Influence of Aviation Emission on the Particle Number Concentration near Zurich Airport

In addition to the much-publicized environmental impact of CO₂ emission by air traffic, aviation particulate emission also deserves attention. The abundant ultrafine particles in the aviation exhaust with diameters less than 100 nm may penetrate deep into the human respiratory system and cause adverse health effects. Here, we quantified the detailed aviation particle number emission from Zurich Airport and evaluated its influences on the annual mean particle number concentrations in the surrounding communities. The actual flight trajectory data were utilized for the first time to develop an emission inventory with high spatial resolution. The estimated total particle number emission was in the magnitude of 10²⁴ particles per year. The annual mean particle mass concentrations in the nearby communities were increased by about 0.1 μg m^-3 due to the aviation emission, equivalent to about 1% of the background concentration. However, the particle number concentration could be increased by a factor of 2-10 of the background level (10⁴ cm^-3) for nearby communities. Further studies are required to investigate the health effects of the increased particle number concentration and to evaluate whether the regulation based on the mass concentration is still sufficient for the air quality near airports.