Can rail transport-related contamination affect railway vegetation? A case study of a busy railway corridor in Poland.

Rail transport is considered a serious risk to the environment; however, its environmental impact has been addressed insufficiently with many resulting uncertainties. A busy railway corridor was used to determine if the side of a railway track could distort the assessment of soil contamination with potentially toxic elements (PTEs) and if soil phytotoxicity changes up to 50 m away from the track. The studied soils showed a moderate to heavy level of contamination with Cu, Ni, Pb and Zn. Cu, Ni and Zn content decreased significantly with the distance from the track while Pb content increased slightly, probably because the Pb came predominantly from exhaust gases, while the source of the remaining elements was the abrasion of railway infrastructure components. The side of the railway track proved to be a significant factor that influenced Ni and Pb content in particular. The phytotoxicity test predominantly showed a slight inhibition of plant growth with a maximum value reaching 70.4% but with an absence of significant differences in phytotoxicity between the distances. The ecological risk assessment did not reveal a serious threat to the environment from the PTEs in the soil. Based on the results, it is appropriate to define a heavily polluted zone at a minimum distance of 50 m from the track, and both sides of the railway track should be assessed so that the actual level of contamination is not underestimated. Further research is needed on this issue urgently due to the severe and hitherto overlooked environmental risks associated with rail transport.

Polluted brownfield site converted into a public urban park: A place providing ecosystem services or a hidden health threat?

The conversion of old brownfield sites into places once again serving society is becoming an upward global trend, especially in urban areas. Due to the increasingly growing pressure on the expansion of urban green spaces, such sites can become, for instance, urban parks. The aim of the study was to assess whether the solution is appropriate and if it does not pose a potential health risk. Heavy pollution of soils was found out by means of the example of the urban park newly established in a reclaimed area of a historic mining town. The high average values in the topsoil were found out mainly in As (132 mg/kg), Cd (6.8 mg/kg), Pb (535 mg/kg) and Zn (1604 mg/kg). The assessment of the non-carcinogenic health risk has revealed possible As-related adverse health effects in children even at irregular park visits. According to the carcinogenic risk assessment, As, Cd, Cr and Ni can be ranked in the category of an acceptable total risk for regulatory purposes. The health status of park vegetation as a significant component of the urban ecosystem was also assessed. Soil phytotoxicity brought about severe damage to the seedlings, with a mortality rate of up to 84% locally. The results indicate that heavily polluted brownfield sites with historic mining-related activities are not suitable for establishing urban parks even after reclamation and nature-based solutions may not be invariably appropriate. Based on the findings, the management steps that ought to be implemented in the process of brownfield redevelopment into the urban park even after its establishment have been highlighted in order to minimize the health risk to park visitors while providing the required ecosystem services by vegetation.

Human health and ecological risk assessment of trace elements in urban soils of 101 cities in China: A meta-analysis.

Urban soils pollution by trace elements arouses the growing interest in China. The aim of this study was to assess urban soil pollution by As, Cd, Cr, Cu, Hg, Ni, Pb and Zn in China and the possible impacts on urban inhabitants and urban green spaces (UGS). Data from more than 17,000 samples were applied to characterize the status of 101 cities. The pollution assessment proved that 11% of the cities are heavily polluted. According to the Hazard Index, the value of risk for the infant population in 15 cities exceed the standardly accepted tolerable levels. The carcinogenic risk assessment demonstrated the potential threat in the cities with the total population approximately 20,566,900. Cr and As were detected to be the most hazardous elements. UGS may be seriously threatened by trace elements toxicity in 38 cities. Cd was found to be the riskiest element for UGS. Ecosystem services of UGS can be significantly disrupted under the current situation in China and their status is expected to deteriorate in the future. For this reason, it is essential to alter the policy of the urbanization process and develop functional concepts of urban green infrastructures adapted to the high level of contamination which shall improve human well-being in China.

The impact of tourism on extremely visited volcanic island: Link between environmental pollution and transportation modes.

The enormous tourism boom raises concern about possible negative environmental impacts worldwide. One of the risks posed by tourism may be heavy metal pollution. On the example of the volcanic island of Santorini, a popular tourist destination, pollution of soils categorized according to the tourism load was monitored. Significant anthropogenic contamination by heavy metals, especially Cu, Cr and Pb, was found out. This contamination may constitute a moderate ecological risk to the island ecosystems. Tourism has been shown to be a significant pollution factor as evidenced by the contaminated soils near the airport. Simultaneously, airport traffic has been proved to be an important emitter of Co, Cr and especially Zn. The comparison with other volcanic islands has shown that on Santorini the content of heavy metals in soils is significantly lower, despite frequently higher tourism intensity. On this basis, it can be concluded that in case of volcanic islands the dominant factor determining the content of heavy metals in the soil is the parent rock. Given high and ever-increasing intensity of tourism on the island, it can be assumed that soil contamination will continue to rise rapidly. Therefore, without proper steps reducing tourism, increase in soil degradation, growing negative impacts on local ecosystems as well as on the quality of produced wine can be expected on Santorini.

