1,721,041 research outputs found
Spatial distribution and ecological risk of potentially toxic elements in peri-urban soils of a historically industrialised area
Full text linkThe spatial distribution and ecological risk of potentially toxic elements (PTEs) were investigated in the topsoil of a peri-urban area surrounding a historical industrial complex in the Scarlino Plain in southwestern Tuscany, Italy. Superficial (0-5 cm) soil samples from 44 sites within a 1.5-km radius of the industrial district were analysed for As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Sn, Tl, V and Zn concentrations after microwave-assisted acid digestion with HNO3 and H2O2. The results revealed significant contamination exceeding regulatory thresholds, predominantly caused by historical pyrite roasting and natural geochemical anomalies. The enrichment of As, Mn, Cu and Zn compared to European baselines was widespread, with As and Zn levels exceeding the Italian screening values in several samples. Principal component analysis identified distinct contamination patterns linked to land use, with the first component (PC1, 49.2% of the variance) associated with pyrite-derived PTEs (As, Cu, Cd, Pb and Zn), whereas PC2 represented geogenic inputs. Despite their combined contribution to soil contamination, this analysis effectively differentiated industrial signatures from those of natural sources. Ecological risk assessment indicated that As and Cd are major concerns in agricultural soils, where anthropogenic and natural sources overlap. These findings underscore the importance of distinguishing between natural and anthropogenic contributions to inform realistic mitigation targets and protect environmental and human health in historically impacted peri-urban areas
Temporal trend (1995-2001) of trace metal concentrations in PM10 and Q. ilex leaves from Florence
No full textEnvironmental biogeochemistry of mercury in Antarctic ecosystems
No full textPolar regions are recognized as important sinks for long-range transport and deposition of Hg derived from natural and anthropogenic sources at lower latitudes. In previous studies we found enhanced Hg accumulation in soils, mosses and lichens from ice-free areas of Victoria Land facing the Terra Nova Bay coastal polynya. This study extends research to the distribution of organic C, total N, S, Hg, Al and Fe in surface soils, cyanobacterial mats and short sediment cores from four lacustrine ecosystems, each with different environmental characteristics and varying distances from the polynya. Results show that planktonic and benthic mats from lakes, along with mosses in the watershed, are the main sinks for Hg in summer meltwater. The C-normalized Hg concentrations in short sediment cores were higher in samples from lakes more exposed to marine aerosols from the coastal polynya. Reactive halogens in the aerosol promote the oxidation and deposition of atmospheric Hg in coastal ecosystems. The analysis of sediment cores did not reveal increasing Hg concentrations in recent sediments, except in the Lake 14 at Edmonson Point. The latter ice-free area is unaffected by the polynya and the increase in Hg concentrations in surface sediments could be due to local changes in lake water level and S biogeochemistry. Although change in sea ice coverage may enhance the role of Antarctic coastal ecosystems as sink in the global Hg cycle, our results seem to exclude possible risks for Antarctic terrestrial and freshwater organisms. © 2006 Elsevier Ltd. All rights reserved
Leaves and Tree Rings as Biomonitoring Archives of Atmospheric Mercury Deposition: An Ecophysiological Perspective
Full text linkTrees mediate critical biogeochemical cycles involving nutrients, pollutants, water, and energy at the interface between terrestrial biosphere and atmosphere. Forest ecosystems significantly influence the global cycling of mercury (Hg), serving as important sinks and potential sources of re-emission through various biotic and abiotic processes. Anthropogenic Hg emissions, predominantly from industrial activities, mining, and fossil fuel combustion, have substantially altered the natural Hg cycle, intensifying ecotoxicological concerns and establishing forests as primary routes for atmospheric Hg deposition into terrestrial reservoirs. This perturbation profoundly affects global atmospheric Hg concentrations, residence times, and spatial distribution patterns. While early investigations focused on forest stands near heavily polluted areas, contemporary research has expanded to diverse ecosystems, revealing that trees provide tissues that function as temporal archives for atmospheric-terrestrial Hg exchange. Leaves