For several years now, there has been increasingly intensive discussion of the emissions and impacts of ultrafine particles (UFP) at the airport in Frankfurt am Main. (Ultrafine particles are those with a diameter of less than 100 nm; 1 nm is one billionth of a metre). The Forum Flughafen und Region (FFR, Airport and Region Forum) has set itself the task of conducting extensive investigations into the exposure caused by ultrafine particles and their effects on health in the Rhine-Main region.