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Citizen Science (CS) projects vary greatly. The aims and goals of a CS project determine the type of citizen involvement and the tools to be used, which in most cases also entail information and communication technology (ICT) that facilitates public participation in scientific research. Resource limitations in CS projects often require adopting suboptimal tools, which, however, may come with hidden costs stemming from poor usability and underwhelming functionality, thus reducing volunteers’ motivation. Meeting the volunteers’ expectations by designing or using existing tools with functional features which fulfill and nurture their motivations, will foster long-term participation and contribute to project sustainability. This paper reviews the types of CS projects, volunteer motivation and retention strategies from the literature and classifies them thematically. This is distilled into guidance that can help CS practitioners to design and implement CS tools and plan and manage CS projects, which better serve their scientific and volunteer-related goals.
Johanna Amalia Robinson; David Kocman; Orestis Speyer; Evangelos Gerasopoulos. Meeting volunteer expectations — a review of volunteer motivations in citizen science and best practices for their retention through implementation of functional features in CS tools. Journal of Environmental Planning and Management 2021, 1 -31.
AMA StyleJohanna Amalia Robinson, David Kocman, Orestis Speyer, Evangelos Gerasopoulos. Meeting volunteer expectations — a review of volunteer motivations in citizen science and best practices for their retention through implementation of functional features in CS tools. Journal of Environmental Planning and Management. 2021; ():1-31.
Chicago/Turabian StyleJohanna Amalia Robinson; David Kocman; Orestis Speyer; Evangelos Gerasopoulos. 2021. "Meeting volunteer expectations — a review of volunteer motivations in citizen science and best practices for their retention through implementation of functional features in CS tools." Journal of Environmental Planning and Management , no. : 1-31.
In this paper, we summarise lessons learned conducting citizen science (CS) activities within the CitieS-Health H2020 project on the topic of noise exposure and health at a primary school in Ljubljana, Slovenia. Activities were organised in the form of a School Tech-Day Event (STDE) as part of the school’s curriculum involving second-grade pupils, ages 7–8. The STDE was aligned with the project’s methodological framework, which is based on co-creation and co-design principles. To this end, the pupils initially were involved in identifying noise-related issues and translation of selected topics into research questions. Next, together with mentors, they participated in the process of hypothesis formulation and the designing of data collection protocols. Finally, they participated in three focussed noise measurement experiments, as well as data analysis and presentation. We report and critically evaluate the whole chain of activities, focussing on the participant dimension using selected components of the citizen science evaluation framework. The event was very well-received by both pupils and teachers, and their active participation and hands-on experience with scientific processes contributed to their improved scientific literacy. Overall, the demonstrated concept of CS activities has great potential for ongoing inclusion in the school curriculum in its current format, or else adjusted according to specifics from other science and technology fields.
David Kocman; Tjaša Števanec; Rok Novak; Natalija Kranjec. Citizen Science as Part of the Primary School Curriculum: A Case Study of a Technical Day on the Topic of Noise and Health. Sustainability 2020, 12, 10213 .
AMA StyleDavid Kocman, Tjaša Števanec, Rok Novak, Natalija Kranjec. Citizen Science as Part of the Primary School Curriculum: A Case Study of a Technical Day on the Topic of Noise and Health. Sustainability. 2020; 12 (23):10213.
Chicago/Turabian StyleDavid Kocman; Tjaša Števanec; Rok Novak; Natalija Kranjec. 2020. "Citizen Science as Part of the Primary School Curriculum: A Case Study of a Technical Day on the Topic of Noise and Health." Sustainability 12, no. 23: 10213.
The merge of new sensing technologies with machine learning methods can be used as a tool to recognize complex activities. A wearable particulate matter (PM) sensor, in combination with a motion tracker, was provided to 97 individuals for 7 days in two seasons. These data sets were used in three different models, constructed by the classification of activity. Using algorithms IBk, J48 and RandomForest for hourly (minute) values, an accuracy of 31.0 (23.1)%, 28.6 (22.0)% and 35.7 (23.0)%, respectively, was achieved. Most misclassified instances concern vaguely defined activities. Low accuracy can also be explained with the differences in time scales. The accuracy could be improved by more clearly defining the activities and collecting per-minute data.
Rok Novak; David Kocman; Johanna Amalia Robinson; Tjaša Kanduč; Denis Sarigiannis; Sašo Džeroski; Milena Horvat. Low-Cost Environmental and Motion Sensor Data for Complex Activity Recognition: Proof of Concept. Proceedings of 7th International Electronic Conference on Sensors and Applications 2020, 2, 54 .
