Performances of low-cost optical PM sensors for indoor air quality monitoring in mobility situations by car around Paris
Résumé
In many industrialized countries, people spend more than one hour a day in their vehicles where particulate matter (PM) could reach high concentrations [1]. Though such a situation has become a matter of public concern, the lack of concentration data makes the monitoring of these ambiances difficult to apprehend. In order to tackle this challenge, attention is redirected towards the low-cost sensing units. Indeed, besides some interesting features such as portability, fast-deployment and cost, these devices can help to remotely characterize and monitor the spatial and temporal patterns of pollution sources [2]. However, once deployed, sensors information may be unreliable if uncertainties or intrinsic sensors’ limitations are not taken into consideration [3]. In this study, the objective is to evaluate performances of low-cost optical PM sensors under running conditions near the Paris ring-road and motorways. An appropriate field test campaign was designed and carried out within an instrumental car equipped with a GPS tracker and, reference and equivalent PM-measurement methods. For PM10 and PM2.5 values, data comparisons were performed across different seasons and pollution contexts (urban and semi-urban). Such an approach allowed to consider the influence of the inside car conditions (temperature and relative humidity) and the one associated to the physico-chemical nature and morphology of the particles encountered in vehicle environment. If this first campaign demonstrated the feasibility of the deployment of micro-sensors for indoor air quality monitoring in mobility situations, the results lead to conclude that some technological improvements have to be implemented to ensure their validation in respect to reference methods.