Noise is now recognised as the second-largest environmental health risk worldwide after air pollution by the World Health Organization. Research has linked long-term exposure to high levels of noise to cardiovascular disease, sleep disturbance, reduced productivity and mental health problems. In the EU, long-term exposure to noise is estimated to cause 12,000 premature deaths and chronic high annoyance for 22 million people per year. Two previous Science for Environment Policy Future Briefs focused on this pressing concern, highlighting research on a) how to reduce exposure to noise pollution (Issue 17) and b) the health costs of environmental pollution (Issue 21).
As global urbanisation continues rapidly, there is a need to find sustainable ways to mitigate rising noise levels in cities. The European Commission has proposed a policy target of reducing the share of people chronically disturbed by transport noise by 30% by 2030 under the Zero Pollution Action Plan. Traditional tools – such as traffic restrictions, sound-absorbing pavements and noise barriers – are expensive, slow to implement and insufficient for complex, densely built environments. As cities search for greener, more climate-friendly approaches to reduce noise levels, the creation and maintenance of urban green spaces has emerged as a promising solution. Research has shown they also help cool cities, manage stormwater, support biodiversity and improve residents’ wellbeing.
There is evidence that green space reduces sound transmission, but little is known about how different spatial arrangements of parks, trees, and vegetation influence noise patterns – particularly in cities where space is limited and development patterns vary widely.
This new study aims to fill this knowledge gap by evaluating land-use data from Lyon, France. The researchers analysed three 2 km by 2 km urban areas in Lyon representing low, medium and high building densities. Using open-source geographic data and crowdsourced noise measurements from citizens’ mobile phones on the Noise Planet platform, they applied spatial modelling tools to predict noise distribution in the three areas. They then examined 12 measurements of green space pattern (including patch size, shape complexity, connectivity, fragmentation, and distribution)1 and explored how combinations of these spatial characteristics influence noise levels differently depending on urban density.
Rather than providing direct recommendations for e.g. the optimum size or composition of green space areas within different urban areas, the work instead provides an overarching comparative view of how green space exerts influence in terms of its physical, morphological and spatial properties. The results show that the arrangement, connectivity, shape and fragmentation of green spaces influence how noise is experienced in a city. The building density of the urban area affects the relationship between green space and noise levels, with the same configuration of green space not having the same noise-reducing effect in a quiet suburban block as it does in a dense urban core.
In low-density areas where there are fewer buildings and larger green spaces, the total amount of green space has the greatest effect on decreasing noise levels, whilst in medium-density areas, the clustering of green spaces matters most. In high-density areas with the greatest number of buildings, fragmented but well-placed small patches of green space can reduce ambient levels of noise (especially when located close to noise sources like major roads).
A key offering from the paper is the methodology developed by the researchers, which could readily be adopted by those in control of urban planning decision-making. The methodology first designates regions as low, medium, or high density, before mapping noise distribution using publicly available tools and raw noise data, and then performing an analysis to identify which metrics, or combination of metrics, is most influential for noise mitigation in the areas of interest. The relationships between these variables and noise patterns can then provide insight into how to pragmatically and effectively create greener, quieter, healthier cities, to offer guidelines for spatial patterns tailored to urban density.
As the work is limited to three examples in one city, further research is needed to validate the findings and consider other factors that may influence noise (e.g. climate, economic conditions, population density, geography). However, the results suggest that cities could adopt evidence-based spatial design principles to make significant progress towards quieter, healthier public spaces with minimal disruption.
Footnotes:
1. The researchers use ‘the green space pattern index’ with three different index categories: area and edge metrics (which describe characteristics such as the size, proportion, perimeter, and edge density of green spaces), shape metrics (which reflect the regularity or complexity of green space shapes), and aggregation metrics (which capture the degree of aggregation, connectivity, and fragmentation of green spaces).
Reference:
Zhang, M. et al. (2025) Examining how green space patterns affect noise distribution in urban areas with varying built-up densities. Journal of Environmental Management 393, 127183. https://doi.org/10.1016/j.jenvman.2025.127183
To cite this article/service:
“Science for Environment Policy”: European Commission DG Environment News Alert Service, edited by the Science Communication Unit, The University of the West of England, Bristol.
Notes on content:
The contents and views included in Science for Environment Policy are based on independent, peer reviewed research and do not necessarily reflect the position of the European Commission. Please note that this article is a summary of only one study. Other studies may come to other conclusions.
