Trace element biomonitoring using mosses in urban areas affected by mud volcanoes around Mt. Etna. The case of the Salinelle, Italy Giuseppe Bonanno & Rosa Lo Giudice & Pietro Pavone Received: 12 November 2010 / Accepted: 29 August 2011 / Published online: 14 September 2011 # Springer Science+Business Media B.V. 2011 Abstract Trace element impact was assessed using mosses in a densely inhabited area affected by mud volcanoes. Such volcanoes, locally called Salinelle, are phenomena that occur around Mt. Etna (Sicily, Italy) and are interpreted as the surface outflow of a hydrothermal system located below Mt. Etna, releas- ing sedimentary fluids (hydrocarbons and NaCl brines) along with magmatic gases (mainly CO 2 and He). To date, scarce data are available about the presence of trace elements, and no biomonitoring campaigns are reported about the cumulative effects of such emissions. In this study, concentrations of Al, As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, V, and Zn were detected in the moss Bryum argenteum, in soil and water. Results showed that the trace element contri- bution of the Salinelle to the general pollution was significant for Al, Mn, Ni, and Zn. The comparison of trace concentrations in mosses from Salinelle and Etna showed that the mud volcanoes release a greater amount of Al and Mn, whereas similar values of Ni were found. Natural emissions of trace elements could be hazardous in human settlements, in particular, the Salinelle seem to play an important role in environ- mental pollution. Keywords Trace elements . Mud volcanoes . Salinelle . Etna . Environmental pollution Introduction Mud volcanoes are usually clay cone-shaped edifices of variable dimensions (from decimeters to kilo- meters) as a result of the extrusion of mud, rock fragments, and fluids such as saline water and gases (Higgins and Saunders 1974). According to Kopf (2003), mud volcanoes occur in 44 main sites throughout the world, both on land and offshore. These volcanoes are temporary structures whose eruptions, generally of short duration (hours to days), can be explosive or effusive, and may show a variable degree of activity. These features can be found in different tectonic settings, but they typically predom- inate at converging plate boundaries and are dissem- inated all along the Alpine–Himalayan collision zone (Bonini 2009). Mud volcanic emissions are consid- ered as the biggest source of natural CH 4 released into the atmosphere, although roughly two thirds of the annual emissions are anthropogenic (Kopf 2003). Though CH 4 rising from hydrocarbon traps is frequently the dominating gas fraction, mud volca- noes can be also driven by CO 2 (Milkov 2000; Kopf 2002; Mazzini et al. 2007). In Italy, mud volcanoes are distributed across northern Apennines and Sicily, and CH 4 is usually the most common gas, normally linked to the Environ Monit Assess (2012) 184:5181–5188 DOI 10.1007/s10661-011-2332-z G. Bonanno (*) : R. Lo Giudice : P. Pavone Department of Botany, University of Catania, via Longo 19, 95125 Catania, Italy e-mail: bonanno.giuseppe@unict.it