Session GI5.7

[Programme]

GI5.7 | Advances in environmental geochemical monitoring and data elaboration to unveil contamination sources and understand processes

Orals |

Mon, 10:45

Posters on site |

Mon, 14:00

Posters virtual

Mon, 14:00

Advances in environmental geochemical monitoring and data elaboration to unveil contamination sources and understand processes

Co-organized by BG2/GMPV1

Convener: Stefano Albanese | Co-conveners: Caterina GozziECSECS, Antonella Buccianti, Gevorg Tepanosyan

Orals

| Mon, 24 Apr, 10:45–12:30 (CEST)

Room 0.15

Posters on site

| Attendance Mon, 24 Apr, 14:00–15:45 (CEST)

Hall X4

Posters virtual

| Attendance Mon, 24 Apr, 14:00–15:45 (CEST)

vHall ESSI/GI/NP

Orals: Mon, 24 Apr | Room 0.15

Chairpersons: Stefano Albanese, Caterina Gozzi, Gevorg Tepanosyan

10:45–10:50

Introduction

10:50–11:00

EGU23-8484

ECS

On-site presentation

Combining compositional data analysis and machine learning to recognize where soil geochemistry is influenced by the presence of pyroclastic covers in Campania region (Southern Italy)

Maurizio Ambrosino, Stefano Albanese, Antonio Lucadamo, and Domenico Cicchella

In 2015, an environmental monitoring plan (http://www.campaniatrasparente.it) was launched with the aim of assessing the conditions of all environmental compartments (air, water, top and bottom soils, vegetables, biological samples) of the Campania region. A total of 5,333 topsoil samples were collected and analysed to determine the concentration of 52 chemical elements by means of Aqua Regia followed by ICP-MS. The main aim of prospecting campaign was to establish the ranges of the natural geochemical background for a few potentially toxic elements (PTEs) to be used as reference to define the degree of contamination of anthropized areas.

In the study area (about 13,600 km²) four volcanic areas are present and their pyroclastic products are spread across the regional territory due to a common (Plinian) explosive behaviour.

Due to the natural enrichment in some PTEs of soil developed on pyroclastic products, to discriminate the anthropic signals from the natural ones using geochemical data it is not a simple task when dealing with Campania soils. Therefore, as a preparatory work, to precisely identify regional areas mantled by “volcanic” soils we trained five machine learning algorithms (MLAs) to recognize when soil geochemistry is linked with the presence of volcanic products. All MLAs were implemented on centered log-ratio transformed data to reduce the closure and scaling effect commonly affecting geochemical data. In total, 1277 volcanic soils (VS) and 353 non-volcanic soils (NVS), respectively, were selected for the training phase. Data related with VS were selected based on the proximity of the samples with the volcanic centres, excluding highly anthropized areas. Data related with NVS were selected by consulting available detailed geological maps of those areas located faraway from volcanic areas where pyroclastic covers are completely absent. During the training phase, a cross-validation procedure was applied for parameters optimization. In the test phase all the MLAs showed an accuracy greater than 98% and the Random Forest algorithm proved to be the most accurate for the prediction of the remaining 3903 unlabelled soils. Therefore, a total of 1739 samples were classified as NVS and 2164 as VS. A subsequent comparison of the results with the existing distribution models of volcanic products has shown that samples classified as VS mainly fall in areas characterized by a high thickness of the pyroclastic fall deposits normally related to i) eruptions occurred in the last 10 Ky; ii) Campanian Ignimbrite eruption (ca. 39 ky BP); iii) Codola eruption (ca. 25 ky BP).

The MLAs results suggested that the most important chemical variables for the specific classification purpose were Ni, Cs, Ca, Co, Rb, Sc, Mn, U, Na. It is also evident that a first classification could be made by using few of these elements, as well. Our findings could be used as a valuable tool to better discriminate soil nature and geochemical characteristic aiming at a more effective assessment of natural background ranges for those elements sourced by both natural processes and human activities.

How to cite: Ambrosino, M., Albanese, S., Lucadamo, A., and Cicchella, D.: Combining compositional data analysis and machine learning to recognize where soil geochemistry is influenced by the presence of pyroclastic covers in Campania region (Southern Italy), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8484, https://doi.org/10.5194/egusphere-egu23-8484, 2023.

11:00–11:10

EGU23-9327

Virtual presentation

Geochemical Evaluation and Spatiotemporal Distribution of Fluoride in Groundwater of the Sedimentary Alluvial Plain of Bankura District, West Bengal, India

