A new airport in the Thames Estuary would cause fewer deaths from air pollution than extending Heathrow and reduce the overall impact of UK aviation on air quality, according to a new study.
The Massachusetts Institute of Technology (MIT) published a report on Saturday (October 13) on the air quality impacts of UK airport capacity expansion.
The study found that airport emissions currently cause about 110 early deaths a year, of which 50 are due to Heathrow.
And, it forecasts that an expanded Heathrow would cause 150 early deaths per year in 2030.
In comparison, it found that a new Thames Estuary hub airport (to replace Heathrow) would cause 60-70% fewer early deaths due to the location of the airport with respect to the population and the prevailing wind direction.
The research was conducted using Engineering and Physical Sciences Research Council (EPSRC) funds in the UK and research funds in the US.
From 2010-2012 the work was primarily undertaken at the Laboratory for Aviation and the Environment, which is a unit of the Department of Aeronautics and Astronautics at the MIT. Additional work was undertaken at the University of Cambridge as part of its Energy Efficient Cities Initiative, where the project started in 2009 before the study leader, Dr Steven Barrett, moved to MIT in 2010.
The report states: “If a third-runway is built at London Heathrow, early deaths due to emissions from Heathrow increases from 110 to 150. This is compensated for by reductions at other London airports as air traffic moves to Heathrow so that nationwide there are about 10 additional early deaths per year.
“If instead of a third-runway at Heathrow, the UK hub airport is moved to the Thames Estuary and Heathrow (the current hub airport) is closed, we find that the hub impacts decrease by 60-70% to about 50 early deaths per year. On a nationwide basis, early deaths due to UK airport emissions decrease by a quarter relative to an unexpanded Heathrow. In other words, airport capacity would be expanded and health impacts reduced under the Thames Hub scenario. “
The report explains that the reason why the Thames Estuary option reduces health impacts is that prevailing winds in the region are southwesterly (towards the northeast). Heathrow is in the major population centre of Greater London, and upwind of a significant portion of it. In contrast, the Thames Hub would be downwind of London, such that much of the pollution from a Thames Hub would blow into the English Channel.
It says: “This means that a Thames Hub option would result in lower population exposure to PM2.5 than the same emissions at Heathrow.”
The report concludes: “UK airport emissions cause about 110 early deaths per year today, rising by 170% in 2030. Employing near-term mitigation measures could avert half of these impacts. Moving the UK hub airport (currently London Heathrow) to the Thames Estuary would reduce health impacts of UK airports by a quarter, and the health impacts of the UK hub specifically by 60-70%.”
The report calculated pollution emissions at the top 20 UK airports (by passenger numbers) computed using an approach based on aircraft engine certification measurements with corrections to account for operational factors.