AMA StyleRok Novak, David Kocman, Johanna Amalia Robinson, Tjaša Kanduč, Denis Sarigiannis, Sašo Džeroski, Milena Horvat. Low-Cost Environmental and Motion Sensor Data for Complex Activity Recognition: Proof of Concept. Proceedings of 7th International Electronic Conference on Sensors and Applications. 2020; 2 (1):54.
Chicago/Turabian StyleRok Novak; David Kocman; Johanna Amalia Robinson; Tjaša Kanduč; Denis Sarigiannis; Sašo Džeroski; Milena Horvat. 2020. "Low-Cost Environmental and Motion Sensor Data for Complex Activity Recognition: Proof of Concept." Proceedings of 7th International Electronic Conference on Sensors and Applications 2, no. 1: 54.
Low-cost sensors can be used to improve the temporal and spatial resolution of an individual’s particulate matter (PM) intake dose assessment. In this work, personal activity monitors were used to measure heart rate (proxy for minute ventilation), and low-cost PM sensors were used to measure concentrations of PM. Intake dose was assessed as a product of PM concentration and minute ventilation, using four models with increasing complexity. The two models that use heart rate as a variable had the most consistent results and showed a good response to variations in PM concentrations and heart rate. On the other hand, the two models using generalized population data of minute ventilation expectably yielded more coarse information on the intake dose. Aggregated weekly intake doses did not vary significantly between the models (6–22%). Propagation of uncertainty was assessed for each model, however, differences in their underlying assumptions made them incomparable. The most complex minute ventilation model, with heart rate as a variable, has shown slightly lower uncertainty than the model using fewer variables. Similarly, among the non-heart rate models, the one using real-time activity data has less uncertainty. Minute ventilation models contribute the most to the overall intake dose model uncertainty, followed closely by the low-cost personal activity monitors. The lack of a common methodology to assess the intake dose and quantifying related uncertainties is evident and should be a subject of further research.
Rok Novak; David Kocman; Johanna Amalia Robinson; Tjaša Kanduč; Dimosthenis Sarigiannis; Milena Horvat. Comparing Airborne Particulate Matter Intake Dose Assessment Models Using Low-Cost Portable Sensor Data. Sensors 2020, 20, 1406 .
AMA StyleRok Novak, David Kocman, Johanna Amalia Robinson, Tjaša Kanduč, Dimosthenis Sarigiannis, Milena Horvat. Comparing Airborne Particulate Matter Intake Dose Assessment Models Using Low-Cost Portable Sensor Data. Sensors. 2020; 20 (5):1406.
Chicago/Turabian StyleRok Novak; David Kocman; Johanna Amalia Robinson; Tjaša Kanduč; Dimosthenis Sarigiannis; Milena Horvat. 2020. "Comparing Airborne Particulate Matter Intake Dose Assessment Models Using Low-Cost Portable Sensor Data." Sensors 20, no. 5: 1406.
Low-cost sensors are a current trend in citizen science projects that focus on air quality. Until now, devices incorporating such sensors have been tested primarily for their technical capabilities and limitations, whereas their usability and acceptability amongst the public rarely goes beyond proof of concept, leaving user experience (UX) unstudied. The authors argue that UX should be taken into account to make sure that products and services are fit for purpose. Nineteen volunteers tested and evaluated a prototype device and provided feedback through semi-structured interviews and during focus group sessions. Their UX was then coded using mixed coding methods regarding device functionality and recommendations for future product development. The results indicate that UX can identify potentially problematic design aspects while giving deeper insights into user needs. For example, UX recognized that one of the most important aspects of user involvement and motivation was successful data harvesting, which frequently failed. This study recommends that future developers of low-cost portable air quality sensor systems prioritize reliable data transmission to minimize data loss. This will ensure an efficient and positive UX that supports user engagement in citizen science based research where collecting sensor-based data is the primary objective.
Johanna Amalia Robinson; David Kocman; Milena Horvat; Alena Bartonova. End-User Feedback on a Low-Cost Portable Air Quality Sensor System-Are We There Yet? Sensors 2018, 18, 3768 .
AMA StyleJohanna Amalia Robinson, David Kocman, Milena Horvat, Alena Bartonova. End-User Feedback on a Low-Cost Portable Air Quality Sensor System-Are We There Yet? Sensors. 2018; 18 (11):3768.
Chicago/Turabian StyleJohanna Amalia Robinson; David Kocman; Milena Horvat; Alena Bartonova. 2018. "End-User Feedback on a Low-Cost Portable Air Quality Sensor System-Are We There Yet?" Sensors 18, no. 11: 3768.