Arghya Ghosh, Narayani Gogoi, Suresh A. Kartha, and Sandip Mondal

The contamination of groundwater by geogenic sources is a major problem in many nations, especially those in the developing world. Fluoride (F) is one of the most pervasive and well-documented geogenic contaminants because of the severe health risks it poses due to its toxicity. F contamination in groundwater in India has been the subject of intense research over the past many decades. In this article, we describe the underlying geochemical process liable for F contamination as well as the factors controlling its spatiotemporal distribution in the Sedimentary Alluvial Plain (SAP) of Bankura District, West Bengal, India. To achieve the desired objective, representative groundwater samples were collected from tube wells and hand pumps at different locations of the study region during pre- and post-monsoon seasons. Collected samples were subjected to F and other hydrochemical analysis following standard test methods. Analysis shows that 37% of all groundwater samples collected during the pre-monsoon period have fluoride levels over 1.5 ppm (the limit specified by the World Health Organization, Geneva, 2004); however, the contamination level dropped to 30% during the post-monsoon period. The investigation of groundwater level changes indicates that, as water levels rise during the post-monsoon, F concentrations decrease due to the dilution effect. Piper trilinear diagram suggested Na-Ca-HCO₃ type of groundwater for both seasons. According to Gibbs diagrams, rock-water interactions (mineral dissolution) are responsible for major ion chemistry in groundwater samples. Factor analysis (FA) of hydrochemical parameters revealed that the occurrence of F in groundwater was due to the weathering and dissolution of fluoride-containing minerals. X-ray diffraction (XRD) analysis of SAP sediments further confirmed the presence of fluoride-bearing minerals (muscovite and fluorite) in the subsurface lithology of the region. A substantial positive loading (> 0.75) of F with pH and bicarbonate for FA demonstrates that F is being leached from the host material by an alkaline-dominated environment. To account for the spatial variability and seasonality to the spatial change of F concentration in groundwater of the SAP, geographical information systems tools and inverse distance weighting interpolation method were used. The results revealed that significant spatiotemporal variability of F contamination was mainly influenced by the recharging rainwater and the average recharge altitude of groundwater in the area under study. The contamination level is significant in the elevated region where replenishing rainwater is more likely to come into contact with fluoride-bearing minerals when it infiltrates and percolates through the vadose zone. This phenomenon increases the F leaching through chemical weathering along groundwater flow pathways. The findings of this study can serve as a scientific foundation for the efficient management of F-contaminated groundwater in the SAP.

How to cite: Ghosh, A., Gogoi, N., Kartha, S. A., and Mondal, S.: Geochemical Evaluation and Spatiotemporal Distribution of Fluoride in Groundwater of the Sedimentary Alluvial Plain of Bankura District, West Bengal, India, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9327, https://doi.org/10.5194/egusphere-egu23-9327, 2023.

11:10–11:20

EGU23-16075

ECS

On-site presentation

Assessing the soil baseline values of a geologically complex territory: the case study of Basilicata region.

Annalise Guarino, Lucia Rita Pacifico, Antonio Iannone, Andrea Gramazio, and Stefano Albanese

The middle and lower reaches of the Basento river and the whole basin of the Cavone river, in Basilicata region (Italy), underwent to a geochemical prospecting involving soil and stream sediments. Specifically, 190 topsoils were collected within a depth range between 10-15 cm from the ground level and 10 bottom soils were sampled within the depth range between 80-100 cm.

Samples were analysed at the Life Analytics laboratory (Battipaglia, Italy), by ICP-MS following an aqua regia digestion, to determine the concentrations of 16 potentially toxic inorganic substances (As, Be, Cd, Co, Cr, CrIV, Cu, Hg, Ni, Pb, Sb, Se, Tl, V, Zn, SO₄).

The purpose of the study has been the definition of the upper background limits (UBLs) for the investigation area. An exploratory data analysis (EDA) was conducted on the dataset to outline the main data structural characteristics. Due to the huge number of samples below detection limits (BDL) for Cd, CrIV, Hg, Se, Tl, only As, Be, Co, Cr, Ni, Pb, Cu, V, Zn and SO₄ were considered for the UBLs definition.

The estimate of the above-mentioned values has been conducted following a series of rigorous statistical tests in line with the "Guidelines for the determination of background values for soils and groundwater" released by the Italian National System for Environmental Protection (SNPA).

In detail, after imputing the few BDL values found in the selected variables by means of K-nearest neighbors (k-NN) algorithm, topsoil and bottom soils data were considered as a whole. Indeed, the dataset was subdivided into 7 subsets according the geopedological units identified based on the local pedological and geological features.

The BoxCox algorithm was applied to the single subsets to normalize data distribution before any statistical treatment. Outliers were identified by mean of the Dixon’s or Rosner’s Outlier tests depending on the sample size, the observation of boxplots and Q-Q plots and the spatial location of some samples considered as hotspots.

For each variable and for each subset, two statical indices (i.e.: 95th upper tolerance limit with 95% coverage (95UTL95) and the 95th upper prediction limit (UPL95)) were calculated. The more conservative among them was chosen as representative for the UBLs.

Results showed that the UBLs found are much lower than the guideline values set by the Italian Environmental Law (Legislative Decree 152/2006). Our findings emphasized how the use of guideline values established at a national level is often inadequate to administrate a geologically and pedologically complex territory such as Italy, favoring the chance of running into a wrong identification of local environmental hazards.

How to cite: Guarino, A., Pacifico, L. R., Iannone, A., Gramazio, A., and Albanese, S.: Assessing the soil baseline values of a geologically complex territory: the case study of Basilicata region., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16075, https://doi.org/10.5194/egusphere-egu23-16075, 2023.

