Monitoring air pollution
Monitored substances - Nitrogen dioxide
Nitrogen dioxide is mainly derived from road transport emissions and other combustion processes such as commercial and domestic heating and the electricity supply industry.
It can irritate the lungs and lower resistance to respiratory infections such as influenza.
Continued or frequent exposure to concentrations that are typically much higher than those normally found in the ambient air may cause increased incidence of acute respiratory illness in children.
Monitored substances - PM10 and PM2.5
Fine particles are composed of a wide range of materials arising from a variety of sources including:
- combustion sources (mainly road traffic)
- secondary particles, mainly sulphate and nitrate formed by chemical reactions in the atmosphere, and sometimes transported from far across Europe
- coarse particles, suspended soils and dusts, sea salt, biological particles and particles from construction work
Smaller particles can be carried deeper into the lungs where they can cause inflammation and a worsening of the condition of people with heart and lung conditions. They may also carry surface-absorbed carcinogenic compounds into the lungs.
Particles are measured in a number of different size fractions according to their mean aerodynamic diameter.
Most monitoring is currently focussed on PM10 (particles smaller than 10 microns), but the finer fractions such as PM2.5 (particles smaller than 2.5 microns) and PM1 (particles smaller than 1.0 micron) are becoming of increasing interest because of their health impact.
The main pollutants routinely monitored in Cambridge currently are nitrogen dioxide, PM10 and PM2.5. In Cambridge there are five monitoring stations with “continuous monitoring” analysers managed by Cambridge City Council. A sixth which is managed externally is located at Station Road. These analysers produce hourly average pollution levels. The monitoring station at Regent Street has been in place since 1999; it is part of Defra’s Automatic Urban and Rural Network (AURN)
- Regent Street - nitrogen dioxide
- Parker Street - nitrogen dioxide, particulates (PM10)
- Gonville Place - nitrogen dioxide and particulates (PM10 and PM 2.5)
- Newmarket Road - nitrogen dioxide and particulates (PM2.5)
- Montague Road - nitrogen dioxide and particulates (PM10)
- Station Road - nitrogen dioxide and particulates (PM10)
There are also around 60 “passive diffusion” tubes throughout the city recording levels of nitrogen dioxide. Although less accurate than continuously analysing monitors they are cheaper to use and provide a wide coverage of measurements across the city in different types of settings.
Map showing location of continuously monitoring analysers
Map showing location of diffusion tubes
Current air quality in Regent Street, Cambridge can be found at the Defra UK-Air website. Past results for this station are also available.
Information on the air quality in Cambridge at Newmarket Road, Parker Street, Gonville Place and Montague Road for the past 24 hours can be found at the Air Quality England website. Past results are also available at this website.
Cambridge City Council data, from 2001 onwards, can be accessed via the links below:
The PM10 data have been taken from continuously analysing monitors and fully ratified by Netcen. An appropriate correction factor has been applied to convert to a gravimetric equivalent, where required.
The PM2.5 have been taken from continuous monitors and fully ratified by Netcen. PM2.5 data do not require a correction.
Diffusion Tube data has been bias-adjusted.
Up to date information on air quality in Station Road, Cambridge can be found at the WeCare4Air website. The station is called 'Brookgate - CB1'. This is an external website and neither this or the monitoring station is managed by us.