Urgent action needed to prevent air pollution rising as Covid restrictions end

Air pollution fell in the Spring but now exceeds pre-pandemic levels in 80% of places despite continued lockdown restrictions.

Press release published on 10 December 2020

  • Air pollution fell in the Spring but now exceeds pre-pandemic levels in 80% of places despite continued lockdown restrictions.
  • Councils must not delay measures to prevent air quality significantly worsening next year.
  • Public transport, cycling and walking should be encouraged over car usage.

Toxic air is set to rise significantly as lockdown restrictions end warns Centre for Cities as it urges councils to press ahead with their stalled pollution reduction plans.

The new analysis shows that, while the spring lockdown reduced NO2 levels by 38% on average across 49 cities and large towns, they rose again in the second half of the year as activity increased.

As a result, NO2 levels have now hit or exceeded pre-pandemic levels in around 80% of places studied during the second half of 2020. This is despite 98% of the country remaining under significant lockdown restrictions – raising concerns that air quality will significantly worsen once life returns to normal next year.

In some cities such as Barnsley, Bournemouth and Portsmouth, NO2 levels in September were already even higher than they were before the spring lockdown.

Places where NO2 emissions rebounded the most by September following spring lockdown
1.       Bristol

2.       Portsmouth

3.       Plymouth

4.       Bradford

5.       Swansea

6.       Swindon

7.       Nottingham

8.       Southend

9.       Exeter

10.   Barnsley

  Source: CREA 2020

As the risk from Covid-19 reduces and life returns to normal next year, policy makers must urgently revisit stalled pre-pandemic plans to reduce air pollution – which has been linked to 40,000 UK deaths per year.

Since March many councils – including Leeds, Bristol, Sheffield – have postponed their pollution reduction plans. This new data makes the case for them look again at implementing air pollution reduction measures.

Data shows that increased post-pandemic home working will not keep air pollution down. It is estimated that more than half of people in London worked from home at the peak of the pandemic, yet NO2 levels in the capital have returned to near pre-March levels. This is because commuting is not biggest cause of pollution and remote workers are more likely to use their car for leisure purposes.

Private vehicle usage is the main generator of toxic air: pollution has increased since May in line with the return of private cars to the road. Meanwhile, public transport usage has remained low. Because of this, mayors and council leaders must press ahead with plans to reduce private vehicle-related emissions.

They should:

  • Discourage car usage by introducing clean air zones that charge drivers
  • Encourage more public transport usage through improvements to bus, rail and tram systems
  • Improve cycling and walking infrastructure to encourage more active forms of travel

Centre for Cities’ Chief Executive Andrew Carter said:

“Toxic air has contributed to the deaths of thousands of Covid-19 victims this year and, even after the pandemic ends, will remain a big threat to health – particularly for those living in urban areas.

“City leaders can reduce threat of air pollution, but it will take political will. Discouraging car usage will be unpopular in the short-term but, if coupled with the necessary improvements to public transport, the long-term benefits to public health and the economy will be huge and our cities will become better places to live. Now is not the time for politicians to delay on this.”

The Centre for Research on Energy and Clean Air’s Data Lead Hubert Thieriot said:

“With the Covid-19 pandemic came immense suffering both on sanitary and social fronts. Incidentally but importantly, it also reminded citizens that air pollution is not a given, and that bold actions on transportation could significantly improve people’s health and quality of life.”

“The role of transportation in UK cities’ air pollution has become apparent to everyone during the COVID-related lockdowns. That shared awareness offers policy makers an historical chance to implement bold transportation policies, as many other cities overseas have shown.”


Notes to editors


  • Air pollution is difficult to measure and there is not one single way to present pollution or to assess the quality of air. In this work we focus on concentration data, which gives an indication of how polluted a place is.
  • The data comes from Defra and is measured at 232 monitoring sites, located either nearby (roadside) or further away (background) from roads and then modelled for a specific area correcting for weather conditions.
  • It focuses on two pollutants: nitrogen dioxide (NO2) and particulate matter with a diameter of 2.5 μm or less (PM2.5). Prior to the crisis, for nitrogen dioxide concentration the UK did not meet the legally-binding target of an annual mean of 40 micrograms per cubic metre (μg/m3). This target was set for 2010, and has failed to be met for 10 consecutive years. And, while legal limits for PM2.5 (set at 25 μg/m3) were not breached in most places, they exceeded World Health Organization guidelines of 10 μg/m3.
  • In this work, only cities with at least one monitoring station from Defra were included, meaning this report looks at 49 out of 63 UK cities Centre for Cities usually analyses.
  • This research is based on data computed for Centre for Cities by the Centre for Research and Energy on Clean Air (CREA) and Environmental Defense Fund Europe.

About Centre for Cities

  • Centre for Cities is a research and policy institute, dedicated to improving the economic success of UK cities.
  • We are a charity that works with cities, business and Whitehall to develop and implement policy that supports the performance of urban economies. We do this through impartial research and knowledge exchange.

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