Use this interactive map to find your nearest monitoring point
What are levels now?
To find out levels being recorded within the last few hours in the Borough visit the Heathrow air watch website. This provides monitoring results for nitrogen dioxide and particulate matter levels at a continuous monitor located in Oaks Road, Stanwell. This independent website provides air quality information specifically for the Heathrow area. You can compare data from several locations around the airport as well as look at trends for the same location from 2001 to just a few hours ago.
We are working with our contractor to bring residents a live link to the other two continuous monitoring stations in the Borough.
To find out levels being recorded across the south east, the National Air Quality Archive has an online UK air pollution forecasting service (external link). Select the "south east" region and you will see the pollution forecast for the next 24 hours. This information can also be accessed from TV teletext page 155 or freephone 0800 556677 - available 24 hours a day.
Monitoring in 2007 – The Headlines
Six different air quality pollutants were monitored in the Borough in 2007: nitrogen dioxide; particulate matter; benzene; carbon monoxide; sulphur dioxide; and ozone.
Levels of benzene, carbon monoxide, sulphur dioxide and ozone were much lower than national air quality objective levels at the locations monitored.
Levels of particulate matter, as PM10 (and PM2.5 where monitored) were below the annual average guideline and with fewer daily peaks than the objective at the monitors in Stanwell and at the M25.
Levels of nitrogen dioxide, as an annual average concentration, met the guideline at the continuous monitors in Stanwell and Sunbury Cross. Residents at The Parade and nearby may though be exposed to levels above the objective. Hourly monitoring reveals that levels of nitrogen dioxide are not of concern to shoppers and passers-by.
The diffusion tube network for monitoring nitrogen dioxide was extended to 47 locations
In 2007, at 12 roadside diffusion tube locations levels of nitrogen dioxide, as an annual average, were higher than the objective. Levels though were generally lower than 2006.
We monitor nitrogen dioxide. Nitrogen dioxide is the principal pollutant of concern in the Borough and the most extensively monitored.
There are a total of 3 continuous monitoring stations, all of which monitor nitrogen dioxide. These are located at Stanwell close to Heathrow Airport, adjacent to the M25 and at Sunbury Cross. The first two monitoring stations are run by BAA, operators of Heathrow Airport, and the Highways Agency, respectively. The third monitoring station is run by us.
We also have a network of 47 diffusion tubes measuring levels of nitrogen dioxide across the Borough. The monitoring network has been expanded and improved during 2007.
New for 2008 the Council is participating in a nitrogen dioxide monitoring study being funded by the Highways Agency. They are responsible for controlling traffic on the motorways and major roads in the Borough. The Agency are funding an extra 3 diffusion tubes at residential properties close to motorways and major roads.
Particulates are also measured at the monitoring stations close to the M25 and Heathrow to keep a check on their levels, although they are not expected to exceed the guidelines.
Carbon monoxide, ozone, and sulphur dioxide are monitored too by the Highways Agency at their monitoring station close to the M25.
Diffusion tubes are a simple and cost-effective method of monitoring. It is a plastic tube (about the size of a finger) which can be attached to a lamp post. Material within the tube is covered in a special coating. The tube is exposed to air at a chosen location over a period of a month. The coating absorbs nitrogen dioxide and so it is possible to find out an average level of nitrogen dioxide present at that location during that month. At the end of each month, the tubes are sealed and then sent off for analysis to an independent laboratory.
The results from each month are then used to work out an average level of nitrogen dioxide for a year. Results from diffusion tubes can only be compared to the annual mean objectives for the pollutants. They are not as accurate and precise as continuous monitors but give a good general indication of average pollutant levels.
A continuous monitoring station is an enclosure that contains one or more instruments to measure air quality continuously. They can vary greatly in size from a small cabinet right up to a walk in container depending on the number and type of instruments held there to measure air quality. The equipment is capable of measuring air quality continuously and results can be available in real time. Results can be averaged over short time periods such as 15 minutes, an hour or 24 hours. Graphical Version l
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