11:20–11:30

EGU23-6351

ECS

Virtual presentation

Geochemical baseline values of chalcophile and siderophile elements in soils around the former mining area of Abbadia San Salvatore (Mt. Amiata, Southern Tuscany, Italy).

Federica Meloni, Barbara Nisi, Caterina Gozzi, Jacopo Cabassi, Giordano Montegrossi, Valentina Rimondi, Daniele Rappuoli, and Orlando Vaselli

Determining the background values of chemical components in environmental matrices is a difficult task. This is particularly true in regions where the human impact due to industrial, mining, agricultural and urban activities coexists with a geological (geogenic) anomaly, which influences the concentration of certain elements in soils, waters and air. In these cases, the term geochemical baseline (GB) is preferable, since it considers the actual content of that element in the superficial environment at a given point in time, including both geogenic and anthropogenic contribution. In this study, a total of 102 top- and sub-soil (collected at 10-50 cm and 50-154 cm depth, respectively) samples and seven rocks, onto which the soils developed, were collected for the determination of GBs for selected chalcophile (As, Cu, Hg and Sb) and siderophile (Co, Cr, Ni, and V) elements in 25.6 km² around the former mining area of Abbadia San Salvatore (Mt. Amiata, Southern Tuscany, Italy). For about one century, cinnabar (HgS) ore deposits have been exploited to produce liquid mercury from the Mt. Amiata volcanic system and its surroundings, which represents a world-class mercury district. The < 2 mm (as required by the national regulamentation) fraction of the samples was pulverized and analysed by ICP-MS (As, Hg and Sb) and ICP-AES (Co, Cr, Ni, and V) after aqua regia digestion. The compositional data analysis of multivariate compositional vectors, based on the log-ratio approach was used to assess the nature of the geochemical . According to our findings, the centred log-ratio (clr) opposed to that of raw/log transformation, enhances the spatial mapping. This also allowed to obtain better-separated variables in the robust Principal Component Analysis (rPCA). Log-ratio geographical maps evidenced that the underlying bedrock geology (parent lithologies), rather than anthropogenic causes, controls the distribution of the great majority of the elements in the top- and sub-soils. The resulting clr-PCA approach, associated with the geological features, indicates that the geochemical pattern of Hg-As is to be related to the volcanic rocks and ore-deposits, although an anthropogenic influence due to the past mining activity in the topsoils cannot be ruled out. Sb, Co, Cr, Ni, and V distribution patterns are in most cases attributed to calcareous and clay lithologies. The anomalous content of Sb found within the volcanic rocks was likely due to the presence of previously undetected old mining dump. The two data populations (volcanic and calcareus-clay lithologis) were separated into two different databases and the outliers were removed when necessary. By processing the two datasets, the US-EPA’s ProUCL software was used for calculating the GBs for the selected suite of elements. The obtained values are paramount for establishing specific guidelines and quality standards in environmental legislation and policy-making to be applied by the Municipality of Abbadia San Salvatore

How to cite: Meloni, F., Nisi, B., Gozzi, C., Cabassi, J., Montegrossi, G., Rimondi, V., Rappuoli, D., and Vaselli, O.: Geochemical baseline values of chalcophile and siderophile elements in soils around the former mining area of Abbadia San Salvatore (Mt. Amiata, Southern Tuscany, Italy)., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6351, https://doi.org/10.5194/egusphere-egu23-6351, 2023.

11:30–11:40

EGU23-8374

On-site presentation

Geochemical transport through the critical zone: Statistics and reconstruction

Karl Fabian, Clemens Reimann, and Belinda Flem

Detecting and quantifying geochemical transport through the critical zone at the continental to regional scale requires reliable statistical procedures that can be uniquely interpreted. We present methods that provide different views on the same data sets and formulate rules for their application and interpretation. The statistical analysis of cumulative distribution functions (CDFs) uses cumulative probability (CP) plots for spatially representative multi-element and multi-media data sets, preferably containing >1000 sites.
Mathematical models demonstrate how contamination can influence elemental CDFs of different sample media. For example large-scale diffuse soil contamination leads to a distinctive shift of the low-concentration end of the distribution of the studied element in its top-soil CP plot, whereas high local contamination influences the high-concentration end. But also bio-geochemical processes can generate recognizable changes in elemental CDFs.
A related and partly unsolved problem is the correct interpretation of compositional data in terms of their transport through the critical zone.

How to cite: Fabian, K., Reimann, C., and Flem, B.: Geochemical transport through the critical zone: Statistics and reconstruction, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8374, https://doi.org/10.5194/egusphere-egu23-8374, 2023.

11:40–11:50

EGU23-8217

ECS

On-site presentation

Assessing the impact of both a forest and a waste fire on the soil chemistry of two areas in Campania region

Lucia Rita Pacifico, Annalise Guarino, Antonio Pizzolante, and Stefano Albanese

In the last decades, intentional illegal burnings increased in the numbers and became a problem of a global interest. As a consequence, human beings can be exposed to potentially toxic elements (PTEs) released during the combustion, dispersed by the wind, and accumulated in the fire’s ashes (Dimitrios, 2020).

