In November 2013 an ivy green screen was installed at St Cuthbert with St Matthias CE Primary School along a wall directly adjacent to the Warwick Road (A3220), Earls Court. Kings College London Environmental Research Group monitored the project on behalf of the Royal Borough.
Monitoring of Nitrogen Dioxide NOX and Particulate Matter PM10 sampled either side of the screen was undertaken for a period of 12 months from November 2013-November 2014. The difference in concentration between the busy roadside side and playground side of the screen was assessed as the green screen matured.
Report on the research findings of a ‘green screen’ project at St Cuthbert’s with St Matthias Primary School to reduce the impact of harmful vehicle emissions.
The screen was found to be an effective pollution barrier once the ivy had started growing and a significant impact could be seen once the screen had matured. The ivy screen led to a decrease in the NO2 concentrations on the playground side of the screen by 24%, this was higher than the measurement uncertainty of 7% and was therefore significant. The decrease in the PM10 concentrations on the playground side of the screen was 38%; this was higher than the measurement uncertainty of 15% and was therefore significant.
Comparing school hours independently a reduction in NO2 concentrations of up to 36% and a reduction the PM10 concentrations of up to 41% was found. This demonstrates that the screen is very effective during daytime hours, when both emissions and exposure are highest.
The reductions in NO2 and PM10 concentrations are broadly similar; the PM10 reductions are slightly higher than those for NO2 once the green screen has fully matured. This may illustrate slightly different effects that the screen is having on gases or particles. As the NO2 concentration is lower than the PM10 the gas may be passing through the screen while the particles are being filtered by the increased foliage.
The project has shown us that the introduction a green screen can have a significant effect in preventing the transport of pollution from the roadside, Further work would be required to assess the impact of the screen at greater distances from the road.
It is recommended that the Committee note the findings of the research.
It is clear that the screen has a significant effect in preventing the transport of pollution from the roadside into the playground.
The results of this research project provide an evidence base for the future use of greening initiatives within the borough to assist in the reduction of local air pollution from road side sources. This would be particularly beneficial to children and vulnerable members of the general public with medical conditions affected by poor air quality.
Director for Environmental Health, RBKC
So look around your local area and you can easily plant some ivy or contact the Borough or your local Councillors about Green walls – you can get support via City Living Local Life at RBKC.
Other Resources and websites that you may find of interest:
Clean Air in London:
Analysis of Air Pollution Exposure in London 2017: