LIVING GREEN SCREENS AS EFFECTIVE POLLUTION BARRIERS

Living green screens are becoming an increasingly popular solution to roadside air pollution. In particular, many primary schools situated on main roads in the most polluted areas of busy cities need a solution to harmful levels of air pollution close to playgrounds.

PM10 particles consist of a mixture of particle solids and droplets that are less than or equal to 10 micrometres in diameter. They are so small that they can easily get into lungs and the bloodstream. Most PM10 particles around our schools come from traffic emissions.

As part of London Mayor Sadiq Khan’s plans to improve pollution, 50 ‘air quality audits’ for primary schools in the worst polluted areas of London took place to identify hardhitting measures to protect the children from toxic air. Prior Weston Primary School, located in the Barbican, was the first school to be audited. Living Green Screens have been used around the perimeter of its playground to help absorb PM10 particulates. An automatic drip line irrigation system keeps maintenance simple. The planters were built on site from sleepers and are lined with a membrane, creating lots of seating. The lush ivy screens have refreshed the school playground, bringing green to a grey space.

Living Greens Screens have proven particularly effective when placed along highly polluted streets with buildings on both sides (street canyons). At these locations the air pollution is higher at street level than the area above the surrounding buildings. Greens Screens are therefore ideal for use in street planting schemes, forming a roadside barrier for highly localised protection from polluted air.

A recent study by Defra and the GLA shows that the use of our pre-grown Green Screens successfully reduced air pollution by “up to 36% and 41% for NO2 and PM10" when they were placed between a busy road and a school playground. We have worked with hundreds of schools across London to install thousands of metres of Green Screens. Not only do the screens help combat air pollution, they also improve the appearance of buildings and outdoor spaces by adding much needed greenery and texture. Exposure to nature has been shown to have positive effects on mental health and wellbeing at schools, including reduced stress levels, increased happiness, and improved concentration. These green walls also help to improve biodiversity by providing a habitat and food source for wildlife such as birds and insects.