Several studies highlighted that PTEs content in the deposited ashes can modify the chemical and the physical characteristics of the soil and, therefore, it can influence the development and growth of local microorganisms and vegetation (Raison, 1979). The geochemical characteristics of ashes depend on the nature of burned material (Dermibas et al. 2003) and on many other variables such as the intensity of combustion, the composition of the underlying soil, the bedrock type, etc.

The aim of the study was to verify at two different sites the environmental impact related with the on-set of two fire events occurred in Campania region (Southern Italy) during the 2017 summer season. One of the fires involved a forest (on the slopes of Mt. Somma-Vesuvius) and one affected a waste disposal site, known as Ilside (close to the city of Caserta). The variation occurred to concentration of PTEs in topsoil was used for the purpose.

Specifically, at both locations, 30 topsoil samples were collected before and right after the fire events. In total 60 samples were collected at the surroundings of Mt. Somma-Vesuvius slopes and 60 at the surroundings of Ilside. The post-fire samples were collected in correspondence of pre-existing sampling sites along the main wind directions recorded at the time of the fires.

To explore the potential elemental contamination occurred in soils due to the fire events, the Enrichment Factor (EFs) of a selection of PTEs was determined and mapped for individual samples. A predominant enrichment of Hg was identified for both areas.

Further, a combined application of multivariate statistics and geospatial analysis was also performed on the calculated EFs.

For the Ilside site (where special waste and e-waste were involved in burning) the association of Hg, Tl, Cu and Co was identified as the main responsible of data variability; for the Vesuvian area, the association of Hg, Cu and Cr was found to be quite strong and possibly associated with forest biomass burning.

This study highlighted how different can be the chemical evidence left by fires occurring in the environment depending on the nature of the burnt materials. At same time, result showed that even the burning of biomasses proceeding from a natural area can input in the environment PTEs which can potentially generate an increase of the pre-existing degree of environmental hazard.

References

Dermibas, A., 2003. Toxic Air Emissions from Biomass Combustion, Energy Sources, 25:5, 419-427.

Dimitrios E. A., 2020. Suburban areas in flames: Dispersion of potentially toxic elements from burned vegetation and buildings. Estimation of the associated ecological and human health risk. Environmental Research, Volume 183, ISSN 0013-9351.

Raison, R.J., 1979. Modification of the soil environment by vegetation fires, with particular reference to nitrogen transformations: a review. Plant Soil 51, 73–108.

How to cite: Pacifico, L. R., Guarino, A., Pizzolante, A., and Albanese, S.: Assessing the impact of both a forest and a waste fire on the soil chemistry of two areas in Campania region, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8217, https://doi.org/10.5194/egusphere-egu23-8217, 2023.

11:50–12:00

EGU23-16341

ECS

On-site presentation

87Sr/86Sr as an efficient tool to investigate environmental processes in winemaking: a Campania (Italy) case study.

Piergiorgio Tranfa, Mariano Mercurio, Massimo D'Antonio, Valeria Di Renzo, Carmine Guarino, Rosaria Sciarrillo, Daniela Zuzolo, Francesco Izzo, Alessio Langella, and Piergiulio Cappelletti

In the last few years Sr isotope geochemistry has contributed substantially to environmental and food traceability research. This is achievable because soils, plants and waters all have a peculiar Sr isotopic signature (⁸⁷Sr/⁸⁶Sr) inherited from the local geological substratum and affected by geological processes as well as the age and initial rubidium concentration of the rocks. Strontium ions released from the bedrock by weathering processes deriving by the interaction of circulating fluids with rocks, enter the environment and accumulates in water and soils. This reservoir of bioavailable Sr may represent a reliable tracer useful to determine the geographical origin of wines as it is known that strontium is taken first by plant roots, then by grapes, and lastly by wine, with no isotope fractionation when compared to the original ⁸⁷Sr/⁸⁶Sr ratio in the soil and rocks. As a result, the study of the Sr isotope ratio in the final product (wine) links directly to its geological origin thus representing a specific geofingerprint for any selected wine. Based on these premises this work aims at confirming the strong link between the product (wine) and its territory, with the final purpose to make it recognizable and distinguishable from similar products and protecting it from possible fraud and adulteration. In this work the ⁸⁷Sr/⁸⁶Sr systematics has been used to analyze a total of 39 samples (37 soil samples and 2 wine samples) from Campania (Italy). For a better understanding, both total Sr fraction and bioavailable Sr fraction were analyzed in soil samples (rhizospheric soils, bulk soils and samples collected from different horizons) in order to better investigate the environmental processes involved during the wine production cycle.

How to cite: Tranfa, P., Mercurio, M., D'Antonio, M., Di Renzo, V., Guarino, C., Sciarrillo, R., Zuzolo, D., Izzo, F., Langella, A., and Cappelletti, P.: 87Sr/86Sr as an efficient tool to investigate environmental processes in winemaking: a Campania (Italy) case study., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16341, https://doi.org/10.5194/egusphere-egu23-16341, 2023.

