Latest data shows two million Londoners living with illegal toxic air

01 April 2019
  • Mayor publishes new data underlining scale of capital’s air quality challenge


  • Figures show more than two million Londoners living in areas exceeding legal air limits – including 400,000 children


  • 80 per cent of Londoners are aware of the Mayor’s ULEZ scheme, which starts a week today


  • Sadiq launches interactive map showing local air quality across London


Two million Londoners – including more than 400,000 children – are living in areas which exceed legal limits for air pollution, new data published today by the Mayor, Sadiq Khan, reveals.


Updates to the London Atmospheric Emission Inventory (LAEI) – which analyses air quality – show that between 2013 and 2016, under the previous Mayor, there were no significant improvements in harmful nitrogen dioxide (NO2) concentrations in London’s air – with some areas actually getting worse.


The picture for London’s schools over the same period is similarly stark: in 2016, more than 400 schools were still in areas which exceeded legal limits for NO2. While the number of primary schools in these areas fell slightly – from 371 to 369 – the number of secondary schools affected grew from 81 to 86. (1)


The new figures come with just one week to go until the introduction of the world-leading Ultra Low Emission Zone (ULEZ) in central London, which will see non-compliant vehicles charged to enter the zone, 24 hours a day, seven days a week.


Since Sadiq took office and began introducing tough measures to tackle London’s toxic air, there have been significant improvements in measured pollution levels. So far this year, there has been a 57 per cent reduction in the number of hours recorded in which the city exceeded the 200ug/m3 limit for NO2, compared to the same period last year. (2)


In the first three months of 2016, 43 monitoring sites in London recorded hours exceeding their legal limits for NO2, with 13 exceeding their annual limit (18 hours). So far in 2019, just 10 monitoring sites have recorded hours with pollution levels above the limit, while none have breached its annual limit.


A recent study by King’s College London looking at the overall rate of improvement in NO2 levels across London found that, compared with legal pollution limits, if the trend of inaction seen between 2010 and 2016 continued it would take 193 years to reach legal compliance (3).


However, further modelling undertaken for City Hall by King’s College London suggests the Mayor’s far-reaching policies would reduce this to just six years, meaning London’s air would be within legal pollution limits by 2025.


New polling reveals more than three-quarters of Londoners (80 per cent) now know some information about the ULEZ (up from 60 per cent last August). The proportion who say they don’t know about ULEZ has halved over the same period, from 40 per cent to 20 per cent.


Meanwhile, 90 per cent of drivers know something about the ULEZ scheme – even though only one in five drivers is expected to drive into the zone.


Transport for London (TfL) continues to work hard to ensure as many Londoners are aware of ULEZ as possible. It has already sent 2.5 million emails, 600,000 letters to drivers who have driven within the central London Congestion Charge Zone since last October, installed more than 300 road signs at entry points to the zone and rolled out a major advertising campaign across the entire TfL network (which will continue beyond the ULEZ launch date).


It has also provided advice and support to more than 6,000 fleet operators and more than 1,000 small businesses, charities and health services.


The Mayor will also launch interactive map, showing air quality across London, using a range of monitoring and modelling data, so Londoners can be better informed about conditions in their local area.

The Mayor of London, Sadiq Khan, said: “From the very outset I have been crystal clear that I would do everything in my power to tackle London’s toxic air crisis. So far in my mayoralty, this includes cleaning up our bus and taxi fleet and establishing the largest air quality monitoring network of any major city.


“The introduction of the world’s first 24-hour seven-day-a-week Ultra Low Emission Zone next week marks a watershed moment in our fight to clean up our filthy air. The data I’ve published today gives an even clearer picture of the urgent need to take action.


“What’s more, our message to Londoners is clearly getting through – and we will continue to do all we can to support Londoners in making the transition away from older, more polluting vehicles.”


Chair in Environmental Health at King's College London, Professor Frank Kelly, said: “London needs effective measures to improve air quality to an acceptable level at which it is not having a negative influence on children’s health.


“The ULEZ is a world-leading initiative that has been designed to have the positive impact that our capital deserves. I applaud the Mayor and his team for taking the bold action needed to protect the health of London’s children.”


Chief Executive of the British Lung Foundation, Dr Penny Woods, said: “We know that air pollution can seriously impact all our health, especially children, the elderly and those with existing lung and heart conditions – there is new evidence almost weekly on the harmful effects of toxic air - so it’s good to see these strong initiatives from the Mayor of London.


“Walking and cycling is not just a great way to keep fit, but can help reduce your exposure and contribution to air pollution, so the interactive map is a great way for people to plan the cleanest routes for active travel. We hope to see similar schemes from other city leaders across the UK.”


So far there have been more than 1.8 million visits to the ULEZ website and more than 3.1 million checks on TFL’S online vehicle compliance checker.

Director of UK100, Polly Billington, said: “These latest figures highlight once again that air quality remains at dangerous levels for an unacceptable number of Londoners. The upcoming ULEZ is a step in the right direction to combat this problem, but it must be accompanied by a range of measures, such as the recently announced vehicle scrappage scheme.

“We welcome the steps taken by the Mayor on this serious issue and support the expansion of the zone in 2021 to help improve air quality not only in the city, but across the London boroughs.“

Notes to editors

To view the interactive air quality map, visit:


(1)          When analysing the number of schools located in areas with illegal air pollution, to ensure consistency and that the comparison between years is fair, the 2019 database of schools has been used for both the 2013 and 2016 analysis. This allows for the fact that over this period a small numbers of schools may have opened or closed, and gives parents the best possible understanding of air quality at their child’s school.


(2)          Excludes Brixton Road monitoring station for both 2016 and 2019 data to ensure a fair comparison as the Brixton Road site was offline from August 2018 to March 2019.




Notes on polling


  • Polling figures are from YouGov Plc. The total sample size was 1,106 London adults for fieldwork undertaken between August 28 and September 28 2018 and 1,006 London adults for fieldwork undertaken between March 11 to 14 2019.


  • The survey was carried out online. The figures have been weighted and are representative of all London adults (aged 18+).


  • Car drivers includes anyone who has personally driven a car in the last year.



Further information


  • Charges for ULEZ will be £12.50 for most vehicles including cars, motorcycles and vans (up to 3.5 tonnes) and £100 for heavier vehicles, including lorries (more than 3.5 tonnes) and buses and coaches (more than five tonnes).


  • Because hourly NO2 exceedances are almost exclusively due to traffic, these improvement suggests that the cleaning up of the Transport for London (TfL) bus fleet and drivers complying with the ULEZ ahead of its introduction are already having a significant positive impact on air quality.


  • The Low Emission Bus Zones have had a major impact on pollution levels: Putney High Street has exceeded legal limits for just four hours so far in 2019 – compared to almost 400 the same period in 2016, or a reduction of 99 per cent.


  • The LAEI is the key tool for air quality analysis and policy development in London. Before this latest update, the most up to-date figures available were for 2013.



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