Dr Luís Novo, SRUC
RSE Small Research Grant awardee

Dr Luís Novo. Photograph: Ian Georgeson Photography

In the last few decades, air pollution and traffic-related metal emissions have been linked with increased morbidity and mortality. Both factors are of particular concern in urban areas, where high pollutant concentrations and dense populations converge.

Particulate matter (PM) produced and kicked up by road traffic comprises microscopic solids or liquid droplets found in the air that can be inhaled and cause severe health problems due to their small size. Short-term exposure can cause coughing, wheezing, and shortness of breath, while long-term exposure can lead to chronic bronchitis, lung cancer, and premature death. Particulate matter can also aggravate pre-existing conditions such as asthma and heart disease.

PM is categorised based on the particles’ aerodynamic diameter. Coarse particles – known as PM10 – such as dust, pollen, and mould have diameters of less than 10 µm. PM2.5 particles, such as combustion particles, organic compounds, and metals, are even finer, with diameters of 2.5 µm or less. While both PM10 and PM2.5 can penetrate deep into the lungs and even reach the bloodstream, the latter poses most significant risk.

Traffic-related air pollutants are released near ground level, producing higher pollutant concentrations in soils adjoining roads than in urban background levels. Roadside soil acts as a sink for metal-enriched traffic emissions. These metals threaten the environment and human health as they can migrate, accumulate in plants and animals, and ultimately enter the food chain.

In this context, green infrastructure – trees, hedges, green walls, etc. – has been increasingly appreciated for its array of ecosystem benefits, including rainfall retention, noise reduction, biodiversity restoration, and the abatement of PM2.5 pollution. Hedges are significant because they constitute a ground-level barrier where traffic-related emissions are greater and more harmful to residents and pedestrians, especially children and the elderly. Despite this, knowledge of urban hedges is relatively limited, particularly concerning metal accumulation and how the traits of different plant species influence PM2.5 capturing.

RSE Small Research Grant awardee Dr Luís Novo, an SRUC Challenge Research Fellow, is conducting a preliminary survey looking into particulate matter and heavy metal concentrations in hedges, soil, and dust across different locations within Edinburgh. The results will illuminate how factors such as traffic volume, roadside distance, and plant traits, among others, influence the hedges’ pollution abatement capacity.

Capturing data from Edinburgh’s urban hedges. Photograph: Ian Georgeson Photography

Dr Novo, whose work focuses on plant-based technologies like phytoremediation and phytomining, is especially interested in unfolding the potential of plants for tackling legacy and emerging pollutants and harvesting technology-relevant elements. His project will deliver invaluable data about the role of urban hedges in alleviating traffic-related heavy metal and PM pollution in Edinburgh. The results will be shared with practitioners, scientists, the local community, and local government authorities, not only to stress the importance of urban green infrastructure but also to aid in adopting more efficient measures and policies.

Dr Novo commented,

Implementing urban green infrastructure is paramount to secure the passive control of roadside metal and PM pollution. The RSE Small Research Grant was crucial to enable an exploratory survey that otherwise would be difficult to conduct. Interestingly, the endorsement from RSE has also facilitated community engagement and collaboration with the project activities. Considering its importance and timeliness, this project will likely lay the groundwork for a more detailed follow-up study to generate greater datasets and analysis across Scotland.”

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Designed to support personally conducted high-quality research by covering eligible costs arising from a defined research project.