12:00–12:10

EGU23-4067

On-site presentation

Application of ion-exchange resin sachets and XRF-CS in heavy metal pollution sources monitoring

Yu-Chen Jian, Ludvig Löwemark, and Alice Chien-Yi Liao

For the past decades, scientists have endeavored to develop efficient and suitable approaches to monitor heavy-metal pollution through technological development. Conventional monitoring methods for heavy metals are still complicated, relatively expensive, and time-consuming. This research aims to develop an innovative heavy-metal monitor, the novel approach of ion-exchange resin sachets combined with X-ray fluorescence core scanner (XRF-CS), to achieve an efficient way to effectively monitor vast areas for contamination. The resin sachets, which have a large capacity to quickly take up heavy metals, were deployed in the river weekly to capture heavy metals and then analyzed using the non-destructive, fast, and cost-efficient Itrax XRF core scanner. Two four-week sampling sessions, performed during the dry and wet periods, respectively, were conducted in northeastern Taiwan, where the environment was contaminated by a copper smelter and coal mine activities in the late twentieth century. The results suggest that ion-exchange resins are useful as long-term monitors of heavy metals in a low pollution-level settings (metal concentration <1 mg/L), and that XRF core scanner data truly reflect metal pollution concentrations as measured by inductively coupled plasma-optical emission spectrometry (ICP-OES). This approach allows us to pinpoint pollution sources along the studied river. Especially, Zn, Ni, Mn, Fe, Cu, Ca, and Sr could be detected near pollution sources, where cps values were 1.8 to 3430.6 times higher than in unpolluted areas. Zn shows the largest difference between polluted and non-polluted areas, with the cps values of the samples in polluted areas 3528 times higher than their non-polluted counterparts. Ni, Mn, Fe, Cu, Ca, and Sr’s cps values were 1.8, 29.2, 46.1, 2.4, 6.2, and 5.9 times higher, respectively, than the corresponding counts measured in non-polluted areas. In addition, our results demonstrate that the intensity of precipitation influences the amount of metal adsorption in the resins; resins showed less adsorption in the dry period, and cps values slightly dropped to 81 to 84 percent of the wet period. In summary, ion-exchange resins are a sensitive tool that can be applied in pollution monitoring at various pollution levels due to their high performance in adsorbing heavy metals. Consequently, ion-exchange resin sachets in combination with XRF core scanner analysis is a cost-effective way to monitor large areas of potentially polluted aquatic systems quickly.

How to cite: Jian, Y.-C., Löwemark, L., and Liao, A. C.-Y.: Application of ion-exchange resin sachets and XRF-CS in heavy metal pollution sources monitoring, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4067, https://doi.org/10.5194/egusphere-egu23-4067, 2023.

12:10–12:20

EGU23-15997

ECS

On-site presentation

Development, data modelling of environmental geochemical monitoring of fluvial (suspended, river bottom, floodplain) sediments using unique automated and passive sampling for the contamination risk assessment according to the EU WFD in the Danube Basin

Zsófia Kovács, Győző Jordán, Péter Szabó, and Mária Bálint and the SIMONA Project Team

This study reports on the unique results of the recently concluded Sediment-quality Information, Monitoring and Assessment System to Support Transnational Cooperation for Joint Danube Basin Water Management (SIMONA) project, the largest of its kind in Europe, which was carried out in 2018-2022 as a project of the EU DTP aiming at delivering a ready-to-deploy sediment-quality monitoring system for the effective and comparable measurements and assessment of sediment quality in surface waters in the Danube River Basin in accordance with the EU Water Framework Directive (WFD). The project has developed, tested, demonstrated an innovative environmental geochemical monitoring platform of fluvial (suspended, river bottom and floodplain) sediments using state-of-the-art automated and passive sampling technology for the contamination risk assessment according to the EU WFD in the Danube Basin. Time series analysis and signal processing of one year multi-variate and multi-matrice monitoring data could be used to identify the geochemical background, temporal trends, periodicities and contamination events in the studied EU-defined Hazardous Substances. Since the applied technology, methods and data interpretation is fully consistent with EU legislation risk assessment, results may provide a ‘best solution’ for the spatial and temporal discrimination of contamination. Results of biological contamination assessment of sediments using microbial tests are also presented.

Keywords: data analysis, geochemistry, mobility, speciation, enrichment, time series analysis

How to cite: Kovács, Z., Jordán, G., Szabó, P., and Bálint, M. and the SIMONA Project Team: Development, data modelling of environmental geochemical monitoring of fluvial (suspended, river bottom, floodplain) sediments using unique automated and passive sampling for the contamination risk assessment according to the EU WFD in the Danube Basin, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15997, https://doi.org/10.5194/egusphere-egu23-15997, 2023.

12:20–12:30

EGU23-8855

Virtual presentation

Gene-environment interactions in human disease development: the example of workers exposed to titanium dioxide (TiO2)

(withdrawn)

Patrizia Zavattari, Loredana Moi, Eleonora Loi, Antonietta Marongiu, Paolo Valera, Matteo Serra, Rocco Gibilras, Maddalena Papacchini, and Marco Di Basilio

Posters on site: Mon, 24 Apr, 14:00–15:45 | Hall X4

Chairpersons: Caterina Gozzi, Gevorg Tepanosyan, Annalise Guarino

X4.171

EGU23-16151

Potentially toxic elements (PTEs) in the soils of a densely populated active volcanic area: the Campi Flegrei case study in Italy.

Stefano Albanese, Pooria Ebrahimi, Antonio Aruta, Domenico Cicchella, Fabio Matano, Benedetto De Vivo, and Annamaria Lima

The line of research on potentially toxic elements (PTEs) is of growing interest to the scientific community for protecting society against adverse health issues. The Campi Flegrei caldera in southern Italy is an active volcanic area where above two million people live, making it an ideal study area for investigating PTEs of natural and anthropogenic origin through the latest advances in geochemical data analysis. Therefore, a total of 394 topsoil samples (0 to 15 cm) were collected for determining the “pseudo-total” concentrations of elements in the <2 mm fraction using a combination of inductively coupled plasma-atomic emission spectrometry (ICP-AES) and inductively coupled plasma-mass spectrometry (ICP-MS), following aqua regia digestion.

The median values show that concentrations of Zn, Cu, Pb, V and As are greater (>10 mg/kg) than Cr, Co, Ni, Tl, Sb, Se, Cd and Hg. The geochemical maps generated by the Empirical Bayesian Kriging interpolation technique indicate that the higher concentrations of Pb, Zn, Cd, Cr, Hg, Ni and Sb are related to the greater population density (>6500 persons per Km²) in the urban area, but the elevated levels of As, Tl, Co, Cu, Se and V are observed in the other parts. In the context of compositional data analysis, the correlation diagram and robust principal component analysis detected: (1) the Pb–Zn–Hg–Cd–Sb–Cr–Ni association that likely shows anthropogenic activities such as heavy traffic load and fossil fuel combustion in the urban area; (2) the Al–Fe–Mn–Ti–Tl–V–Co–As–U–Th association that mostly represents the contribution of pyroclastic deposits; and (3) the Na–K–B association that probably reveals the weathering degree.

To choose the PTEs with potential health risks for the local inhabitants, the PTE quantities in soil are compared with the corresponding contamination thresholds established by the Italian legislation for residential land use. The Tl, Pb and Zn contents exceed the threshold in more than 15% of the collected samples, but Tl which derives from a natural source (e.g., leucite) is culled before evaluation. Then, children (0-6 years old) are considered for health risk assessment because: (1) Pb has significant adverse health effects in children; and (2) the more frequent hand-to-mouth behavior in children under 6 years old is linked to the higher chance of exposure. The probabilistic health risk modeling for the children <6 years old highlights negligible (hazard quotient below 1) Pb and Zn non-carcinogenic risk and unexpected (cancer risk ≤1E-06) Pb carcinogenic risk for exposure through soil ingestion. However, for the inhalation pathway, the children aged <1 year old have the highest chance (90%) of acceptable (i.e. from 1E-6 to 1E-4) Pb carcinogenic health risk. This should not be overlooked because Naples is under high environmental pressure and previous studies reported increased Pb and Zn quantities in soil between 1974 and 1999. Overall, the results of geostatistical interpolation, compositional data analysis and probabilistic health risk modeling potentially uncover the link between soil geochemistry and human health in densely populated active volcanic areas.

How to cite: Albanese, S., Ebrahimi, P., Aruta, A., Cicchella, D., Matano, F., De Vivo, B., and Lima, A.: Potentially toxic elements (PTEs) in the soils of a densely populated active volcanic area: the Campi Flegrei case study in Italy., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16151, https://doi.org/10.5194/egusphere-egu23-16151, 2023.

X4.172

EGU23-1225

Experiments of arsenic (V) adsorption on birnessite: implications on arsenic cycling

Hao Wei Huang, Huai-Jen Yang, Li-Yun Huang, and Chia-Ju Chieh

Birnessite occurs as a major manganese oxide in sediments. It is characterized by a high adsorption capacity for trace elements, including arsenic. However, the effects of birnessite on arsenic cycling were less intensively investigated than that of goethite, a commonly recognized arsenic host. Therefore, this study utilizes arsenic-bearing solutions containing 0.1–50 ppm arsenic to synthesize birnessite and uses arsenic sequential extraction procedure (SEP) analysis to quantify its arsenic co-precipitation and adsorption capacity.
SEPs showed that adsorbed/structural arsenic ratio grew from 0:100 to 60:40, with arsenic concentration increasing from 0.1–50 ppm, implying saturation of structural arsenic. SEPs quantify the adsorbed and structural As of birnessite being 0.831 and 1.308 mg/g, respectively. However, the low arsenic concentrations of < 1% in residual solutions indicate nonattainment of the maximum adsorption capacity. Subsequent adsorption experiments using higher initial arsenic concentrations reaching 250 ppm determined the maximum arsenic adsorption capacity to be 19.81 mg/g at pH 7, comparable to the values of 15.3–22.5 mg/g at pH 6.5 (Manning et al., 2002; Singh et al., 2010) and that of 3.79–15.73 mg/g for goethite. It then appears that birnessite adsorption/desorption is more effective than precipitation/dissolution in controlling arsenic cycling. However, the consideration based on the maximum adsorption capacity might overrate the controls of adsorption/desorption relative to precipitation/dissolution because the natural water generally contains less arsenic than that used for the adsorption experiments. Therefore, we conducted adsorption experiments with low arsenic concentrations of 0.5 ppm and a solid/liquid ratio of 0.01 to 0.001. The results showed that adsorption capacity rose abruptly to 1.416 mg/g in two weeks and then slowly increased to 1.523 mg/g after three months. This feature indicated incomplete filling of the adsorption sites on the surface of birnessite at low As concentration despite its large specific surface area. Another controlling factor was the abundance of birnessite in sediments. If 10% of MnO (0.05–0.15%) in the Chianan sediments in southern Taiwan occurred as birnessite, the adsorbed arsenic was calculated to be 0.0005–0.022 mg, corresponding to < 2 % of adsorbed arsenic in 1 g sediments, based on the SEP data of Yang et al. (2016). In the extreme case that all the Mn occurred as birnessite, birnessite could account for up to 25% of the adsorbed arsenic. Apparently, birnessite is not a major contributor to surface arsenic cycling. However, this inference must be evaluated by considering the adsorption and co-precipitation data from goethite and goethite proportions in sediments.

How to cite: Huang, H. W., Yang, H.-J., Huang, L.-Y., and Chieh, C.-J.: Experiments of arsenic (V) adsorption on birnessite: implications on arsenic cycling, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1225, https://doi.org/10.5194/egusphere-egu23-1225, 2023.

X4.173

EGU23-12763

Soil geochemical association of PTE and associated health risk in Kotayk marz (region), Armenia

(withdrawn)

Lilit Sahakyan and Gevorg Tepanosyan

X4.174

EGU23-7980

ECS

A transect of mercury concentrations in fish (Black bass, Micropterus salmoides) from the Valdeazogues river, Almadén Hg mining district, South Central Spain.

José Ignacio Barquero, Pablo Higueras, Jesus J. Hidalgo, Jose M. Esbri, Saturnino Lorenzo, and Efren Garcia-Ordiales

The Almadén district has been the World’s largest producer of mercury (Hg), for more than 2000 years. The mining activity in the district ceased some 10 years ago; however, the generalized pollution of soils and stream sediments, as well as the atmospheric emissions from these and other sources, still represent possibilities to toxify the human food chain. The Valdeazogues river crosses completely the district, with some 150 km2 extension, and including a huge mine, three mines of median importance, and up to 60 points where cinnabar (HgS) has been recognized.

Largemouth bass (Micropterus salmoides) is a carnivorous freshwater gamefish, very common along the Valdeazogues river. For years it was fished to complement the diet of the local inhabitants, although nowadays is not so common to consume it. We obtained 28 specimens, with sizes between 69 and 335 mm and weight between 11 and 552 gr, in a transect from the El Entredicho open pit to downstream the district (some 36,3 km). The specimens were analyzed using atomic absorption spectrometry with Zeeman effect.

Results show important variations throughout the transect; the largest fish in terms of weight and length had the highest Hg concentration (5246 ng/g), much higher than the fish with the lowest concentration (473.2 ng/g), which was not the specimen with the lowest size. Besides, as we go downstream the Valdeazogues River, moving away from the Entredicho Mine (considered to be the main source of contamination), Hg concentrations drops considerably until stabilizing at approximately 1200 - 1500 ng/g.

How to cite: Barquero, J. I., Higueras, P., Hidalgo, J. J., Esbri, J. M., Lorenzo, S., and Garcia-Ordiales, E.: A transect of mercury concentrations in fish (Black bass, Micropterus salmoides) from the Valdeazogues river, Almadén Hg mining district, South Central Spain., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7980, https://doi.org/10.5194/egusphere-egu23-7980, 2023.

Posters virtual: Mon, 24 Apr, 14:00–15:45 | vHall ESSI/GI/NP

Chairpersons: Annalise Guarino, Stefano Albanese, Caterina Gozzi

vEGN.20

EGU23-13317

The occurrence of dichlorodiphenyltrichloroethanes (DDT) and its metabolites in Chinese forest soils: Implications for sources and environmental processes

