Assessment Of Soil Contamination Research Articles

Set of Enzymatic Bioassays for Assessment of Soil Contamination.

A concept of the comprehensive assessment of soil contamination is proposed. According to it, the conclusion regarding the presence of toxic substances in the analyzed sample is based on the inhibition of enzymatic reactions responsible for various functions of a living organism, such as luminescence, respiration, etc. These functions are taken as test functions in classical bioassays with the use of living objects (luminous bacteria, daphnia, algae, and others). The regularities of the impact of different classes of toxicants on the activity of particular enzymes or coupled oligo-enzyme chains have been established. These enzyme reactions are selected as potential test objects: markers of contamination. Three enzyme systems with the maximal sensitivity to different classes of toxicants have been chosen for the set of enzymatic bioassays: butyrylcholinesterase, NAD(P)H:FMN-oxidoreductase + luciferase, and lactate dehydrogenase + NAD(P)H:FMN-oxidoreductase + luciferase. The possibility to use enzymes instead of living organisms in the bioassay of natural complex systems has been shown.

Zirconium as a suitable reference element for estimating potentially toxic element enrichment in treated wastewater discharge vicinity.

The suitability of a reference element or normalizer used in assessing soil contamination levels using enrichment factor (EF) is important for soil quality assessment and monitoring. This study evaluated the results of using three reference elements Ti, Fe, and Zr for EF determination of Rb and Sr in soils within treated wastewater discharge vicinity, Central Botswana. The upper continental crust (UCC), world average values (WAV), and the local background values (LBV) were used in EF assessment of eight pedons. The elemental concentrations of the soils were determined with portable X-ray fluorescence (pXRF) analyzer. Relationships between the elements were strongly significant between Rb and Ti (r = 0.600, p < 0.01), Rb and Fe (r = 0.735, p < 0.01), Sr and Ti (r = 0.545, p < 0.01), and Sr and Fe (r = 0.841, p < 0.01). Second-level correlation analysis between contamination factor (CF) and EF levels showed Zr as the best reference element for Rb and Sr in the soils. Results from this study provide baseline knowledge necessary for contamination assessment and monitoring of soils with similar environmental conditions.

HYGIENIC ASSESSMENT OF THE CONTENT OF CHEMICALS IN THE SOIL OF MINING AREAS OF THE TRANS-BAIKAL REGION

Introduction. Intensive exploration and processing of mineral raw materials in the Trans-Baikal territory has caused the accumulation of considerable amount of industrial mining waste with high content of chemical elements of different classes of hazard. Currently 33 tailings storage facilities (TSF) accumulating approximately 3 milliard tons of different industrial waste are located in the territory of the region. The aim of the research is the hygienic assessment of soil contamination in the residential areas adjacent to TSFs. Material and methods. Atomic absorption spectrophotometry method was used for the determination of heavy metals. The study presents the results of analyses of 444 samples of gross content of lead, zinc, copper, mercury, arsenic, and cadmium in the soil of Khapcheranga, Sherlovaya Gora, Kadaya, Vershino-Darasunsky, and Vershino-Shakhtaminsky mining villages throughout the duration of 2012 - 2015. Results. During the period of the study the total value of soil contamination with Zc calculated by the median concentrations in Khapcheranga Village amounted to 4.7 6.9, in Vershino-Shakhtaminaky - to 6.7 8.8, which corresponds to the «allowable» level of the contamination. Zc calculation by maximum concentrations has shown the soil to be referred to the category from “moderately dangerous” to “extremely dangerous”; this value in Khapcheranga Village amounted to 48.7 - 235.3, in Vershino-Shakhtaminsky Village - to 23.76 - 164.8. Discussion. In the residential areas the allowable degree of soil contamination was determined to be predominantly observed; Khapcheranga and Vershino-Shakhtaminsky villages are the exceptions. The results of the assessment give the evidence of tge increased lead, cadmium and arsenic content throughout the entire area of the villages, while the highest levels of accumulated toxic substances are registered in the areas located near the TSF Conclusion. Thus, several zones of natural and anthropogenous contamination with increased concentrations of heavy metals and arsenic have been formed in the Trans-Baikal Territory. This dictates the need to study the influence of geochemical anomalies on the health of population.