The distributions of the total mercury (T-Hg), methylmercury (MeHg), and ethylmercury (EtHg) concentrations in soil and their relationship to chemical composition of the soil and total organic carbon content (TOC, %) were investigated. Core samples were collected from hill slope on the right and left riverbanks of the Idrija River. Former smelting plant is located on the right bank. The T-Hg average in each of the core samples ranged from 0.25 to 1650 mg kg. The vertical T-Hg variations in the samples from the left bank showed no significant change with depth. Conversely, the T-Hg varied with depth, with the surface, or layers several centimeters from the surface, tending to show the highest values in the samples from the right bank. Since the right and left bank soils have different chemical compositions, different pathways of mercury delivery into soils were suggested. The MeHg and EtHg concentrations ranged from n.d. (not detected) to 444 μg kg and n.d. to 17.4 μg kg, respectively. The vertical variations of MeHg and EtHg were similar to those of TOC, except for the near-surface layers containing TOC greater than 20%. These results suggest that the decomposition of organic matter is closely related to organic mercury formation.
Takashi Tomiyasu; Hitoshi Kodamatani; Ryusuke Imura; Akito Matsuyama; Junko Miyamoto; Hirokatsu Akagi; David Kocman; Jože Kotnik; Vesna Fajon; Milena Horvat. The dynamics of mercury near Idrija mercury mine, Slovenia: Horizontal and vertical distributions of total, methyl, and ethyl mercury concentrations in soils. Chemosphere 2017, 184, 244 -252.
AMA StyleTakashi Tomiyasu, Hitoshi Kodamatani, Ryusuke Imura, Akito Matsuyama, Junko Miyamoto, Hirokatsu Akagi, David Kocman, Jože Kotnik, Vesna Fajon, Milena Horvat. The dynamics of mercury near Idrija mercury mine, Slovenia: Horizontal and vertical distributions of total, methyl, and ethyl mercury concentrations in soils. Chemosphere. 2017; 184 ():244-252.
Chicago/Turabian StyleTakashi Tomiyasu; Hitoshi Kodamatani; Ryusuke Imura; Akito Matsuyama; Junko Miyamoto; Hirokatsu Akagi; David Kocman; Jože Kotnik; Vesna Fajon; Milena Horvat. 2017. "The dynamics of mercury near Idrija mercury mine, Slovenia: Horizontal and vertical distributions of total, methyl, and ethyl mercury concentrations in soils." Chemosphere 184, no. : 244-252.
Review of biogeochemical processes studied in three Slovenian rivers (River Kamniška Bistrica, River Sava\ud in Slovenia and River Idrijca), which represent an ideal natural laboratory for studying biogeochemical processes\ud and anthropogenic impacts in catchments with high weathering capacity is presented. The River Kamniška\ud Bistrica, the River Sava in Slovenia and the River Idrijca water chemistry is dominated by HCO3-, Ca2+ and Mg2+,\ud and Ca2+/Mg2+ molar ratios indicate that calcite/dolomite weathering is the major source of ions to the river system.\ud The Kamniška Bistrica River, the River Sava and River Idrijca and its tributaries are oversaturated with respect\ud to calcite and dolomite. pCO2 concentrations were on average up to 25 times over atmospheric values for River\ud Kamniška Bistrica, 20 times for River Sava and 13 times over atmospheric values for River Idrijca. δ13CDIC values\ud ranged from -12.7 to -2.7 ‰ in River Kamniška Bistrica, from -12.7 to -6.3 ‰ in River Sava in Slovenia, from -10.8\ud to -6.6 ‰ in River Idrijca, respectively. In all investigated rivers we found out that carbonate dissolution is the\ud most important biogeochemical process affecting carbon isotopes in the upstream portions of the catchment, while\ud carbonate dissolution and organic matter degradation control carbon isotope signatures downstream, except for\ud River Idrijca where both processes contribute equally from source to outflw to River Soča
Tjaša Kanduč; David Kocman; Timotej Verbovšek. Biogeochemistry of some selected Slovenian rivers (Kamniška Bistrica, Idrijca and Sava in Slovenia):insights into river water geochemistry, stable carbon isotopes and weathering material flws. Geologija 2017, 60, 9 -26.
AMA StyleTjaša Kanduč, David Kocman, Timotej Verbovšek. Biogeochemistry of some selected Slovenian rivers (Kamniška Bistrica, Idrijca and Sava in Slovenia):insights into river water geochemistry, stable carbon isotopes and weathering material flws. Geologija. 2017; 60 (1):9-26.
Chicago/Turabian StyleTjaša Kanduč; David Kocman; Timotej Verbovšek. 2017. "Biogeochemistry of some selected Slovenian rivers (Kamniška Bistrica, Idrijca and Sava in Slovenia):insights into river water geochemistry, stable carbon isotopes and weathering material flws." Geologija 60, no. 1: 9-26.
Aquatic ecosystems are an essential component of the biogeochemical cycle of mercury (Hg), as inorganic Hg can be converted to toxic methylmercury (MeHg) in these environments and reemissions of elemental Hg rival anthropogenic Hg releases on a global scale. Quantification of effluent Hg releases to aquatic systems globally has focused on discharges to the global oceans, rather than contributions to freshwater systems that affect local exposures and risks associated with MeHg. Here we produce a first-estimate of sector-specific, spatially resolved global aquatic Hg discharges to freshwater systems. We compare our release estimates to atmospheric sources that have been quantified elsewhere. By analyzing available quantitative and qualitative information, we estimate that present-day global Hg releases to freshwater environments (rivers and lakes) associated with anthropogenic activities have a lower bound of ~1000 Mg·a−1. Artisanal and small-scale gold mining (ASGM) represents the single largest source, followed by disposal of mercury-containing products and domestic waste water, metal production, and releases from industrial installations such as chlor-alkali plants and oil refineries. In addition to these direct anthropogenic inputs, diffuse inputs from land management activities and remobilization of Hg previously accumulated in terrestrial ecosystems are likely comparable in magnitude. Aquatic discharges of Hg are greatly understudied and further constraining associated data gaps is crucial for reducing the uncertainties in the global biogeochemical Hg budget.
David Kocman; Simon J. Wilson; Helen M. Amos; Kevin H. Telmer; Frits Steenhuisen; Elsie M. Sunderland; Robert P. Mason; Peter Outridge; Milena Horvat. Toward an Assessment of the Global Inventory of Present-Day Mercury Releases to Freshwater Environments. International Journal of Environmental Research and Public Health 2017, 14, 138 .
AMA StyleDavid Kocman, Simon J. Wilson, Helen M. Amos, Kevin H. Telmer, Frits Steenhuisen, Elsie M. Sunderland, Robert P. Mason, Peter Outridge, Milena Horvat. Toward an Assessment of the Global Inventory of Present-Day Mercury Releases to Freshwater Environments. International Journal of Environmental Research and Public Health. 2017; 14 (2):138.
Chicago/Turabian StyleDavid Kocman; Simon J. Wilson; Helen M. Amos; Kevin H. Telmer; Frits Steenhuisen; Elsie M. Sunderland; Robert P. Mason; Peter Outridge; Milena Horvat. 2017. "Toward an Assessment of the Global Inventory of Present-Day Mercury Releases to Freshwater Environments." International Journal of Environmental Research and Public Health 14, no. 2: 138.
Tjaša Kanduč; Zoran Samardžija; Nataša Mori; Andrej Jerebic; Ines Levačič; Miha Kračun; Johanna A. Robinson; Stojan Žigon; Željko Blažeka; David Kocman. Hydrogeochemical and isotopic characterization of Pesnica River, Slovenia. Geologija 2016, 59, 179 -192.
AMA StyleTjaša Kanduč, Zoran Samardžija, Nataša Mori, Andrej Jerebic, Ines Levačič, Miha Kračun, Johanna A. Robinson, Stojan Žigon, Željko Blažeka, David Kocman. Hydrogeochemical and isotopic characterization of Pesnica River, Slovenia. Geologija. 2016; 59 (2):179-192.
Chicago/Turabian StyleTjaša Kanduč; Zoran Samardžija; Nataša Mori; Andrej Jerebic; Ines Levačič; Miha Kračun; Johanna A. Robinson; Stojan Žigon; Željko Blažeka; David Kocman. 2016. "Hydrogeochemical and isotopic characterization of Pesnica River, Slovenia." Geologija 59, no. 2: 179-192.
Tuzla is among the most polluted cities of Bosnia and Herzegovina. The main source of pollution in the area is soil heavily contaminated by mercury released from a former chloralkali plant. This paper is focused on the characterization of mercury contaminated soil and air surrounding the chloralkali plant. In soil, the mobility and transformation of mercury were investigated by sequential extraction, while the methylation and reduction potentials were determined by the use of a radioactive tracer. Mercury emission from soil was determined by laboratory and by flux chamber measurements in the field. In addition, mercury concentrations in air were estimated by the analysis of air and the transplanted lichen Hypogymnia physodes. Mercury in soils in the vicinity of the chloralkali plant exceeded the background value by a factor of more than 3000. The fractionation of mercury in surface soil by sequential extraction showed that the mercury in soil was primarily bound to organic matter and a fraction containing elemental mercury and mercury (I) chloride is also significant. The obtained methylation and reduction potentials are low. The mercury flux from soil was estimated by two approaches. Fluxes of up to 8000 ng/m2/day were measured at the most polluted site; evaporation from soil was shown to be the primary source of elevated mercury in air. Air concentration mapping also revealed other sources of mercury; the most likely is the 715 MW coal power plant in the vicinity of former chloralkali facility.
Jasna Huremović; Milena Horvat; Jože Kotnik; David Kocman; Suzana Žižek; Sergio Ribeiro Guevara; Tidža Muhić-Šarac; Mustafa Memić. Characterization of Mercury Contamination Surrounding a Chloralkali Production Facility in Tuzla, Bosnia and Herzegovina. Analytical Letters 2016, 50, 1049 -1064.
AMA StyleJasna Huremović, Milena Horvat, Jože Kotnik, David Kocman, Suzana Žižek, Sergio Ribeiro Guevara, Tidža Muhić-Šarac, Mustafa Memić. Characterization of Mercury Contamination Surrounding a Chloralkali Production Facility in Tuzla, Bosnia and Herzegovina. Analytical Letters. 2016; 50 (6):1049-1064.
Chicago/Turabian StyleJasna Huremović; Milena Horvat; Jože Kotnik; David Kocman; Suzana Žižek; Sergio Ribeiro Guevara; Tidža Muhić-Šarac; Mustafa Memić. 2016. "Characterization of Mercury Contamination Surrounding a Chloralkali Production Facility in Tuzla, Bosnia and Herzegovina." Analytical Letters 50, no. 6: 1049-1064.
Global mercury emission inventories include anthropogenic emissions, contributing via current use or presence of mercury in a variety of products and processes, as well as natural source emissions. These inventories neglect the contribution of areas contaminated with mercury from historical accumulation, which surround mines or production plants associated with mercury production or use. Although recent studies have shown that releases of mercury from these historical sites can be significant, a database of the global distribution of mercury contaminated sites does not exist, nor are there means of scaling up such releases to estimate fluxes on a regional and global basis. Therefore, here we estimated for the first time the contribution of mercury releases from contaminated sites to the global mercury budget. A geo-referenced database was built, comprising over 3000 mercury contaminated sites associated with mercury mining, precious metal processing, non-ferrous metal production and various polluted industrial sites. In the assessment, mercury releases from these sites to both the atmosphere as well as the hydrosphere were considered based on data available for selected case studies, their number, the reported extent of contamination and geographical location. Annual average global emissions of mercury from identified contaminated sites amount to 198 (137-260) Mgyr(-1). Of that, 82 (70-95)Mgyr(-1) contribute to atmospheric releases, while 116 (67-165) Mgyr(-1) is estimated to be transported away from these sites by hydrological processes. Although these estimates are associated with large uncertainties, our current understanding of mercury releases from contaminated sites indicates that these releases can also be of paramount importance on the global perspective. This is especially important as it is known that these sites represent a long-term source of releases if not managed properly. Therefore, the information presented here is needed by governments and NGO's in order to re-focus resources in making decisions regarding mitigation and remediation strategies on a global level.
David Kocman; Milena Horvat; Nicola Pirrone; Sergio Cinnirella. Contribution of contaminated sites to the global mercury budget. Environmental Research 2013, 125, 160 -170.
AMA StyleDavid Kocman, Milena Horvat, Nicola Pirrone, Sergio Cinnirella. Contribution of contaminated sites to the global mercury budget. Environmental Research. 2013; 125 ():160-170.
Chicago/Turabian StyleDavid Kocman; Milena Horvat; Nicola Pirrone; Sergio Cinnirella. 2013. "Contribution of contaminated sites to the global mercury budget." Environmental Research 125, no. : 160-170.
Spring water chemistry and carbon cycling in our study mainly depend on geological composition of the aquifer. The investigated Alpine springs in Slovenia represent waters strongly influenced by chemical weathering of Mesozoic limestone and dolomite, only one spring was located in Permo-Carboniferous shales. The carbon isotopic composition of dissolved inorganic carbon (DIC) and suspended organic carbon (POC) as well as major solute concentrations yielded insights into the origin of carbon in Alpine spring waters. The major solute composition was dominated by carbonic acid dissolution of calcite. Waters were generally close to saturation with respect to calcite, and dissolved CO2 was up to fortyfold supersaturated relative to the atmosphere. δ13 C of DIC indicates the portion of soil CO2 contributed in water and is related with soil thickness of infiltrating water in aquifer and could be therefore used as a tool for vulnerability assessment. The δ13 C of DIC ranged from − 15.8‰ to − 1.5‰ and indicated less and more vulnerable aquifers. Mass balances of carbon for spring waters draining carbonate rocks suggest that carbonate dissolution contributes from approximately 49% to 86% and degradation of organic matter from 13.7% to 51.4%, depending on spring and its relation with rock type, soil environment, and geomorphic position. Stable oxygen isotope composition of water (δ18OH2O), and tritium values range from − 12.2 to − 9.3‰ and from 6.4 to 9.8 TU, respectively and indicate recharge from modern precipitation. According to active decay of tritium and tritium in modern precipitation the age of spring waters are estimated to be about 2.6 years for springs located in Julian Alps, about 5 years for springs located in Karavanke and about 5 years for springs located in Kamniško–Savinjske Alps.
