Trace element concentrations in soils along urbanization gradients in the city of Wien, Austria

Accumulation of Microplastics and Potentially Toxic Elements in Plant Leaves Along an Urbanization Gradient in Bangladesh

Potentially toxic elements (PTEs) and microplastics (MPs) in the atmosphere raise widespread apprehension due to their association with the ecosystem and public health. The accumulation of airborne MPs and PTEs was analyzed in Polyalthia longifolia leaves, and the Pollution Index (PI) was calculated along an industrial, residential, and rural gradient in Bangladesh. Only polyethylene terephthalate (PET) was found in the highest concentration in industrial areas compared to other areas. In leaves, a significantly higher Cd, Pb, and Zn concentration was found in industrial regions compared to residential and rural areas. For Cd, the PI was observed to be higher than 1 in rural areas, indicating a moderate level of pollution; it was higher than 3 in residential areas, showing considerable pollution; and it was found to be more than 6 in industrial areas. The higher concentration of both MPs and PTEs with increasing urbanization reflects the influence of anthropogenic activities. The findings of the study demonstrate the fascinating potential of P. longifolia tree leaves as a promising bioindicator for air quality biomonitoring.

Unveiling the spatial differentiation drivers of major soil element behavior along traffic network accessibility

Advancements in transportation networks have induced a spatial-temporal convergence effect, accelerating socio-economic elements flow and dismantling the conventional "core-periphery" urbanization gradient. Accessibility of transportation networks emerges as a reliable indicator of urbanization. There has been a growing global and Chinese focus on the various forms of metal pollution in urban soil. This study aims to investigate the driving forces and effects of urbanization factors (Gross Domestic Product (GDP), value added of secondary industries (VA), night light (NL), population density (PD), and road density (Distance)), soil property factors (pH, electrical conductivity (EC), and total organic carbon (TOC)), and topographic factors (elevation (DEM), aspect, and slope) on toxic heavy metal elements (Cd, As, and Hg) and trace elements (Mn, Ti, V) in surface soil (0-20 cm) across varying accessibility levels in the Beijing-Tianjin-Hebei urban agglomeration. Results reveal significant influence of accessibility on Cd and Hg levels (p < 0.05), with higher accessibility areas displaying elevated element concentrations. According to the evaluation results of the single-factor pollution index, Cd and V have the highest pollution exceedance rates (93.18% and 75.76%, respectively). Moran's Index results highlight typical spatial clustering of elements, with hotspots in areas of high accessibility. Urbanization has led to distinct spatial agglomeration patterns in element concentrations and environmental factors. Geographic detector analysis reveal that in low accessibility areas, metal element pollution and distribution are influenced by a combination of complex factors, including soil properties (pH), terrain conditions (DEM), and the urbanization process (VA). In high accessibility areas, toxic heavy metal elements are primarily driven by urbanization factors, largely influenced by transportation activities, industrial development, and population density, while elements Mn, Ti, and V are still influenced by both natural processes and urbanization activities. These findings suggest that urbanization intensifies the impact on potential toxic elements in soil, and that trace elements are increasingly affected by urbanization, warranting further attention.

Heavy metal contamination and health risk assessment of horticultural crops in two sub-cities of Addis Ababa, Ethiopia

This particular study was aimed to establish the level of heavy metals in different horticultural crops cultivated by irrigation and the soil in two sub-cities of Addis Ababa, Ethiopia, and quantitatively assess the health treat they pose for the consumer. A total of 151 vegetable samples comprised of lettuce (Lactuca sativa), cabbage (Brassica oleracea var. capitate), cucumber (Cucumis sativus), potato (Solanum tuberosum), parsley (Petroselinum crispum), Swiss chard (Beta vulgaris subsp. vulgaris), beetroot (Beta vulgaris), green onion (Allium porrum L.) and 28 soil samples were collected for this study. Six toxic elements were analyzed using microwave plasma atomic emission spectroscopy (MP-AES) after microwave assisted digestion of the samples. The concentrations of examined trace elements in vegetables (mg/kg) were found in the range of 5.50-93.00 for zinc; below detection limit (BDL)- 18.50 for copper; BDL-2.50 for nickel; BDL-17.00 for lead; 5.00-4256.50 for manganese and 22.00-8708.00 for iron. Considering the mean Pb content values, all vegetables exceeded the maximum permissible level set by the joint FAO/WHO commission in both irrigation sites. In case of Mn parsley, swiss chard, and green onion all from site two exceeded the maximum allowable values. With the exception of potato from irrigation site one, all vegetables exceeded the maximum permissible limit set for Fe concentration and out of which parsley, swiss chard, and green onion, all from site two, exceeded by more than double amount. The same trend is observed for the concentration of Mn and Fe in the soil samples. In fact, in both irrigation sites their concentration exceeded the allowable limits set by United Nation Environment Program (UNEP) for agricultural soils. The metal pollution load index revealed that in most of the vegetables studied the overall pollution load of trace metals were higher in Kolfe Keranyo irrigation site. The risk assessment study using indices like estimation of daily/weekly dietary exposure, hazard quotient and metal pollution load index all suggested consumption of the studied vegetables poses a significant health risk for the consumer. For adults the calculated target hazard quotient for the trace element Pb is higher than 1 (one) for all of studied vegetables ranging from 11.086 (cucumber) to 17.881 (beetroot) with a 98.216% and 98.464% contribution to the hazard indices, respectively. For a child consumer, Mn showed a higher target hazard quotient vales ranged from 0.0107 (cucumber) to 0.0495 (green onion) with a 70.86% and 88.85% contribution to the total hazard indices, respectively. The soil pollution indices also indicated that the degree of metal enrichment in soils and sediments are higher than the allowable limits. Therefore, a prompt action is required to curb the problem and ensure the public safety along the food system line.

