1,354,084 research outputs found
Toxicity Assessment of Contaminated Soils from a Mining Area in Northeast Italy by Using Lipid Peroxidation Assay.
No full textContamination by heavy metals in soils may strongly affect the environmental quality. Lipid peroxidation
caused by heavy metals in plants was investigated as a relevant bioassay of toxicity. Soils and wild plants
(dandelion and willow) were collected from an abandoned mine area in northeast Italy, and the concentration
of different heavy metals (Ni, Cr, Cu, Pb, Zn, Fe and Mn) were measured and analyzed. Soils affected by
mining activities presented total Zn, Cu, and Pb concentrations (2566, 3975, 20,815 mg kg−1 respectively)
above toxic thresholds, and 58% for Fe. Heavy metal-induced oxidative stress was evidenced by the generation
of reactive radicals, followed by an increase in malondialdehyde (MDA) production up to 41.64 μM in
willow leaves. We found that MDA concentration in plant tissues differed significantly among species and
plant organs. The higher concentration of metal in soil corresponded with the higher concentration of
MDA in the plant. The combined results of metal concentration, MDA content and translocation coefficients
in plants show that the investigated plants are rather highly tolerant towards environmental pollution.
This suggests that they could be useful in phytoremediation of metal contaminated sites
Potential toxicity assessment of anthropogenic pressure by heavy metals in semi-enclosed artificial lagoon ecosystems in the Gulf of Aqaba, Red Sea
No full textTHE IMPACT OF OLIVE MILL WASTEWATER ON THE PHYSICOCHEMICAL AND BIOLOGICAL PROPERTIES OF SOILS IN NORTHWEST JORDAN.
No full textSoil contamination may influence negatively soil health, which often limits and sometimes disqualifies soil biodiversity and decreases plant growth. Soil health is the continued capacity of the soil to function as a vital living system, providing essential ecosystem services. Within soils, all bio-geo-chemical processes of the different ecosystem components are combined. These processes are able to sustain biological productivity of soil, to maintain the quality of surrounding air and water environments, as well as to promote plant, animal, and human health. A common criterion to evaluate long term sustainability of ecosystems is to assess the quality of soil. However, the increased concentration and distribution of toxic substances in soils by mismanagement of industrial activities, overuse of agrochemicals and waste disposal are causing worldwide concern. A major environmental concern in the Mediterranean countries is the production of the large quantities of olive oil mill wastewater (OMW) produced during olive oil extraction process. OMW inhibits several groups of bacteria and fungal species, thus affecting soil stability. In the present study, we investigated the effect of OMW on the soil physical, chemical characteristics and the microarthropods structure. All soil samples were collected from an olive mill garden in Northwest Jordan. Biological soil quality index (QBS-ar) values appeared to decrease with respect to soil pollution by OMW. All investigated parameters were significantly different depending on the levels of OMW contamination in soil. Anthropogenic activities influenced the microarthropod community, altering both quantity and quality of soil chemical and physical structure of the microhabitats. Preliminary data obtained in this study suggest that the application of QBS-ar index could be a useful tool for evaluating surface soils health status
Diversity and dynamics of seaweed associated microbial communities inhabiting the lagoon of venice
No full textSeaweeds are a group of essential photosynthetic organisms that harbor a rich diversity of associated microbial communities with substantial functions related to host health and defense. Environmental and anthropogenic stressors may disrupt the microbial communities and their metabolic activity, leading to host physiological alterations that negatively affect seaweeds’ performance and survival. Here, the bacterial communities associated with one of the most common seaweed, Ulva laetevirens Areshough, were sampled over a year at three sites of the lagoon of Venice affected by different environmental and anthropogenic stressors. Bacterial communities were characterized through Illumina sequencing of the V4 hypervariable region of 16S rRNA genes. The study demonstrated that the seaweed associated bacterial communities at sites impacted by environmental stressors were host-specific and differed significantly from the less affected site. Furthermore, these communities were significantly distinct from those of the surrounding seawater. The bacterial communities’ composition was significantly correlated with environmental parameters (nutrient concentrations, dissolved oxygen saturation, and pH) across sites. This study showed that several more abundant bacteria on U. laetevirens at stressed sites belonged to taxa related to the host response to the stressors. Overall, environmental parameters and anthropogenic stressors were shown to substantially affect seaweed associated bacterial communities, which reflect the host response to environmental variations
Biogeochimica degli elementi potenzialmente tossici: dai suoli alle piante ed alla catena alimentare : elementi per una valutazione del rischio per la salute umana
