Air Quality*

Expanding Heathrow may affect people and places due to changes in air quality and odour.

*This page contains one (1) question located within the “Have your say” section at the bottom of the page.

The influence of Heathrow on air quality falls sharply with distance from the airport. In the area outside of the airport boundary, the main source of pollution that affects air quality is road traffic, the majority of which is not related to the airport.


Although the expansion of Heathrow will change and, in some places, increase emissions of air pollutants, our surface access proposals will minimise these effects by increasing public transport use and cleaner more sustainable modes of travel to and from the airport.

We will also manage emissions from aircraft by carefully designing the way the airport is laid out and designing aircraft stands that provide electricity and air to avoid the need for aircraft to use their engines whilst parked.

What is Air Quality?

Air quality is the term used to describe the degree to which the air that people breathe is free of pollutants. The most important air pollutants in the UK in relation to health effects are nitrogen dioxide (NO2) and particles (Particulate Matter, PM10 and PM2.5). Sulphur dioxide (SO2) concentrations have also been considered in our assessment.

Aspects of our proposals that could cause effects

The activities required for the construction of the new north west runway, terminals, aprons and satellites, together with the works required to divert and construct new local roads, have the potential to affect the quality of air locally. This may be because of the extensive earthworks needed causing dust, as well as exhaust emissions from construction equipment and vehicle engines.

The flights and road traffic that will use an expanded Heathrow will produce emissions that could increase levels of pollutants in the air.

A summary of the effects reported in the Preliminary Environmental Information Report (PEIR)

The greatest effects are likely to occur in areas to the north west of the existing airport, where earthworks will be required to prepare for the new runway. Construction sites will be established in this area, which will result in construction vehicle movements and emissions. Construction vehicles will remain on the motorway network wherever possible but will need to travel on the A4 to connect to work sites from the M4 motorway.

Due to the use of good practice measures contained in our Draft Code of Construction Practice, construction activities are predicted to cause no significant effects in relation to dust or odour. No significant effects in relation to NO2 levels are predicted during the construction phase given the temporary nature of construction effects and the further work that will be done to manage road traffic during construction.

During operation of an expanded Heathrow, air quality is expected to improve with time because of the introduction of cleaner road vehicles and increasingly modern aircraft which meet tighter emission standards.

No significant effects are predicted in relation to PM and SO2 emissions from aircraft, airfield activities and road traffic during construction or operation.

The increased number of flights will generate extra trips to the airport, but our surface access proposals, including improved public transport access, will mean that the effect on air quality will be minimised.

Measures for reducing potential effects

As outlined  in our construction section,we will employ best practice measures that are used effectively at major construction sites across the country to limit emissions of dust and odour during construction.

A Construction Traffic Management Plan and Construction Workforce Travel Plan will be prepared and implemented to reduce the effect of construction road traffic.

The design of an expanded Heathrow includes proposals to help control and manage emissions. These include connections for stationary aircraft to use plug-in electrical power rather than their engines and electric vehicle charging equipment.

Our surface access proposals are vital to help manage the effects on air quality. Of importance for air quality are:

  • A road user charging strategy which includes a Heathrow Ultra Low Emissions Zone and proposals for the introduction of a Heathrow Vehicle Access Charge
  • Public transport proposals which increase the use of existing and committed public transport schemes to the airport
  • Car parking proposals which will see a phased reduction in colleague parking with passenger parking increasing, but with a reduction in the amount of parking spaces available per passenger over time.

Our overall proposals

In addition to the question on this page, we also want to know what you think about our overall proposals to manage the environmental effects of expansion and, in particular:

  • whether there are any other initiatives or proposals that we should consider to address the emissions from airport related traffic or airport operations;
  • our proposals to help health and well-being, in particular whether there are any proposals that you think we should consider to address the effect of the Project on the health and wellbeing of our colleagues, neighbours and passengers;
  • our noise insulation schemes;
  • what factors are most important as we develop our proposals for noise management, in particular our proposals for the design and implementation of a noise envelope;
  • our proposals for maximising new jobs and training, in particular, whether there are any other ways that we can maximise skills and training opportunities to benefit our local communities;
  • on our approach to addressing effects on the historic environment, including any particular proposals you would like us to consider.

To respond to our proposals please answer the overarching question on the Environmental Introduction page.

Have your say

Our surface access proposals will help us manage airport-related emissions and our Preferred Masterplan has been designed to reduce the impact of the airport on local air quality. Chapter 7 of the Preliminary Environmental Information Report, published as part of this consultation sets out in detail the work we have done to assess the effects on air quality from the construction and operation of an expanded Heathrow.

View next topic in this group: