Planting and Playgrounds

New evidence shows planting around school playgrounds protects children from air pollution: Scientists have published new evidence showing that selective planting of vegetation between roads and playgrounds can substantially cut toxic traffic-derived air pollution reaching school children.

The new findings, published in the journal Scientific Reports, demonstrate that roadside vegetation can be designed, installed and maintained to achieve rapid, significant and cost-effective improvement of air quality. Exposure to traffic-related air pollution has been linked with a range of health risks including cardiovascular, respiratory and neurological health. These risks are likely to be exacerbated in young children attending primary schools next to busy roads as their major organs are still developing and children have a higher breathing rate than adults.

Exposure to fine particulate matter in air pollution is reportedly the largest environmental risk factor contributing to cardiovascular deaths and disease globally, and is linked to around six to nine million premature deaths each year. A team of researchers led by Barbara Maher, Emeritus Professor at Lancaster University, and supported by Groundwork Greater Manchester, installed “tredges” (trees managed as a head-high hedge) at three Manchester primary schools during the summer school holidays of 2019.

One school had an ivy screen installed, another had western red cedar and the third school had a mixture of western red cedar, Swedish birch and an inner juniper hedge. A fourth school, with no planting, was used as a control. The school with the ivy screen saw a substantial reduction in playground particulate matter concentrations, but an increase in black carbon. The playground with the mixture of planting saw lower reductions in air pollution to that of the western red cedar. The biggest overall reductions in particulate matter and black carbon were shown at the school with western red cedar planted. The results showed almost half (49%) of black carbon and around 46% and 26% of the fine particulates, PM2.5 and PM1 emitted by passing traffic were captured by the western red cedar tredges.