London Luton Airport Limited


New air quality monitoring from summer 2019

What our new monitoring station will do

We have reviewed all air quality monitoring undertaken at major UK airports and noted that there is a range of different pollutants monitored across the country.

The table below shows our findings. All airports monitor nitric oxide (NO) and nitrogen dioxide (NO2), which are collectively referred to as NOx, while all but two monitor particulate matter PM10.

In addition, three airports monitor ozone (O3), two monitor sulphur dioxide (SO2), two monitor smaller particulate matter (PM2.5), two monitor benzene, one monitors carbon monoxide (CO), and one monitors black carbon.

We have taken the decision to monitor all the pollutants above, plus PM1 and other Volatile Organic Compounds (VOCs); in addition to benzene, we will also monitor naphthalene and toluene.

There are no UK air quality standards for PM1, toluene or naphthalene. However, there are occupational exposure limits for naphthalene and toluene, and PM1 is a growing interest in current research.

Pollutants currently monitored at UK airports









Black carbon



















East Midlands































London City


























When the data will be available

Since June 2019, the monitoring station has been collecting data 24 hours a day, seven days a week, 365 days per year (other than during any maintenance operations).

The averaging time for each pollutant is one hour or less, so that we are not just recording daily, weekly or monthly averages, but are to see the variation in concentration on an hourly basis.

That data is being reviewed monthly and we will publish an annual report of our findings and any required mitigation action. We also prepare and publish shorter reports on a quarterly basis.

Site location

  • The location was selected because of its proximity to nearby sensitive receptors (residential property) and as it is between these and the airport. The monitoring site is deliberately located closer to the airport than the nearest residential properties which are located to the north of Eaton Green Road. This will mean that stronger concentrations of pollutants are measured than would be experienced at the nearest residential properties.
  • The site is located north-east of the airport, downwind of the airport under the predominant wind direction, south-westerly. A south-westerly wind is characteristic of Luton and the south of the UK generally.
  • The proposed location means the monitor would not be significantly affected by the presence of trees or buildings.
  • The site is owned by Luton Council and would be undisturbed by construction, either of our proposed commercial development or our proposals for airport expansion. As such, it is able to provide a long-term monitoring record. As many air quality objectives are based on annual averages, a long-term (multiple years) record is very valuable for distinguishing trends in air quality.
  • Automatic air quality monitors require mains power to operate and are required to be easily accessible for maintenance; the chosen site fulfils both these criteria without significant additional works.

Given the focus on understanding the effects of the airport on air quality for our nearest neighbours, our new ‘supersite’ is positioned in the most appropriate location. We have elected to sample a wide range of pollutants at this location as it represents the best opportunity to capture such data before it reaches residential areas.
Figure 1 shows the location of the supersite.

More monitoring

    In addition to the above monitoring:
  • we also carry out monthly monitoring of NO2 using diffusion tubes at 10, mainly roadside, locations
  • we carry out monthly monitoring of the following VOCs: benzene, toluene, ethylene, xylene, naphthalene and 1,3-butadiene; at five locations
  • The airport operator (LLAOL) monitors monthly NO2 using diffusion tubes at 17 locations; and
  • LLAOL monitors PM10 at an automatic monitoring site on the airport.

Figure 1 shows the locations of all of these monitors.

Location of the supersite, and other monitoring undertaken by LLAL, LLAOL and Luton Council
Figure 1: Location of the supersite, and other monitoring undertaken by LLAL, LLAOL and Luton Council - click to enlarge

The combination of a small number of automatic monitors providing high quality, high time resolution monitoring data – with a greater number of devices for monthly monitoring (diffusion tubes) that provides information on spatial distribution – is standard practice for monitoring. This methodology is used in air quality assessments and by local authorities. It is a good use of the benefits of the different monitoring methods.

A link to real-time air quality monitoring

We have taken steps to include monitoring data from the supersite online as part of the Herts and Beds Air Quality Network

It is important to note that, as with all automatic ambient air quality monitoring data, the data is provisional until it has been ratified. Ratification is only completed at the end of the calendar year.

If you want to see the destinations you can travel to, make a booking, or find out more about the operations of LTN, please go to