Beyond megacities: tracking air pollution from urban areas and biomass burning in Brazil

Most of the world's population lives in rural areas or small to medium-sized cities (totalling 68% of the world population), all of which are impacted by distant air pollution sources. In Brazil, primary pollutant emissions have decreased in urban centres because of government actions, while secondary pollutants such as surface ozone (O-3) increased. In addition, O-3 and its precursors can be worsening air quality in areas already affected by biofuels production, especially ethanol. We provide almost 3 months of hourly data (June 7, 2019 to August 25, 2019) for concentrations of O-3, CO2 and other priority pollutants from a mobile station positioned to distinguish among pollutant plumes (biomass burning, metropolitan area of SAo Paulo (MASP) and other cities). Although the concentrations of O-3 and CO2 were highest in the plumes from biomass burning, the MASP accounted for up to 80% of the O-3 concentration in communities over 200km away.