The concentrations, size distributions, and elemental compositions of atmospheric aerosol particles over a small but representative (in terms of size, population, and geographical characteristics) insular coastal city in the North Aegean Sea were measured during winter and summer. Mean PM_2.0 and PM_1.0 concentrations at the city centre were respectively 26 and 21 μg m⁻³ during the cold period, and 21 and 15 μg m⁻³ during the warm period. Although these concentrations are considerably lower compared to corresponding values of PM_2.5 and PM_1.0 recorded in large cities in the region, they are still very close to the mean annual standards set by the EU for PM_2.5. Higher average mass concentrations (by ca. 26–36% for Total Suspended Particles, PM_2.0 and PM_1.0) were observed in the cold period compared to those in the warm period due to the additional emissions from domestic heating and the weaker atmospheric dilution. The elemental composition measurements showed that crustal and anthropogenic elements (i.e., K, Ca, Ti, Mg, Fe, As, S) in the collected particle samples were also enriched when polluted air masses were transported from Northeastern Turkey. These measurements also showed that natural sources contribute sea-salt and re-suspended soil to the particulate matter load in the city's atmosphere. Non-exhaust traffic emission sources were also found to be an important contributor, as indicated by the good correlations (R² = 0.40–0.91) between crustal and traffic-related elements (i.e., Zn, Cr, Cu, and Mn). Overall, PM measurements in the urban environment in the region are relatively high, being influenced by both local sources and long-transported air masses.

The unprecedented growth in aviation during the last years has resulted in a notable increase of local air pollution related to airports. The impacts of aviation on air quality can be extremely high particularly around airports serving remote insular regions with pristine atmospheric environments. Here we report measurements that show how the atmospheric aerosol is affected by the activity at a small airport in a remote region. More specifically, we provide measurements performed at the airport of Mytilene, Greece, a regional yet international airport that serves the entire island of Lesvos; the third largest island of the country. The measurements show that the activity during landing, taxiing and take-off of the aircrafts accounted for up to a 10-fold increase in particulate matter (PM) mass concentration in the vicinity of the airport. The number concentration of particles having diameters from 10 to 500 nm also increased from ca. 4 × 10² to 8 × 10⁵ particles cm^− 3, while the mean particle diameter decreased to 20 nm when aircrafts were present at the airport. Elemental analysis on particle samples collected simultaneously at the airport and at a remote site 3 km away, showed that the former were significantly influenced by combustion sources, and specifically from the engines of the aircrafts. Our results show that despite their small size, local airports serving remote insular regions should be considered as important air pollution hotspots, raising concerns for the exposure of the people working and leaving in their vicinities to hazardous pollutants.