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Prof. Dr. Dimitrios Alexakis
Laboratory of Geoenvironmental Science and Environmental Quality Assurance - University of West Attica

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Research Keywords & Expertise

0 Water Quality
0 environmental geochemistry
0 Health Risk Assessment
0 Aqueous Geochemistry
0 Environmental Geotechnics

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Short Biography

Originally researcher in Environmental Geochemistry (1996-2009), I have been a Research Fellow at Department of Geology (National and Kapodistrian University of Athens), then Lecturer of Environmental Geochemistry. Previous appointments included: (a) Visiting Researcher at the University of Sheffield (UK), cooperation with the Groundwater Protection and Restoration Group (GPRG) and the Environment Agency, and (b) Laboratory Teaching Staff at National Technical University of Athens. Currently, I serve as an Associate Professor at University of West Attica (UNIWA). Also, I am the Founder and Director of the LAboratoRy of GEoenvironmental Science & Environmental Quality Assurance (LAR.GE.). (https://orcid.org/0000-0002-4495-5330).

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Journal article
Published: 25 July 2021 in Sustainability
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In this research, a new machine-learning approach was proposed to evaluate the effects of eight input parameters (surface area, relative compactness, wall area, overall height, roof area, orientation, glazing area distribution, and glazing area) on two output parameters, namely, heating load (HL) and cooling load (CL), of the residential buildings. The association strength of each input parameter with each output was systematically investigated using a variety of basic statistical analysis tools to identify the most effective and important input variables. Then, different combinations of data were designed using the intelligent systems, and the best combination was selected, which included the most optimal input data for the development of stacking models. After that, various machine learning models, i.e., XGBoost, random forest, classification and regression tree, and M5 tree model, were applied and developed to predict HL and CL values of the energy performance of buildings. The mentioned techniques were also used as base techniques in the forms of stacking models. As a result, the XGboost-based model achieved a higher accuracy level (HL: coefficient of determination, R2 = 0.998; CL: R2 = 0.971) with a lower system error (HL: root mean square error, RMSE = 0.461; CL: RMSE = 1.607) than the other developed models in predicting both HL and CL values. Using new stacking-based techniques, this research was able to provide alternative solutions for predicting HL and CL parameters with appropriate accuracy and runtime.

ACS Style

Ahmed Mohammed; Panagiotis Asteris; Mohammadreza Koopialipoor; Dimitrios Alexakis; Minas Lemonis; Danial Armaghani. Stacking Ensemble Tree Models to Predict Energy Performance in Residential Buildings. Sustainability 2021, 13, 8298 .

AMA Style

Ahmed Mohammed, Panagiotis Asteris, Mohammadreza Koopialipoor, Dimitrios Alexakis, Minas Lemonis, Danial Armaghani. Stacking Ensemble Tree Models to Predict Energy Performance in Residential Buildings. Sustainability. 2021; 13 (15):8298.

Chicago/Turabian Style

Ahmed Mohammed; Panagiotis Asteris; Mohammadreza Koopialipoor; Dimitrios Alexakis; Minas Lemonis; Danial Armaghani. 2021. "Stacking Ensemble Tree Models to Predict Energy Performance in Residential Buildings." Sustainability 13, no. 15: 8298.

Journal article
Published: 21 June 2021 in Sustainability
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Karst features such as polje are highly vulnerable to natural and anthropogenic pollution. The main objectives of this study were to investigate the soil quality in the Ioannina polje (north-west Greece) concerning arsenic (As) and zinc (Zn), and delineate their origin as well as compare the As and Zn content in soil with criteria recorded in the literature. For this purpose, the geomorphological settings, the land use, and the soil physicochemical properties were mapped and evaluated, including soil texture and concentrations of aqua-regia extractable As and Zn. The concentration of elements was spatially correlated with the land use and the geology of the study area, while screening values were applied to assess land suitability. The results reveal that 72% of the total study area has a very gentle slope. This relief favors urban and agricultural activity. Thus, the urban and agricultural land used cover 92% of the total area. The spatial distribution for As and Zn in the soil of the study area is located on very gentle slopes and is strongly correlated with the geological parent materials and human-induced contamination sources. Arsenic and Zn can be considered enriched in the soil of the area studied. The median topsoil contents (in mg kg−1) for As (agricultural soil 16.0; urban soil 17.8) and Zn (agricultural soil 92.0; urban soil 95.0) are higher compared to the corresponding median values of European topsoils. Land evaluation suitability concerning criteria given from the literature is discussed. The proposed work may be helpful in the project of land use planning and the protection of the natural environment.

ACS Style

Dimitrios Alexakis; George Bathrellos; Hariklia Skilodimou; Dimitra Gamvroula. Spatial Distribution and Evaluation of Arsenic and Zinc Content in the Soil of a Karst Landscape. Sustainability 2021, 13, 6976 .