A preliminary assessment of potential ecological risk and soil contamination by heavy metals around a cement factory, western Saudi Arabia

AbstractTwenty surface soil samples (0-10 cm) and shoots of a perennial shrub Zygophyllum coccineum L. were collected around a cement factory on the western coast of Saudi Arabia, in order to assess concentrations of some heavy metals (Cr, Cu, Ni, Pb and Zn). The most noticeable among all heavy metals was Pb that showed an average concentration of 460.15±86.60 μg g-1 followed by Cr (138.67±30.89 μg g-1), Zn (54.41±43.79 μg g-1), Ni (41.22±12.60 μg g-1) and Cu (33.48±12.52 μg g-1). Based on biological concentration factor analysis, Z. coccineum can be considered as an accumulator only for zinc (BCF &gt;1). Estimation of various ecological contamination factors revealed the significant impact of Pb in the environmental pollution in the region. It is also understood that the primary contribution to the ecological risk index (RI) mainly originated from various anthropogenic influences such as industrialization and urbanization. The different statistical analysis further revealed the potential effect of soil characteristics on the occurrence and dispersal of heavy metals in the study area.

241Am on the territories adjacent to the Belarusian sector of the Chernobyl NPP resettlement zone: soil contamination, foodstuffs and population internal dose assessment

241Am is the only radionuclide of Chernobyl radioactive fallout the content of which until 2058 continues to increase. The purpose of this work is to assess the 241Am internal exposure doses of residents of settlements on the territory adjacent to the resettlement lands of the Chernobyl nuclear power plant. To achieve this goal the current levels of 241Am and accompanying 137Cs content in the soil and foodstuffs were determined at the private settlements of the Bragin district of Gomel region of Belarus. 241Am (Eγ 59.6 keV) content in soil samples and 137Сs (Eγ 661 keV) content in soil/food samples were determined by gamma spectrometry. Determination of 241Am specific activity in food samples was performed by the radiochemical method using selective extraction-chromatographic resins. With an average level of 1.3 kBq/m2 , the maximum soil contamination density of 241Am can reach 3.6 kBq/m2 , and for 137Cs it is one or two orders of magnitude higher and ranges from 50 kBq/m2 to 350 kBq/m2 . The maximum specific activity of 241Am in products is determined in samples of leafy parsley – 33 mBq/kg, and in samples of potatoes, beets, onions per feather – not exceed 5 mBq/kg. The content of accompanying 137Cs in samples of plant products is in the range of 3-12 Bq/kg. In estimation of the internal dose of exposure by the food chain it is conservatively assumed that the population receives all the main components of the diet in their own farmstead. Calculation of the dose of internal exposure during inhalation is made under the assumption that the population performs work in the garden 4 hours a day for 7 months. The total expected dose of internal exposure from 241Am residents of settlements is dominated by the inhalation component, while the oral route is dominant in the formation of the total dose of internal exposure from concomitant 137Сs, which is 20 or more times higher than 241Am.

Оценка загрязненности почв тяжелыми металлами вокруг Дашкесанского горно-обогатительного комбината

The article is devoted to the results of the determination and assessment of the content of heavy metals (HM) in the soil around the Dashkesan mining and processing factory of the Azerbaijan Republic. Combine open-pit mining method produces iron ore with its subsequent enrichment by flotation. Quarry blasting, transportation and crushing of ore by flotation swallowing; open pit and waste rock dumps after ore concentration (heaps) are the main sources of environmental pollution. Air currents and meltwaters contaminants HM fall into the soil. By the method of atomic absorption spectrometry in soil, the total content of Pb, Co, Cd, Cr, Cu, Zn was determined. The assessment of soil contamination by heavy metals was carried out by the Clarke number, the MPC and the total amount (Zc) of the TM. According to the Pb, Cd, Cu, Zn content, the soils are estimated as unpolluted, and according to the Co and Cr content - extremely polluted (MPC exceedance is more than 4 times). According to the total content of HM (Zc), soils are also assessed as extremely polluted. There is no regularity in the distribution of HM content in the soil around the source of pollution. As the distance from the source of contamination increases, the HM content in the soil changes spontaneously, which is a result of the influence of orographic and geological factors.

