

Lord Whitty

Air quality is monitored in different ways at a large number of sites across London.

First, there are seven fully automated air quality monitoring sites in London which form part of the Government's Automatic Urban and Rural Air Quality Monitoring Network (AURN). This network is made up of over 100 automatic monitoring stations across the country which are situated at a mixture of roadside, background and suburban locations. Site details are available via the department's website www.defra.gsi.gov.uk. Information from them is available in real time on an hourly basis for most key pollutants. The results are incorporated into the Government's air quality information service and made available over the Internet and via teletext, as well as via a freephone service.

The Government also have a large non-automatic air quality monitoring network. Non-automatic (or "passive") air quality monitoring involves less frequent monitoring of pollutant concentrations and is used to calculate daily, weekly or monthly averages. Samples are collected by physical means (such as by diffusion tube or filter) and are then subjected to chemical analysis, with the final concentrations calculated from these results. This network includes over 1,000 non-automatic monitoring sites across the country, of which over 70 are in London.

In addition to this, local authorities also have a key role to play in monitoring air quality in London and elsewhere. All local authorities are required to review and assess their air quality with a view to identifying possible pollution hotspots. As part of this process, most local authorities undertake both automatic and non-automatic monitoring of air quality at representative locations throughout their areas. The Government oversee this process and advise authorities on the technical aspects of monitoring, including on the appropriate siting of monitoring stations.

Within London, each of the London boroughs carries out its own automatic and passive monitoring. The London Automatic Air Quality Monitoring Network (LAQMN) comprises about 66 urban, suburban and rural locations, of which 16 urban or suburban sites are affiliated to the national AURN. In addition to this, all of the London boroughs carry out their own non-automatic monitoring at a number of sites. Comprehensive details of these sites are not held centrally.