The first health and wellbeing project will focus on the role and mechanism of biogenic volatile organic compounds (VOCs) in promoting positive health outcomes. There is now compelling evidence that VOCs released by certain species of plants can induce physiological and psychological changes that improve aspects of physical and mental health including for example, reduced levels of stress and anxiety along with lower levels of stress hormones and elevated nature killer cells in our blood serum when participants walk in environments that have high levels of these compounds in the ambient air. However, an important knowledge gap concerning the influence of these compounds is how much variation in ambient levels found across city spaces, affects the associated health outcomes. For example, is there a greater benefit to be obtained both in short term and longer-term health outcomes if you walk in city green spaces which have a higher number of trees which emit VOCs such as pinene (and know in laboratory settings to have important positive health benefits), compared with areas which do not have species that emit these VOCs? Our aim is to address this question and to quantify a dose-response relationship for ambient VOCs and how this varies with vegetation type and cover across the city. Once this first step has been completed, we will then set up a series of experiments with participants from different age groups, and socio-economic status to determine over a set-interval of time, the benefits of visiting on a weekly basis on a set of physical and mental health outcomes.

The first phase of research is taking place between March and June 2023. We aim to quantify the difference in biogenic VOCs between sites around Oxford with different vegetation coverage. To do this we will sample the ambient levels of VOCs in the air at a number of wooded sites and quantify their VOC profile with GC-MS analysis.

The second phase of the research will take place between March and June 2024. This will be a trial pilot study before the main randomised controlled trial in which participants will visit the areas profiled over the course of several weeks. We will assess whether the difference in VOCs between the sites can explain any differences in physiological and self-reported wellbeing.