Mercury (Hg) solubility and reactivity in soils at two extremely contaminated ancient small scale cinnabar roasting sites in the surroundings of the Hg mining area of Idrija (Slovenia) were ...determined in order to assess the mobility of Hg in the aqueous phase and to evaluate the extent of leaching of Hg into Idrijca River and further downstream. Water leaching experiments were performed on soil and SOM (soil organic matter) samples from historical roasting sites Pšenk and Frbejžene trate. The determined concentrations of leachable Hg in soil samples from the studied areas range from 16 to exceptionally high concentration of 18,000μg/kg, representing 0.0002 to 1.1% of total Hg in these samples, while in SOM samples leachable Hg concentrations range between 13.3 and 6000μg/kg, which corresponds to 0.0017–0.074% of total Hg determined in SOM. The soluble Hg concentrations in investigated soil profiles range from 183 to 18,000μg/kg (0.038–1.7% of total Hg). On the average, more than 90% of soluble Hg occurs in a non-reactive complex bound form, suggesting the preferential binding of Hg to humic matter. Soluble Hg in studied soil profiles generally increases with depth. The obtained results show that Hg is effectively transported to deeper soil layers, mainly as soluble organic complexes. It is estimated that there is still about 10kg of soluble Hg stored in soils of the investigated roasting sites, which is continuously leached to surface waters and deeper into the soil.
•Water leaching experiments were performed on soil and SOM samples.•Total soluble, complex-bound and reactive Hg was defined.•Extremely high concentrations (up to 18,000μg/kg) of soluble Hg were determined.•More than 90% of soluble Hg occurs in a non-reactive complex bound form.•We estimate that soluble Hg stored in soils is mobilized to the groundwater.
The aim of this paper was to test the new sampling media—earthworm casts in a highly contaminated area. The investigation was carried out at the ancient Hg ore roasting site Pšenk in the surroundings ...of Idrija, where extremely high Hg contents in soils and SOM were determined in previous investigations. 32 earthworm cast samples were collected in the research grid 30×30m in order to compare the Hg contents and spatial distribution in earthworm casts to the values and distributions in SOM and soil (0–15cm). Extremely elevated Hg concentrations were determined in earthworm casts from the studied area ranging from 5.4 to 4330mg/kg with the median of 31mg/kg. The Hg values in casts are somewhat lower than in soil (6.3–8600mg/kg) and slightly higher compared to soil organic matter (SOM) (1.5–4200mg/kg). Strong correlation (r²=0.75) between Hg contents in casts and soil was found, while correlation between casts and SOM was positive but weaker (r²=0.35). Spatial distribution of Hg in earthworm casts show the highest concentrations in the central part of investigated area, similar to the distribution in soil. Hg contents rapidly decrease from the center toward the margins of the studied area, where they reach values of less than 50mg/kg. It was shown that Hg contents and dispersion in casts are comparable to those in soil, which indicates that at investigated area soil contamination is strongly reflected in contamination of earthworm casts.
► We compare Hg contents in soil, SOM and earthworm casts. ► The determined Hg contents are in the order of soil>earthworm casts>SOM. ► There is strong correlation between Hg contents in casts and soil. ► Soil contamination is strongly reflected in contamination of earthworm casts.
Results are presented of the first airborne LiDAR survey ever flown in Europe for the purpose of mapping the surface expression of earthquake‐prone faults. Detailed topographic images derived from ...LiDAR data of the Idrija and Ravne strike‐slip faults in NW Slovenia reveal geomorphological and structural features that shed light on the overall architecture and kinematic history of both fault systems. The 1998 MW = 5.6, and 2004 MW = 5.2 Ravne Fault earthquakes and the historically devastating 1511 M = 6.8 Idrija earthquake indicate that both systems pose a serious seismic hazard in the region. Because both fault systems occur within forested terrain, a tree removal algorithm was applied to the data; the resulting images reveal surface scarps and tectonic landforms in unprecedented detail. Importantly, two sites were discovered to be potentially suitable for fault trenching and palaeo‐seismological analysis. This study highlights the potential contribution of LiDAR surveying in both low‐relief valley terrain and high‐relief mountainous terrain to a regional seismic hazard assessment programme. Geoscientists working in other tectonically active regions of the world where earthquake‐prone faults are obscured by forest cover would also benefit from LiDAR maps that have been processed to remove the canopy return and reveal the forest floor topography.
Mercury distribution and partitioning was studied in the River Idrijca system, draining the area of the former Idrija mercury mine, Slovenia. Mercury dynamics were assessed by speciation analysis of ...mercury in water and river bed sediment samples during a 2-year study at locations on the River Idrijca and its major tributaries. Simultaneously, the influence of some major physico-chemical parameters that influence the fate of mercury in the aquatic environment was investigated. The distribution of mercury species in the River Idrijca catchment indicated contamination from mine tailings distributed in the town of Idrija and erosion of contaminated soils. The partitioning between dissolved and particulate mercury phases in river water was found to be mostly controlled by the variable content of suspended solids resulting from changing hydrological conditions and complexation with various ligands present in river water, among which dissolved organic carbon (DOC) seems to be the most important. Overall results indicate that mercury is transported downstream from the mining area mainly as finely suspended material including colloids rather than in the dissolved phase. This riverine transport occurs mostly during short, but extreme hydro-meteorological conditions when remobilization of mercury from the river bed sediments occurs. A significant part of the mercury particulate phase in water corresponds to cinnabar particles. During its transport, important Hg transformation mechanisms that increase the risk of mercury uptake by biota take place, evidenced by the increase in the relative contribution of reactive mercury (Hg R ), dissolved gaseous mercury (DGM) and monomethylmercury (MeHg) downstream from the Idrija mine. However, our data revealed relatively low methylation efficiency in this contaminated river system. We attribute this to the site specific physico-chemical conditions responsible for making inorganic mercury unavailable and limiting the capacity of methylating bacteria.
