Preprint: A walk in the park – identifying healthy greenspaces using scents

Preprint: A walk in the park – identifying healthy greenspaces using scents

botanic gardens map

William T. Kay, Anya Lindström Battle, Mahal Humberstone, Molly Tucker, Kieran E. Storer, Geoffrey Kite, Katherine Willis

medRxiv 2025.08.27.25334443; doi: https://doi.org/10.1101/2025.08.27.25334443

Abstract

  1. Biogenic volatile organic compounds (bVOCs) are carbon-based secondary metabolites emitted by all kingdoms of life, often playing roles in stress protection, growth modulation, and inter-organism communication. In plants, bVOCs such as terpenes (e.g., alpha-pinene) are highly prevalent and have been linked to diverse health benefits including stress reduction, enhanced cognitive function, and neuroprotection. In contrast, urban environments contain anthropogenic VOCs (aVOCs) produced from vehicles and industrial activity. Examples of aVOCs such as benzene, toluene, ethylbenzene and p-xylene (BTEX compounds) are all associated with serious health risks. Our study proposes a novel, health-oriented metric for site evaluation.

  2. Primarily, we identified which volatiles appeared in the air across six urban greenspaces on a single date in Oxford Using Tenax™ filters and GCMS analysis. Data were processed using workflows optimised for large metabolomics-style datasets resulting in the identification of 245 unique compounds of biological interest – a significant increase from those identified in previous open-air studies. Using multivariate analysis, we show sites contain significantly different volatile profiles and further, by monitoring a single over 12 months, that temperature, humidity, wind-speed and rainfall all affect the presence of health-promoting compounds.

  3. Target 12 of the Global Biodiversity Framework calls for expanding high-quality, health-promoting urban greenspaces. Our findings (i) support the integration of VOC profiling into urban planning and public health strategies to enhance the well-being of urban populations, and (ii) that environmental variables further enable us to prescribe the most beneficial periods for outdoor recreational activities.