Urban Cycling Lab: A citizen science protocol for assessing and reducing exposure to environmental stressors among bike commuters.

Bike commuters are regularly exposed to environmental stressors that impact their health and well-being. The Urban Cycling Lab in Ljubljana, developed within an Urban Living Lab and citizen science framework, engaged stakeholders in assessing exposure to particulate matter and noise, and in co-creating strategies to reduce it. This citizen science intervention combined sensor-enhanced ICT tools with behaviour change theory to assess both environmental and behavioural aspects of exposure. Exposure assessment included low-cost personal sensors as well as chemical analysis in biological samples to evaluate environmental exposure, while biochemical analysis of biological samples aimed to evaluate potential biological effects of exposure. Participants collected data using portable sensors and accessed real-time exposure comparisons via the Route Exposure Comparator web app. Biological samples (peripheral blood and spot urine) were collected from each participant at the end of data collection period. Data on sociodemographic characteristics, commuting habits, and environmental health literacy were collected via questionnaires. Ethnographic methods captured participants' perceptions, route choices, and the intervention's influence on commuting behaviour. This paper presents the methodology used to implement this intervention and provides a transferable model for participatory environmental exposure assessment.•Designed and implemented a citizen science intervention to assess cyclists' exposure to air pollution and noise using sensor-enhanced ICT tools.•Promoted environmentally informed route choices through behaviour change strategies and digital feedback.•Applied survey and ethnographic methods to explore commuting behaviours and intervention impact.