Nitrogen dioxide in the Royal Borough

Monitoring

Nitrogen dioxide in the Royal Borough is monitored using the automatic chemiluminescence continuous analyser. (The emission of light as a result of a chemical reaction.) This method produces high-resolution readings of nitrogen dioxide by measuring nitric oxide (NO) and total oxides of nitrogen (NOx) and then subtracting one reading from the other.

Nitrogen Dioxide is monitored using the above method in the Royal Borough at sites in:

North Kensington
West London
Cromwell Road
Knightsbridge
Chelsea Old Town Hall

For detailed information on each site see the Monitoring Site Tables. For details about monitoring at other locations please see: Nitrogen Dioxide Difusion Tube Annual Report 2006 – [PDF file] (File size 242Kb).

You can get the latest readings and or historical data for the North Kensington, West London and Cromwell Road sites at www.airquality.co.uk

You can get the latest readings and or historical data for Knightsbridge and Chelsea Old Town Hall sites at http://www.londonair.org.uk/london/asp/home.asp

Long term trends

For information on the sources and health effects of nitrogen dioxide pollution visit Sources and health effects of air pollution.
Nitrogen dioxide has been monitored at a number of locations in the Royal Borough since 1987. An examination of the data for the past 10 years shows:

There is no clear trend affecting all sites
A slight downward trend can be observed at the North Kensington and west London sites though it is less obvious at the latter site
The North Kensington site has for the first time in 2004 dropped just below the below the objective level after having hovered around the objective level for some years
The majority of sites are well above the objective levels and indications are that levels are unlikely to met the 2005 objective other than at the North Kensington urban background site and
These results support the modelling work which also indicates that nitrogen dioxide levels within the Royal Borough will continue to exceed the Government objectives in 2005.

Annual mean levels of nitrogen dioxide

Annual mean levels of nitrogen dioxide - micrograms/cubic metre (mg/m³)
Year	Annual Mean Air Quality Objective	Cromwell Road	Marylebone Road	West London	North Kensington	Knightsbridge	Chelsea Town Hall
1994	40	84		59.2
1995	40	93.6		53.5	51.6
1996	40	91.7		53.5	49.7
1997	40		91.7	55.4	51.6
1998	40	82.1	91.7	51.6	45.8
1999	40	91.7	89.8	55.4	45.8
2000	40	87.9	91.7	53.5	40.1	74.5	86
2001	40	76.4	84	51.6	42	82.1	86
2002	40	72.6	80.2	45.8	40.1	84	84
2003	40	76	107	55.4	43.9	93.6	97.4
2004	40	80	108	50	38.8	86.5	91