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Passive samplers were used to measure the atmospheric concentrations of SO2 naturally emitted at three volcanoes in Italy (Etna, Vulcano and Stromboli) and of H2S naturally emitted at three volcanic/geothermal areas in Greece (Milos, Santorini and Nisyros). The measured concentrations and dispersion patterns varied with the strength of the source (open conduits or fumaroles), the meteorological conditions and the area topography. At Etna, Vulcano and Stromboli, SO2 concentrations reach values that are dangerous to people affected by bronchial asthma or lung diseases (>1000 μg m−3). H2S values measured at Nisyros also exceed the limit considered safe for the same group of people (>3000 μg m−3). The data obtained using passive samplers represent time-averaged values over periods from a few days up to 1 month, and hence concentrations probably reached much higher peak values that were potentially also dangerous to healthy people. The present study provides evidence of a peculiar volcanic risk associated with tourist exploitation of active volcanic areas. This risk is particularly high at Mt. Etna, where the elderly and people in less-than-perfect health can easily reach areas with dangerous SO2 concentrations via a cableway and off-road vehicles.

Biomonitoring may be defined as the use of organisms and biomaterials (biomonitors) to obtain informations on certain characteristics of a particular medium (atmosphere, hydrosphere etc.). In particular, mosses accumulate large amounts of trace metals, making them good bioaccumulators to estimate atmospheric pollution. The moss-bags technique, introduced in the early 1970’, has become very popular. Such active biomonitoring technique is particularly useful in highly polluted areas and has been extensively used in industrial and/or urban areas to examine deposition patterns and to recognize point sources of pollution. The main objective of this study, which represents the first application of the moss-bags technique in an active volcanic area, was to test its efficacy in such environment. Complementary objectives were: to determine the different behavior and the geographic dispersion of volcanogenic elements emitted from Mt. Etna; to check the usefulness of a simpler analytical techniques (leaching instead of mineralization of the moss samples). A mixture of Sphagnum species was picked in a clean area, treated in laboratory (washed, dried and packed)and exposed in field for 1 month. Sites were chosen considering the prevailing wind at Mt. Etna’s summit. Milled samples were analyses for major and trace elements concentrations, after microwave digestion (HNO3 + H2O2), by ICP-MS and ICP-OES techniques. The same elements were also analyzed after simple leaching with deionized water (1/50 weight ratio for 4 hours). Leaching solutions were also analyzed by IC for F, Cl and SO4. Analyses clearly showed the efficacy of the moss-bags technique also in this peculiar environment. Several elements were strongly enriched in the mosses exposed to the volcanic missions. The highest enrichment was measured on the rim of the summit craters, but evidences of metals bioaccumulation were also found in down wind sites, at several km from the volcanic source. The accumulation factor (exposed/unexposed moss) allowed us to distinguish a group of elements (Tl, Bi, Se, Cu, As, Cd, S), which are highly mobile in the high temperature volcanic environment. Also alkali metals showed a significant increase in their concentrations, probably because of their affinity for the halide species carried by the volcanic plume. Also the simple and cheap leaching technique gave important indications on the plume dispersion pattern, especially for highly volatile elements (F, Cl, S, Tl).

This paper presents the preliminary results of a biomonitoring study based on the use of moss bags exposed at 24 sites on Etna volcano. Sphagnum mosses were used to study bioaccumulation originating from atmospheric deposition, by measuring the tissue contents of major and a large suite of trace elements. Elements, such as Tl, Bi, As, Se, Cu and Cd, display high concentrations in the exposed samples close to the active vents. This study confirms the effectiveness of the moss bags technique also in active volcanic areas.

