During 2001 the Mount Etna had a large eruption producing a large amount of pyroclasticproducts consisting of a mixture of glass, minerals and soluble salt materials (SAF)encrusting solid particles.Inhalation of the finest of these materials induced pulmonary diseases in people living insubjected areas and gave us the possibility to collect bronchoalveolar lavages (BAL) frompeople in care in Catania hospitals.Concentrations of several trace elements measured in these BAL fluids (BALF) evidencestrong enrichments in several trace elements compared to reference values. Relatedenrichments factors, calculated with respect to composition of volcanic ejecta (EFASH),show similar values in BALF and in SAF for V, Cr, Fe, Cu, As, lanthanides (apart fromCe), Pb and U, suggesting that these elements have originated by leaching of finest inhaledvolcanic particles. EF values calculated with respect to Upper Continental Crust (EFUCC)for Co and Mn resulting close to 1 similarly indicate that these elements are probablyreleased in human lungs from inhaled particles of non-volcanic, lithogenic nature. On thecontrary, both EFASH and EFUCC values calculated for other investigated trace elementssuggest the occurrence of further sources of inhaled solids, probably from anthropogenicsources. To test this hypothesis EF values of the latter elements with respect to a typicalroad dust composition (EFRD) have been calculated and this origin is strongly suggestedfor Ni, Cu, Cd and Pb. But La, Ce and Y EFRD values remain unexplained in terms ofparent material and a further anthropogenic origin for these elements can be invokedprobably originated by fluid catalytic converters used during hydrocarbon refineryactivities, that are usually characterised by high Y, La and Ce contents.Statistical evaluation of BALF compositions according to Principal Component Analysiscorroborates above mentioned suggestions identifying three main components in thevariance space: the first one (46% of the variance) grouping the same elements previouslyattributed to the volcanic origin (except Pb), the second one (27% of the variance)grouping Ni, Cd, Y, La and Ce and a third component (12% of the variance) identified byCo, Ni, Cu, Pb and, secondarily, La and Ce. These results show that statistical andgeochemical assessment of BALF analyses are together able to identify suspendedatmospheric solids in the environment recognising mixtures of natural and anthropogenicproducts.
|Numero di pagine||1|
|Stato di pubblicazione||Published - 2011|