Volume 15, No. 2, April 2015, Pages 410-425 PDF(3.4 MB)
Chemical Composition of Fine and Coarse Aerosol Particles in the Central Mediterranean Area during Dust and Non-Dust Conditions
Antonella Malaguti, Mihaela Mircea, Teresa M.G. La Torretta, Chiara Telloli, Ettore Petralia, Milena Stracquadanio, Massimo Berico
ENEA - National Agency for New Technologies, Energy and Sustainable Economic Development, via Martiri di Monte Sole 4, 40129 Bologna, Italy
- Dust contribution to fine and coarse aerosol in a central Med. area was measured.
- Changes in chemical composition due to the presence of dust particles were found.
- An increase of SIA in the fine and coarse fraction was favoured by dust particles.
- The effect of different dust indicators based on chemical tracers was investigated.
A two-month field campaign was carried out from May to June 2010 at a remote site (Trisaia ENEA Research Centre) in the Southern Italy aiming to identify and quantify the changes of aerosol chemical composition in the presence of Saharan dust. The 24-hr PM10 and PM2.5 filter samples were analyzed by mass, carbonaceous species, inorganic ions and elemental composition. Saharan dust transport events were identified with two approaches: one recommended by EC (2011) and one based on indicators derived from measurements. Three indicators were used: PM2.5/PM10 mass concentrations ratio, Ca/Al ratio and Al concentration. Based on these criteria, four Saharan dust transport events were identified, but only one had elevated dust concentration and leaded to an exceedance of the European short-term (24 hour) limit value of 50 µg/m3 for PM10 (June 16th). The comparison of chemical composition of fine and coarse aerosol fractions during dust and non-dust conditions shows that the presence of dust increases NH4 and nssSO4 concentrations in the fine fraction and NO3 and nssSO4 concentrations in the coarse fraction. OC and EC concentrations also increase in the fine fraction during dust transport. The uptake of primary and secondary species, inorganic and organic, by dust particles changes their composition and, thus, their properties and this may have implications for human health and climate change.
Saharan dust; Fine and coarse chemical composition; Central Mediterranean (Southern Italy).