Boris Johnson has been forced to accept that London’s Oxford Street has some of the worst air pollution in the world.

In an exchange of letters with the Environment Audit Committee (EAC) of MPs, the mayor said he now accepts scientific evidence from Britain’s leading air research group that the street has some of the world’s highest recorded levels of nitrogen dioxide.



The mayor of London had said in a Twitter exchange in July that it was a “ludicrous urban myth” that Britain’s premier shopping street was one of the world’s most polluted thoroughfares, saying that the capital’s air quality was “better than Paris and other European cities”.



B*ll*cks: ludicrous urban myth. London air qual better than Paris and many other Euro cities- and go to Beijing or Mexico city@JonRegnart — Boris Johnson (@MayorofLondon) July 16, 2014

This followed a presentation in June by King’s College London air researcher David Carslaw which questioned whether the hourly and annual average levels of nitrogen dioxide (NO2) pollution – mainly caused by diesel traffic – were the highest in the world. Carslaw’s slide had read: “Highest annual mean concentration and most hourly NO2 exceedences in the World? Highest in the (long) history of air pollution?”



But Johnson backed down this week following a letter from EAC chair Joan Walley, who sought assurance that King’s College funding would not be threatened by its pollution research. “We are not disputing King’s college data, but rather only asking only that in future more rigour will be applied to public statements,” Johnson wrote.



A device for measuring air quality is located in Oxford Street on July 9, 2014 in London, England. Researchers from King’s College London have found that concentrations of nitrogen dioxide in Oxford Street are the worst on earth. Photograph: Peter Macdiarmid/Getty Images

He also denied that King’s funding was threatened. “There is absolutely no threat, veiled or otherwise, to King’s College funding. The only reference to a threat has been made by a single anonymous source close to King’s who spoke to the Times. Greater London authority funding decisions are not influenced by King’s research”.



Since the Twitter exchange Johnson and Transport for London, the local government body responsible for most of the transport system in Greater London, has proposed what it calls “the world’s first ultra-low-emission zone (ULEZ)” which would come into effect in September 2020. It will require all vehicles entering it to comply with new emission standards for nitrogen oxide (NOx) and particulate matter (PM10) or pay a daily fine.



Transport for London, which has come under intense pressure from Europe, Westminster and campaigners to meet EU air pollution laws, expects the new zone to ensure that more than 80% of central London meets the nitrogen dioxide annual legal limits by 2020, as well as halve PM10 and NOx emissions. However, it has been criticised because EU legislation requires cities to meet NO2 limits by 2015.

A spokesperson for the mayor’s office said: “The mayor’s view has not changed. He has never disputed the King’s College data, but has always been clear that this data was taken out of context and misrepresented. The claim that Oxford Street is the most polluted in the world was erroneous and the mayor does not accept it. King’s College themselves agree that their data was misrepresented and reiterated this point to the London Assembly’s environment committee just last week.”

