Air quality monitoring
The following air pollutants are monitored in Camden:
- nitrogen dioxide (NO2) and nitrogen oxides (NOx)
- particulate matter (PM10/PM2.5)
- sulphur dioxide (SO2)
- ozone (O3)
- carbon monoxide (CO)
How are pollution levels monitored?
Pollution levels are monitored using a number of different instruments. Some of these are very basic pieces of equipment, while others are state of the art, using complex electronic systems and computer technology. An outline of our monitoring instrumentation is given below
Automatic monitoring stations
These stations consist of a permanent housing, such as a portacabin, which contains a number of sophisticated electronic instruments. Air is continuously pumped into each analyser and the level of the pollutant in the air recorded.
Inside Swiss Cottage Monitoring Station - NOx and PM10 Analysers
The pollution levels are automatically stored by the analyser and the data sent via telephone lines to a central data management system operated by the London Air Quality Network. The data is regularly checked and audited to ensure that high quality measurements are reported.
The equipment used in these monitoring stations is very sensitive to changes in temperature, so the housing is air-conditioned. The analysers are also 'calibrated' by the Council air pollution team every two weeks to make sure they are working correctly.
The air pollution measurements obtained from these monitoring station is then be compared to the Government’s air quality standards by the Council as part of their duties related to Local Air Quality Management.
Orisis particle monitors
Osiris monitor sample different sized air-borne particulates including dust. This information is useful since the size of the particles can help identify the source of emissions eg fine particles arise from vehicle exhausts and coarse particles from dusty industrial activities (such as concrete batching plant) and construction work.
Camden operates four Orisis monitors. These are indicative, real-time, portable particulate matter monitors that use light-scattering technology to measure the concentration of different sized particles (PM1, PM2.5 and PM10).
| Monitoring Locations | Pollutants measured |
|---|---|
| Swiss Cottage – Finchley Road | PM10/2.5 |
| Camley Street Nature Reserve | PM10/2.5 |
| Bloomsbury – Russell Square Gardens | PM10/2.5 |
| Camden Transport Depot – York Way | PM10/2.5 |
Currently a co-location study is being carried out to compare PM10 measurements from the Osiris and TEOM/FDMS instruments at Swiss Cottage and London Bloomsbury. This will be used to evaluate the degree of PM10 data variation between the Osiris monitor and more accurate particulate monitors. This will then enable for a local correction factor to be determined which can be applied to Osiris PM10 measurements.
Diffusion tubes
These are passive samplers and air ‘diffuses’ in rather than being pulled through a pump. They are used to monitor nitrogen dioxide concentrations.
The tubes are mounted on lamp columns or buildings over a four week period. They are then collected and sent to a laboratory for analysis and determination of monthly NO2 levels.
Although they cannot be used to provide up to the minute pollution levels, they are cheap and easy to use. We use diffusion tubes to monitor long term trends of nitrogen dioxide.
Where are air pollution levels monitored?
Pollution levels are monitored at many sites across the borough. We are not able to monitor every street, so we choose sites which are representative of public exposure to air pollution. The following site criteria are used when locating monitors.
- Kerb side: monitor placed 1 - 5 metres from the kerb
- Road side: monitor placed between 5 - 20 metres from the kerb
- Background: monitor placed over 20 metres from any road
Camden’s automatic monitoring stations are located at:
Swiss Cottage (Finchley Road) Pollutants monitored at this kerbside site include nitrogen oxides and fine particulates (PM10 & PM2.5).
Shaftesbury Avenue Pollutants monitored at this busy roadside site include nitrogen oxides and fine particulates (PM10).
Russell Square Gardens (Bloomsbury) Pollutants monitored at this site includes nitrogen oxides, fine particulates (PM10 & PM2.5), ozone, sulphur dioxide and carbon monoxide.
Camden also has a NOx/NO2 monitor (Airpointer) located on a CCTV column outside 55 Tottenham Court Road. This is being used to monitor the impacts of various traffic management schemes.
Where can I get information regarding air pollution levels?
Daily, weekly and monthly pollution levels for all our automatic monitoring sites can be viewed at:
Meteorological station
An automatic meteorological monitoring station is located at Camley Street Nature Reserve. The station measures real time wind speed and direction, air temperature, humidity and rainfall. These readings are used to investigate the influence of weather conditions on air pollution levels in Camden.
Given the location of the weather station, it will also play an important role in identifying the source of dust emissions from the various industries and construction sites around the King’s Cross.