No full textI metalli pesanti sono presenti nell’ambiente in varie concentrazioni. Alcuni sono essenziali per le piante e gli animali e sono importanti, sia per la produzione di cibo, sia per la salute umana. L’aumento della concentrazione di elementi potenzialmente tossici, come i metalli pesanti, e il loro rilascio nell’ecosistema hanno raggiunto un livello talmente elevato in termini di impatti da rendere necessario il loro controllo. La contaminazione del suolo da metalli pesanti influenza notevolmente la qualità dell’ambiente. Come prova della tossicità causata dai metalli pesanti è stata studiata la perossidazione lipidica nelle piante. Sono stati prelevati dei campioni di suolo e di piante (tarassaco e salice) in una zona mineraria abbandonata nel Nord-Est Italia, e sono state determinate le concentrazioni di diversi metalli pesanti (Cd, Cr, Cu, Pb, Zn, Fe e Mn). Lo studio ha evidenziato che lo stress ossidativo indotto dai metalli pesanti ha prodotto la generazione di radicali reattivi seguiti da un aumento della produzione di malondialdeide (MDA) di 41.64 μM nelle foglie di salice. La concentrazione di MDA nei tessuti differisce sia tra le specie, sia tra le parti della pianta. È stato osservato che la concentrazione di metalli nel suolo è correlata con l’aumento della concentrazione di MDA nelle piante. Inoltre, lo studio dei microartropodi del suolo (QBS-ar) ha mostrato un’elevata sensibilità alla contaminazione dei metalli. Combinando i risultati della concentrazione dei metalli, dell’attività enzimatica del suolo, del QBS-ar e della concentrazione di MDA è possibile affermare che le piante esaminate si dimostrano tolleranti all’inquinamento. Ciò suggerisce che potrebbero essere utilizzate nella phytoremediation di siti contaminati da metalli pesanti.Heavy metals occur naturally in the ecosystem with large variations in concentration. Some of them are essential for plants and animals and are thus important for food production and to human health. Contamination by heavy metals in soils, however, may strongly affect also the environmental quality. Yet, when heavy metals concentration is elevated to a point higher than a safe threshold, they all become toxic. The over production of potentially toxic elements (such as heavy metals) and their release into the ecosystem has presently reached a level that their impact on the environment has to be kept under control. Monitoring HM toxicity to the environment and the human health, therefore, is needed. Lipid peroxidation caused by heavy metals in plants was investigated as a relevant bioassay of toxicity. Soils and wild plants (dandelion and willow) were collected from an abandoned mine area in northeast Italy, and the concentration of different heavy metals (Cd, Cr, Cu, Pb, Zn, Fe and Mn) were measured. Heavy metal-induced oxidative stress was evidenced by the generation of reactive radicals, followed by an increase in malondialdehyde (MDA) production up to 41.64 μM in willow leaves. We found that MDA concentration in plant tissues differed significantly among species and plant organs. The higher concentration of metal in soil corresponded with the higher concentration of MDA in the plant. Moreover, soil microarthropods (QBS-ar) evaluation demonstrated high sensitivity to metal contamination, together with the measurement of soil enzymatic activity, both being related with beneficial soil functions.The combined results of metal concentration, soil enzymatic activities, QBS-ar and MDA content show that the investigated plants are rather highly tolerant towards environmental pollution. This suggests that they could be useful in phytoremediation of metal contaminated sites
Metal bioaccumulation and oxidative stress in ulva laetevirens in the venice lagoon: Early warning biomarker for metal bioaccumulation
No full textTransitional water systems (TWSs) may be threatened by various metals originating from increased agricultural, industrial activities, or urban effluents. Macroalgae are one of the biological quality elements used to monitor and assess the health status of TWS due to their structural and functional key role in marine ecosystems. Here, metal accumulation from the macroalgae Ulva laetevirens Areschoug (1854) and oxidative stress by lipid peroxidation (LPO) biomarker were investigated during four sampling seasons from three sampling sites (SMM: Santa Maria del Mare; PM: Porto Marghera; SG: San Giuliano) of Venice Lagoon, affected by different anthropogenic stressors. The metal pollution index (MPI) scores for U. laetevirens increased in the order SMM < PM < SG (sea inlet < industrial area < Osellino River estuary), with average values per site of 2.99, 4.37, and 6.33, respectively. The level of LPO was statistically correlated with the concentration of toxic metal(loid)s (As, Pb, Hg) measured in macroalgae, and seasonality affected both levels of LPO and metal bioaccumulation, with peak values during spring and summer. These findings highlighted the efficiency and usefulness of the oxidative stress test (LPO) on the common macroalga U. laetevirens as an early warning signal for health assessment in aquatic ecosystems
Heavy metals contamination in soils and their transfer to common wheat (Triticum aestivum L.): a case study.
