Vehicle traffic showing exhaust fumes on a busy London road

Air Quality Project

Air Quality Project, 2021-2023

Working in partnership with the Hampstead Neighbourhood Forum, the Heath & Hampstead Society, and the London Borough of Camden, Green School Runs carried out a local air quality monitoring project focused on nitrogen dioxide (NO₂) levels at ten locations across Hampstead.

The ‘Air Quality’ project began with the installation of diffusion tubes on 27 September 2021. The results were later compared with data from a similar study conducted in 2015. That earlier study had revealed unexpectedly high NO₂ levels for a green, residential area like Hampstead, and played a key role in shaping some of the environmental policies included in the Hampstead Neighbourhood Plan — formally adopted following a public referendum in 2018.

This follow-up project aimed to assess changes over time and raise continued awareness about air pollution in the area.

The team was advised by Camden’s Air Quality Officer throughout the project. The readings collected were of reference quality, suitable for comparison with Camden’s official air quality data.

Dozens of volunteers contributed to the success of the project, including pupils from three local schools: Devonshire House, Maria Montessori School, and UCS Junior Branch. Each group of students took responsibility for monitoring the diffusion tubes located near their own school, actively participating in the data collection process, thus learning about air quality firsthand.

Project Updates

The HNF (Hampstead Neighbourhood Forum) Air Quality Project volunteers, including teachers and student from three local schools, have now managed to collect a year's worth of NO2 air pollution data in 10 locations across Hampstead. The HNF and Camden Council are still waiting for guidance from DEFRA before they can publish any specific figures, but an initial analysis of the data shows the following trends:

- NO2 pollution around Hampstead has fallen significantly since 2015. It is encouraging to see a marked improvement in NO2 levels in recent years, suggesting that measures to reduce air pollution such as the extension of the ULEZ (starting October 2021) and an increase in electric cars are having a positive effect. However the numbers also show that we still have some way to go to reduce air pollution to levels deemed safe by public health experts.

- NO2 levels have reduced more in some places than others: significant levels of NO2 pollution remain along busy roads such as Pond Street, South End Green and Heath Street, and roads with heavy school traffic such as Arkwright Road and Lyndhurst Road. Pollution levels here are still many times higher than the annual average limit suggested by the WHO.

- NO2 levels were found to be higher in the colder months than in the summer. Some of this is likely to be related to a reduction in commuting and the absence of school traffic during the summer holidays, but heating also plays a role in air pollution.

A limitation of looking at average levels of air pollution is that, while it gives a good indication of the overall problem, it masks the peak levels of pollution during rush hour, which have a detrimental effect on human health.

Unfortunately, the scope of this project did not allow the monitoring of other air pollutants in Hampstead, especially harmful particulate matter, which is produced by traffic (including electric cars), wood burning stoves (including eco-designed stoves) and emissions from manufacturing.

The first two months of laboratory data suggest a reduction in NO2 pollution compared with the levels we recorded six years ago, though it remains in excess of legal limits. However, it is far too soon to predict the final results.

There is certainly no cause for complacency about the quality of the air we breathe. In recent years epidemiologists have learned more about how air pollution harms us, and the World Health Organisation has lowered the limits that it suggests we should consider to be safe. The government is considering revising the legal limits, and Camden plans to hold a consultation soon on its next Clean Air Action Plan.

Air Quality Project