Before the London Olympics, in order to effectively improve the air quality in London, the Mayor of London and Olympic Committee member Boris Johnson announced that large trucks and small buses must meet the low-emission zone standards by January 2012  These vehicles were originally It has been included in the low-emission zone since October 2010  If it does not meet the emission standards, it will be fined
The biggest pollution problem in London is air pollution, and the pollutants in the air mainly come from the emission of traffic flow
 This shows that the biggest cause of pollution in London is the amount of pollution emitted by traffic