High phytoremediation and translocation potential of an invasive weed species (Amaranthus retroflexus) in Europe in metal-contaminated areas

We demonstrated the metal accumulation potential of Amaranthus retorflexus, a European weed species, both in moderately and strongly metal-contaminated sites. Metal accumulation in roots, stems, and leaves were studied. We also calculated the bioaccumulation factor (BAF), and translocation factor (TF) values to quantify the metal accumulation, and translocation between plant organs. Our findings indicated that metal accumulation correlated with metal concentration; that is plant organs accumulated higher concentration of metals in the contaminated area than in the control one. We found that the concentrations of Ba, Mn, Sr and Zn were the highest in leaves, and Al, Cr, Cu, Fe and Pb in roots. High BAF value was found for Sr in all studied areas, indicating this metal's high accumulation potential of Amaranthus retorflexus. High TF values were found for Al, Ba, Cu, Fe, Mn, Sr and Zn; these metals were successfully transported to aboveground plant organs. We demonstrated that A. retroflexus, a fast-growing, rapidly spreading weed in Europe, was especially useful for heavy metal phytoremediation and phytoextraction.

Heavy metal uptake by plant parts of Populus species: a meta-analysis

Populus species are well documented for being potentially suitable for phytoremediation purposes regarding their accumulation characteristics. However, published results are contradictory. Based on the data gathered during an extensive literature search, we aimed to assess and revise the metal accumulation potential in the root, stem, and leaf of Populus species growing in contaminated soils, with meta-analysis. We evaluated the influences of pollution level, soil pH, and exposure time on the metal uptake patterns. We found accumulations of Cd, Cr, Cu, Pb, and Zn to be significant in each plant part, while that was only moderate for Ni, and limited for Mn. By calculating the soil pollution index (PI), we observed significantly intensive, PI-independent accumulation for Cd, Cr, Cu, Ni, Pb, and Zn. A decrease in soil pH significantly increased the uptake of Mn and significantly decreased the accumulation of Pb in the stem. Metal uptake was significantly influenced by exposure time as well; Cd concentration was significantly decreased in the stem, while concentrations of Cr in the stem and leaf, and Mn in the stem were significantly increased with time. These aforementioned findings support a well-founded metal-and-growth condition-specific application of poplars in phytoremediation processes, also triggering further in-depth assessments to enhance the efficiency of relevant poplar-based technologies.

Trace Elements in Soil and Urban Groundwater in an Area Impacted by Metallurgical Activity: Health Risk Assessment in the Historical Barga Municipality (Tuscany, Italy)

Trace elements were measured in soil and groundwater collected within the Fornaci di Barga urban area (Serchio River Valley, Tuscany, Italy), a territory that integrates natural assets with touristic vocation, impacted by long-lasting metallurgical activity. Epidemiological studies highlighted that the area surrounding the industrial plants is characterized by a persistent excess of diseases, attributed to heavy metal pollution. Soils were taken in school gardens, public parks, sport grounds and roadsides. The results indicate that Cu, Zn and Cd represent the main contaminants in surface soil, likely originated by deposition of airborne particulate matter from metallurgical activity. Risk assessment considering soil ingestion and dermal contact exposure routes revealed that the cadmium Hazard Quotient approaches unity for children, and the cadmium risk-based concentration obtained by combining exposure information with toxicity data is only slightly lower compared with the cadmium maximum concentration actually measured in soil. Groundwater does not show evidence of trace metal contamination, suggesting that the migration of contaminants from soil to subsurface is a slow process. However, assessment of the possible interconnections between shallow and deep-seated aquifers requires monitoring to be continued. The obtained results highlight the possible link between space clusters of diseases and metal concentration in soil.

Can Urban Grassland Plants Contribute to the Phytoremediation of Soils Contaminated with Heavy Metals

The main objective of this study was to investigate whether the most common wild plant species of urban grassland can be used for phytoremediation of soils polluted with heavy metals. The study was conducted in the city of Varaždin, in northern Croatia. The content of heavy metals (Cd, Cu, Fe, Mn, Ni, Pb, Zn) was determined in soil samples as well as in unwashed and washed plant samples (Taraxacum officinale, Plantago lanceolata, Trifolium repens). The results show that the most polluted site is the railway station, while most sites are polluted by road traffic. The soils are most enriched with Pb, Cu, Zn and Cd. The bioconcentration factors for all three plant species are <1, indicating the relatively low capacity of phytoextraction. A considerable amount of heavy metals is found in the dust deposited on the plant surface, which is confirmed by a statistically significant difference between washed and unwashed plant samples. In addition, the biomass of each plant species that can be removed (in t/ha year), the mass of specific heavy metal that can be removed (in kg/ha), and the years required for phytoremediation are reported. In conclusion, phytoremediation with only common plant species of urban grassland is not possible within a reasonable period of time.

Heavy metal load and effects on biochemical properties in urban soils of a medium-sized city, Ancona, Italy

Urban soils are often mixed with extraneous materials and show a high spatial variability that determine great differences from their agricultural or natural counterparts. The soils of 18 localities of a medium-sized city (Ancona, Italy) were analysed for their main physicochemical and biological properties, and for chromium (Cr), copper (Cu), cobalt (Co), lead (Pb), nickel (Ni), zinc (Zn), and mercury (Hg) total content, distribution among particle-size fractions, and extractability. Because of the absence of thresholds defining a hot spot for heavy metal pollution in urban soils, we defined a "threshold of attention" (ToA) for each heavy metal aiming to bring out hot spot soils where it is more impellent to intervene to mitigate or avoid potential environmental concerns. In several city locations, the soil displayed sub-alkaline pH, large contents of clay-size particles, and higher TOC, total N, and available P with respect to the surrounding rural areas, joined with high contents of total heavy metals, but low availability. The C biomass, basal respiration, qCO2, and enzyme activities were compared to that detected in the near rural soils, and results suggested that heavy metals content has not substantially compromised the soil ecological services. We conclude that ToA can be considered as a valuable tool to highlight soil hot spots especially for cities with a long material history and, for a proper risk assessment in urban soils, we suggest considering the content of available heavy metals (rather than the total content) and soil functions.

Assessment of Soil Physical and Chemical Properties among Urban and Peri-Urban Forests: A Case Study from Metropolitan Area of Brasov

Cities are affected by the impact of rapid urbanization on changes to soil properties. The aim of this study was to assess the physical and chemical properties of the soil of urban and peri-urban forests and to define which soil property is more significant for these two types of forests. The research took place in urban and peri-urban forests in the metropolitan area of Brasov, Romania. Among the properties determined were: particle size distribution, reaction, soil organic matter content, and the base saturation degree. As supplementary data, for plots from urban forests, the heavy metal content was determined. The results revealed that soils from urban forests had an alkaline reaction and the ones from peri-urban forests had a moderately acid reaction. The soil from the peri-urban plots was sandier and the other ones were more clayey. Testing the differences between the forests led to significant differences in the case of seven properties of which we mentioned pH and sand and clay content. Using PCA, the most significant and important soil properties for urban forests were the sum of basic exchangeable cations, cation exchange capacity, soil organic matter, and silt and clay contents. This study is more relevant in light of the EU Soil Strategy, which sets out a framework and concrete measures to protect and restore soils.

Legacy Lead in Urban Garden Soils: Communicating Risk and Limiting Exposure

Lead (Pb) exposure has long been recognized as a hazard to human health. Urban garden soils often contain elevated levels of Pb, mainly from legacy sources, which is a main barrier for urban gardening. The capacity of gardeners to access, understand, and act on scientific data related to soil contamination is also variable. This synthesis paper briefly summarizes the current scientific knowledge on soil Pb in urban gardens. Our objective is to produce clear recommendations about assessing actual risks and limiting exposure. First, we synthesize the nature and extent of soil contamination with Pb, and then describe how the bioavailability and risk of this contamination to humans is assessed. We then go on to potential exposure pathway through plants and remediation methods to improve soil health and reduce human exposure. We have developed best management practices for practitioners that include: (1) urban soil testing should be prioritized because of the high probability of Pb contamination, and urban gardening should not begin until thorough testing or remediation has been done; (2) documentation of land-use history should be required in all property transactions so that the potential for soil (and other) contamination can be clearly identified; (3) amendments cannot be relied upon as a treatment for contaminated soils to reduce risk to gardeners because they do not always make contaminants less harmful; (4) certain crops (such as fruiting vegetables) are much less susceptible to contamination than others and thus should be prioritized in urban gardens; (5) wherever feasible, raised beds filled with upcycled local mineral and organic materials are the preferred substrate for urban gardening. Further monitoring of potentially contaminated and remediated soils as well as effective communication with the public are necessary to ensure human safety.

