A study to assess the efficacy of a green screen to prevent the transport of vehicle emissions from the nearby road into the playground was carried out at in the Royal Borough of Kensington and Chelsea. An ivy screen was installed and NOX and PM10 were measured directly on either side of the screen using reference NOX analysers and indicative PM analysers. The difference in concentration between the roadside side and playground side of the screen was assessed as it matured.

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 pollution concentrations on the playground side of the screen by 24% for NO2 and 38% for PM10; both were higher than the measurement uncertainty and thus significant. Comparing school hours independently a reduction in concentrations of up to 36% and 41% were found for NO2 and PM10, respectively. This demonstrates that the screen is very effective during daytime hours, when both emissions and exposure are highest.

Although it is clear that the screen has a significant effect in preventing the transport of pollution from the roadside into the playground, further work would be required to assess the impact of the screen at greater distances from the road.

The full report can be found can be found here.

The study was funded by the Council, the GLA and Defra and more information can be found on the Royal Borough of Kensington and Chelsea Air quality projects page. />

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Item date 21/04/2017