AMA Style

Dimitrios Alexakis, George Bathrellos, Hariklia Skilodimou, Dimitra Gamvroula. Spatial Distribution and Evaluation of Arsenic and Zinc Content in the Soil of a Karst Landscape. Sustainability. 2021; 13 (12):6976.

Chicago/Turabian Style

Dimitrios Alexakis; George Bathrellos; Hariklia Skilodimou; Dimitra Gamvroula. 2021. "Spatial Distribution and Evaluation of Arsenic and Zinc Content in the Soil of a Karst Landscape." Sustainability 13, no. 12: 6976.

Journal article
Published: 10 June 2021 in Applied Sciences
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Assessing the suitability of urban and agricultural land is essential for planning sustainable urban and agricultural systems. The main objective of this study is to evaluate the suitability of land in Ioannina plain (western Greece) concerning the soil contents of two potentially toxic elements, cadmium (Cd) and cobalt (Co). Geochemical and spatial analysis methods were applied to assess the distribution of Cd and Co in the soil of the Ioannina plain and identify their origin. The primary anthropogenic sources of Cd and Co in the topsoil of the study area can be attributed to traffic emissions, aircraft operations, vehicle crushing and dismantling activities. Element content is compared to international guidelines and screening values. Cadmium and Co concentration in the soil of the study area is well above the European topsoil mean. Thus, the urban and agricultural lands cover the vast majority (92%) of the total area. Cadmium concentration in soil of the study area with a mean (mg kg−1) 1.7 and 2.0 was observed in agricultural and urban land use, respectively. Cobalt content in soil of the area studied with a mean (mg kg−1) 30.8 and 37.1 was recorded in agricultural and urban land use, respectively. Land evaluation suitability by adopting criteria provided from the international literature is discussed.

ACS Style

Dimitrios Alexakis; George Bathrellos; Hariklia Skilodimou; Dimitra Gamvroula. Land Suitability Mapping Using Geochemical and Spatial Analysis Methods. Applied Sciences 2021, 11, 5404 .

AMA Style

Dimitrios Alexakis, George Bathrellos, Hariklia Skilodimou, Dimitra Gamvroula. Land Suitability Mapping Using Geochemical and Spatial Analysis Methods. Applied Sciences. 2021; 11 (12):5404.

Chicago/Turabian Style

Dimitrios Alexakis; George Bathrellos; Hariklia Skilodimou; Dimitra Gamvroula. 2021. "Land Suitability Mapping Using Geochemical and Spatial Analysis Methods." Applied Sciences 11, no. 12: 5404.

Journal article
Published: 09 June 2021 in Hydrology
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The achievement of sustainable development goals in groundwater resources related to water quality issues is a critical question in many regions. This study aims to combine powerful tools for helping stakeholders and policymakers achieve sustainable development goals in groundwater resources of agricultural areas. The DPSIR (Driver–Pressure–State–Impact–Response) model in combination with the Canadian Council of Ministers of Environment Water Quality Index and Groundwater Directive 2006/118/European Community—Threshold Values was applied using a hydrogeochemical dataset derived from the analysis of groundwater samples collected from 31 monitoring sites in an unconfined alluvial aquifer. Elevated Cl (up to 423.2 mg L−1), NO3 (up to 180.1 mg L−1) concentration and electrical conductivity (up to 2037 μS cm−1) value are observed for groundwater samples of the study area. The outcome of the “One Out-All Out” procedure revealed that the groundwater in 42% of the monitored sites is unsuitable for drinking according to the health-based guideline values established by Directive 98/83/European Community. A difficulty to achieve targets under Sustainable Development Goals 3 and 6 in the study area is revealed. The proposed response actions are reported.

ACS Style

Dimitrios Alexakis. Linking DPSIR Model and Water Quality Indices to Achieve Sustainable Development Goals in Groundwater Resources. Hydrology 2021, 8, 90 .

AMA Style

Dimitrios Alexakis. Linking DPSIR Model and Water Quality Indices to Achieve Sustainable Development Goals in Groundwater Resources. Hydrology. 2021; 8 (2):90.

Chicago/Turabian Style

Dimitrios Alexakis. 2021. "Linking DPSIR Model and Water Quality Indices to Achieve Sustainable Development Goals in Groundwater Resources." Hydrology 8, no. 2: 90.

Original article
Published: 25 May 2021 in Environmental Earth Sciences
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The Mediterranean countries' coastal-karstic aquifer systems are facing increased pressure due to seawater intrusion and drought impacts. There is a need to understand better karstic systems' functional mechanisms for developing the most appropriate management scenario of water resources in these systems. In this study, the application of Non-Linear Autoregressive neural networks (NAR) on a dataset from mid-1968 to 1994 was deployed for predicting values of discharge flow rates and salinity of Almyros spring (Heraklion-Crete, Greece). Two neural networks were trained for the prediction of the discharge rates and the chloride concentration. The neural networks operated with the Levenberg–Marquardt algorithm's aid and attained a coefficient of determination R = 0.83, and R = 0.86, respectively, indicating a high degree of prediction capacity.

ACS Style

Georgios K. Bekas; Dimitrios E. Alexakis; Dimitra E. Gamvroula. Forecasting discharge rate and chloride content of karstic spring water by applying the Levenberg–Marquardt algorithm. Environmental Earth Sciences 2021, 80, 1 -12.

AMA Style

Georgios K. Bekas, Dimitrios E. Alexakis, Dimitra E. Gamvroula. Forecasting discharge rate and chloride content of karstic spring water by applying the Levenberg–Marquardt algorithm. Environmental Earth Sciences. 2021; 80 (11):1-12.

Chicago/Turabian Style

Georgios K. Bekas; Dimitrios E. Alexakis; Dimitra E. Gamvroula. 2021. "Forecasting discharge rate and chloride content of karstic spring water by applying the Levenberg–Marquardt algorithm." Environmental Earth Sciences 80, no. 11: 1-12.

Journal article
Published: 25 April 2021 in Sustainability
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The assessment of seismic vulnerability is critical for lifelines such as wastewater treatment plants (WTPs) because failures may result in environmental degradation, deterioration of water quality and human diseases development. The main scope of this research is the testing and application of a rapid, simple methodology for assessing the seismic structural vulnerability (SSV) of WTPs (according to the qualitative method Rapid Visual Screening), using structural variables as indices of these infrastructures. An original new method involving the assessment of the SSV of thirteen steps (four for a sample set of WTPs and nine for an individual one) is introduced following systematic literature retrieval. The analysis highlights twenty one factors that may determine the SSV of WTPs: three factors involving general characteristics, five factors involving seismicity and geotechnical data, six factors involving technical data (including structural data) and seven additional factors about WTPs’ materials (concrete and the steel reinforcement of concrete frames). The structural data is analyzed to six additional factors. The implementation of the proposed methodology constitutes a simple, rapid methodological approach for assessing the SSV of WTPs using unique factors that were pinpointed and identified for the first time in this study.

ACS Style

Ploutarchos Kerpelis; Spyridon Golfinopoulos; Dimitrios Alexakis. A Proposed Theoretical Approach for the Estimation of Seismic Structural Vulnerability of Wastewater Treatment Plants. Sustainability 2021, 13, 4835 .

AMA Style

Ploutarchos Kerpelis, Spyridon Golfinopoulos, Dimitrios Alexakis. A Proposed Theoretical Approach for the Estimation of Seismic Structural Vulnerability of Wastewater Treatment Plants. Sustainability. 2021; 13 (9):4835.

Chicago/Turabian Style

Ploutarchos Kerpelis; Spyridon Golfinopoulos; Dimitrios Alexakis. 2021. "A Proposed Theoretical Approach for the Estimation of Seismic Structural Vulnerability of Wastewater Treatment Plants." Sustainability 13, no. 9: 4835.

Journal article
Published: 16 April 2021 in Sustainability
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This study proposes a simple method to produce a flood hazard assessment map in burned and urban areas, where primary data are scarce. The study area is a municipal unit of Nea Makri, a coastal part of the eastern Attica peninsula (central Greece), which has been strongly urbanized and suffered damage from urban fires in 2018. Six factors were considered as the parameters most controlling runoff when it overdraws the drainage system’s capacity. The analytical hierarchy process (AHP) method and a geographical information system (GIS) were utilized to create the flood hazard assessment map. The outcome revealed that the areas with highest flood hazard are distributed in the eastern and southern parts of the study area, as a result of the combination of lowlands with gentle slopes, torrential behavior of the streams, streams covered by construction, increasing urbanization and burned areas. The uncertainty and the verification analyses demonstrate a robust behavior for the model predictions, as well as reliability and accuracy of the map. Comparing the existing urban fabric and road network to the potential flood hazard areas showed that 80% of the urban areas and 50% of the road network were situated within areas prone to flood. The method may be applied to land use planning projects, flood hazard mitigation and post-fire management.

ACS Style

Hariklia Skilodimou; George Bathrellos; Dimitrios Alexakis. Flood Hazard Assessment Mapping in Burned and Urban Areas. Sustainability 2021, 13, 4455 .

AMA Style

Hariklia Skilodimou, George Bathrellos, Dimitrios Alexakis. Flood Hazard Assessment Mapping in Burned and Urban Areas. Sustainability. 2021; 13 (8):4455.

Chicago/Turabian Style

Hariklia Skilodimou; George Bathrellos; Dimitrios Alexakis. 2021. "Flood Hazard Assessment Mapping in Burned and Urban Areas." Sustainability 13, no. 8: 4455.

Article
Published: 27 March 2021 in Environmental Monitoring and Assessment
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The present work investigates the increase of confirmed cases of West Nile virus and the relationship between weather-related patterns and the geographical expansion of West Nile virus in Greece, with a special focus on West Attica, Central Greece, a semi-arid, ecologically fragile Mediterranean area. Using data from the European Environment Agency, European Drought Observatory of Joint Research Centre, the pairwise relationship between surface air temperature anomalies, precipitation anomalies, soil moisture index anomalies, and the fraction of absorbed photosynthetically active radiation anomalies (fAPAR) was evaluated during summer time of 2018, a particularly intense virus outbreak. The empirical results of this study indicate that total precipitation during 2018 was extremely high, nearly 500% above the average. These conditions contributed to the increase of soil moisture index anomaly and fAPAR, creating an ideal microenvironment (wet soils and green pastures) for mosquito breeding. This phenomenon was directly associated with a drastic outbreak of West Nile virus cases in the area, compared with earlier years. Our results indicate how unusually high values of summer precipitation may have contributed (both through direct and indirect ecological channels) to the rapid spread of the West Nile virus in West Attica, causing a significant number of confirmed cases and fatalities. Climate change may bring forth other issues aside from natural disasters, including—but not limited to—virus expansion.

ACS Style

Anastasios Mavrakis; Christina Papavasileiou; Dimitrios Alexakis; Evangelos C. Papakitsos; Luca Salvati. Meteorological patterns and the evolution of West Nile virus in an environmentally stressed Mediterranean area. Environmental Monitoring and Assessment 2021, 193, 1 -11.

AMA Style

Anastasios Mavrakis, Christina Papavasileiou, Dimitrios Alexakis, Evangelos C. Papakitsos, Luca Salvati. Meteorological patterns and the evolution of West Nile virus in an environmentally stressed Mediterranean area. Environmental Monitoring and Assessment. 2021; 193 (4):1-11.

Chicago/Turabian Style

Anastasios Mavrakis; Christina Papavasileiou; Dimitrios Alexakis; Evangelos C. Papakitsos; Luca Salvati. 2021. "Meteorological patterns and the evolution of West Nile virus in an environmentally stressed Mediterranean area." Environmental Monitoring and Assessment 193, no. 4: 1-11.

Research article
Published: 01 March 2021 in Environmental Science and Pollution Research
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The Driver–Pressure–State–Impact–Response (DPSIR) framework is applied for assessing the pressures and impacts on groundwater bodies of two Mediterranean sites (Megara and Oropos–Kalamos basins). The study areas present joint driving forces (drivers) and pressures. The main driving forces in the areas studied mainly include geology, agricultural activities, and urban development, while the main pressures mainly include the weathering of ultramafic rock masses, application of agrochemicals, and groundwater abstractions for irrigation and drinking uses. Hexavalent chromium (Cr+6), chromium total (Crtotal), manganese (Mn), and nitrate (NO3−) contamination of groundwater bodies are attributed to both anthropogenic and lithological sources. Elevated Crtotal (up to 70.3 μg L−1), Mn (up to 87.7 μg L−1), and NO3− (up to 411 mg L−1) contents are recorded for groundwater samples in Megara basin. High Crtotal (up to 34.3 μg L−1), Cr6+ (up to 27.9 μg L−1), Mn (up to 132.5 μg L−1), and NO3− (up to 30 mg L−1) are also observed for groundwater samples in the Oropos–Kalamos basin. The major response actions needed for the management options of groundwater bodies are discussed. Among the proposed remedial measures, the installation of a continuous groundwater monitoring network and the control in the usage of nitrogen fertilizers seems to be the most effective and tangible for immediate action.

ACS Style

Dimitrios E. Alexakis; Kyriaki Kiskira; Dimitra Gamvroula; Christina Emmanouil; Constantinos S. Psomopoulos. Evaluating toxic element contamination sources in groundwater bodies of two Mediterranean sites. Environmental Science and Pollution Research 2021, 1 -10.

AMA Style

Dimitrios E. Alexakis, Kyriaki Kiskira, Dimitra Gamvroula, Christina Emmanouil, Constantinos S. Psomopoulos. Evaluating toxic element contamination sources in groundwater bodies of two Mediterranean sites. Environmental Science and Pollution Research. 2021; ():1-10.

Chicago/Turabian Style

Dimitrios E. Alexakis; Kyriaki Kiskira; Dimitra Gamvroula; Christina Emmanouil; Constantinos S. Psomopoulos. 2021. "Evaluating toxic element contamination sources in groundwater bodies of two Mediterranean sites." Environmental Science and Pollution Research , no. : 1-10.

