Poor air quality at UK airports is a serious concern for many local residents. Official reports often conclude that the main source of air pollution is road traffic, either to or from the airport, or in the vicinity generally. As a result, little attention is given in government policy to ways to minimise emissions from aircraft and other airport related emission sources. Yet there’s evidence to suggest that these emissions can sometimes dominate pollutant concentrations close to airports. And while air quality in the Heathrow area frequently hits the headlines because it breaches legal limits, less information is available about smaller UK airports that can have houses situated in close proximity to the boundary fence.
The Government’s air quality policy and strategy is also focused on compliance with legal limits rather than taking health-based evidence into account, and there appears to be a widening gap between the two, particularly for particulate matter.
The combustion of aviation fuel by aircraft produces nitrogen oxides (NOX), a major air pollutant associated with severe asthma and other respiratory diseases. In addition, the sulphur content in aviation kerosene fuel produces tiny particles (particulate matter or PM) and is typically between 60 and 70 times higher than in road fuel.
Whether or not these emissions contribute significantly to air pollution for those in the immediate vicinity depends on many factors including weather, wind direction, and background levels to name a few.
However, according to Dr Gary Fuller, a leading air pollution scientist at Kings College London:
“At the perimeter fence, hundreds of metres from the runway, the number of particles can be about the same as these found at the kerb of a busy London street, just a couple of metres from the traffic.” (G. Fuller (2018)The Invisible Killer: the rising global threat of air pollution – and how we can fight back.)
A research team at Imperial College London (Hansell et al, 2013) looked into possible health impacts of pollution on the 3.6 million people living around London Heathrow Airport. Comparing available health data against flight paths, they found that there were more incidents of adverse health impacts, such as strokes and heart attacks. As these areas are also subject to higher levels of aircraft noise, further studies are underway to see if this correlation with health relates to noise, air quality, or a combination of the two.
Residents living near to the perimeter of Southend Airport, meanwhile, are very worried about emissions coming from a new aircraft holding point on one of the airport’s taxiways – just metres from housing and a children’s playground – where aircraft engines run for several minutes at a time. The noise from the aircraft, they say, is deafening, and the smell of fumes from the aircraft is very strong. One resident told us that a few days ago they “could smell it in our house and even taste it. … We can’t enjoy the garden and can’t let the kids out”.
The residents have raised the issue with Southend Airport which has advised them that the taxiway is used for reasons of safety and efficiency at its busiest times, and that it would not be cost effective or practical to install a new taxiway away from the residential area. There is currently no Defra guidance on any risk to health from aircraft fumes, the airport has indicated, either for airport staff or members of the public. It has, however, agreed to install an air quality monitor near to the community’s homes, initially to measure NO2 levels.
As we argued in our air quality discussion paper, published in advance of the Aviation Strategy Green Paper, there are currently a number of information gaps with respect to air pollution from aviation, including what happens to particulate matter emissions at higher altitudes (they are currently excluded from modelling above the landing and take-off cycle) and what kind of monitoring airports should routinely be undertaking and reporting. Given the many factors that influence air pollution, the Government should, we argue, update its own mapping of air pollution levels around UK airports with respect to legal limit values and WHO recommended maximum levels for pollutant concentrations.