Biomonitoring may be defined as the use of organisms and biomaterials (biomonitors) to obtain information on certain characteristics of a particular medium (atmosphere, hydrosphere etc.). In particular, mosses accumulate large amounts of trace metals, making them good bioaccumulators to estimate atmospheric pollution. The moss-bags technique, introduced in the early 1970’, has become very popular. Such active biomonitoring technique is particularly useful in highly polluted areas and has been extensively used in industrial and/or urban areas to examine deposition patterns and to recognize point sources of pollution. The main objective of this study, which represents the first application of the moss-bags technique in an active volcanic area, was to test its efficacy in such environment. Complementary objectives were: to determine the different behaviour and the areal dispersion of volcanogenic elements emitted from Mt. Etna; to characterize the morphology and mineralogy of particles transported in the plume-system, basing on microscopy investigation. A mixture of Sphagnum species was picked in a clean area, treated in laboratory (rinsed, dried and packed) and exposed in field for 1 month. Sites were chosen considering the prevailing wind at Mt. Etna’s summit. Milled samples were analyses for major and trace elements concentrations, after microwave digestion (HNO3 + H2O2), by ICP-MS and ICP-OES techniques. Morphology and mineralogy of volcanic particulate were investigated by using a SEM with EDS. Analyses clearly showed the efficacy of the moss-bags technique also in this peculiar environment. Several elements were strongly enriched in the mosses exposed to the volcanic emissions. The highest enrichment was measured close to the summit crater, but evidences of metals bioaccumulation were also found in down wind sites, at several km from the volcanic source. The accumulation factor (exposed/unexposed moss) allowed us to distinguish a group of elements (Tl, Bi, Se, Cu, As, Cd, S), which are highly mobile in the high temperature volcanic environment. Also alkali metals showed a significant increase in their concentrations, probably because of their affinity for the halide species carried by the volcanic plume. Microscopic observations evidenced sulphate and halide crystals on particles trapped by the mosses. Mosses exposed at sites directly fumigated by the volcanic plume showed crystal growth also directly on the moss surface.

8. A biomonitoring survey using leaves of tree (Betulla aethnensis, Pinus nigra and Populus tremula) and two endemic species (Senecio aethnensis and Rumex aethnensis) above treeline level, was performed on Mt. Etna, in order to evaluate the dispersion and the impact of volcanic emissions. Samples of leaves were collected in summer 2008 from 30 sites in the upper part of the volcano (800-3000 m a.s.l). Acid digestion of samples was carried out with a microwave oven, and 44 elements were analyzed by using plasma spectrometry (ICP-MS and ICP-OES). The highest concentrations of all investigated elements were found in the samples collected closest to the degassing craters, and in the downwind sector, confirming that the eastern flank of Mt. Etna is the most impacted by volcanic emissions. Leaves collected along two radial transects from the active vents on the eastern flank, highlight that the levels of metals decrease one or two orders of magnitude with the distance from the source. This variability is higher for volatile elements (As, Bi, Cd, Cs, Pb, Sb, Tl) than for more refractory elements (Al, Ba, Sc, Si, Sr, Th, U). The different species of plants show significant differences in the bioaccumulation of most of the analyzed elements, in particular lanthanides, which are systematically enriched in Rumex leaves. The high concentrations of many toxic elements in the two endemic species allow us to consider these plants as highly tolerant species to the volcanic emissions, and suitable for biomonitoring researches.

A biomonitoring survey, above tree line level, using two endemic species (Senecio aethnensis and Rumex aethnensis)was performed on Mt. Etna, in order to evaluate the dispersion and the impact of volcanic atmospheric emissions. Samples of leaves were collected in summer 2008 from 30 sites in the upper part of the volcano (1500-3000 m a.s.l). Acid digestion of samples was carried out with a microwave oven, and 44 elements were analyzed by using plasma spectrometry (ICP-MS and ICP-OES). The highest concentrations of all investigated elements were found in the samples collected closest to the degassing craters, and in the downwind sector, confirming that the eastern flank of Mt. Etna is the most impacted by volcanic emissions. Leaves collected along two radial transects from the active vents on the eastern flank, highlight that the levels of metals decrease one or two orders of magnitude with increasing distance from the source. This variability is higher for volatile elements (As, Bi, Cd, Cs, Pb, Sb, Tl) than for more refractory elements (Al, Ba, Sc, Si, Sr, Th, U). The two different species of plants do not show significant differences in the bioaccumulation of most of the analyzed elements, except for lanthanides, which are systematically enriched in Rumex leaves. The high concentrations of many toxic elements in the leaves allow us to consider these plants as highly tolerant species to the volcanic emissions, and suitable for biomonitoring researches in the Mt. Etna area.

Fumarolic alteration crusts and efflorescences have been sampled at the Sousaki solfataric field. Samples have been analysed for mineralogical (XRD) and chemical composition (HNO3 digestion and leaching with distilled water). Results show that mineralogical and chemical compositions (major, minor and trace metals) are controlled by microenvironmental conditions. The sample collected in the anoxic part of a cave is composed almost exclusively by native sulfur. The samples collected in the oxidizing part of the cave and outside in relatively sheltered position are mainly composed by very soluble sulfates. Chemical composition evidence strong enrichments in Al, Ca, Cr, Fe, Mg and Ni which are present in highly soluble form and derive from the fumarolic alteration of the outcropping rocks (Marls and peridotites). One sample collected outside the cave, well exposed to atmospheric agents, is composed almost exclusively of gypsum and the chemical composition reveals, with respect to the previous samples, a relative enrichment of elements (Ba, Ca, K, Pb and Sr) forming less soluble sulfates. The presence of toxic metals like Al, Cr and Ni in high concentrations and highly soluble form evidences the potential impact of the fumarolic activity on the local environment.