A statistic comparison of multi-element analysis of low atmospheric fine particles (PM2.5) using different spectroscopy techniques

Over the past few decades, the metal elements (MEs) in atmospheric particles have aroused great attention. Some well-established techniques have been used to measure particle-bound MEs. However, each method has its own advantages and disadvantages in terms of complexity, accuracy, and specific elements of interest. In this study, the performances of inductively coupled plasma-optical emission spectrometry (ICP-OES) and total reflection X-ray fluorescence spectroscopy (TXRF) were evaluated for quality control to analyze data accuracy and precision. The statistic methods (Deming regression and significance testing) were applied for intercomparison between ICP-OES and TXRF measurements for same low-loading PM_2.5 samples in Weizhou Island. The results from the replicate analysis of standard filters (SRM 2783) and field filters samples indicated that 10 MEs (K, Ca, V, Cr, Mn, Fe, Ni, Cu, Zn, and Pb) showed good accuracies and precision for both techniques. The higher accuracy tended to the higher precision in the MEs analysis process. In addition, the interlab comparisons illustrated that V and Mn all had good agreements between ICP-OES and TXRF. The measurements of K, Cu and Zn were more reliable by TXRF analysis for low-loading PM_2.5. ICP-OES was more accurate for the determinations for Ca, Cr, Ni and Pb, owing to the overlapping spectral lines and low sensitivity during TXRF analysis. The measurements of Fe, influenced by low-loading PM_2.5, were not able to determine which instrument could obtain more reliable results. These conclusions could provide reference information to choose suitable instrument for the determination of MEs in low-loading PM_2.5 samples.

Investigation of metal concentrations in roadside soils and plants in urban areas of Amritsar, Punjab, India, under different traffic densities

Vehicular emissions containing traces of different heavy metals are known to cause significant contamination of roadside soils and plants. The present study was conducted to investigate the heavy metal concentrations in roadside soil and plant samples (Alstonia scholaris, Nerium oleander, Tabernaemontana divaricata, and Thevetia peruviana) collected from urban areas of Amritsar city of Punjab, India, under different traffic densities. The soil and plant samples were collected in pre- and post-monsoon seasons from seven roadside sites under varying levels of traffic density and analyzed for four heavy metals (Cd, Cu, Pb, and Zn). In addition to that, total protein and carotenoid contents in plant samples were also determined. pH and electrical conductivity analysis of roadside soil samples revealed slight to strongly alkaline and non-saline nature of soil. Significant reduction in contents of total proteins and carotenoids was observed in plants collected from sites with moderate to high traffic density. The trend of heavy metal contents in plants and their corresponding soil samples was observed to be Zn > Cu > Pb > Cd for both the seasons. Index of geo-accumulation indicated moderate contamination of soil with metals analyzed, while bio-accumulation factor (BAF) showed both absorption and accumulation of metals in plants under study. The study revealed significant contamination of roadside soil and plants of Amritsar city which was linked to vehicular emissions posing potential risk to human health.

Comprehensive Evaluation of Metal Pollution in Urban Soils of a Post-Industrial City-A Case of Łódź, Poland

The pollution of urban soils by metals is a global problem. Prolonged exposure of habitants who are in contact with metals retained in soil poses a health risk. This particularly applies to industrialized cities with developed transport networks. The aim of the study was to determine the content and spatial distribution of mobile metal fractions in soils of the city of Łódź and to identify their load and sources. Multivariate statistical analysis (principal component analysis (PCA), cluster analysis (CA)), combined with GIS, were used to make a comprehensive evaluation of the soil contamination. Hot-spots and differences between urban and suburban areas were also investigated. Metals were determined by atomic absorption spectrometry (AAS) after soil extraction with 1 mol L^-1 HCl. In most sites, the metal content changes in the following order: Zn > Pb > Cu > Ni > Cd. About one-third of the samples are considerably (or very highly) contaminated, (contamination factor, CF > 3) with Cu, Pb, or Zn. In almost 40% of the samples, contaminated soils were found (pollution load index, PLI > 1). All metals have a strong influence on the first principal component (PC1), whereas second principal component (PC2) is related to pH. Polluted soils are located in the downtown, in the south and east part of the city. The distribution of contamination coincides with the urban layout, low emission sources and former industrial areas of Łódź.

Effects of urbanization on Cd accumulation in agricultural soils: From the perspective of accessibility gradient

Road accessibility clearly reflects the spatial heterogeneity of urbanization. This study therefore adopted accessibility gradient to analyze the effects of urbanization on Cadmium (Cd) accumulation in agricultural soils. In total, 212 soil samples were collected along the accessibility gradient from agricultural soils in the Guangzhou-Foshan metropolitan region. Cd concentration showed a clearly decreasing pattern in agricultural soils with a decrease in accessibility level. The decreasing patterns varied in different accessibility ranges. The urban-rural ecotone (accessibility range 10-15) was the region with the most drastic changes in Cd accumulation. The influencing factors of Cd accumulation in agricultural soils mainly include industrial pollutants, agriculture chemicals, mining activities, domestic wastes, and soil properties. The importance of these factors varies across different accessibility ranges. Our findings imply that the characteristic variation of Cd accumulation with the road accessibility gradient must be considered in the formulation of targeted policies for controlling Cd contamination in agricultural soils.

