LONDON, Jan. 3 (Xinhua) -- Pollution from planes using Heathrow airport in London has been detected in the central part of the British capital, which is more than 20 km away, a study revealed Friday.
Carried out by researchers from King's College London, the study is the first to find that airports are a major source of ultra-fine particles (less than 100 nm in diameter) harmful to health.
Results from air quality monitoring stations in north Kensington and in Marylebone Road, about 22.5 km from the airport, were used to estimate levels of the particles in the air.
Results were greatest when blown in from the airport on a westerly wind, according to the report.
Ultra-fine particles are produced by fuel burning and are a subset of PM2.5 particles that are most commonly emitted from traffic brakes and tyres.
The smaller the particle, the deeper they can penetrate into lungs. Ultra-fine particles have been linked to brain cancer.
Instead of other airports serving London, Heathrow was chosen due to its proximity to the detectors used by the London Air Quality Network.
Besides Heathrow, the study also measured emissions from three European airports, including Barcelona, Zurich and Helsinki, between 2007-2017.