New research suggests a third runway at Heathrow could cause an extra 100 deaths a year linked to pollution from the airport.
The report, by Cambridge University and the Massachusetts Institute of Technology, shows a plan backed by mayor Boris Johnson for an airport in the Thames Estuary, would cut the number of deaths.
Scientists say the estuary scheme would see a 70% decrease in the number of people dying due to pollution caused by Heathrow.
Piers Hopkirk has our report:
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