London delivers clean games

London 2012 produced one of Team GB’s most successful medal hauls, but it might also be one of the least polluted games in history.

Scientists have taken to the skies around London’s M25 to measure key markers of pollution, and conclude that the London 2012 Olympic Games are one of the least polluted thanks to the appalling weather before the games.

As part of the Clearflo – Clean Air for London – project, atmospheric scientists have been monitoring air and ground conditions. For the last two years they have measured carbon monoxide, ozone, nitrogen dioxide and aerosol levels, trying to establish what happens to urban pollution and where it goes.

“Put simply, the reason the air quality is so good is because the weather has been so bad this summer,” said Dr Grant Allen from the University of Manchester. “The areas of low pressure have left us with very clean air, unusually clean for summer months over the UK. The pollution that is generated moves away in the evenings and goes in variety of directions depending on wind direction.”

The Olympics have provided an excellent case study for the scientists, since traffic levels and activity have been monitored closely and quantified, said Allen.

Scientists have monitored pollution levels during the Games, looking for a tell-tale shift in the pollution regimes. As a result, Allen hopes to more accurately predict air quality for London in the future, as well as a better understanding of how London pollution affects those downwind.

“With more accurate predictions, we can hope to mitigate the known health impacts associated with poor air quality,” he said. “By sampling the air going into and coming out of London with the aircraft, and using measurements on the ground within the city itself, we can say something about what was added to the air as it passed over London and what this means for those living downwind.”