A biomonitoring survey, above treeline level, using two endemic species (Senecio aethnensis and Rumex aethnensis) was performed on Mt. Etna, in order to evaluate the dispersion and the impact of volcanic emissions. Samples of leaves were collected in summer 2008 from 30 sites in the upper part of the volcano (1500-3000 m a.s.l). Acid digestion of samples was carried out with a microwave oven, and 44 elements were analysed by using plasma spectrometry (ICP-MS and ICP-OES). The highest concentrations of all investigated elements were found in the samples collected closest to the degassing craters, and in the downwind sector, confirming that the eastern flank of Mt. Etna is the most impacted by volcanic emissions. Leaves collected along two radial transects from the active vents on the eastern flank, highlight that the levels of metals decreas one or two orders of magnitude with the distance from the source. This variability is higher for volatile elements (As, Bi, Cd, Cs, Pb, Sb, Tl) than for more refractory elements (Al, Ba, Sc, Si, Sr, Th, U). The two different species of plants do not show significant differences in the bioaccumulation of most of the analyzed elements, except for lanthanides, which are sistematically enriched in Rumex leaves. The high concentrations of many toxic elements in the leaves allow us to consider these plants as highly tolerant species to the volcanic emissions, and suitable for biomonitoring researches.

Nisyros Island, Greece, is a stratovolcano known for its intense hydrothermal activity. On June 2013, during a multidisciplinary field campaign, soil samples were collected in the caldera area to determinate the main mineralogical assemblages and to investigate the distribution of trace element concentrations and the possible relationship to the contribution of fluids of deep origin. Soil samples were analysed with XRD and for the chemical composition of their leachable (deionized water) and pseudo total (microwave digestion) fraction both for major and trace elements. The results allow to divide the samples in 2 groups: Lakki Plain and Stefanos Crater. The latter, where a fumarolic area is located, shows a mineralogical assemblage dominated by phases typical of hydrothermal alteration. Their very low pH values (1.9 – 3.4) show the strong impact of fumarolic gases which are probably also the cause of strong enrichments in these soils of highly volatile elements like S, As, Se, Bi, Sb, Tl and Te. © 2014, Editrice Compositori s.r.l., All rights reserved.

The studied area is a 130km long fast spreading graben in Central Greece. Its complex geodynamical setting includes both the presence of a subduction slab at depth responsible for the recent (Quaternary) volcanic activity in the area and the western termination of a tectonic lineament of regional importance (the North-Anatolian fault). A high geothermal gradient is made evident by the presence of many thermal springs with temperatures from 19 to 82°C, that discharge along the normal faults bordering the graben. In the period 2004-2012, 58 gas and 69 water samples were collected and their chemical and isotopic analysis revealed a wide range of compositions.Two main groups of thermal waters can be distinguished on the basis of their chemical composition. The first, represented by dilute waters (E.C.

Passive samplers were used to measure the atmospheric concentrations of SO2 naturally emitted at three volcanoes in Italy (Etna, Vulcano and Stromboli) and of H2S naturally emitted at three volcanic/geothermal areas in Greece (Milos, Santorini and Nisyros). The measured concentrations and dispersion patterns varied with the strength of the source (open conduits or fumaroles), the meteorological conditions and the area topography. At Etna, Vulcano and Stromboli, SO2 concentrations reach values that are dangerous to people affected by bronchial asthma or lung diseases (>1000μgm-3). H2S values measured at Nisyros also exceed the limit considered safe for the same group of people (>3000μgm-3). The data obtained using passive samplers represent time-averaged values over periods from a few days up to 1month, and hence concentrations probably reached much higher peak values that were potentially also dangerous to healthy people. The present study provides evidence of a peculiar volcanic risk associated with tourist exploitation of active volcanic areas. This risk is particularly high at Mt. Etna, where the elderly and people in less-than-perfect health can easily reach areas with dangerous SO2 concentrations via a cableway and off-road vehicles. © 2012 Elsevier B.V.