No full textStudio preliminare della biodiversità macrofitica in tre stazioni del Golfo di Aqaba (Giordania)
No full textThe number of species and the coverage of the macrophytes recorded in three stations on the Jordan coast in the Gulf of Aqaba are reported. The results show a clear diversity of richness and evenness among the macrophytic communities of the different stations. Moreover, the low number of species can be related to the oligotrophic conditions of the sea
Morphological changes induced by heavy metals in dandelion (Taraxacum officinale Web.) growing on mine soils.
No full textPurpose Heavy metal accumulation produces significant
physiological and biochemical responses in vascular plants.
Plants growing on abandoned mine sites are of particular
interest, since they are genetically tolerant to high metal
concentrations. In this work, we examined the effect of heavy metals (HMs) on the morphology of T. officinale growing in pots with mine soils, with the following objectives: (1) to determine the evolution of HM concentration in leaves and roots over 3 years of cultivation; (2) to highlight possible
damage at anatomical and cytological level.
Materials and methods Wild specimens of Taraxacum
officinale Web., with their soil clod, were gathered from three
sites with different contamination levels by heavy metals (Cd,
Cr, Cu, Fe, Pb, Zn) in the abandoned Imperina Valley mine
(Northeast Italy). A control plant was also gathered from a
non-contaminated site nearby. Plants were cultivated in pots at the botanical garden of the University of Florence (HBF), and appeared macroscopically not affected by toxic signals (reduced growth, leaf necrosis) possibly induced by soil HM
concentration. Leaves and roots taken at the same growing
season were observed by light microscopy and transmission
electron microscopy. Results and discussion Light microscopy observations show a clear difference in the cellular organisation of noncontaminated and contaminated samples. The unpolluted samples present a well-organised palisade tissue and spongy photosynthetic parenchyma. Samples from contaminated sites, instead, present a palisade parenchyma less organised, and a reduction of leaf thickness proportional to HM concentration.
The poor structural organisations, and the reduced
foliar thickness of the contaminated plants, are related to soil
contamination. Differences in root micromorphology concern
the cortical parenchyma. Moreover, all the samples examined
present mycorrhiza. Ultrastructure observations of the parenchyma cells show mitochondrial structure alteration, with
lacking or reduced cristae of the internal membrane at increasing metal content. Instead, chloroplast organisation does not present significant differences, particularly in number and compartmentalization of thylakoids.
Conclusions Although macromorphology does not present
evidence of phytotoxicity, the recorded observations of the
micromorphological characteristics of leaves and roots, show
a suffering state of the plants, strictly related to HM content.
Leaching reduced partly the HM content of the soil, therefore
decreasing their phytotoxic effect. A gradual restoration of
leaf organisation suggests that somewhat resilience occurred
in plants. Moreover, the presence of stress-tolerant mycorrhizal fungi could contribute to reduce metal toxicity
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