Tjaša Kanduč; Nataša Mori; David Kocman; Vekoslava Stibilj; Fausto Grassa. Hydrogeochemistry of Alpine springs from North Slovenia: Insights from stable isotopes. Chemical Geology 2012, 300-301, 40 -54.
AMA StyleTjaša Kanduč, Nataša Mori, David Kocman, Vekoslava Stibilj, Fausto Grassa. Hydrogeochemistry of Alpine springs from North Slovenia: Insights from stable isotopes. Chemical Geology. 2012; 300-301 ():40-54.
Chicago/Turabian StyleTjaša Kanduč; Nataša Mori; David Kocman; Vekoslava Stibilj; Fausto Grassa. 2012. "Hydrogeochemistry of Alpine springs from North Slovenia: Insights from stable isotopes." Chemical Geology 300-301, no. : 40-54.
A mercury emission model was developed to estimate non-point source mercury (Hg) emissions occurring over the year from the Idrijca River catchment, draining the area of the world's second largest Hg mine in Idrija, Slovenia. Site-specific empirical correlations between the measured Hg emission fluxes and the parameters controlling the emission (comprising substrate Hg content, soil temperature, solar radiation and soil moisture) were incorporated into the mercury emission model developed using Geographic Information System technology. In this way, the spatial distribution and significance of the most polluted sites that need to be properly managed was assessed. The modelling results revealed that annually approximately 51 kg of mercury are emitted from contaminated surfaces in the catchment (640 km(2)), highlighting that emission from contaminated surfaces contributes significantly to the elevated Hg concentrations in the ambient air of the region. Very variable meteorological conditions in the modelling domain throughout the year resulted in the high seasonal and spatial variations of mercury emission fluxes observed. Moreover, it was found that mercury emission fluxes from surfaces in the Idrija region are 3-4 fold higher than the values commonly used in models representing emissions from global mercuriferous belts. Sensitivity and model uncertainty analysis indicated the importance of knowing not only the amount but also the type of mercury species and their binding in soils in future model development.
David Kocman; Milena Horvat. Non-point source mercury emission from the Idrija Hg-mine region: GIS mercury emission model. Journal of Environmental Management 2011, 92, 2038 -2046.
AMA StyleDavid Kocman, Milena Horvat. Non-point source mercury emission from the Idrija Hg-mine region: GIS mercury emission model. Journal of Environmental Management. 2011; 92 (8):2038-2046.
Chicago/Turabian StyleDavid Kocman; Milena Horvat. 2011. "Non-point source mercury emission from the Idrija Hg-mine region: GIS mercury emission model." Journal of Environmental Management 92, no. 8: 2038-2046.
The atmospheric distribution and deposition of Hg in the area of the former Idrija Hg-mine, Slovenia, were investigated. Mapping of air Hg0 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 Hg0 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 (THgP). No correlation was found between the THgP and the dissolved phases (THgD), 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.
David Kocman; Polona Vreča; Vesna Fajon; Milena Horvat. Atmospheric distribution and deposition of mercury in the Idrija Hg mine region, Slovenia. Environmental Research 2011, 111, 1 -9.
AMA StyleDavid Kocman, Polona Vreča, Vesna Fajon, Milena Horvat. Atmospheric distribution and deposition of mercury in the Idrija Hg mine region, Slovenia. Environmental Research. 2011; 111 (1):1-9.
Chicago/Turabian StyleDavid Kocman; Polona Vreča; Vesna Fajon; Milena Horvat. 2011. "Atmospheric distribution and deposition of mercury in the Idrija Hg mine region, Slovenia." Environmental Research 111, no. 1: 1-9.
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 (HgR), 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.
David Kocman; Tjaša Kanduč; Nives Ogrinc; Milena Horvat. Distribution and partitioning of mercury in a river catchment impacted by former mercury mining activity. Biogeochemistry 2010, 104, 183 -201.
AMA StyleDavid Kocman, Tjaša Kanduč, Nives Ogrinc, Milena Horvat. Distribution and partitioning of mercury in a river catchment impacted by former mercury mining activity. Biogeochemistry. 2010; 104 (1-3):183-201.
Chicago/Turabian StyleDavid Kocman; Tjaša Kanduč; Nives Ogrinc; Milena Horvat. 2010. "Distribution and partitioning of mercury in a river catchment impacted by former mercury mining activity." Biogeochemistry 104, no. 1-3: 183-201.