Changes in Morphometric Traits of Ground Beetles Along Urbanization Gradients

Urbanization has a significant impact on abiotic and biotic factors in nature. We examined the morphometric characters of four carabid species (Abax parallelepipedus, Carabus scheidleri, Carabus violaceus, and Pterostichus oblongopunctatus) along urbanization gradients in and around the cities of Vienna (Austria) and Debrecen (Hungary). We found significant differences among urban, suburban, and rural areas in the parameters of antennomers, the maxillary palpus, the labial palpus, and the length of the tibia and the elytra of the carabids studied. We also found significant differences between males and females based on the parameters of antennomers, the maxillary palpus, the labial palpus, the femur, and the elytra. An interaction between urbanization and sex was found in the case of antennomers, the maxillary palpus, the labial palpus, the femur, and the elytra. Our findings suggested that in the cases of species from Carabini tribus the parameters of antennomers, the maxillary palpus, and the elytra could be useful for assessing the effects of urbanization because these morphometric characters responded sensitively to the environmental stress, whereas the most useful parameters are those of antennomers and the tibia for the species of Pterostichini tribus. Our findings also revealed that females are more sensitive to environmental stress than males.

Pollution intensity-dependent metal accumulation in ground beetles: a meta-analysis

Survival of organisms in polluted habitats is a key factor regarding their long-term population persistence. To avoid harmful physiological effects of pollutants' accumulation in organisms, decontamination and excretion could be effective mechanisms. Among invertebrates, ground beetles are reliable indicators of environmental pollution. Published results, however, are inconsistent, as some studies showed effective decontamination and excretion of pollutants, while others demonstrated severe toxic symptoms due to extreme accumulation. Using ground beetles as model organisms, we tested our pollution intensity-dependent disposal hypothesis for five pollutants (Cd, Cu, Mn, Pb, and Zn) among four soil pollution intensity levels (low, moderate, high, and extreme) by categorical meta-analysis on published data. According to our hypothesis, decontamination and excretion of pollutants in ground beetles are effective in lowly or moderately polluted habitats, while disposal is ineffective in highly or extremely polluted ones, contributing to intense accumulation of pollutants in ground beetles. In accordance with the hypothesis, we found that in an extremely polluted habitat, accumulation of Cd and Pb in ground beetles was significantly higher than in lowly polluted ones. These findings may suggest the entomoremediation potential of ground beetles in an extremely polluted environment.

Risk assessment of soil heavy metals associated with land use variations in the riparian zones of a typical urban river gradient

Urbanization-induced land use changes in riparian area alter soil and water regimes in complex ways, which may also affect the migration and transformation of soil heavy metals and increase the risk of release. In this study, soil samples from the riparian zone of Beiyun River, which located in the rapidly urbanized Beijing metropolis, were collected and analyzed for heavy metals (As, Cd, Cr, Cu, Mn, Ni, Pb, and Zn). Then their zoning distribution pattern along river (section 1 to section 4 from upper to low reaches) and the correlation of heavy metals between riparian soils and riverine sediments were investigated. Results showed that the average soil heavy metal concentrations of Cd, Cr, Cu and Zn in riparian zone were approximately 2.2, 1.7, 1.9 and 2.0 times higher than the background values. Sectionally, the concentrations of Cd, Ni, Pb and Zn displayed a decreasing order with section 2 > section 3 > section 4 > section 1, while the highest values of Cr and Cu were found in section 3. The concentrations of all heavy metals except Cr in artificial garden land were higher than those in other land use types, and the concentrations of Cr among five land use types were in the order of grass land > farmland > artificial garden land > forest land > forest-grass land. Generally, most of the heavy metals in the riverine sediments had higher contents than those in riparian zones, especially Cu and Zn. There was a decreasing order for the average geo-accumulation index (I_geo) of measured heavy metals in the soils of riparian zone: Zn (0.15) > Cr (0.08) > Cu (0.07) > Cd (-0.08) > As (-0.57) > Pb (-0.67) > Mn (-0.75) > Ni (-0.86), whereas they had different "high-low" orders in different land use types. The I_geo index indicated most regions of riparian zone were moderately polluted with Cd, Cr, Cu and Zn, especially in grass land and forest land. Also, Cd, Cr and Zn in riparian zone have positive relationships with the concentrations in riverine sediments. Health risk assessment showed that the contribution of ingestion HQ to HI was the highest among the three exposure pathways (ingestion, inhalation and dermal contact), and children had higher non-carcinogenic risk and carcinogenic risk index than adult. Our findings suggest that land use and soil in riparian zone should be protected and managed scientifically to control the riverine pollution and ensure human health.

