Air quality impacts of aviation activities at a mid-sized airport in central Europe

Despite ample evidence that pollutant emissions from aircraft may cause or exacerbate human health problems and have considerable environmental impacts, ambient air quality measurements including particle number size distributions (PNSD) near airports are scarce. We performed two measurement campaigns of particulate (ultrafine particles (UFP) and PM1.0, PM2.5, PM10) and gaseous (NO, NO2, O3) pollutants near a mid-sized airport in Central Europe (Findel, Luxembourg) during summer 2018 and winter/spring 2019. Mean UFP number concentrations (5-350 nm) were dominated by nucleation mode particles that are one of the major environmental health risks in Europe. Mean values during summer (-9200 # cm-3) exceeded those measured during winter (-7800 # cm-3). PNSD maxima of UFP occurred at sizes of 12.6 nm in the summer and 14.6 nm in the winter when air masses arrived from the airport sector to the measurement site. K-means cluster analysis revealed that air masses arriving from forest or urban background sectors are characterized by an UFP signal that is a factor of five to 10 lower than of the airport sector. During the winter/spring season the main airport NO2 (and PM2.5) emissions are attributed to exhaust gases from heating systems of airport buildings. Pollutant concentrations (except O3), including UFP were diminished during daytime due to turbulent mixing, although flight movements were highest during that time. This study presents a new perspective on the critical role of mixed layer temporal dynamics on the dilution of pollutant and UFP concentrations that is influenced by airport siting and terrain.