The ecological risk assessment of soil contamination with Ti and Fe at military sites in Ukraine: avoidance and reproduction tests with Folsomia candida

The aim of this research was to assess the effect of soil contamination with titanium (Ti) and iron (Fe) at military sites in Ukraine using the avoidance and reproduction tests with Folsomia candida (springtail). The soil used for the tests was sampled in 2017 from Dolyna, Ivano-Frankivsk region, Ukraine from two plots, namely a contaminated and a control site. The sample site is a former military site previously used for tank training. At the control site mainly the concentrations of Ti and Fe were exceeded. The control soil was free from contamination. The avoidance test and reproduction test were conducted with the use of springtail species F. candida. The following nine levels of contamination with heavy metals were established: 1%, 1.5%, 5%, 10%, 15%, 25%, 50%, 75% and 100%. The duration of the avoidance test was 7 days, and that of the reproduction test was 28 days. Overall, the results show that the avoidance and reproduction tests with collembolans have the potential to be used as screening tools in an ecological risk assessment of heavy metals. In the avoidance test, the concentrations from 1.5 to 100% significantly decreased the number of F. candida in the contamination site in comparison to the control site. At the same time, avoidance was not observed in the first concentration (1%). According to the reproduction test, the negative effect on the number of F. candida juveniles was observed beginning at the 10% dose. The half maximal effective concentration (EC50) for the avoidance test was 50.12%, while that for the reproduction test was 22.39%. The contamination with heavy metals at the military areas indicated the short- and long-term toxicity risk on the springtail F. candida.

Multivariate Statistical Characterisation of Soil Quality in the Lower Danube River Riparian Areas

Increasing anthropogenic influences on the environment has caused negative changes in natural ecosystems and soil contamination with potentially toxic metals has become a worrying issue at global level, due to the negative impact on the environment and human health. For the purpose of assessing soil contamination in the riparian areas of the Lower Danube River, a number of 144 soil samples were collected twice a year, in the period of June 2013 � December 2016, from 9 monitoring locations, from 0.05 m and 0.3 m depths, and the following indicators: Cr, Cu, Mn, Ni, Pb, Zn, including Ca, Mg, Corg, SO42- and humus content have been monitored. The soil was sampled, conserved and analysed according to the European standards in force. Metal concentrations were determined using flame (FAAS) and graphite furnace (GFAAS) atomic absorption spectrometry after �aqua regia� digestion of dried, homogenised and 0.5 mm sieved soil sub-samples. Comparing the average concentration values of the analysed potentially toxic metals, a decreasing tendency following the order Cr]Pb]Ni]Cu]Zn]Mn was observed and by reporting the average values at the normal limits, the order Zn]Cu]Mn]Ni]Pb]Cr of magnitude was obtained. To investigate possible correlations and interdependencies of potentially toxic metals content in the riparian soil, multivariate statistical methods were used. After applying Principal Component Analysis (PCA), 3 main components were identified, with a combined share of about 74 % of the original data-set variance. It was observed that during the monitoring period the average values of the all monitored elements from the studied soils were slightly below the normal reference values, according to the national legislation.

Source and background threshold values of potentially toxic elements in soils by multivariate statistics and GIS-based mapping: a high density sampling survey in the Parauapebas basin, Brazilian Amazon.