Journal article
Published: 25 February 2021 in Land
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The spatial distribution of potentially toxic elements in land near a heavily loaded highway in the West Attica region (Greece) is discussed. This study aimed to investigate the extent of soil contamination with trace elements on land in the margin of highways. The concentration of thirty-five elements in topsoil, car ash, and road sediment bulk samples was determined. Statistical and spatial analysis was applied for evaluating the geochemical dispersion of the examined elements. Geo-accumulation index was estimated. Elements content were compared to criteria and screening values established by the literature. The concentration of As, Cu, Mn, Ni, P, Pb, and Zn in topsoil appeared to be influenced by traffic emissions. It is found that engine exhaust, tyre wear, and brake lining contribute to the As, Ba, Cu, Mn, Ni, P, Pb, and Zn content recorded in topsoil in the margin of highways. The bulk sample of road sediment is moderately contaminated to extremely contaminated with Cu, Mn, Ni, P, Pb, and Zn. Comparison of elements content in topsoil with screening values revealed that Al, As, B, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Sb, V, and Zn pose a potential risk for plants.

ACS Style

Dimitrios Alexakis. Multielement Contamination of Land in the Margin of Highways. Land 2021, 10, 230 .

AMA Style

Dimitrios Alexakis. Multielement Contamination of Land in the Margin of Highways. Land. 2021; 10 (3):230.

Chicago/Turabian Style

Dimitrios Alexakis. 2021. "Multielement Contamination of Land in the Margin of Highways." Land 10, no. 3: 230.

Editorial
Published: 04 February 2021 in Water
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Groundwater and surface water contamination is related to the presence of chemical substances, which strongly influence the water suitability for human consumption as well as for industrial and agricultural uses

ACS Style

Dimitrios Alexakis. Water Quality Indices: Current and Future Trends in Evaluating Contamination of Groundwater Resources. Water 2021, 13, 401 .

AMA Style

Dimitrios Alexakis. Water Quality Indices: Current and Future Trends in Evaluating Contamination of Groundwater Resources. Water. 2021; 13 (4):401.

Chicago/Turabian Style

Dimitrios Alexakis. 2021. "Water Quality Indices: Current and Future Trends in Evaluating Contamination of Groundwater Resources." Water 13, no. 4: 401.

Review
Published: 18 January 2021 in Water
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This study presents an overview about the arsenic (As) contamination and its sources in two European countries. Arsenic is a highly toxic element in its inorganic form and it is carcinogenic to human seven in low concentrations. The occurrence of As in surface water, stream and marine waters, groundwater, bottled water, sediment, soil, mines, and seafood, its environmental origin, and its impacts on human health are discussed. The classes of Geoaccumulation Index for As in Greece ranges from practically uncontaminated to extremely contaminated, and in Cyprus varies between practically uncontaminated and heavily contaminated. In many cases, the As contamination reaches very high concentrations and the impacts may be crucial for the human health and ecosystems. Physicochemical properties, regional climate and geological setting are controlling the occurrence and transport of As. In Greece and Cyprus, the geology, lithology, and ore-deposits are the most important factors for the variation of As contents in water, soil, and sediment. The dominant As species are also determined by the location and the redox conditions. The findings of this paper may be useful for scientists and stakeholders monitoring the studied areas and applying measures for protection of the human and terrestrial ecological receptors (plants, avian, mammals).

ACS Style

Spyros Golfinopoulos; Soterios Varnavas; Dimitrios Alexakis. The Status of Arsenic Pollution in the Greek and Cyprus Environment: An Overview. Water 2021, 13, 224 .

AMA Style

Spyros Golfinopoulos, Soterios Varnavas, Dimitrios Alexakis. The Status of Arsenic Pollution in the Greek and Cyprus Environment: An Overview. Water. 2021; 13 (2):224.

Chicago/Turabian Style

Spyros Golfinopoulos; Soterios Varnavas; Dimitrios Alexakis. 2021. "The Status of Arsenic Pollution in the Greek and Cyprus Environment: An Overview." Water 13, no. 2: 224.

Journal article
Published: 27 October 2020 in Land
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The purpose of this study is the evaluation of fire effect on contaminated land and the assessment of the associated risk of human health and terrestrial ecological receptors. Ash and soil samples were gathered from burned and unburned areas (central Evia, Greece) which are adjacent with a Natura 2000 area. The geochemical dataset includes 20 sampling sites and 35 elements. The wildfire severity was investigated by applying a macroscopic approach and field observations. Statistical and spatial analysis were applied for delineating the distribution of elements in ash and soil. Elemental balance approach was performed for estimating net gain (+) or loss (−) to the ash. Element contents in sampling sites were compared to screening values proposed by the literature. Hundreds of hectares of burned land including wildland areas in central Evia are contaminated with (contents in mg Kg−1), Co (up to 43.5), Cr (up to 244), Mn (up to 1158), Ni (up to 463) associated with geogenic sources such as serpentinite peridotites and Ni-laterite deposits. Aluminum, As, Cd, Co, Cr, Fe, Mn, Ni, Pb, V and Zn contents recorded in the sampling sites are posing a potential risk to human health and ecological receptors.

ACS Style

Dimitrios E. Alexakis. Contaminated Land by Wildfire Effect on Ultramafic Soil and Associated Human Health and Ecological Risk. Land 2020, 9, 409 .

