publicações selecionadas A global observational analysis to understand changes in air quality during exceptionally low anthropogenic emission conditions Evolution of Vehicle Emission Factors in a Megacity Affected by Extensive Biofuel Use: Results of Tunnel Measurements in São Paulo, Brazil Simulation of O<sub>3</sub> and NO<sub><i>x</i></sub> in São Paulo street urban canyons with VEIN (v0.2.2) and MUNICH (v1.0)