This report presents the EMEP activities in 2019 and 2020 in relation to transboundary fluxesof particulate matter, photo-oxidants, acidifying and eutrophying components, with focus onresults for 2018. It presents major results of the activities related to emission inventories,observations and modelling. The report also introduces specific relevant research activitiesaddressing EMEP key challenges, as well as technical developments of the observation andmodelling capacities.