Black carbon as a new air quality and health indicator of limited traffic zone (LTZ) interventions: The results of the 'Area C' monitoring campaigns at residential and kerbside sites in Milan, Italy

Background . An air quality monitoring project was carried out in 2012 to assess environmental and health effects of Milan ‘Area C’ LTZ. It was based on measurements of Black Carbon (BC) particles, a suitable metric for traffic pollution. Aims . To evaluate the environmental and health potential effects of the Area C LTZ. Methods . BC, PM10 and PM2.5 real-time 2 weeks measurements were performed in and outside LTZ in different seasons, both at residential and kerbside sites, BC measured by Aethalometers (Magee, USA) and PM by Aerocets (MetOne, USA). Results . At kerbside sites in summer, during working days with LTZ in force, in and outside Area C 24h mean (SD) BC concentrations were 2.5 (0.6) ug/m3 and 4.7 (2.1) ug/m3 respectively (p Conclusions . A significant difference was found in BC concentrations inside ‘Area C’ LTZ, with an improvement of one to two BC epidemiological change units, a remarkable reduction in particulate toxicity and related expected mortality and morbidity.