The latest figures revealed by the Mayor of London suggest that efforts to clean London’s air are working as data from air quality monitoring sensors around the city show a 97% reduction in the number of hours that air quality exceeded legal limits.

Mayor of London Sadiq Khan stated: “Toxic air is a national health crisis contributing to thousands of premature deaths ever year. I have taken bold action in London with measures such as the world’s first Ultra Low Emission Zone and Low Emission Bus Zones, and it’s undeniable that these are making a difference to the air we breathe.

“We’re doing all we can in the capital, with proven results, so there are no excuses left for the Government’s failure to match our levels of ambition.”

Compared to 2016, where 4000 hours exceeded the hourly legal limit for air quality, in 2019, London’s air quality exceeded the hourly legal limit for only around 100 hours.

However, many locations still have high pollution levels (including for particulate matter). At the monitoring site in Vauxhall this is particularly noticeable, although initial research suggests the findings are impacted by a nearby ventilation shaft from the Tube.

From 2004 to 2017, London breached the permitted number of exceedances for NO2 within the first week of January. In 2019, this only happened at one site and not until July.

Looking at particular areas of London in detail, on Oxford Street in Westminster for 2019, monitors did not record a single hour above legal limits, an improvement on 168 hours in 2016. NO2 exceeded legal limits for 168 hours in 2016. In 2019. However, further action is needed as Oxford Street did not meet the annual average level.

At Putney High Street in Wandsworth, NO2 levels have stayed within legal limits so far in 2019/20, compared to 1,279 hours of illegal levels in 2016.

Londoner’s long-term exposure to air pollution is falling, as every site being monitored has reported a reduced NO2 levels reading. This averages at around 21% reduction between 2016 and 2019. The most significant reductions have been seen where Low Emission Bus Zones are in effect.