Real time assessment of stress experienced during travel times in Barcelona, Spain, using novel smart phone technology

Background With the development of ubiquitous sensing technology, opportunities are opening up for novel research on real-time and real-life responses to stressors in the environment. Our aim was to assess levels of stress as a result of typical urban commute-time exposures. Methods We equipped 36 volunteers in Barcelona for 5 days with an Android phone fitted with CalFit to measure geo-position and physical activity, and with a Bodymedia Sensewear, which measures Galvanic Skin Response (GSR). Variables reflecting potential stressors or soothers (traffic, air pollution or greenery) at a microscale level were collected. We identified travel periods and modes and linked minute-by-minute GSR and physical activity measurements to various stressors at each geoposition. We developed generalized additive models of GSR as a function of stressors, accounting for physical activity. Results We conducted a preliminary assessment on 764 one-minute measurements from participants walking, 690 cycling, 634 in the metro, ...