§ Mr. PollardTo ask the Secretary of State for Environment, Food and Rural Affairs what recent action she has taken to measure trends in air quality in St. Albans, with special reference to nitrogen oxide levels near motorway junctions; and if she will make a statement. [61787]
§ Mr. MeacherThere are currently three non-automatic nitrogen dioxide monitoring stations in St. Albans, which are part of the UK nitrogen dioxide diffusion tube monitoring network. The sites are in roadside and urban background locations. The trends at these sites are shown in the table, in addition to a fourth site which closed at the end of 2000. Concentrations at all sites have increased since monitoring began in 1993, although levels are close to or well below the annual mean standard for nitrogen756W dioxide of g/m3. St. Albans district council also operate other diffusion tube sites which are not part of the UK network, one of which is near the motorway.
Annual mean nitrogen dioxide (g/m3) at four sites in St. Albans, 1993–2001. Measurements using diffusion tubes Annual mean NO2 (g/m3) Roadside Intermediate Background St. Albans Background 1993 25.7 18.5 15.4 14.7 1994 33.5 24.3 22.3 16.4 1995 42.7 39.9 34.4 27.0 1996 56.1 42.1 42.2 33.4 1997 42.4 32.8 29.5 25,3 1998 36.8 30.8 22.3 23.8 1999 44.3 35.1 29.3 27.0 2000 42.8 34.9 27.9 23.5 2001 41.8 NM1 28.6 24.3 1 Monitoring site closed at the end of 2000.