Machine Learning Allows Calibration Models to Predict Trace Element Concentration in Soils with Generalized LIBS Spectra

Determination of trace elements in soils with laser-induced breakdown spectroscopy is significantly affected by the matrix effect, due to large variations in chemical composition and physical property of different soils. Spectroscopic data treatment with univariate models often leads to poor analytical performances. We have developed in this work a multivariate model using machine learning algorithms based on a back-propagation neural network (BPNN). Beyond the classical chemometry approach, machine learning, with tremendous progresses the last years especially for image processing, is offering an ensemble of powerful and constantly renewed algorithms and tools efficient for the different steps in the construction of a spectroscopic data treatment model, including feature selection and neural network training. Considering the matrix effect as the focus of this work, we have developed the concept of generalized spectrum, where the information about the soil matrix is explicitly included in the input vector of the model as an additional dimension. After a brief presentation of the experimental procedure and the results of regression with a univariate model, the development of the multivariate model will be described in detail together with its analytical performances, showing average relative errors of calibration (REC) and of prediction (REP) within the range of 5-6%.

Genotoxic assessment of selected native plants to deferentially exposed urban ecosystems

The aim of this study is to provide an analysis of the impact of ecogenotoxicity on native flora abortivity in various urban areas. In which, there was an analysis of 5 groupings of locations with a differing environmental load intensity within the city of Bratislava (Slovakia) over a 2-year period. Our results show varying data depending on the proximity of each site relating to a direct source of pollution and the potential impact of localized wind currents on the distribution of pollutants in the urban environment. The highest value of pollen abortivity in the city was observed in a group of locations exposed to heavy traffic pollution loads. Abortivity of native flora near heavy traffic road areas correlated with the imissions data measured in the same area. Wind-exposed uncovered sites also experienced higher values of native flora abortivity. These results confirmed the varying intensity of genotoxic impact in differing localities and also suggest that xenobiotic effects on flora can occur remotely from the original source of pollution.

Spatial distribution of heavy metal concentrations in peri-urban soils in eastern China

Complex land use patterns and intense human activities significantly affect the spatial distribution of heavy metals in soils. This is especially true in peri-urban areas. The land use in peri-urban areas is complex and the risk of heavy metal pollution is relatively high. Identifying the correlations between land use patterns and spatial distribution of heavy metals in peri-urban soils is important for enhancing soil security and sustaining soil ecosystem services in areas undergoing rapid urbanisation. In this study, soil samples were collected from 82 experimental sites in a typical peri-urban watershed in eastern China. Copper (Cu), zinc (Zn), cadmium (Cd), nickel (Ni), arsenic (As), chromium (Cr), lead (Pb) and mercury (Hg) concentrations at different soil depths were analysed. Results showed that heavy metal concentrations in peri-urban soils were significantly affected by land use type and varied with soil depth. Farmland had the highest heavy metal concentrations, whereas forestland had the lowest concentrations; the concentrations in soils decreased with increasing soil depth. Spatial analysis of heavy metals in soils showed that their concentrations rapidly increased with the increasing percentage of town areas in buffer zones. This indicated that land use structure influenced the heavy metal concentrations in peri-urban soils and the influences were correlated to the locations of towns and villages. Correlation analysis showed that Cu, Zn, Cd, Pb and Hg concentrations in soils were significantly affected by altitude, distance from roads, distance from towns and villages and soil clay content. Interestingly, historic land use was also found to affect heavy metal concentrations in forestland. These results can provide scientific guidance for designing effective soil management practices for peri-urban areas.

Influence of Al2O3 Nanoparticles on the Soil Elements

The behavior of nanoparticles released to the soil has been extensively studied in recent years; however, the effects of nanoparticles on the distribution of soil elements and on sowing are still unknown. To this end, to examine the distribution of selected elements in soil, soil samples were treated weekly with 1.0 mg and 20.0 mg of Al₂O₃ nanoparticles for 3 weeks. Additionally, different types of plants (including taproot, fibrous root and ornamental bulbous plants) were sowed in the soil samples. After each treatment, surface soil samples were collected and digested with acid digestion. The concentrations of selected elements (Ca, Mg, Fe, Al, Cu, Co, Ni) were determined using a microwave plasma atomic emission spectrometer. Al₂O₃ treatment for 3 weeks, both low and high doses, had no effect on the Al content in soil samples when compared to the controls. Additionally, Al₂O₃ showed desorption properties on the analyte elements.

Co-contamination of antibiotics and metals in peri-urban agricultural soils and source identification

To identify the dominant sources of contamination in peri-urban land, this study investigated the concentrations and distributions of antibiotics and metals in agricultural soil of this area. An index of landscape development intensity (LDI) was used to characterize the distribution of human disturbance-related land use. The results showed that total antibiotic concentration in the soil reached 395.55 μg/kg and that chlortetracycline was the predominant antibiotic compound, with a relatively high mean concentration of 30.62 μg/kg. In soils, the mean concentrations of Cu, Zn, and Pb were 38.41, 127.88, and 56.61 mg/kg and those of Al, Fe, and K were 83.73, 24.17, and 23.42 g/kg, respectively. A redundancy analysis showed that the landscape pattern in a 300-m buffer zone can well explain the variation in the concentrations of antibiotics and metals (24%, p < 0.05). The LDI in the 300-m buffer zone significantly correlated with the concentrations of total antibiotics and total amounts of Cu and Zn in the soil, suggesting that the risk of soil contamination increases with the intensity of anthropogenic activities. A structural equation modeling analysis indicated that Al, Cu, and Zn could significantly aggravate accumulation of tetracycline antibiotics in the soil, whereas there were only significantly direct paths from Cu to ciprofloxacin and norfloxacin. Overall, the results showed that aggravated co-contamination of antibiotics and metals occurs in agricultural soil under intensive human disturbance.