A high-density regional-scale soil geochemical survey comprising 727 samples (one sample per each 5 × 5km grid) was carried out in the Parauapebas sub-basin of the Brazilian Amazonia, under the Itacaiúnas Basin Geochemical Mapping and Background Project. Samples were taken from two depths at each site: surface soil, 0-20cm and deep soil, 30-50cm. The ground and sieved (< 75µm) fraction was digested using aqua regia and analyzed for 51 elements by inductively coupled plasma mass spectrometry (ICPMS). All data were used here, but the principal focus was on the potential toxic elements (PTEs) and Fe and Mn to evaluate the spatial distribution patterns and to establish their geochemical background concentrations in soils. Geochemical maps as well as principal component analysis (PCA) show that the distribution patterns of the elements are very similar between surface and deep soils. The PCA, applied on clr-transformed data, identified four major associations: Fe-Ti-V-Sc-Cu-Cr-Ni (Gp-1); Zr-Hf-U-Nb-Th-Al-P-Mo-Ga (Gp-2); K-Na-Ca-Mg-Ba-Rb-Sr (Gp-3); and La-Ce-Co-Mn-Y-Zn-Cd (Gp-4). Moreover, the distribution patterns of elements varied significantly among the three major geological domains. The whole data indicate a strong imprint of local geological setting in the geochemical associations and point to a dominant geogenic origin for the analyzed elements. Copper and Fe in Gp-1 were enriched in the Carajás basin and are associated with metavolcanic rocks and banded-iron formations, respectively. However, the spatial distribution of Cu is also highly influenced by two hydrothermal mineralized copper belts. Ni-Cr in Gp-1 are highly correlated and spatially associated with mafic and ultramafic units. The Gp-2 is partially composed of high field strength elements (Zr, Hf, Nb, U, Th) that could be linked to occurrences of A-type Neoarchean granites. The Gp-3 elements are mobile elements which are commonly found in feldspars and other rock-forming minerals being liberated by chemical weathering. The background threshold values (BTV) were estimated separately for surface and deep soils using different methods. The '75th percentile', which commonly used for the estimation of the quality reference values (QRVs) following the Brazilian regulation, gave more restrictive or conservative (low) BTVs, while the 'MMAD' was more realistic to define high BTVs that can better represent the so-called mineralized/normal background. Compared with CONAMA Resolution (No. 420/2009), the conservative BTVs of most of the toxic elements were below the prevention limits (PV), except Cu, but when the high BTVs are considered, Cu, Co, Cr and Ni exceeded the PV limits. The degree of contamination (Cdeg), based on the conservative BTVs, indicates low contamination, except in the Carajás basin, which shows many anomalies and had high contamination mainly from Cu, Cr and Ni, but this is similar between surface and deep soils indicating that the observed high anomalies are strictly related to geogenic control. This is supported when the Cdeg is calculated using the high BTVs, which indicates low contamination. This suggests that the use of only conservative BTVs for the entire region might overestimate the significance of anthropogenic contamination; thus, we suggest the use of high BTVs for effective assessment of soil contamination in this region. The methodology and results of this study may help developing strategies for geochemical mapping in other Carajás soils or in other Amazonian soils with similar characteristics.

Assessment of pesticides in soil from obsolete pesticides stores: a Caribbean case study.

The fate of highly hazardous or persistent pesticides in soils and their potential for environmental and health risks depends on the physical and chemical properties of the pesticide, soil properties including biological health and climatic conditions. Assessing the fate and impact of pesticides in soil is complicated in the Caribbean due to the high diversity of soils and duality of climate. The FAO supported national competent authorities from 11 countries in the Caribbean in the assessment of obsolete stocks and potentially contaminated soil. The Environmental Management Tool Kit (EMKT) prioritised Fond Cole and Camden Base as the only critical sites. Preliminary site investigations that utilised the rapid environmental assessment (REA) methodology identified that contamination was restricted to an impervious layer at the Camden site. Pesticide properties varied across groups, with the organochlorides exhibiting greater sorptive capacity and lower leaching potential relative to the organophosphates. All tested soils were non-saline with alkaline pH and notably sandy in texture with low adsorptive capacity. Analysis of pesticide levels revealed low to undetected quantities across contaminated sites. Traces of Endrin and Dieldrin were found in Marienburg, Suriname. Overall, assessment of soil contamination from stored obsolete pesticides revealed minimal contamination, however, detailed assessment considering contamination gradients should be performed where pesticides were identified.