The article deals with the position held by the Slovenian magazine Kaplje Drops in the Slovenian collective memory. Published in the town of Idrija between 1966 and 1972, i.e. in the period of party ...liberalism in former Yugoslavia, Kaplje was a publication from the periphery that ‘swam against the current’, although its role was almost entirely ignored. The article’s aim is therefore to determine how the magazine’s contributors represented and (re)produced Slovenian identity and its constitutive elements, and which forms and strategies of national(istic) discourse were used. The methodology is based on a critical discursive analysis of selected articles that touch on the above-mentioned themes from all 26 issues of the magazine, including a special issue released upon the twentieth anniversary of the date the magazine voluntarily came to an end.
The atmospheric distribution and deposition of Hg in the area of the former Idrija Hg-mine, Slovenia, were investigated. Mapping of air Hg
0 concentrations was performed to assess the spatial ...distribution and major sources of mercury to the atmosphere in the area. In addition, analyses of mercury speciation in the air over Idrija were performed during a 4-day sampling campaign in September 2006 to better understand the fate and transformation of Hg in the atmosphere of this specific mercury polluted site. The speciation results were then compared to the results of mercury speciation in the wet and throughfall deposition sampled on a precipitation event basis from October 2006 to September 2007. The Hg
0 concentration in air was mostly below 10
ng
m
−3, with the highest concentration in the area of the former smelter complex exceeding 5000
ng
m
−3. Mercury-bearing airborne particles (TPM) seem to dominate the atmospheric Hg deposition, which revealed noticeable variations between precipitation events (11–76
ng
m
−2
day
−1), mostly as a function of the amount of precipitation. Hg in precipitation was largely (∼50%) associated with the particulate phase (THg
P). No correlation was found between the THg
P and the dissolved phases (THg
D), suggesting that particulate phase Hg is mostly the result of dry deposition. In the throughfall, significantly higher (2–10 fold) Hg concentrations than in associated event precipitation were observed, mostly due to Hg in the particulate phase (∼70% THg). As shown by SEM/EDXS microscopy, an important amount of mercury in the precipitation and throughfall samples is due to the presence of cinnabar particles as a result of the aeolian erosion of cinnabar-containing surfaces in the area.
► Soils surrounding the smelting plant are the main source of Hg in the Idrija region. ► Atmospheric Hg in the Idrija Hg-mine region is subjected to long range transport. ► Mercury-bearing airborne particles dominate the atmospheric deposition.
Purpose
Concentrations and transformations of mercury were measured in river, estuarine, and marine sediments to determine factors affecting the fate of mercury entering the northern Adriatic Sea.
...Materials and methods
Radiotracer methodology was used to compare rates of mercury methylation (
203
Hg), MeHg demethylation (
14
C), and sulfate reduction (
35
S) in sediment depth profiles to concentrations of total and dissolved mercury species in the lower freshwater region of the Isonzo River, the coastal lagoons, and in the Gulf of Trieste, northern Adriatic Sea.
Results and discussion
Mercury was readily methylated and demethylated in all sediments, but the relative activity of these processes varied greatly with location. Methylation activity increased greatly from freshwater to the marine regions; however, demethylation was extremely high in the estuarine and lagoon sites. Ratios of methylation to demethylation were low in these coastal sites but increased further offshore in the gulf, which agreed with increased ratios of MeHg to total Hg (%MeHg) in gulf sediments. Comparisons of microbial activities indicated that sulfate reduction strongly controlled both methylation and demethylation. However, Hg methylation in coastal lagoon sediments was controlled by rapid demethylation and the bioavailability of Hg that was affected by Hg adsorption and precipitation. Methylation in offshore marine sites correlated with sulfate reduction but not the partitioning of Hg between pore water and solid phases. The decrease in sulfide production offshore exacerbated Hg methylation.
Conclusions
The freshwater to marine gradient in the Idrija/Soča/Isonzo/Adriatic region is dynamic, exhibiting horizontally variable rates of microbial activities and Hg transformations that create “hot spots” of MeHg accumulation that are controlled differently in each region.
The influence of geomorphological factors to Hg contamination of the Idrijca River alluvial sediments because of the historical mining and ore roasting activities has been studied. Main source of Hg ...in alluvial sediments was dumping of ore roasting residues and mining waste into the river channel and its erosion downstream. The position of the material in relation to the geomorphological properties is highly related with its Hg content. Floodplains were found to be the most contaminated geomorphological units (mean Hg content 335
mg/kg), with Hg concentration rapidly dropping in the first terrace (155
mg/kg). The least contaminated material was found in the higher terraces (3.8
mg/kg). Sampling upstream Idrija (average Hg content is 22.1
mg/kg) shows that not only mine and ore roasting plant increased Hg levels in alluvial deposits but also contaminated sites upstream Idrija contribute to Hg contamination. Geochemical background for alluvial sediments for this area is estimated to be 0.75
mg/kg. Downstream Idrija, 9 hotspots were determined where highly contaminated material is actively eroded and carries a high risk of further contamination of the Soča River and northern Adriatic Sea ecosystems.
► Hg contamination of alluvial sediment because of mining tradition in Idrija. ► High rate of contamination, up to 2000
mg/kg, enrichment factors up to 15,000. ► Floodplain most contaminated geomorphological unit. ► Exponential decrease of contamination in relation to the distance from the source. ► Geochemical background for Hg in alluvial sediments estimated to 0.75
mg/kg.
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