A comprehensive field study of air quality along a road surrounded by buildings confirmed that fences can help reduce traffic-related pollution by up to 1.7m and reduce pollutants inhaled by pedestrians, young children and cyclists.
The study, led by researchers at the University of Surrey’s Center for Global Clean Air Research (GCARE), placed a large array of instruments in and around a fence to measure the presence of various pollutants in various locations and described the impact of the fence. different heights and distances from the road.
This study develops a new understanding of the distribution of different air pollutants around a fence in a shallow street canyon where the width of the road is at least twice the height of the surrounding buildings:
- the overall concentration of air pollutants behind the fence changes;
- the effect of wind speed and direction on pollutant exchange in the presence of thickets; and
- horizontal and vertical distribution of air pollutants.
The information obtained will guide the improved design of green infrastructure barriers and validate microscale distribution models. However, it revealed a complex picture dependent on many factors (wind speed and direction, fence characteristics, pollutant type, and more), emphasizing that more field studies are needed to validate future modeling studies.
Measurements were taken over the course of about six weeks along Du Cane Road near White City in West London as part of the EPSRC-funded INHALE project, which saw the University of Surrey collaborate with researchers from Imperial College London and the University of Edinburgh. This shallow alley canyon was chosen for its long roadside fences, traffic and type of transportation (including cyclists) using the road, and proximity to a ground-based air quality monitoring station. Du Cane Road has one lane in each direction and runs through a residential area.
In 2019, air pollution was ranked as the fourth leading risk factor for premature death worldwide. It has been reported by the European Commission as the second biggest environmental problem after climate change because levels of air pollutants in many European cities exceed allowable limits.
Professor Prashant Kumar, Founding Director of the Global Center for Clean Air Research (GCARE), said: “Many factors have an impact on air quality, and there is no detailed study of the true impact of greenery in making the air cleaner – This study makes significant advances, but the effects of air pollutants on urban Much more research is needed to properly understand how best to help disperse air pollutants in the canopy layer, the air layer that runs from the ground surface to the tops of buildings and trees, in complex built environments such as street canyons.”
Findings published Environment International.
New online tool to help residents reduce the impact of traffic-related air pollution
Prashant Kumar et al. Understanding the effects of roadside fences on the horizontal and vertical distributions of air pollutants in street canyons. Environment International (2021). DOI: 10.1016 / j.envint.2021.106883
Provided by the University of Surrey
Quotation: Fences reduce pollution at respiratory height in shallow street canyons, study confirms October 14, 2021 from https://phys.org/news/2021-10-hedges-pollution-height-shallow-street.html (2021, Oct. 14) )
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