How does Heathrow air quality compare to the rest of London? New map released


By Heathrow

Published 29th September 2015

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How does Heathrow air quality compare to the rest of London? A new map released by Heathrow showcases how air quality around the airport is already ahead of the rest of London, further supporting Airports Commission analysis that showed expansion could take place within limits.

Key points:

  • New map graphically shows areas immediately around the airport are meeting legal air quality limits now, but many locations elsewhere across London do not

  • Air quality around Heathrow has been improving over recent years and will continue to get better in the future, allowing for Heathrow to expand and not exceed air quality limits.

Heathrow Airport is not the London problem…

A new graphic released by Heathrow airport today using independent data clearly shows how road vehicles, and not emissions from operations on the airport, are the biggest contributor to air pollution in London.

The information is drawn from the independent nation-wide network of pollution monitors run by the Government and by local authorities and is visually shown in a new graphic that demonstrates widespread exceedences of air quality limits across Greater London, while the nine monitors within 1 km of Heathrow airport show air quality has been consistently within the limit for the last 8 years or more.

Road traffic the main issue…

The graphic shows only two monitors in the vicinity of Heathrow are in breach the air quality limits, both of which are beside major roads. The first, just within 2kms of the airport fence, is 35 metres from the M4 motorway, at which only 16% of the pollution comes from airport-related sources, while the other is beside a busy road junction in an urban centre, and the airport’s emissions are only 6% of its total.

Put another way, even if Heathrow were completely closed down immediately, there would still be exceedances at these two locations. The latest forecasts by Defra show that both of these monitors are expected to be compliant by 2020, five years ahead of areas of central London.

Put another way, even if Heathrow were completely closed down immediately, there would still be exceedances at these two locations. The latest forecasts by Defra show that both of these monitors are expected to be compliant by 2020, five years ahead of areas of central London.

This graphic is consistent with the conclusions of the Airports Commission, set up by the Prime Minister, which concluded Heathrow air quality in the future will be better than now. Following a £20 million, two and a half year detailed study of where the next runway should be, the Commission has confirmed a third runway at Heathrow can go ahead without breaching air quality legal limits, as long as the airport continues to implement its mitigation plans.

Heathrow’s excellent track record of improving air quality

The airport already has an excellent record of improving air quality, and have reduced annual emissions from airport activity by 16% over five years. Heathrow’s Blueprint for Reducing Emissions outlines a 10 point plan of tangible actions to reduce Heathrow’s emissions, including a commitment to turn every car or small van we own to electric by 2020.

Heathrow is already reducing emissions and improving air quality. Here’s a look at some of the improvements we’ve already made, and how this will continue with expansion.

Matt Gorman, Heathrow Director of Environment and Sustainability said this graphic highlights that road traffic is the real issue and that Heathrow is already working with partner’s to help improve conditions.

“Heathrow understands air quality is a real concern for local communities and it’s an issue London needs to tackle urgently. We have made it clear that Heathrow airport has and will continue to play its part. But this data shows that the real culprit of pollution in London is road traffic, so we need other partners to play their role,” Matt Gorman said.

“We’re working with partners like the Mayor’s office on a strategy to reduce emissions from non-airport related road-traffic which is the major cause of pollution in the Heathrow area.”


1. The new graphic as well as information on Heathrow’s “Blueprint for Reducing Emissions” is available here:

2.Methodology: Data has been drawn from Defra, Kings College London and Ricardo during the five-year period of 2009–2013.At the time data for 2014 had not been fully ratified (checked by the equipment operators) and compiled. Since the original data collection was undertaken, more data for 2014 has been released so has been added to the dataset where available. The data capture threshold was set at 75% to balance the need for high quality data with having sufficient data to determine the trend at each site. It is the same threshold as used in the GLA’s 2014 comparison of London’s air quality with that in other cities around the world.

3. Air Quality Monitoring: Heathrow has a policy of full public disclosure of our expansion plans and we are committed to consulting closely with the public, local community, businesses, passengers, airport users and elected representatives to understand all the issues. All our air quality data is available publicly:

4. EU compliance and Heathrow Expansion: The Airports Commission’s independent analysis has confirmed that expansion at Heathrow will not delay compliance with EU limits.Our modelling shows that concentrations around the airport boundary are similar in both 2R (two runway) and 3R (three runway) cases. This is to be expected since, although the total aircraft emissions are greater in the 3R case, they are spread over a larger area and necessarily the level of activity per runway, taxiway or stand is no higher than it is now, since the airport is already at full capacity. Because concentrations drop off substantially over a distance of several hundred metres from the source, and as the airport is several kilometres across, the effect at the boundary is that concentrations are nearly independent of airport size. Concentrations of NO2 at the continuous monitoring stations around the airport are no more than 3 μg m−3 higher with the third runway than the 2R business-as-usual case.The Airports Commission made an important broader point about the nature of the air quality issue (ACFR paragraphs 14.110 & 14.112) that: “Tackling air quality is not, however, only the responsibility of the airport operator. Heathrow is situated close to the M25, M4 and other major roads and the majority of emissions in the area are caused by road traffic unrelated to the airport… The air quality issue around Heathrow is a manageable part of a wider problem, the underlying causes of which will need to be addressed by the Government.” This observation is supported by the fact that pollutant concentrations at the worst locations in the region of Heathrow (over 2km north of the airport) are predominantly due to non-airport traffic.

5. Mitigation measures: For the last 15 years, Heathrow Airport has maintained and implemented a series of action plans aimed at delivering improvements to air quality around the airport. These have contained a wide range of measures to reduce emissions, and we are continuing to implementing more.Current measures are described in our Blueprint For Reducing Emissions, which can be accessed here:


By Heathrow

Published 29th September 2015