Using geospatial trajectories to explore how the COVID-19 pandemic affects the associations between environmental attributes and runnability of park trails.

The worldwide coronavirus disease 2019 (COVID-19) pandemic and the associated social distancing measures have produced alterations in park visits of individuals, as well as their park-based physical activity (e.g. running exercise). Although studies on the influence of the COVID-19 pandemic on changes in running activity patterns are becoming an emerging focus, less is known about how these changes are related to the environmental attributes of parks before and after the pandemic, the knowledge of which is essential to planning green infrastructure that better supports physical activities. Therefore, we employed a volunteered geographic information approach to investigate the runnability of park trails in Shenzhen, utilizing self-tracking routes from Strava, in order to uncover the associations between trail characteristics and park features with the running intensity before and after the pandemic. Multilevel regression model analyses revealed that trail network connectivity was the only environmental attribute indicating consistent and positive associations with running intensity. Blue space density was positively correlated with running intensity in urban parks but indicated no significant association in forest parks before the pandemic. In the pre-pandemic era, population density was positively related to running intensity in urban and forest parks. However, after the pandemic, the associations between running behaviours and population density remained positive in forest parks but turned insignificant in urban parks. The outbreak of the pandemic also altered the influence of other park features (e.g. park shape and trail density) on running intensity. The evidence-based knowledge provides planners with significant insights into pandemic-resilient park planning for the post-COVID era.

Do objective and subjective traffic-related pollution, physical activity and nature exposure affect mental wellbeing? Evidence from Shenzhen, China.

Urban environment (e.g. greenspaces, air pollution and traffic noise) and individuals' behaviours (e.g. physical activity) have all been associated with mental wellbeing. The large majority of studies on the influence of nature exposure on mental wellbeing assumed that multiple pathways act independently, ignoring the interactions among potential correlated pathways that engage simultaneously. The parallel mediation approach fails to explore the complex associations of combined exposure to air pollution, traffic noise and nature exposure with physical activity, which in turn affect mental wellbeing. Hence, the interest of understanding the sophisticated interactions among different pathways is warranted. We utilized structural equation modelling to simultaneously evaluate whether actual and perceived traffic-related pollution and physical activity mediate the associations between mental wellbeing and nature exposure, which was assessed by Normalized Difference Vegetation Index (NDVI), green view index (GVI), green space density and park accessibility. In summer 2022, we conducted questionnaires from 1772 adults residing in 117 neighbourhoods in Shenzhen, China. Nature exposure was positively and directly associated with mental wellbeing in the single mediator model that considered physical activity only. The indirect effects of nature exposure on mental wellbeing were observed through all pathways in all models, except through the perceived acoustic quality pathway in the serial mediation model. In addition, the percentage mediated by perceived air quality was higher than that of perceived acoustic quality. The influence of nature exposure on mental wellbeing was only for a small proportion mediated by the physical activity pathway. The associations between nature exposure and mental wellbeing were modified by individual characteristics, such as gender, age, income level and alcohol usage, but not employment status and smoking behaviour. These findings point out the importance of both objective and subjective environmental features and human behaviours on mental wellbeing, as well as the necessity of considering multiple pathways simultaneously.