AMA Style

Dimitrios E. Alexakis. Contaminated Land by Wildfire Effect on Ultramafic Soil and Associated Human Health and Ecological Risk. Land. 2020; 9 (11):409.

Chicago/Turabian Style

Dimitrios E. Alexakis. 2020. "Contaminated Land by Wildfire Effect on Ultramafic Soil and Associated Human Health and Ecological Risk." Land 9, no. 11: 409.

Journal article
Published: 02 July 2020 in Water
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Until now, there was no simple procedure to test the performance of water quality indices (WQIs) or, in other words, to perform their meta-evaluation. The purpose of this study is to provide a meta-evaluation approach of two widely used WQIs and suggestions for selecting one or both of them for application in groundwater quality assessment as proposed by the European Union. The meta-evaluation concept is based on testing the performance of two widely known WQIs by applying classification of Water Framework Directive (WFD; 2000/60/EC) and Groundwater Directive (GWD; 2006/118/EC) which was used as a reference. The Canadian Council of Ministers of Environment (CCME) and National Sanitation Foundation (NSF-WQI) have been selected for evaluation. These WQIs were applied in an agricultural area of the Mediterranean region where six sub-datasets for an entire hydrological year were available. This study uses all the available water quality data (52 monitoring stations × 2 sampling periods × 15 parameters) which is systematically collected at the area studied. The CCME-WQI is a rather strict index since it estimates statistically significantly lower values than the NSF-WQI. Based on the performance of the examined indices, it is shown that, mostly, the CCME-WQI classification findings are close to those of the GWD.

ACS Style

Dimitrios E. Alexakis. Meta-Evaluation of Water Quality Indices. Application into Groundwater Resources. Water 2020, 12, 1890 .

AMA Style

Dimitrios E. Alexakis. Meta-Evaluation of Water Quality Indices. Application into Groundwater Resources. Water. 2020; 12 (7):1890.

Chicago/Turabian Style

Dimitrios E. Alexakis. 2020. "Meta-Evaluation of Water Quality Indices. Application into Groundwater Resources." Water 12, no. 7: 1890.

Article
Published: 04 June 2020 in Geosciences Journal
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On the occasion of the July 2018 wildfire in the West Attica region (Kineta area, Geraneia Mountain) this study aimed to the assessment of soil quality in Kineta area and the effect of fire on soil properties and the bioavailable forms of copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn), which is a topic poorly documented. Topsoil (0–5 cm depth) and subsoil (5–25 cm depth) samples were collected from burned sites and unburned control sites two months after the wildfire event. The area is mainly covered by pine trees (Pinus halepensis). Statistical analysis and Geographical Information System (GIS) database elaboration proved successful tools for this research. The type of methodology applied in this study consists of Diethylene-Triamine-Penta-Ace-tic acid (DTPA) chemical extraction, pH, Cation Exchange Capacity (CEC), Electric Conductivity (EC) and soil organic matter (OM) evaluation, factor analysis, GIS database and comparison of soil parameters with quality standards and levels given from the literature. Results of this study indicated that wildfires significantly (p < 0.05) increased pH values, as well as, OM, FeDTPA and MnDTPA higher contents in topsoil at burned sites than topsoil in unburned locations. This higher availability of elements in the soil may be associated with the addition of ash during a fire. At the same time, relationships between various parameters have been identified from factor analysis and reflect genetic association. A GIS elaboration showed the spatial relationship among high positive factor scores, lithology, Mn-oxides and soil condition (burned or unburned soil). In particular, ZnDTPA contents in Kineta soils constitute a case of lithogenic contamination, while high concentrations of MnDTPA demonstrate the role of wildfire in enhancing levels of available elements in topsoil.

ACS Style

Dimitrios Alexakis; Ioannis Kokmotos; Dimitra Gamvroula; George Varelidis. Wildfire effects on soil quality: application on a suburban area of West Attica (Greece). Geosciences Journal 2020, 25, 243 -253.

AMA Style

Dimitrios Alexakis, Ioannis Kokmotos, Dimitra Gamvroula, George Varelidis. Wildfire effects on soil quality: application on a suburban area of West Attica (Greece). Geosciences Journal. 2020; 25 (2):243-253.

Chicago/Turabian Style

Dimitrios Alexakis; Ioannis Kokmotos; Dimitra Gamvroula; George Varelidis. 2020. "Wildfire effects on soil quality: application on a suburban area of West Attica (Greece)." Geosciences Journal 25, no. 2: 243-253.

