A novel multipollutant wearable device for personal air quality monitoring

Air quality monitoring networks rely on a limited number of fixed stations, whose costs and spatial coverage limit the assessment of individual exposure. Thus, the use of Low-Cost Sensors (LCSs) have seen growing adoption, as they offer real-time measurements with high temporal resolution at lower cost. The University of Milano-Bicocca, in collaboration with Rome Advanced District (ROAD) and the Italian firm XEarPro Srl, developed Respiro, a wearable multipollutant device for monitoring air quality in indoor and outdoor environments. The Respiro device has been used in three different applications in the Biccocca neighborhood of Milan: 16 devices were used for personal monitoring along two different predefined tracks; 32 devices were deployed within the European project MeetME@School, a citizen science initiative; and 3 devices were deployed in a short-term intercomparison campaign against a reference instrument (Dust Monitor Grimm 1.108). Field testing showed good agreement (Spearman correlation > 0.77) with the reference instrument for both PM1.0 and PM2.5, while PM10 showed weaker performance, consistent with the typical behavior of optical particle counters. Inter-device variability remains below 5% cv across all parameters. Results indicate that Respiro is a promising tool for exposure assessment and for the spatial characterization of PMx at neighbourhood scale.