Results obtained by a laboratory flux measurement system (LFMS) focused on investigating the kinetics of the mercury emission flux (MEF) from contaminated soils of the Idrija Hg-mine region, Slovenia are presented. Representative soil samples with respect to total Hg concentrations (4–417 μg g−1) and land cover (forest, meadow and alluvial soil) alongside the River Idrijca were analysed to determine the variation in MEF versus distance from the source, regulating three major environmental parameters comprising soil temperature, soil moisture and solar radiation. MEFs ranged from less than 2 to 530 ng m−2 h−1, with the highest emissions from contaminated alluvial soils and soils near the mining district in the town of Idrija. A significant decrease of MEF was then observed with increasing distance from these sites. The results revealed a strong positive effect of all three parameters investigated on momentum MEF. The light-induced flux was shown to be independent of the soil temperature, while the soil aqueous phase seems to be responsible for recharging the pool of mercury in the soil available for both the light- and thermally-induced flux. The overall flux response to simulated environmental conditions depends greatly on the form of Hg in the soil. Higher activation energies are required for the overall process to occur in soils where insoluble cinnabar prevails compared to soils where more mobile Hg forms and forms available for transformation processes are dominant.
D. Kocman; M. Horvat. A laboratory based experimental study of mercury emission from contaminated soils in the River Idrijca catchment. Atmospheric Chemistry and Physics 2010, 10, 1417 -1426.
AMA StyleD. Kocman, M. Horvat. A laboratory based experimental study of mercury emission from contaminated soils in the River Idrijca catchment. Atmospheric Chemistry and Physics. 2010; 10 (3):1417-1426.
Chicago/Turabian StyleD. Kocman; M. Horvat. 2010. "A laboratory based experimental study of mercury emission from contaminated soils in the River Idrijca catchment." Atmospheric Chemistry and Physics 10, no. 3: 1417-1426.
The Sava River is the biggest tributary to the Danube River. As a part of the 6th FW EU project, Sava River Basin: Sustainable Use, Management and Protection of Resources (SARIB), ecological status of sediments was investigated. In order to assess the geographical distribution in sediment contamination of the Sava River, inorganic and persistent organic pollutants were analyzed in sediments at 20 selected sampling sites along the Sava River from its spring to its outfall into the Danube River. For comparability of data to other river basins the sediment fraction below 63 microm was studied. Due to complexity of the work performed, the results are published separately ("Part I: Selected elements" and "Part II: Persistent organic pollutants"). In the present study, the extent of pollution was estimated by determination of the total element concentrations and by the identification of the most hazardous highly mobile element fractions and anthropogenic inputs of elements to sediments. To assess the mobile metal fraction extraction in 0.11 mol L(-1), acetic acid was performed (first step of the Community Bureau of Reference extraction procedure), while anthropogenic inputs of elements were estimated on the basis of normalization to aluminum (Al) concentration. According to the Water Framework Directive, the following elements were investigated in sediments: cadmium (Cd), lead (Pb), nickel (Ni), and mercury (Hg). Furthermore, copper (Cu), zinc (Zn), chromium (Cr), arsenic (As), and phosphorous (P) were determined. The analyses of sediments demonstrated slightly elevated values for Hg, Cr, and Ni in industrially exposed sites (concentrations up to 0.6, 380, and 210 mg kg(-1), respectively). However, the latter two elements exist in sparingly soluble forms and therefore do not represent an environmental burden. P concentrations were found in elevated concentrations at agricultural areas and big cities (up to 1,000 mg kg(-1)).
Radmila Milačič; Janez Ščančar; Simona Murko; David Kocman; Milena Horvat. A complex investigation of the extent of pollution in sediments of the Sava River. Part 1: Selected elements. Environmental Monitoring and Assessment 2009, 163, 263 -275.
AMA StyleRadmila Milačič, Janez Ščančar, Simona Murko, David Kocman, Milena Horvat. A complex investigation of the extent of pollution in sediments of the Sava River. Part 1: Selected elements. Environmental Monitoring and Assessment. 2009; 163 (1-4):263-275.
Chicago/Turabian StyleRadmila Milačič; Janez Ščančar; Simona Murko; David Kocman; Milena Horvat. 2009. "A complex investigation of the extent of pollution in sediments of the Sava River. Part 1: Selected elements." Environmental Monitoring and Assessment 163, no. 1-4: 263-275.