Profile Distribution and Source Identification of Potentially Toxic Elements in North Nile Delta, Egypt

ABSTRACTVertical distribution and source appointment of potentially toxic elements (PTEs) provide a deeper vision for soil contamination. Contamination factor (CF), contamination degree (CD), enrichment factor (EF), principal component analysis (PCA), and cluster analysis (CA) were used for soil contamination assessment in north Nile Delta, Egypt. Twenty-one soil profiles representing main geomorphic units were dug, and 63 soil samples were collected at three depth intervals (0–30, 30–60 and 60–90 cm). Mean values of the three layers showed that Al, Fe, Mn, Cr, Cu, Pb, Mo, and V did not exceed average natural content of the Earth’s crust, while As, Cd, Co, Ni, and Zn exceeded that limit, except in the sand sheets unit. The studied elements showed irregular vertical distribution trend, except Cr, Ni, and Mo. Both Cr and Ni showed a downward migration, while Mo accumulated in the topsoil. Based on mean values, the CF indicated low contamination with Cr, Cu, Pb, Mn, Mo and V, moderate contamination with Cd and Zn, considerable contamination with As, Co, and Ni, while the CD was low to considerable. Furthermore, the EF indicated safe degree for Cr, Cu, Pb, Mo and V, deficiency to a minimal degree for Cd and Zn, while moderate degree for As, Co, and Ni. The PCA and CA indicated that soil parent materials controlled Al, Fe, Mn, Cu, Cr, Co, Pb, Ni, Mo, and V, while agricultural activities controlled As, Cd and Zn. Similar investigations should be considered in various regions in Egypt to verify potential sources of PTEs and to manage pollution of agricultural fields.

Assessment of total soil contamination with heavy metals in the coastal area of the cape peschany

In the autumn of 2018, in the coastal zone of the Caspian region, namely, in the area of Cape Peschany, scientific field studies of the state of the soil were carried out. 7 test sites (TS) were investigated.Studied more than 30 soil samples taken from depths of 0-5 and 5-20 cm spectrophotometer laboratoryHACH DR-2400 (USA) determined the total contents of heavy metals (HM). For analyz ephase threetotal soil pollution (TSP) or TS, using different approaches, the used value of the content of chemicalelements in the background area TS-the background. The soil of the Karakia-Karakol reserve was used asa background. Only the value of KC&gt;1 was taken into account in the calculation of ZC. Perhaps in thisregard, for TS-3 (garden), the lowest total soil pollution index was obtained, including negative valuesof ZC(r). The results of the calculations, only on TS-2, ZСТ=16.5 level of contamination moderate threaton the remaining TS and within the acceptable level. Statistical processing of the results in the programStatistica 10 showed that the criterion of Kruskal-Wallis is statistically significant for the elements of Cr,Cd, Cu and Co.Key words: Caspian Sea, Cape Peschany, soil, heavy metals, total pollution.

Assessment of Potentially Toxic Elements in Technosols by Tailings Derived from Pb–Zn–Ag Mining Activities at San Quintín (Ciudad Real, Spain): Some Insights into the Importance of Integral Studies to Evaluate Metal Contamination Pollution Hazards

This work presents an integral methodological approach to assess the environmental potential hazards posed by metals and metalloids hosted by spolic technosols derived from old tailings from a mining operation for galena (PbS, with high Ag contents)-sphalerite (ZnS, with a varied cohort of trace elements contents) in central Spain. We studied the total and soluble concentrations and spatial distribution of Pb, Zn, Cd, As, and Fe and the mineralogy of these soils, as well as an ecotoxicological evaluation by means of bioassays. The indices assessing soil contamination such as pollution load index (PI) and natural mobility index (NMI) have been calculated. Furthermore, the phytotoxic effect of the soil samples has been determined and a chronic sediment toxicity test using the benthic ostracod Heterocypris incongruens was applied. The geochemical study of 33 spolic technosols samples indicates large to extremely large metal and metalloid total contents: up to 48,600 mg kg−1 Pb, 34,000 mg kg−1 Zn, 500 mg kg−1 Cd, and 1000 mg kg−1 As. Given that sphalerite is usually the most important host mineral for cadmium in hydrothermal mineral deposits, there is a high correlation (R = 0.75) between this element and Zn. On the other hand, despite being two metallogenically intertwined elements in ore deposits, Pb and Zn show a less significant relationship, which can be attributed both to heterogeneities in the mineralogical composition of the veins, and to the complex history of the mineral concentration process: In the older process, the interest was only for Pb, meanwhile in the late period, the interest was focused in Zn. The Phytotoxkit® bioassay showed that soils with high PTEs presented very high toxicity, particularly the inhibition germination is related to Pb, As, and Cd content and root inhibition with Pb content. Both indexes were correlated with pH and electrical conductivity; samples with lower pH and higher soluble salt content are those with higher seed germination inhibition and root growth inhibition. On the other hand, the Ostracodtoxkit® bioassay showed very high sensitivity, with 100% mortality. The applied bioassays confirmed the soil toxicity and it is highly recommended to complement the results from environmental chemistry with results from bioassays, in order to provide a more complete and relevant information on the bioavailability of contaminants and to characterize the risk of contaminated areas.

Correction to: Assessment of tailings stability and soil contamination of Kef Ettout (NW Tunisia) abandoned mine

Correction to: Assessment of tailings stability and soil contamination of Kef Ettout (NW Tunisia) abandoned mine

Enrichment of potentially toxic elements in the fine fraction of soils from Iraq and Kuwait

The fine fraction of soils in arid and semi-arid regions can be readily suspended into the atmosphere by winds and transported long distances, carrying potentially toxic elements (PTEs) associated with these source materials. In this study, environmentally available PTE loadings for As, Cd, Cr, Cu, Ni, Pb, V, and Zn were measured in the fine fraction (< 75 μm) of 19 bulk soil samples collected in 2007 from 4 sites in Iraq and 15 sites in Kuwait. Soil samples were mechanically sieved and particle size distribution in the fine fraction was measured using laser diffraction particle sizing. Major and minor element composition was determined in the soil fine fraction using energy-dispersive X-ray fluorescence. Sub-samples were digested using strong acids and analyzed using high-resolution inductively coupled mass spectrometry to assess the maximum environmental availability of PTEs in each fine fraction of each soil sample. Measured environmentally available PTE loadings were normalized to soluble iron to allow for an assessment of soil contamination at and between sites that included weathering effects and was more focused on the mobile fraction of the total PTE load. Physiologically based fluid extractions were also performed on select samples to assess potential bioavailability of PTEs through ingestion and inhalation. Results show significant PTE loadings and anthropogenic contamination in the fine fraction of soils from Iraq and Kuwait. All sites showed moderate-to-high Ni contamination but loadings and contamination levels for all PTEs varied among sites in Iraq and Kuwait as a function of weathering, local geology, and inputs from non-local and/or anthropogenic sources. PTE contamination tended to be higher in the fine fraction of soil collected at the sites in Iraq, and the lowest overall PTE loadings were found at sites in northern Kuwait where the mean measured particle diameter was largest. Potential bioavailability of PTEs via inhalation was generally low (< 10% of loading) but a significant portion of the PTE load for As, Cu, and Pb (and V and Zn at select sites) was available via ingestion. The fine fraction of soils collected from Iraq and Kuwait in this study had significant environmentally available PTE contamination. Sites from Lower Mesopotamia in Iraq were the most impacted. PTE loadings and contamination were strongly influenced by local-scale weathering and geology, proximity to urban PTE sources, and inputs from non-local and/or anthropogenic sources. Sites with a smaller mean particle diameter had the greatest levels of PTE contamination. Potential bioavailability of PTEs was generally low.

