Evaluation of the environmental impact of volcanic emissions from the chemistry of rainwater: Mount Etna area (Sicily)

The S, halogen and NO3 contents of rainwater samples from the Etnean area w ere studied in order to define the environmental impact of plume emissions on the local environment. Samples, collected on a network of 11 bulk rain g auges, show significant variability in anion content, which can be ascribed to different meteorological and environmental conditions at each sampling site and to a variable distance from the different source areas. Data analy sis suggests that S, F, Cl and Br are mainly magma-derived, whereas NO3 mai nly originates from anthropogenic sources. Samples collected from sites clo se to craters display considerable temporal variability, with increased ani on concentrations being recorded during periods of intense plume degassing. Variations in precipitation also induce significant modifications in the c hemistry of the meteoric-derived Etnean groundwaters. (C) 2001 Elsevier Sci ence Ltd. All rights reserved.