Preliminary Study about the Origin of Trace Elements in the Atmospheric Deposition in Two Brazilian Subtropical Estuaries

The atmospheric deposition of dissolved trace elements was investigated in two subtropical estuarine systems, located on the coast of Parana, Southeast Brazil. The samples (n = 91) were collected in three periods, from May to September 2010, in four different areas. Trace elements concentrations (Al, Fe, Zn, Mn, Ba, Ca, Mo, V, As, Cu, Co, Ni, Cr and Pb) were determined for dissolved fraction using inductively coupled plasma-mass spectrometry (ICP-MS). pH measurements revealed the occurrence of a slightly acidic precipitation in the investigated points. Among the trace elements, Zn was the most abundant, followed by Al, Fe, Mn, Cu, Ba and V. The analysis of the enrichment factors enabled the identification of the different sources of the analysed elements. The origin of the Al and Fe elements were entirely continental, whereas Zn was primarily associated with human activities. Thus, the atmospheric deposition may be a primary route of exposure to anthropogenic Zn for estuarine biota.