capture high-resolution records of contemporary Hg dynamics at sub-annual timescales, whereas annual growth rings preserve multi-decadal chronologies of historical atmospheric exposure. Incorporating this dual temporal perspective is crucial for analysing Hg deposition trends and assessing the efficacy of environmental policies designed to control and mitigate Hg pollution. This review critically evaluates recent developments concerning the ecophysiological determinants of Hg accumulation in trees, highlighting how combined foliar and dendrochemical analytical methods strengthen our mechanistic understanding of vegetation-atmosphere Hg exchange. To enhance biomonitoring approaches, we emphasised the need for methodological standardisation, deeper integration of ecophysiological variables, and consideration of climate change implications as priority research areas. Furthermore, integrating Hg measurements with functional markers (δ13C and δ18O) and Hg isotope analyses strengthens the capacity to differentiate between physiological and environmental influences on Hg accumulation, thereby refining the mechanistic framework underlying effective tree-based Hg biomonitoring
Lichen biomonitoring of trace element deposition in urban, industrial and reference areas of Italy
No full textTrace elements in striped dolphin (Stenalla coeruleoalba) form the western Mediterranean
No full textEffetti dell'H2S sul contenuto di elementi in traccia nel lichene epifita Parmelia sulcata.
No full textEcophysiological indicators of native Cistus ladanifer L. at Riotinto mine tailings (SW Spain) for assessing its potential use for rehabilitation
No full textThe aim of this study was to evaluate the potential use of Cistus ladanifer in the restoration of the sulfide mine of Riotinto (SW, Spain). A field study was performed sampling three different mining and one uncontaminated sites (control) where C. ladanifer was already established. Soil physico-chemical properties as well as nutrients and potential toxic elements in the different plant parts and soil were evaluated. In comparison with the control site, soils of Riotinto had a lower pH and P concentration, high concentration of Al and Fe oxides and a very low Ca availability (Ca:Mg:K 4:2:1). In general, the concentrations of Ca, Mg, K, P, Sin leaves and stems of plants from Riotinto and the control site were in the same range whereas those of As, Cd, Cu, Mn, Ni, and Zn were higher in the samples from the mining area. The element accumulation pattern was leaves > stem and root cortex > fine roots > inner tissue of roots. The plants from mining sites were able to translocate Cd, Mn, Ni and Zn from roots to shoots. The chemical composition of the plants sampled in the mining area reveals that, with some exceptions, C. ladanifer has excluder behaviour for most potentially toxic elements. The efficient nutrient uptake in such harsh environment in which low nutrient availability combines with high concentration of heavy metals provides the species as C. ladanifer with a high adaptation capacity, an important feature for its use for re-vegetation and stabilization of soils affected by mine wastes
Biomagnification of mercury in an Antarctic marine coastal food web
No full textTotal Hg concentrations were determined in marine sediments and biota from the inner shelf of Terra Nova Bay (Antarctica). Like published data on air, snow and soils from the same region, Hg levels in the finest fraction of marine sediments were among the lowest ever reported for coastal marine environments (0.012 ± 0.007 μg g-1 dry wt). A progressive increase in Hg concentrations was found in organisms at different levels of the marine food web (phytoplankton < zooplankton and benthic primary consumers < detritivorous and opportunistic benthic invertebrates < epipelagic fish < demersal fish and plankton-feeding seabirds < fish-eating penguins < predatory birds and Weddell seal). In general, primary producers and consumers showed slightly lower Hg concentrations (0.076 ± 0.023 μg g-1 dry wt) than organisms of related species from other seas, but values in feathers (2.91 ± 1.93 μg g-1 dry wt) of the Antarctic skua and in tissues of a Weddell seal (44.0 and 24.0 μg g-1 dry wt in the liver and spleen, respectively) were similar to those in skuas and seals from the northern hemisphere. Trophic connections between organisms in well developed benthic communities, phytoplankton and fish and environmental factors such as enhanced upwelling of cold water, sea ice and low light are deemed to enhance natural biomagnification processes of Hg in the pristine Antarctic coastal environment
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