Chengkai Qu, Ruiqi Wang, and Wen Sun

Dichlorodiphenyltrichloroethane (DDT) and its metabolites are highly toxic and pose chronic effects to the biosphere. As a natural storage pool, forests have great potential to capture them from the atmosphere and migrate them to the forest soil, which, in turn, influences the safety of the forest ecological environment. In this study, a systematical survey of DDT and its metabolites has been carried out to measure their spatial variations in Chinese forest soils. The main objectives of this study were to (1) investigate the levels, distribution and sources of DDT and its metabolites, and further estimate their mass inventories in Chinese forest soils, (2) explore the impact of soil properties on their distribution, and (III) assess the ecological and health risks of DDT and its metabolites. The research results were as follows. The average concentration of ΣDDTs reached up to 9.75 ng/g, and p,p’-DDT is the main component. Significant difference in the concentration of ΣDDTs was observed between the southeast and northwest regions (p<0.01), which may be related to multiple factors such as pesticide use, rainfall and altitude. The forest soil quality inventory is about 0.58×103 tons, which is lighter than that of domestic farmland soil. 56.1% of soil samples were less than the low value of risk assessment (ERL). The concentration of ΣDDTs in the East and middle is higher than that in the West, and the high value is mainly distributed in the coastal areas. DDTs were mainly from the input of the mixed source composed of industrial DDT and dicofol, of which at least 97% came from industrial DDT and up to 4% from dicofol. ΣDDTs was only positively correlated with precipitation and population density (p<0.05). The degradation of DDT in soil occured from primary stage to high stage. The possible degradation pathways involved in DDTs entering forest soil were preliminarily deduced. Firstly, the surrounding pollution sources volatilize DDTs from soils to the atmosphere through secondary emission. In this process, DDT was continuously transformed into DDE through photodecomposition. The atmosphere rich in DDTs were transported to the forest area and then into the forest surface soil through atmospheric dry and wet deposition. Then, DDT transported continuously accumulated and degraded in forest soil. In the alternation of anaerobic and aerobic process, the main degradation pathways are DDT→DDD→DDMU, DDT→dicofol+DBP, DDT→DDE→DDMU, DDMU→DDNU.

How to cite: Qu, C., Wang, R., and Sun, W.: The occurrence of dichlorodiphenyltrichloroethanes (DDT) and its metabolites in Chinese forest soils: Implications for sources and environmental processes, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13317, https://doi.org/10.5194/egusphere-egu23-13317, 2023.

vEGN.21

EGU23-15671

ECS

Spatio-temporal variations of phosphorus (P) fractions in surface sediments of the southern Caspian Sea

Pooria Ebrahimi, Mohammad Javad Nematollahi, Hassan Nasrollahzadeh Saravi, Rolf David Vogt, Fariba Vahedi, and Mahdie Baloei

Sediments act as a sink and a secondary source of contaminants, accounting for a central part of coastal and marine biogeochemical cycles. Phosphorus (P) is a macronutrient that governs primary productivity and phytoplankton growth, but excess P influx results in algae bloom and deteriorates aquatic ecosystems. This study assesses seasonal fluctuations, spatial distribution and fractions of P in the sediments of the southern Caspian Sea. In this study, at eight sampling points, composite samples of the surface (from 0 to 10 cm) seabed sediments were collected at 10 and 30 m water depths. The sampling campaigns were carried out in the four seasons and a total of 64 sediment samples were obtained. Total organic matter (TOM), total P (TP) concentration and particle size distribution were determined. Then, P was fractionated using a four-step sequential procedure to quantify the loosely bound P (LP), the reductant soluble P (FeP), the metallic oxide-bound P (AlP) and the calcium carbonate (CaCO₃) bound P (CaP). The inorganic P (IP) pool refers to the sum of LP, FeP, AlP and CaP, while the organic P (OP) was calculated by subtracting IP from TP.

The results show that seasonal fluctuations of mean TP were statistically insignificant (p-value > 0.05). Still, the highest levels were recorded in autumn (1555 mg kg^-1), followed by winter (1405 mg kg^-1), spring (1378 mg kg^-1) and summer (1130 mg kg^-1). These minor temporal variations in P levels are associated with the seasonal differences in the amount of runoff and the intensity of rivers discharging into the Caspian Sea, and thereby their sediment load and the physicochemical characteristics. The large riverine influx resulted in TP contamination hotspots in the river deltas of Anzali wetland, Babolrood and Sefidrud (northern Iran), where high loadings of suspended particles are discharged into the sea. The spatial TP distribution is thus site-specific and uneven. The main P fraction was CaP, reflecting the phosphate (PO₄^3-) strong affinity for, and association with, calcium-bearing minerals. Only a minor fraction of P was determined as LP. The fraction of the mud-size particles was the main explanatory factor for the spatial distribution of overall low levels of non-residual (or bioavailable) P forms (i.e., LP, FeP and AlP) during spring and summer, while the sand fraction had the greatest explanatory value for the distribution of residual (non-bioavailable) P form (CaP) during autumn and winter. This study demonstrates that P bioavailability in sediments is mostly controlled by the physicochemical characteristics of the sediment material, which again is steered by seawater chemistry. A low content of bioavailable P fractions could therefore be related to the relatively low content of fine-grained (i.e. below 63 µm) particles in sediments of the southern Caspian Sea.

How to cite: Ebrahimi, P., Nematollahi, M. J., Nasrollahzadeh Saravi, H., Vogt, R. D., Vahedi, F., and Baloei, M.: Spatio-temporal variations of phosphorus (P) fractions in surface sediments of the southern Caspian Sea, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15671, https://doi.org/10.5194/egusphere-egu23-15671, 2023.