Smelling Wellness: Human Health Gains from Botanic Garden Scentscapes

This study investigated whether ambient biogenic volatile organic compounds (bVOCs) scent profiles emitted by botanic glasshouse vegetation influence quantifiable human health and wellbeing outcomes, extending evidence previously obtained in clinical settings. Over 11 months in 2024 (January–December), human participant trials were conducted at the Oxford Botanic Garden to compare the physiological and psychological impacts of 30-minute exposures in five different vegetation-rich glasshouses, each characterised by a distinct and complex bVOCs profile, with those of a plant-free control room containing minimal bVOCs. Pre- and post-intervention assessments were conducted on 43 participants using the State-Trait Anxiety Inventory (STAI), heart-beat rate (beats per minute), and heart rate variability (HRV), a widely used index of autonomic regulation. Glasshouse exposure produced significant reductions in STAI anxiety scores and decreases in heart-beat rate, while HRV indices remained stable relative to the control condition. Distinct scent profiles in the glasshouses included volatiles previously associated with therapeutic effects in clinical settings, suggesting that such vegetated environments may deliver meaningful physiological and psychological benefits. Overall, these findings highlight the potential public health value of aromatic plant species and the importance of incorporating them into urban green space planning and policy.