Tackling Air Quality in Croydon

Blue sky and clouds

September 7, 2021

Situated just 10 miles south of central London and a stone’s throw to Brighton, Croydon has long been a popular area to live and work with an ever-growing population. With excellent transport links across the south of England, the borough has almost 150 schools, many of which in short distance from high traffic areas. Combined with an increasing number of motor vehicles, the risk to the air quality in and around schools is a concern.

Croydon’s Air Quality Action Plan includes the action to ‘reduce pollution and minimise exposure’ at schools. Good quality data is essential for understanding the issue and measuring potential improvements against a baseline.

The process

From January to December 2020, MP Smarter Travel were commissioned to monitor air quality using nitrogen dioxide diffusion tube monitoring, at 96 schools throughout the borough. The testing was held over a one-year basis, collecting and replacing the test tubes on a monthly basis. All of the installations, come rain or shine, were carried out with zero emissions by bicycle. In order to complete the installations, our consultants covered an average 180km each month in just two days. Testing and monitoring air quality around schools is quick, the equipment is discreet and the installation doesn’t cause any disruption to pupils, students or local residents.

These tubes were installed at the beginning of each month and were sent to a lab to review and analyse the levels of nitrogen dioxide. A monthly report was provided to Croydon Council with a final review summarising the results and a recommendation for improving air quality.

Key statistics:

  • 2,340km cycled over the course of the project
  • 1,056 diffusion tubes installed
  • Nitrogen dioxide readings recorded in June 2021 were almost 50 per cent less that in January 2021


As the testing took place in January 2020, prior to the COVID pandemic, through to the end of the calendar year, we were able to capture a diverse range of results that reflected the impact of the various COVID-related lockdowns.

The results demonstrated a sharp decrease in NO2 from March 2020 (average 26.19 µg/m³) to April 2020 (average 18.64 µg/m³), as lockdown was put in place and many children attended school via zoom and parents worked from home. As restrictions were eased and COVID cases reduced, we found a gradual increase in NO2 between July and September associated with higher traffic levels. This shows a strong correlation between COVID restrictions and reduction of NO2 pollution.

As children across the country, not just Croydon, return to school, emissions are likely to rise again. The challenge now for schools is to educate, encourage and implement travel plans for their students that engages them and promotes a healthier environment.

Air quality monitoring is crucial to forming a clear understanding of the impact of air pollution on public health, particularly in children. If healthier environments and habits are established at a young age, they are more likely to continue a healthy lifestyle as they go into adulthood. By monitoring air in and around cities, we can use this data to locate and address problem areas quickly, with strategies such as:

  • School travel plans
  • Healthy school streets
  • Low traffic neighbourhoods
  • Green screen installations
  • Cycle training; and
  • Improved wayfinding

All of which can be easily implemented to lower pollution before it gets out of control. On top of this, areas with less and quieter traffic create more enjoyable places to live and work that encourage social interaction and attract more visitors/residents to come to the area.

Air quality monitoring is just the start of helping schools, communities and our cities become cleaner and more enjoyable to be in. Find out more about our work including school travel plans, TfL STARS workshops and our sustainable transport projects in our blog and case studies.

If you’d like to speak to us about our air quality monitoring service, contact us directly by emailing us at info@mpsmartertravel.co.uk or calling 0207 960 2553.