BREATHE: A feasibility study of green barriers to mitigate air pollution in school playgrounds

Grantham Scholar Dr Maria del Carmen Redondo Bermudez now works with the Content Team at the Centre for Climate Engagement. At the Grantham Centre she looked at nature-based solutions – a green barrier of vegetation – to mitigate air pollution around schools.

For a quick guide to green barriers you can read this interview with Maria.

BREATHE: the green barrier project

The urban landscape and its dynamics cause some of the most severe environmental and health problems. Air pollution caused by transportation has captured attention for its harmful effects on health, especially for its effect on vulnerable age groups, such as children. By modifying the urban landscape through the addition of vegetation with traits that mitigate air contaminants, BREATHE aims to address the air pollution problem with a ‘nature-based solution’.

Maria standing near a busy road using her pollution measuring tool
Maria measuring particulate matter of 10 and 2.5 microns – 5 and 20 times smaller than the size of a human hair.

The BREATHE project is environmental and social research, as well as technological innovation. Specifically, this project investigates the use of green barriers to mitigate air pollution. Through the use of green barriers, we aim to improve the health and well-being of children who are currently exposed to low quality air in school playgrounds.

Green barriers are vertical and horizontal spatial arrangements of various types of vegetation. Two schools – one in Sheffield and one in Buenos Aires – will receive green barriers. Find out more about GoGoGreen at Hunters Bar Infants School in Sheffield.

After they have been installed, the impact of the green barriers on air quality, health and psychological well-being will be assessed. And we will also examine the feasibility of carrying out the project in a developing country.

Once we have collected data, outcomes and lessons learned will be communicated. Our hope is to reproduce the positives in both the developed and developing world.

Outreach and impact

Team behind playground green barrier to launch toolkit for schools.
The University of Sheffield research team responsible for the award-winning green barrier at Hunter’s Bar Infant School launch a toolkit to guide schools through the process of developing their own playground pollution barriers.

In 2022 the BREATHE Barrier was shortlisted for the People’s Choice Award by Sheffield Design Awards.

Green infrastructure, schools and air pollution papers from Grantham Scholar. Congratulations to Maria del Carmen Redondo Bermudez on her 2 papers about green infrastructure in schools and air pollution. Here, Maria explains why these papers are important and outlines their key findings.

BREATHE in action - children planting the living barrier
Volunteers from Hunters Bar Infant School help plant the living barrier Oct 2019

CNBC news interviewed Maria in June 2020. They spoke to her about her project and linked it up to other global efforts to combat air pollution. Look here to read: In cities around the world, living walls and green barriers could lift our moods and help tackle pollution.

Do you want to know more about BREATHE and green barriers? Then read this interview with Maria to find out about the green barrier and how it reduces air pollution for children at the school.

The Nature of Cities Festival (Feb 2021): Maria presented an online ‘field trip’ to her green infrastructure projects in two schoolyards (in Sheffield and Buenos Aires) (ESP & ENG).

Grantham Centre Annual Symposium 2020: Maria spoke about her work and the pandemic. Specifically, how air pollution can make Covid-19 much worse for sufferers. You can find more in this write up: Symposium ’20: Racial justice, Covid and the SDGs.

‘A breath of fresh air!’ at Pint of science (May 2019): A talk with Rohit Chakraborty.

Folk Forest Festival (July 2019): Outdoor talk about trees and air quality.

Science stall at Blue Dot Festival (2019): Air quality interactive activities with the Urban Flows Observatory

COP25 in Madrid: attended as an observer from TUoS and the Grantham Centre


Urban Wilderness (2021). Maria has a placement with Urban Wilderness, the landscape architecture firm that co-designed the green barrier at HBIS. Maria will be the Planning and Engagement Coordinator for Our City Green Festival. Our Green City is an initiative to create green interventions in the city, along with festival events to promote a post-covid sustainable recovery’.

Maria Carmen Redondo Bermudez’ publications

Redondo Bermúdez MdC, Chakraborty R, Cameron RW, Inkson BJ, Val Martin M. A Practical Green Infrastructure Intervention to Mitigate Air Pollution in a UK School Playground. Sustainability. 2023; 15(2):1075.

Redondo Bermúdez, M.d.C.; Kanai, J.M.; Astbury, J.; Fabio, V.; Jorgensen, A. Green Fences for Buenos Aires: Implementing Green Infrastructure for (More than) Air Quality. Sustainability 2022, 14, 4129.

María del Carmen Redondo-Bermúdez, Anna Jorgensen, Ross W. Cameron, Maria Val Martin, Green infrastructure for air quality plus (GI4AQ+): Defining critical dimensions for implementation in schools and the meaning of ‘plus’ in a UK context, Nature-Based Solutions,
Volume 2, 2022, 100017, ISSN 2772-4115,

María del Carmen Redondo-Bermúdez, Idris Tugrul Gulenc, Ross W. Cameron, Beverley J. Inkson, ‘Green barriers’ for air pollutant capture: Leaf micromorphology as a mechanism to explain plants capacity to capture particulate matter, Environmental Pollution, Volume 288, 2021,
117809, ISSN 0269-7491,

Redondo Bermúdez M..C. (2020) Plants, Ambient Air Quality, and Human Health. In: Leal Filho W., Wall T., Azul A.M., Brandli L., Özuyar P.G. (eds) Good Health and Well-Being. Encyclopedia of the UN Sustainable Development Goals. Springer, Cham. del Carmen Redondo Bermudez


Prof Anna Jorgensen

Department of Landscape Architecture


Prof Beverley Inkson

Professor of Nanomaterials

Dr Ross Cameron

Department of Landscape Architecture

Dr Maria Val Martin

Leverhulme Centre for Climate Change Mitigation