Variability of trace element distribution in Noccaea spp., Arabidopsis spp., and Thlaspi arvense leaves: the role of plant species and element accumulation ability.

Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was applied for the determination of Cd and Zn distributions within the leaves of Cd- and Zn-hyperaccumulating plants, Noccaea caerulescens, N. praecox, and Arabidopsis halleri, in contrast to nonaccumulator species, Thlaspi arvense and A. thaliana. The elemental mapping of the selected leaf area was accomplished via line scans with a 110-µm-diameter laser beam at a 37-µm s-1 scan speed and repetition rate of 10 Hz. The lines were spaced 180 µm apart and ablated at an energy density of 2 J cm-2. The elemental imaging clearly confirmed that Cd was predominantly distributed within the parenchyma of the T. arvense, whereas in the Noccaea spp. and A. halleri, the highest intensity Cd signal was observed in the veins of the leaves. For Zn, higher intensities were observed in the veins for all the plant species except for A. thaliana. Close relationships between Zn and Ca were identified for the Noccaea spp. leaves. These relationships were not confirmed for A. halleri. Significant correlations were also proved between the Cd and Zn distribution in A. halleri, but not for the Noccaea spp. For both T. arvense and A. thaliana, no relevant significant relationship for the interpretation of the results was observed. Thus, the LA-ICP-MS imaging is proved as a relevant technique for the description and understanding of the elements in hyperaccumulating or highly accumulating plant species, although its sensitivity for the natural element contents in nonaccumulator plant species is still insufficient.

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.

Cold deep subduction recorded by remnants of a Paleoproterozoic carbonated slab.

The absence of low-thermal gradients in old metamorphic rocks (<350 °C GPa-1) has been used to argue for a fundamental change in the style of plate tectonics during the Neoproterozoic Era. Here, we report data from an eclogite xenolith in Paleoproterozoic carbonatite in the North China craton that argues for cold subduction as early as 1.8 Ga. The carbonatite has a sediment-derived C isotope signature and enriched initial Sr-Nd isotope composition, indicative of ocean-crust components in the source. The eclogite records peak metamorphic pressures of 2.5-2.8 GPa at 650-670 °C, indicating a cold thermal gradient, 250(±15) °C GPa-1. Our data, combined with old low-temperature events in the West African and North American cratons, reveal a global pattern that modern-style subduction may have been established during the Paleoproterozoic Era. Paleoproterozoic carbonatites are closely associated with granulites and eclogites in orogens worldwide, playing a critical role in the Columbia supercontinent amalgamation and deep carbon cycle through time.

Investigation of the microstructure and mineralogical composition of urinary calculi fragments by synchrotron radiation X-ray microtomography: a feasibility study.

The outcomes from the feasibility study on utilization of synchrotron radiation X-ray microtomography (SR-µCT) to investigate the texture and the quantitative mineralogical composition of selected calcium oxalate-based urinary calculi fragments are presented. The comparison of the results obtained by SR-µCT analysis with those derived from current standard analytical approaches is provided. SR-µCT is proved as a potential effective technique for determination of texture, 3D microstructure, and composition of kidney stones.

Utilization of laser-assisted analytical methods for monitoring of lead and nutrition elements distribution in fresh and dried Capsicum annuum l. leaves.

Laser induced breakdown spectroscopy (LIBS) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) have been applied for high-resolution mapping of accumulation and distribution of heavy metal (lead) and nutrition elements (potassium, manganese) in leaves of Capsicum annuum L. samples. Lead was added in a form of Pb(NO3)2 at concentration up to 10 mmol L⁻¹ into the vessels that contained tap water and where the 2-months old Capsicum annuum L. plants were grown another seven days. Two dimensional maps of the elements are presented for both laser-assisted analytical methods. Elemental mapping performed on fresh (frozen) and dried Capsicum annuum L. leaves are compared.

Sunflower Plants as Bioindicators of Environmental Pollution with Lead (II) Ions.