Journal article
Published: 20 January 2020 in Environmental Research
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The results of the assessment of burned residential and wildland areas associated with the July 2018 western Attica wildfire are summarised. The dispersion of major and trace elements in a fire impacted suburban landscape which is adjacent in the north with a Natura 2000 area is evaluated. The dataset includes 35 elements and 27 sampling sites spatially distributed in wildland and residential areas. Field observations and a macroscopic method were applied for investigating the wildfire severity. Statistical and spatial analysis tools were used for data treatment. Major and trace element contents were compared to levels and criteria provided by the United States Environmental Protection Agency, Canadian Council of Ministers of the Environment and Australian Department of Environment and Conservation. Aluminum, As, Co, Fe, Mn, Ni, Sb and Zn concentrations observed in wildfire ash pose potential risk to human health. Median ash concentrations for Al, As, B, Ba, Cd, Cu, Fe, Mn, Ni, Pb, S, Sb, and Zn exceeds the plant–avian–mammalian screening levels in wildland and residential areas. Geogenic or anthropogenic origin of the elements is discussed. The associated health risk on human health and terrestrial ecological receptors (plant, avian, mammalian) is assessed.

ACS Style

Dimitrios E. Alexakis. 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 2020, 183, 109153 .

AMA Style

Dimitrios E. Alexakis. 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. 2020; 183 ():109153.

Chicago/Turabian Style

Dimitrios E. Alexakis. 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 183, no. : 109153.

Journal article
Published: 01 May 2019 in Environmental and Engineering Geoscience
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Total contents of 36 potentially toxic elements are summarized for agricultural topsoil (n = 12; soil depth = 0–20 cm), subsoil (n = 12; soil depth = 20–40 cm), and representative rock samples collected from a Mediterranean site (Megara Plain, Greece). The five-stage sequential extraction procedure for the geochemical partitioning of cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), manganese (Mn), and nickel (Ni), proposed by Tessier, was applied to topsoil and subsoil collected from the study area. Soil Cd was highly associated with exchangeable fraction, illustrating high bioavailability of this element. The order of mobility of the elements was as follows: Cd > Cu > Co > Zn > Ni > Cr > Mn. Results from sequential extraction experiments illustrated that the bioavailability of Cu, Co, and Zn is moderate, while Ni, Cr, and Mn presented low bioavailability, indicating that these elements could pose a limited threat to the quality of crops. Cadmium is the chief contamination controlling factor posing moderate potential ecological risk. The contamination sources of the examined elements are discussed.

ACS Style

Dimitrios Alexakis; Dimitra Gamvroula; Eleni Theofili. Environmental Availability of Potentially Toxic Elements in an Agricultural Mediterranean Site. Environmental and Engineering Geoscience 2019, 25, 169 -178.

AMA Style

Dimitrios Alexakis, Dimitra Gamvroula, Eleni Theofili. Environmental Availability of Potentially Toxic Elements in an Agricultural Mediterranean Site. Environmental and Engineering Geoscience. 2019; 25 (2):169-178.

Chicago/Turabian Style

Dimitrios Alexakis; Dimitra Gamvroula; Eleni Theofili. 2019. "Environmental Availability of Potentially Toxic Elements in an Agricultural Mediterranean Site." Environmental and Engineering Geoscience 25, no. 2: 169-178.

Article
Published: 05 September 2018 in Environmental Monitoring and Assessment
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A 1-year monitoring study is presented on the chemical status of two surface water reservoirs in a decentralized Mediterranean island. Water samples were collected at varying depths in the two surface water reservoirs and different seasons between November 2015 and September 2016, covering both wet and dry periods of the year. Samples were analyzed in order to determine major chemical parameters and priority substances based on the EU Water Framework Directive (2000/60/EC) and the latest revision of the Priority Substances Policy Directive (2013/39/EU). Tested parameters in both reservoirs did not exceed the set limits. Increased pollutant concentrations were observed in the bottom samples. More than 200 pesticide active substances were determined but none of them was above the parametric trigger value (0.1 μg L−1). Toxic metals were not detected in the examined water samples, whereas the relatively high concentrations of Mn and Cu in the bottom samples are mainly attributed to geogenic background concentrations. Based on the results of the present study, it can be concluded that the chemical situation of both water reservoirs is considered acceptable; however, continuous monitoring should be implemented in the area.

ACS Style

G. Pavlidis; E. Ploumistou; H. Karasali; K. Liapis; Chris Anagnostopoulos; A. Charalampous; Dimitrios Alexakis; D. Gamvroula; Vassilios A. Tsihrintzis. Evaluation of the water quality status of two surface water reservoirs in a Mediterranean island. Environmental Monitoring and Assessment 2018, 190, 570 .

AMA Style

G. Pavlidis, E. Ploumistou, H. Karasali, K. Liapis, Chris Anagnostopoulos, A. Charalampous, Dimitrios Alexakis, D. Gamvroula, Vassilios A. Tsihrintzis. Evaluation of the water quality status of two surface water reservoirs in a Mediterranean island. Environmental Monitoring and Assessment. 2018; 190 (10):570.

