Elucidating the sources and dynamics of PM10 aerosols in Cienfuegos (Cuba) using their multi-stable and radioactive isotope and ion compositions
In this study, PM10 aerosol samples were collected at 4 urban and 1 rural sites in the region of Cienfuegos (Cuba) and analyzed for their chemical compositions (total carbon (TC), total nitrogen (TN), NH4+, Cl-, NO3- and SO42-) and their stable carbon (delta C-13) and nitrogen (delta N-15), and radioactive (Pb-210, Be-7, Cs-137 and K-40) isotope systematics, in order to better constrain both their sources of pollution and their atmospheric dynamics. The average PMic, concentrations varied from 21.67 +/- 8.54 mu g.m(-3) at the rural site to 39.01 +/- 8.23 mu g m(-3) at an urban site characterized by high road traffic. Chemical compositions showed low variability and similar abundances of the ionic species, but we observed strong correlations between i) NH4+ and SO42- that indicates the formation of secondary ammonium bisulfate (NH4HSO4), and ii) between PM10, and TC highlighting the significant influence of carbonaceous aerosols. We are reporting here the first Pb-210 aerosol concentrations in this region and demonstrate that, coupled with the corresponding Be-7 concentrations, they allow characterizing the dynamics of the regional continental air masses. delta C-13 values in PM10, appear to be controlled by i) emissions from different types of combustion sources, including fossil fuel and biomass burning and ii) carbonate inputs from the industrial activities located around the limestone quarries, east of the city.