This report presents the EMEP activities in 2018 and 2019 in relation to transboundary fluxes of particulate matter, photo-oxidants, acidifying and eutrophying components, with focus on results for 2017. It presents major results of the activities related to emission inventories, observations and modelling. The report also introduces specific relevant research activities addressing EMEP key challenges, as well as technical developments of the observation and modelling capacities.