Size distribution and chemical composition of airborne particles at Akrotiri Research Station, Crete, Greece

Particulate matter measurements were performed at the Akrotiri research station on the island
of Crete (Greece) using an 8-stages Andersen non-viable impactor. The main purpose of the
current work was to measure the ambient levels of PM10 particulate matter as well as the
concentrations of metals and ions in 8 different PM size fractions with aerodynamic diameter
cutoff at 9, 5.8, 4.7, 3.3, 2.1, 1.1, 0.7, 0.4 and a back-up filter for particles below 0.4 μm.
The mean PM10 concentration during the first sampling period of August 2007 was equal to
28.2 ± 14.0 μg m-3 (10/08/2007 – 26/08/2007), whereas during the second sampling period
(09/07/2008 – 16/07/2008) was 40.2 ± 16.9 μg m-3. Moreover, mean concentrations of PM2.1
particulate matter were measured on the average equal to a 41.0 % and 37.2 % of PM10,
respectively for the two corresponding sampling periods. The measurements showed high
concentration of fine particles (with aerodynamic diameter less than 0.9 μm), whereas the
mass concentration peak was located at an aerodynamic diameter close to 4 - 5 μm. Sulphate
was the most abundant anion PM10, whereas sea production ions, such as chlorine, sodium
and nitrate, were also in elevated concentrations presented. In addition, the crustal element
Fe was in higher concentrations in comparison to the measured heavy metals.