Complementing mobile measurements with Walking Interviews: a case study on personal exposure of commuters in Chennai, India

When commuters move around the city they are exposed to different environmental stressors, of which air and noise pollution have an especially adverse physical and mental health impact. Most exposure research uses sensor data (stationary or wearable) or closed questionnaires to measure personal exposure. However, these methods do not give insight into on-site perceptions of exposed individuals and their related behaviour. To address this, we discuss (1) existing methods to research perceived and measured exposure in transit and (2) introduce a novel mixed-method approach, which we tested in a case study in Chennai, India. We used Walking Interviews and GPS-tracking to investigate perceptions and behaviour regarding air and noise pollution on the move and combined it with data of wearable sensors. The results show that the perception of air and noise pollution is highly context-dependent. This mixed-method approach is advantageous for an investigation of perceived and objective exposure and the related behavioural patterns while moving around the city. Such qualitative and quantitative exposure data of commuters can be spatially visualized and communicated to decision-makers with help of qualitative geographic information system (GIS) approaches. We argue that the potential of this mixed-methods approach to support healthier daily commutes in urban areas should be further elaborated in urban and transport-related studies.