In this study, the influence of lead (II) ions on sunflower growth and biochemistry was investigated from various points of view. Sunflower plants were treated with 0, 10, 50, 100 and/or 500 µM Pb-EDTA for eight days. We observed alterations in growth in all experimental groups compared with non-treated control plants. Further we determined total content of proteins by a Bradford protein assay. By the eighth day of the experiment, total protein contents in all treated plants were much lower compared to control. Particularly noticeable was the loss of approx. 8 µg/mL or 15 µg/mL in shoots or roots of plants treated with 100 mM Pb-EDTA. We also focused our attention on the activity of alanine transaminase (ALT), aspartate transaminase (AST) and urease. Activity of the enzymes increased with increasing length of the treatment and applied concentration of lead (II) ions. This increase corresponds well with a higher metabolic activity of treated plants. Contents of cysteine, reduced glutathione (GSH), oxidized glutathione (GSSG) and phytochelatin 2 (PC2) were determined by high performance liquid chromatography with electrochemical detection. Cysteine content declined in roots of plants with the increasing time of treatment of plants with Pb-EDTA and the concentration of toxic substance. Moreover, we observed ten times higher content of cysteine in roots in comparison with shoots. The observed reduction of cysteine content probably relates with its utilization for biosynthesis of GSH and phytochelatins, because the content of GSH and PC2 was similar in roots and shoots and increased with increased treatment time and concentration of Pb-EDTA. Moreover, we observed oxidative stress caused by Pb-EDTA in roots where the GSSG/GSH ratio was about 0.66. In shoots, the oxidative stress was less distinctive, with a GSSG/GSH ratio 0.14. We also estimated the rate of phytochelatin biosynthesis from the slope of linear equations plotted with data measured in the particular experimental group. The highest rate was detected in roots treated with 100 µM of Pb-EDTA. To determine heavy metal ions many analytical instruments can be used, however, most of them are only able to quantify total content of the metals. This problem can be overcome using laser induced breakdown spectroscopy, because it is able to provide a high spatial-distribution of metal ions in different types of materials, including plant tissues. Data obtained were used to assemble 3D maps of Pb and Mg distribution. Distribution of these elements is concentrated around main vascular bundle of leaf, which means around midrib.

Qualitative detection of Mg content in a leaf of Hedera helix by using X-ray radiation from a laser plasma source.

In this article, a method to reveal the presence of Mg content inside the different parts of leaves of Hedera helix is presented. In fact a sample of a Hedera helix's leaf, commonly characterized by a green and a white side, is analyzed under X-ray radiation. The presence of two zones with different colors in the Hedera helix's leaf has not been explained. In this connection, there are presently three hypotheses to explain the characteristic double-color appearance of the leaf. The first hypothesis suggests a different cytoplasmic inheritance of chloroplasts at the cell division, the second a different allelic composition, homozygote and heterozygote, between the two zones, and finally the third the action of a virus which changes the color properties in the Hedera's leaves. The resulting effect is a different content of "something" between the green and the white side. We utilized X-ray radiation, obtained from a plasma source with a Mg target, to image Hedera helix leaves and we found that the green side of the leaf is highlighted. We may suppose that the reason why the X-rays from a Mg plasma source, allow us to pick up the green side is probably due to the greater presence of the amount of Mg (from chlorophyll or other complexes and/or salts) in the two sides, green and white, of the leaf.

Multi-instrumental Analysis of Tissues of Sunflower Plants Treated with Silver(I) Ions - Plants as Bioindicators of Environmental Pollution.

The aim of this work is to investigate sunflower plants response on stressinduced by silver(I) ions. The sunflower plants were exposed to silver(I) ions (0, 0.1, 0.5,and 1 mM) for 96 h. Primarily we aimed our attention to observation of basic physiologicalparameters. We found that the treated plants embodied growth depression, coloured changes and lack root hairs. Using of autofluorescence of anatomical structures, such aslignified cell walls, it was possible to determine the changes of important shoot and rootstructures, mainly vascular bungles and development of secondary thickening. Thedifferences in vascular bundles organisation, parenchymatic pith development in the rootcentre and the reduction of phloem part of vascular bundles were well observable.Moreover with increasing silver(I) ions concentration the vitality of rhizodermal cellsdeclined; rhizodermal cells early necrosed and were replaced by the cells of exodermis.Further we employed laser induced breakdown spectroscopy for determination of spatialdistribution of silver(I) ions in tissues of the treated plants. The Ag is accumulated mainlyin near-root part of the sample. Moreover basic biochemical indicators of environmentalstress were investigated. The total content of proteins expressively decreased withincreasing silver(I) ions dose and the time of the treatment. As we compare the resultsobtained by protein analysis - the total protein contents in shoot as well as root parts - wecan assume on the transport of the proteins from the roots to shoots. This phenomenon canbe related with the cascade of processes connecting with photosynthesis. The secondbiochemical parameter, which we investigated, was urease activity. If we compared theactivity in treated plants with control, we found out that presence of silver(I) ions markedlyenhanced the activity of urease at all applied doses of this toxic metal. Finally we studiedthe effect of silver(I) ions on activity of urease in in vitro conditions.