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Should the British Expand Heathrow Airport?

Air pollution from U.K. airports leads to about 100 early deaths in the United Kingdom each year. Expanding Heathrow could help or hurt these numbers, depending on the strategy undertaken.

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


Air pollution from aviation in the U.K. leads to about 110 premature deaths across the country each year. An estimated 28% of these early deaths occur in people living within 20 miles of Heathrow. In turn, the British are facing a challenging question – just how should they manage growing demand for air travel?

This question is at the heart of the “third runway” drama previously mentioned by Plugged In’s Tali Trigg. By the summer’s end, U.K. Airports Commission Chairman Lord Howard Davies will release his recommendation to the U.K. government in support of one of the following shortlisted options for managing increasing demand for air travel:

  1. add a second runway at Gatwick Airport

  2. add a third runway at Heathrow Airport

  3. extend the northern runway at Heathrow Airport


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This month, the Airport Commission unexpectedly reopened its public consultation on air quality. This decision follows a U.K. Supreme Court ruling that the government must take immediate action to reduce air pollution in order to comply with EU limits as well as a general election that “returned a strengthened cohort of anti-Heathrow Conservative MPs in government.”

According to research out of MIT and Cambridge, air quality concerns related to a Heathrow expansion are valid – though perhaps avoidable if near-term mitigation strategies can be deployed.  In studies published in 2013, MIT’s Steve Yim and Steven Barrett along with Marc Stettler from Cambridge estimated the number of aviation-attributable deaths in the UK due to air pollution from U.K. airports. They then looked at what might happen if the country decided to either expand Heathrow airport or build a new Thames Hub airport to replace what is currently world’s second busiest airport in terms of total annual passengers.

[Note: the proposal for the Thames Hub airport – dubbed “Boris Island” for London’s iconic Mayor – was ruled out in September, though it could theoretically still be pushed ahead by the U.K. government]

In their study, Yim, et. al began by estimating the current number of early deaths caused by emissions from:

  1. aircraft landing and takeoff

  2. aircraft auxiliary power units (APUs)

  3. ground support equipment (GSE)

They did not include emissions related to local ground transport, including cars, buses, or taxis.

Overall, the researchers found that an estimated 110 early deaths occur in the United Kingdom each year due to airport emissions. Considering uncertainties regarding emissions levels (which change significantly depending on operating conditions) and resulting human exposure levels (i.e. who ends up breathing in these emissions) this value could range from between 72-160 early deaths per year across the country. The authors note that 70% of these early deaths are due to the five major airports found in the London region.

After estimating current early mortality rates, the authors used the same air quality modeling approach and a concentration-response function (to calculate public health impacts) to estimate how early mortality rates might change over the next fifteen years.

All told, they looked at six scenarios for this publication, including:

  1. Future background – i.e. what if the UK removed all of its airports

  2. No expansion of London Heathrow (constrained growth)

  3. Expansion of London Heathrow (unconstrained growth)

  4. Replacement of London Heathrow by a new airport in the Thames Estuary (unconstrained growth)

  5. Expansion of London Heathrow with mitigation methods including jet fuel desulphurisation, electrification of ground service equipment (GSE), the use of fixed-ground electrical power, and the widespread use of single engine taxiing

  6. A new airport in the Thames Estuary with the same mitigation methods applied in #5

According to their analysis, premature death rates could more than double by 2030, even if Heathrow Airport’s growth is constrained. However, short-term mitigation methods for reducing air pollution at Heathrow could have a strong positive impact on local health:

Near-term mitigation measures - including the desulphurisation of jet fuel, electrification of ground support equipment, widespread use of single engine taxiing, and provision and use of fixed ground electrical power, have the potential to offset more than half of the health impacts of airport emissions....

According to their analysis, even an expanded Heathrow airport could decrease its health impacts by 48% by 2030 if these mitigation measures are used effectively.

This study does not conclude as to whether or not expanding Heathrow Airport is the “best” option to manage increasing air travel demand. However, it does provide insight into how a Heathrow expansion project could impact air pollution and public health in the United Kingdom compared with other options.

References:

[1] Yim, et. al “Air quality and public health impacts of UK airports. Part I: Emissions” Atmospheric Environment 45 (2011) 5415-5424

[2] Yim, et. al “Air quality and public health impacts of UK airports. Part II: Impacts and policy assessment” Atmospheric Environment 67 (2013) 184-192

Photo Credit:

[1] Photo of Qantas plane on approach to Heathrow Airport by Arpingstone and found using Creative Commons.

[2] Photo of Heathrow Terminal 5 by Pandard and found using Creative Commons.