Chicago/Turabian Style

G. Pavlidis; E. Ploumistou; H. Karasali; K. Liapis; Chris Anagnostopoulos; A. Charalampous; Dimitrios Alexakis; D. Gamvroula; Vassilios A. Tsihrintzis. 2018. "Evaluation of the water quality status of two surface water reservoirs in a Mediterranean island." Environmental Monitoring and Assessment 190, no. 10: 570.

Original articles
Published: 20 October 2017 in Journal of Environmental Science and Health, Part A
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Due to the extent of non-point source agricultural pollution, protective measures to control agrochemicals from entering aquatic systems are necessary. Measures may include, among others, vegetated buffer strips (VFS), no spray buffer zones, alley crops and agroforestry systems (AFS). The scope of the present work is to examine the pollution abatement potential of a maize-olive (MO) AFS. The efficiency of a combined MO trees system in reducing nutrients and herbicides is tested through soil monitoring in an experimental plot, located in Koropi, Eastern Attica, Greece, in the period May 2015 to November 2015. The monitored pollutants were nitrogen and phosphorus, as well as two herbicides: pendimethalin and nicosulfuron. Soil samples were collected every 3-5 weeks at various soil horizons and distances from the tree row. Pollutant concentrations were determined using liquid chromatography tandem mass spectrometry (LC-MS/MS), ion chromatography (IC) and spectrophotometry techniques. The studied MO tree system exhibited the potential to reduce pollutant migration, with removals ranging 36.8-78.9% for [Formula: see text], 79.3-100% for [Formula: see text], 76.7-100% for [Formula: see text], 79.4-100% for [Formula: see text] and 70-100% for the examined herbicides. The higher removal percentages were observed in the upper soil layers (5-35 cm, below the crops), and where the finer tree roots extend. Thus, the results indicate that planting of trees in cultivated fields can contribute to the reduction of agrochemical pollution of the subsurface soil and in extension of groundwater.

ACS Style

George Pavlidis; Vassilios A. Tsihrintzis; Helen Karasali; Dimitrios Alexakis. Tree uptake of excess nutrients and herbicides in a maize-olive tree cultivation system. Journal of Environmental Science and Health, Part A 2017, 53, 1 -12.

AMA Style

George Pavlidis, Vassilios A. Tsihrintzis, Helen Karasali, Dimitrios Alexakis. Tree uptake of excess nutrients and herbicides in a maize-olive tree cultivation system. Journal of Environmental Science and Health, Part A. 2017; 53 (1):1-12.

Chicago/Turabian Style

George Pavlidis; Vassilios A. Tsihrintzis; Helen Karasali; Dimitrios Alexakis. 2017. "Tree uptake of excess nutrients and herbicides in a maize-olive tree cultivation system." Journal of Environmental Science and Health, Part A 53, no. 1: 1-12.

Journal article
Published: 22 January 2016 in Water Resources Management
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Water quality indices (WQIs) are efficient and powerful tools for evaluating, organising and communicating information on the overall quality of surface water bodies. The use of these indices may be very helpful in evaluating the water quality of aquatic systems in relation to the EU Water Framework Directive (WFD). In this study, two well-known water quality indices have been selected for evaluation: the CCME (Canadian Council of Ministers of the Environment) and NSF (National Sanitation Foundation). These WQIs were applied in the Polyphytos reservoir-Aliakmon river in Greece where monthly water quality data were available for the period June 2004 to May 2005. The available dataset included values of the following parameters: water depth, water temperature, dissolved oxygen, electrical conductivity, pH, transparency (Secchi disk depth), BOD5, COD, total phosphorus (TP), chlorophyll-a (Chl-a), ammonium (NH4+), nitrite (NO2−) and nitrate (NO3−), and total Κjeldahl nitrogen (TKN). The application of the two WQIs was made using specialised, freely available software-tools. A comparison of their performance and a qualitative judgement on their suitability on expressing the quality of a surface water body is presented. The classification results were compared with those obtained by the WFD-ECOFRAME approach of the EU. Based on the applicability and drawbacks of the examined indices, useful conclusions were derived and discussed. Among others, it is concluded that the NSF-WQI is a more robust index and produces a classification nearer that of the WFD-ECOFRAME approach when compared to the CCME-WQI.

ACS Style

Dimitris Alexakis; Vassiliοs A. Tsihrintzis; George Tsakiris; Georgios D. Gikas. Suitability of Water Quality Indices for Application in Lakes in the Mediterranean. Water Resources Management 2016, 30, 1621 -1633.

AMA Style

Dimitris Alexakis, Vassiliοs A. Tsihrintzis, George Tsakiris, Georgios D. Gikas. Suitability of Water Quality Indices for Application in Lakes in the Mediterranean. Water Resources Management. 2016; 30 (5):1621-1633.

Chicago/Turabian Style

Dimitris Alexakis; Vassiliοs A. Tsihrintzis; George Tsakiris; Georgios D. Gikas. 2016. "Suitability of Water Quality Indices for Application in Lakes in the Mediterranean." Water Resources Management 30, no. 5: 1621-1633.