Search results for "Trace metal"

Do Volcanic Eruptions Solve Global Atmospheric Mercury Pollution?

2011

Besides human activities, volcanoes also introduce significant quantities of potentially harmful chemical compounds into the environment, mainly in the forms of gases and particles. High-temperature emissions from persistently degassing volcanoes are a known source of trace metal emissions to the atmosphere which may have important environmental consequences. Among these metals, mercury (Hg) is of particular interest since it is a toxic volatile metal found at elevated concentrations in remote regions of the world. Many natural Hg pathways include a recycled component of anthropogenic material. The anthropogenic contribution to the global atmospheric Hg budget is now well constrained, with …

Halogens and trace metal emissions from the ongoing 2008 summit eruption of Kīlauea volcano, Hawai`i

2012

Volcanic plume samples taken in 2008 and 2009 from the Halemàumàu eruption at Kīlauea provide new insights into Kīlauea's degassing behaviour. The Cl, F and S gas systematics are consistent with syn-eruptive East Rift Zone measurements suggesting that the new Halemàumàu activity is fed by a convecting magma reservoir shallower than the main summit storage area. Comparison with degassing models suggests that plume halogen and S composition is controlled by very shallow (<3m depth) decompression degassing and progressive loss of volatiles at the surface. Compared to most other global volcanoes, Kīlauea's gases are depleted in Cl with respect to S. Similarly, our Br/S and I/S ratio measurem…

Geochemical and eco-toxicological evaluations in box-core sediments from the Sicilian coast, central Mediterranean

2007

Full scale evaluation of atmospheric mercury budget from persistent volcanic degassing

2009

In the recent years, there has been an increase in environmental concerns related to the pollution of many trace metals emitted from volcanic degassing because of their toxicity and long residence times in the earth’s ecosystems. Among volcanogenic trace elements, mercury (Hg) is one of the most environmentally-significant in light of its potential harmful effects on biological systems. At present, however, the global Hg flux from volcanic sources is still poorly known. We report on Hg levels in volcanic plumes and fumaroles that, in combination with sulphur analyses and SO2 flux data, lead to global Hg estimates. We found that mercury transport in the plume is mainly in the gas-phase, as H…

Influence of seabird guano on the trophic status and contamination levels of a Sicilian transitional area

2009

Monitoring Volcanic Eruptions Using Trace Metals In Tree-Rings: Preliminary Results From Mt. Etna

2010

8. Active volcanoes can influence surrounding vegetation both through passive degassing during quiescent periods and through eruptive degassing, by introducing into the atmosphere several metals as gases and particles. The chemical composition of tree-rings has been generally used to investigate the effects of anthropogenic gas emissions and dendrochemical methods have successfully recorded variations in the pollution levels. The use of tree-rings analysis in active volcanic areas has shown that vascular plants could be used as archives of volcanogenic metals deposition. Tree cores of Pinus Nigra and Populus tremula were collected in sites located both on the downwind (Citelli and Mt. Fonta…

The impact of Mt. Etna volcanic emissions on the atmospheric deposition: developments and improvements during three decades of studies

2022

Volcanic emissions are an important source of gases and particles to the atmosphere. Mount Etna discharges a permanent volcanic plume consisting of water vapor and gaseous species (CO2, SO2, HCl and HF, mainly), metals, acid droplets, and solid particles. This plume interacts with meteoric water during precipitations events, so the chemical signature of the plume is impressed on the rainwater. Over the past 32 years, the impact of Etna's emissions on atmospheric deposition has been investigated in many research projects by our team. Sampling methodologies and analytical procedures have been improved over the years. The first study of the concentration of water-soluble inorganic ions in week…

Does differential iron supply to algae affect Daphnia life history? : An ionome-wide study

2019

The availability of iron (Fe) varies considerably among diet items, as well as ecosystems. Availability of Fe has also changed due to anthropogenic environmental changes in oceanic as well as inland ecosystems. We know little about its role in the nutrition of ecologically important consumers, particularly in inland ecosystems. Physiological studies in several taxa indicate marked effects of dietary Fe on oogenesis. We predicted that differential Fe supply to algae will impact algal Fe concentration with consequences on the life history of the freshwater grazer, Daphnia magna. We found that algal Fe concentration increased with Fe supply, but did not affect algal growth, indicating that the…