Exploring river pollution based on sediment analysis in the Upper Tisza region (Hungary)

We assessed contamination in the Upper Tisza region (Hungary, Central Europe), analyzing the elemental concentrations in sediment cores of oxbows. Our hypothesis was that the metal contamination which occurred in the year 2000 and which came from the mining area in Transylvania (Romania) may be detected even 15 years after the contamination, based on the vertical profile of sediment cores. Sediment cores were collected from five oxbows, and the following elements were measured with microwave plasma-atomic emission spectrometry (MP-AES): Cu, Cr, Ba, Fe, Mn, Pb, Sr, and Zn. Among the oxbows studied, there was one protected oxbow, three were used for fishing, and one was contaminated with sewage. Our results indicated that the year of contamination is still observable in the vertical profile of the sediment cores. The pollution index (PI) was used to characterize the sediment enrichment of metal elements in the sediment cores. In the case of Cu, Pb, and Zn, the contamination which originated in the year 2000 was detected in the layers of the sediment cores. The contamination levels of Cu, Pb, and Zn were high or moderate in the studied oxbows. All oxbows were moderately contaminated by Mn, while a moderate level of contamination was found for Fe in the protected oxbow, one fishing oxbow, and the sewage-contaminated oxbow. In the fishing oxbows, a low level of contamination was found for Fe. The contamination level of Sr was low in the protected oxbow and in the two fishing oxbows, while in one of the fishing oxbows and in the sewage-contaminated oxbow, a moderate level of Sr contamination was found. The pollution index scores indicated that the contamination level for Ba and Cr was low in the sediment cores of the oxbows studied. Our results indicated that the contamination of the Tisza River from the mining area in Northern Romania has been continuous and is still ongoing.

Airborne foliar transfer of PM bound heavy metals in Cassia siamea: A less common route of heavy metal accumulation

In order to investigate possible foliar transfer of toxic heavy metals, concentrations of Cd, Pb, and Fe were measured in samples of: Cassia siamea leaves (a common tree) Cassia siamea foliar dust, nearby road dust, and soil (Cassia siamea tree roots) at six different sites in/around the Bilaspur industrial area and a control site on the university campus. Bilaspur is located in a subtropical central Indian region. The enrichment factor (EF) values of Pb and Cd, when derived using the crustal and measured soil Fe data as reference, indicated significant anthropogenic contributions to Pb and Cd regional pollution. Based on correlation analysis and scanning electron microscopy (SEM) observations, it was evident that Pb and Cd in foliar part of Cassia siamea were largely from airborne sources. The SEM studies of leaf confirmed that leaf morphology (epidermis, trichome, and stomata) of Cassia siamea helped accumulate the toxic metals from deposited particulate matter (PM). There is a line of evidence that the leaf of Cassia siamea was able to entrap PM in respirable suspended particulate matter (RSPM) range (i.e., both in fine and coarse fractions). The overall results of this study suggest that Cassia siamea can be a potential plant species to control the pollution of PM and PM-bound metals (Pb and Cd) in affected areas.

Assessment of metal retention in newly constructed highway embankments

Newly constructed embankments should provide both a specific bearing capacity to enable trafficability in emergency cases and a sufficient pollutant retention capacity to protect the groundwater. A number of lysimeters were installed along the A115 highway to determine total and dissolved metal concentrations in road runoff and in the soil solution of newly constructed embankments. Dissolved concentrations in soil solution of the embankments did not exceed the trigger values of the German legislation. Depending on the metal, total concentrations in soil solution were more than twice as high as dissolved concentrations. The high infiltration rates lead to increased groundwater recharge beneath the embankments (up to 4100 mm a^-1). Although metal concentrations were not problematic from the legislators' point of view, the elevated infiltration rates beside the road facilitated the transfer of high metal loads into deeper soil layers and potentially into the groundwater as well.

