Experimental and model assessment of PM_2.5 and BC emissions and concentrations in a Brazilian city – the Curitiba case study

Abstract. Data on airborne fine particle emissions and concentrations in cities are valuable to traffic and air quality managers, urban planners and landscape architects, health practitioners, researchers, and ultimately to legislators and decision makers. This study aimed at determining the emissions and ambient concentrations of black carbon (BC) and fine particles (PM_2.5) in the city of Curitiba, southern Brazil. The methodology applied combined a month-long monitoring campaign that included both fixed and mobile instruments, the development of emission inventories, and the dispersion simulation from the regional down to the street scale.

The mean urban background PM_2.5 concentrations during the campaign were below 10 µg m⁻³ in Curitiba city center, but two- to three-fold higher in a residential area, indicating the presence of unidentified local sources, possibly linked to wood combustion. Mean BC concentrations seemed to be more uniformly distributed over the city, with urban background levels around 2 µg m⁻³, which rose to about 5 µg m⁻³ in heavily trafficked street canyons. The dispersion modeling also showed high PM_2.5 and BC concentrations along the heavily transited ring road and over the industrial area southwest of Curitiba. However, the lack of in situ data over this area prevented the corroboration of the model outputs. The integrated approach used in this study can be implemented in other Brazilian cities as long as an open data policy and a close cooperation between municipal authorities and academia can be achieved.