The preparation and characterization of a soil reference material (SOIL-1) from a site polluted with mercury due to the past mercury mining in Idrija, Slovenia is reported. Homogeneity tests and intercomparison exercises for total (T-Hg) and methylmercury (MeHg) were performed. In addition, selective sequential extraction was applied for Hg fractionation, and multielemental analyses were performed by k(0) standardization neutron activation analysis (k(0)-INAA) and inductively coupled mass spectrometry (ICP-MS) for other trace elements. Comparison of different analytical methods, as well as the distribution of data were critically evaluated using descriptive statistics and analysis of variance (ANOVA). Due to the nugget effect (cinnabar particles representing more than 90% of the mercury), homogeneity for T-Hg determination was difficult to achieve. The intercomparison exercise indicated that in order to obtain comparable results for total mercury (T-Hg) sample decomposition by HF must be performed. These data are then in good agreement with non-destructive methods such as k(0)-INAA. Accepted reference values calculated taking into account the results obtained by six and three laboratories, respectively, were 67.1+/-11.3 mg kg(-1) for T-Hg and 4.0+/-1.3 ng g(-1) for MeHg (95% confidence intervals). However, the results obtained for Hg fractionation displayed significant differences in the organically bound fraction and elemental Hg. Results obtained by two laboratories using totally different analytical protocols for other elements showed excellent agreement for most elements. In summary, the results obtained for the SOIL-1 sample were of sufficient quality to suggest its use for quality control in laboratories dealing with mercury contaminated soils.
David Kocman; Nicolas S. Bloom; Hirokatso Akagi; Kevin Telmer; Lars Hylander; Vesna Fajon; Vesna Jereb; Radojko Jaćimović; Borut Smodiš; Justinian R. Ikingura; Milena Horvat. Preparation and characterization of a soil reference material from a mercury contaminated site for comparability studies. Journal of Environmental Management 2006, 81, 146 -154.
AMA StyleDavid Kocman, Nicolas S. Bloom, Hirokatso Akagi, Kevin Telmer, Lars Hylander, Vesna Fajon, Vesna Jereb, Radojko Jaćimović, Borut Smodiš, Justinian R. Ikingura, Milena Horvat. Preparation and characterization of a soil reference material from a mercury contaminated site for comparability studies. Journal of Environmental Management. 2006; 81 (2):146-154.
Chicago/Turabian StyleDavid Kocman; Nicolas S. Bloom; Hirokatso Akagi; Kevin Telmer; Lars Hylander; Vesna Fajon; Vesna Jereb; Radojko Jaćimović; Borut Smodiš; Justinian R. Ikingura; Milena Horvat. 2006. "Preparation and characterization of a soil reference material from a mercury contaminated site for comparability studies." Journal of Environmental Management 81, no. 2: 146-154.
Mercury (Hg) fractionation was investigated in contaminated soil in the Idrija Hg-mine region, Slovenia. The main aim of this study was to test and apply sequential extraction and quantification of different Hg phases in order to estimate the mobility and potential bioavailability of Hg in contaminated soils. Separation of Hg phases was performed by means of a selective sequential extraction procedure complemented by volatilization of elemental mercury (Hg0). The influence of temperature, moisture and storage on Hg0 volatilization was also investigated. The total Hg concentrations varied between 8.4 and 415 mg kg−1 and were up to 40-fold higher than the maximum permissible set by Slovenian legislation. Fractionation measurements indicated cinnabar as the predominant Hg fraction, followed by Hg0. Accumulation of cinnabar predominantly occurred in coarse grained flood plain sediments, where on average it constituted more than 80% of total Hg. In contrast non-cinnabar fractions were found to be enriched in areas where fine grained material was deposited, reaching up to 60% of total Hg. The strong positive correlation (R2 = 0.71–0.99) among non-cinnabar fractions suggested that these fractions predominantly control the mobility and potential bioavailability of Hg. Sample pretreatment before fractionation influenced the partition of Hg between different fractions, and therefore fractionation in fresh, nontreated samples is suggested. In addition, the specificity of the extraction steps needs further attention, as it was shown that some extraction steps, such as the organo-chelating Hg fraction, do not provide meaningful results. This further suggests that protocols for mercury fractionation need further harmonization in order to improve the comparability of the results and their use in risk assessment. Volatile mercury fluxes averaged between 0.04 and 6.5 ng g−1 h−1. Good agreement (R2 = 0.81–0.95) was found between the non-cinnabar fractions and evaporation of Hg0. Both the temperature and sample moisture had significant effects on mercury volatilization. The results in this study were obtained at 70 °C, which may be somewhat high, in particular for bacterial activity which may also play an important role in Hg volatilization. Therefore it is strongly suggested that further optimisation of the protocol to assess Hg volatilization from soil is required.
David Kocman; Milena Horvat; Joze Kotnik. Mercury fractionation in contaminated soils from the Idrija mercury mine region. Journal of Environmental Monitoring 2004, 6, 696 -703.
AMA StyleDavid Kocman, Milena Horvat, Joze Kotnik. Mercury fractionation in contaminated soils from the Idrija mercury mine region. Journal of Environmental Monitoring. 2004; 6 (8):696-703.
Chicago/Turabian StyleDavid Kocman; Milena Horvat; Joze Kotnik. 2004. "Mercury fractionation in contaminated soils from the Idrija mercury mine region." Journal of Environmental Monitoring 6, no. 8: 696-703.