This report summarizes the results of the air pollution monitoring carried out by the London Air Quality Network (LAQN) during 2000.

During 2000 the LAQN continued to expand with the addition of twelve monitoring sites.

For the first time, the LAQN Annual Report contains analysis of measurement from the London sites directly funded by the Department of the Environment, Food and Rural Affairs (DEFRA)

Network annual mean concentrations have been analysed for the period November 1996 to November 2001

• Network annual mean NO2 has declined by around 10% and NOx concentrations have fallen by 26%.
• Network annual mean O3 peaked during 2000, with a maximum increase of 30%. The network annual mean fell sharply during the end of 2000 with provisional data from 2001 suggesting an overall rise of 15%.
• Network annual mean CO, SO2 and PM10 show marked overall decreases. Annual mean concentrations during 2000 and 2001 have been relatively stable

Each of the pollutants monitored by the LAQN during 2000 have been compared to the Air Quality Strategy (AQS) objectives (DETR, 2000a, DETR 2000b).

• The annual mean objective for NO2 was exceeded at the majority of kerbside and roadside sites. The objective was also exceeded at many inner London background sites and those in West London. Around one third of the area of Greater London exceeded the objective.
• The 'incident' based objective for NO2 was exceeded at kerbside sites at Marylebone Road, Redbridge 2 and Redbridge 3. The objective was also exceeded at the roadside sites Kensington & Chelsea 3 and Hammersmith and Fulham.
• The CO objective was exceeded at the kerbside site Redbridge 2.
• All LAQN sites met the objective for SO2.
• The O3 objective was exceeded at seven outer London sites.
• The PM10 AQS incident based objective was exceeded at nine sites
• The annual mean objective for PM10 was exceeded at the kerbside site in Marylebone Road and at the roadside site in Enfield 2.