Assessment of sugar beet lime measure efficiency for soil contamination in a Mediterranean Ecosystem. The case study of Guadiamar Green Corridor (SW Spain)

Contamination has been identified as one of the main threats for soil conservation worldwide. Availability of high-quality information on soil contamination, its impacts and effects is still required at global level. Well documented case studies provide valuable information to understand long-term trends associated with management of contaminated soils. The temporal evolution of contamination and associated factors have been studied in the Guadiamar river basin, after a mine waste spillage of about 6 hm3 of acidic waters and toxic sludge enriched with trace elements. An extensive database has been compiled, harmonized and standardized from the numerous and heterogeneous sectorial studies and monitoring carried out in the area since 1998, and has been used for spatio-temporal analysis of the effectiveness of individual and mixed soil remediation measures as a pilot case for data exploitation. Database variables consider six ecosystem compartments (soil, water, sediment, air, plant and animal biomass), management (remediation measures applied over time and space), land use and cover, and present and predicted climate. The pilot developed for remediation effectiveness considered 11 different treatments, including mixed addition of compost, red clays and sugar beet lime (SBL). Harmonization and Standardization processes were carried out according to EU-HYDI, INSPIRE and ENVASSO recommendations. However, correlation and regression analyses were applied to standardize pH and Cd values from our case study with R Software. According to the land use, high doses of SBL with other soil amendments don't provide high benefits for the reduction of Cadmium pseudototal. The created database provided a relevant resource of information for the management of the Guadiamar area and other similar cases. Also, the present methodology and harmonized data-based will be useful for soil contamination assessment across Europe allowing the development of decision support tools and decision making for the selection of effective and available remediation strategies.

Pollution indices as comprehensive tools for evaluation of the accumulation and provenance of potentially toxic elements in soils in Ojców National Park

The Ojców National Park (ONP) is located nearby several currently operating, large industrial centres, which can be sources of potentially toxic elements (PTE). Over the last two decades, the ONP has been the subject of several studies. However, there have not been any comprehensive studies concerning the assessment of PTE-rich pollution within the soils of ONP; namely, what constitutes the basis for: i) determining the content, abundance, and distribution of PTE in soils within the park; ii) quantitatively estimating the degree of pollution of these soils using different indices; and iii) assessing the impact of the geochemical background as applied in indices of pollution. The PTE content of the soil samples analysed in this study showed that the ONP's surface A horizons were characterized by PTE values ranging from two to ten times higher than the measured levels in the C horizon. In order to comprehensively assess the degree of pollution, a wide range of pollution indices – Geoaccumulation Index (Igeo); Single Pollution Index (PI); Contamination Factor (Cf); Degree of Contamination (Cdeg); Potential Ecological Risk (RI); The Probability of Toxicity (MERMQ) and ‘Improved’ Nemerow Index (INI) were calculated using various types of geochemical backgrounds. High levels of PTE in soil were caused mostly by the influence of anthropogenic inputs from neighbouring (Kraków) and distant industrial centres (Olkusz-Jaworzno, Bukowno and Upper Silesia Industrial Region). Deposition of PTE-rich pollutants from local emitters is also determined to a large extent by the prevailing transboundary SW winds. The different distribution of PTE within the profile was dependent on the type of soil and its properties (texture, content of total organic carbon), as well as perhaps a reflection of a geochemical-anthropogenic anomaly occurring in the ONP region. Based on RI and MERMQ values, the area of the ONP should be subject to evaluation and further assessment of PTE pollution levels in order to minimize further exposure and contamination of the ONP. Furthermore, choice of the proper geochemical background plays an important role in the soil contamination assessment. Authors suggest applying of both the local and reference geochemical background in order to comprehensively assess the degree of soil contamination.