Human Health Risks Associated with Metals from Urban Soil and Road Dust in an Oilfield Area of Southeastern Algeria

Hassi Messaoud town is a recent city that is situated inside the oil field, which hosts an important petroleum extraction field and refinery. Large-scale and long-term oil refinery and corresponding industrial activities may contaminate the surrounding soil/dust and could lead to pollution levels that can affect human health. The soil and road dust samples were analysed for different trace elements: copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn). Geo-accumulation index (I(geo)), pollution index (PI), and integrated pollution index (IPI) were calculated to evaluate the heavy metal contamination level of urban soil and road dust. The I(geo) values indicate unpolluted to moderate polluted of investigated metals in the soil samples. The assessment results of PI support the results of I(geo), and IPI indicates heavy metals in road dust polluted seriously. The noncarcinogenic health risk assessment shows that ingestion of soil/dust particles is the route for exposure to heavy metals, followed by dermal adsorption. The human exposure risk assessment based on different exposure pathways showed that the hazard index (HI) was <1.0 for all of the elements. The relative exposure risk (noncarcinogenic) was greater for toddlers. Although the overall risk was within the acceptable limit of 1.00, the HI of Pb from the soil (0.103) and road dust (0.132) was close to the threshold limits, which over the long-term may pose a health risk.

Assessment of the quality of polluted areas based on the content of heavy metals in different organs of the grapevine (Vitis vinifera) cv Tamjanika

In this study, the samples of the spatial soil and organs of the grapevine (Vitis vinifera) cultivar Tamjanika were collected from the selected zones near the Mining and Smelting Complex Bor (East Serbia). They were analyzed by ICP-OES to determine the content of Cu, Zn, Pb, As, Cd, and Ni with the aim of ascertaining if these data may help in the assessment and improvement of the quality of environment in polluted areas such as Bor and its surrounding area. The results obtained from the calculated biological and enrichment factors, as well as from the Pearson correlation study and hierarchical cluster analysis confirmed that very useful information is recorded in plant organs: root, stem, leaves, and fruit. Yet, when the atmospheric pollution is the sphere of interest, the most informative data are found in unwashed leaves. The results of this study indicated also that the investigated plant species has some highly effective strategies involved in tolerance to the stress induced by heavy metals, which makes it an excellent candidate for phytostabilization purposes. Planting of this grapevine cultivar can be recommended in all areas that are severely polluted with heavy metals.

Human exposure risks for metals in soil near a coal-fired power-generating plant

Coal-fired thermal power stations (TPSs) may contaminate the surrounding soil and could lead to pollution levels that can affect human health. Soil samples collected from the immediate vicinity of a TPS were analysed for heavy metals. TPS soils were enriched with arsenic (As), strontium (Sr), copper (Cu), mercury (Hg), barium (Ba), vanadium (V), beryllium (Be), cadmium (Cd), cobalt (Co), chromium (Cr), and nickel (Ni). Enrichment factor, principal component, and cluster analyses suggest that As, Cd, Co, Cr, and Hg in TPS soils originated from the TPS, whereas Pb and Zn were from vehicular/traffic-related emissions. The human exposure risk assessment based on different exposure pathways showed that the hazard index (HI) was <1.0 for all of the elements. The relative exposure risk was greater for toddlers. Although the overall risk was within the acceptable limit of 1.00, the HIs of Co (0.15) and Cr (0.082) were close to the threshold limits, which over the long-term may pose a health risk.

Assessment of Some Heavy Metals Pollution and Bioavailability in Roadside Soil of Alexandria-Marsa Matruh Highway, Egypt

To assess the roadside soils contamination with Pb, Cd, and Zn, 34 soil samples were collected along Alexandria-Marsa Matruh highway, Egypt, and analyzed by using the atomic absorption. The contamination with these metals was evaluated by applying index of geoaccumulation(Igeo), contamination factor (CF), pollution load index (PLI), the single ecological risk index(Ei), and the potential ecological risk index (PERI). The average concentrations of Pb, Cd, and Zn were 38.2, 2.3, and 43.4 μg/g, respectively.Igeoindicates the pollution of soil with Pb and Cd as opposed to Zn.Eishows that the roadside soils had low risk from Pb and Zn and had considerable to high risk from Cd. Most of the samples (62%) present low PERI risk associated with metal exposure and the rest of the samples (38%) are of moderate PERI. The bioavailable fraction (EDTA-Extract) was 72.5 and 37.5% for Pb and Cd contents, respectively. These results indicate the remarkable effect of vehicular and agricultural activities on Pb and Cd contents in soil.

Land use/cover change detection and urban sprawl analysis in Bandar Abbas city, Iran

The process of land use change and urban sprawl has been considered as a prominent characteristic of urban development. This study aims to investigate urban growth process in Bandar Abbas city, Iran, focusing on urban sprawl and land use change during 1956–2012. To calculate urban sprawl and land use changes, aerial photos and satellite images are utilized in different time spans. The results demonstrate that urban region area has changed from 403.77 to 4959.59 hectares between 1956 and 2012. Moreover, the population has increased more than 30 times in last six decades. The major part of population growth is related to migration from other parts the country to Bandar Abbas city. Considering the speed of urban sprawl growth rate, the scale and the role of the city have changed from medium and regional to large scale and transregional. Due to natural and structural limitations, more than 80% of barren lands, stone cliffs, beach zone, and agricultural lands are occupied by built-up areas. Our results revealed that the irregular expansion of Bandar Abbas city must be controlled so that sustainable development could be achieved.