Assessment of tailings stability and soil contamination of Kef Ettout (NW Tunisia) abandoned mine

The abandoned mining wastes still represent one of the significant environmental hazards. Kef Ettout tailings is one example that was exposed to severe ambient conditions and must be assessed to determine its potential risks. The initial mine wastes, the tailings, and agricultural soils were investigated. The results showed that the winds and runoff water distributed the potentially toxic metals and the alkaline pH of tailings and soils, the carbonate, and TOC content controlled the metal bioavailability. About 22% of Pb and 70 and 98% of Zn and Cd, respectively, were leached from tailings. Despite the initial wastes were richer in Zn (1.5 times) than in Pb, the tailings kept much more Pb (1.6 times) than Zn. In agricultural soils, the mean concentrations of Pb, Zn, and Cd were 69, 141, and 1.8 mg kg−1, respectively. The enrichment factor and geoaccumulation index showed that more than 75% of soils were considered strongly contaminated. Speciation results indicated that about 97% of initial wastes metals were bounded to residual fractions. However, in tailings, 9–30, 4–10, and < 6% of Pb, Zn, and Cd, respectively, were in stable forms. Redistribution index (Utf) and relative binding intensity (IR) of metal tailing had confirmed that the tailings continued to provide more Zn quantity than Pb and Cd. In soils, the highest percentages of Pb and Zn were closely associated with organic matter, the Cd was significantly bounded to the exchangeable fraction, and the mean decreasing factor mobility order was Cd (66) < Pb (73) < Zn (78). Therefore, this tailings type must be rehabilitated to limit its risks, particularly of Zn.

Assessment of soil contamination by oil-derived compounds in the Kielce agglomeration using gas chromatography coupled with mass spectrometry (GC-MS)

Soil contamination with petroleum-derived compounds is one of the most serious ecological problems. Their main source in urbanized areas is public transport. According to the Regulation of the Polish Minister of Environment about the assessment of earth’s surface contamination, hydrocarbon compounds are divided into: gasolines and oils, aromatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs). The subject of the research is the use of a gas chromatography coupled with mass spectrometry (GC-MS) method to assess the degree of soil contamination in the vicinity of the main communication routes of the Kielce agglomeration. This method is useful for the detection and identification of many organic compounds occurring in samples in very small quantities, which cannot be determined by common methods. For the purpose of this study, 14 soil samples were collected. After carrying out extraction with various methods, the ultrasonic solvent extraction method was chosen as the most effective way of extracting hydrocarbon impurities for the GC-MS studies. During single analysis, both oil fraction and PAHs quantities were determined.

Assessment of phytotoxicity, environmental and health risks of historical urban park soils

Urban soil areas can be contaminated with potentially dangerous heavy metals (HM), which might have got there by means of the human activity. The aim of the present study was to determine the contamination level of the city park soils and its impact on urban ecosystem. The indices assessing soil contamination such as Enrichment Factor (EF), Geoaccumulation Index (Igeo), Nemerow Pollution Index (IPIN), and indices assessing health risks, namely Hazard Index (HI) and Carcinogenic Risk (CR), have been calculated. Furthermore, the phytotoxic effect of the soil samples has been determined. The soil contains in average 58.6 mg/kg Zn, 0.3 mg/kg Cd, 27.2 mg/kg Pb and 16.6 mg/kg Cu. Based on EF index, it has been confirmed that the increased amounts of Zn, Cd and Pb in the soil are of the anthropogenic origin. The soil may be classified as moderately to strongly polluted in the case of Zn and Pb according to Igeo. Nevertheless, soil contamination in the park is at a safe level as per IPIN. Based on HI and CR indices, it is possible to state that the soil in the park does not pose any health risks. Subject to the outcomes of the toxicity test, the concentrations of HMs found out in the soils are not inhibitory for plants.