Article

Roadsoil contamination by polycyclic aromatic hydrocarbon: level and impact on germination of Lycopersicum esculentum and Cucumis sativus

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Abstract

The distribution and accumulation of polycyclic aromatic hydrocarbons (PAH) in soil and their impact on three selected species—Lycopersicum esculentum, Cicer arietinum, and Cucumis sativus—have been investigated in areas with high traffic pollution such as the city of Sfax, in the south of Tunisia. PAH were identified in 147 soil samples (0–10 cm). The variation between the physicochemical characteristics of three soils influenced the spatial distribution of PAH. Soil acidity at sites near the Manzel Chaker road can therefore increase the availability of hydrocarbons. Similarly, increasing of organic matter content in these sites can decrease the biodegradation of PAH. The soils near Manzel Chaker road had the highest content followed by those of Tunis road soil. Chrysene, fluoranthene, benzo(a)anthracene, and indeno(1.2.3.cd)pyrene were the most abundant compounds with a content of 49 µg/g, 51 µg/g, 3.8 µg/g, and 45 µg/g respectively. The calculation of the number of germinated seeds by referring to the number of seed germinated, also the root biomass and the shoot elongation of tomato, showed the sensitivity of this species to contamination of Gremda and Manzel Chaker soils. The use of PCA indicated the absence of the impact of fluorene, fluoranthene, naphthalene, and chrysene on the germination of tomato and cucumber and their impact on the aerial part of tomato, but no significant effect on the germination and growth of cucumber was detected. This later has shown resistance to pollution by PAH which can be linked to morphological and genetic aspects.

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The present research assessed soil contamination along the roadside in the central littoral region of Tunisia. Road Gremda (toward the northwest), road Manzel Chaker (toward the southwest) and road Tunis (toward the north) were chosen for this study. Fourteen stations located on different road sides were sampled. Soil samples were analyzed for Pb, Zn, Cu, Cr and Fe. The range of the metals was as follows: Pb 1.23–88 µg/g, Zn 1.23–295.2 µg/g, Cu 3.8–11.04 µg/g, Fe 1972.7–3647.9 µg/g and Cr 10.8–32.2 µg/g. Iron is an abundant element in the Earth’s crust, and it was considered in this work as a reference for naturally occurring metals and was used in the determination of geoaccumulation index. Soil metallic contamination affected the percentage and kinetic of germination of tomato and chickpea, whereas these parameters did not affect cucumber. Contamination of soil by the polycyclic aromatic hydrocarbons reaching 1550 mg/kg affected only the rate of germination of tomato and chickpea. Cucumber showed a resistance to both of metals and polycyclic hydrocarbons which can attest the resistance of this species. The hydrocarbon content recorded in the soil affected shoot elongation of tomato, while the metal contamination affected the root elongation of this species. In contrast, cucumber showed resistance to both types of pollutants. This species has shown an accumulation of Pb, Zn and Cr, especially when germinated on Gremda soil.
Thesis
Le but de ce travail est d'étudier et de mettre au point des méthodes d'analyses simples, rapides et fiables, permettant de doser les hydrocarbures dans des échantillons solides ou aqueux. Dans un premier temps, nous avons étudié des techniques basées sur l'extraction liquide-liquide et liquide-solide des hydrocarbures, couplées à la détection par spectrométrie infrarouge à transformée de Fourier. Nous avons montré que cette méthode n'était performante que pour des échantillons solides dont la concentration en hydrocarbures dépasse 200 mg/kg et pour des échantillons liquides dont la concentration est supérieure à 50 mg/l. En dessous de ces valeurs, les rendements d'extraction sont faibles. De plus, l'IRTF necessite l'emploi de solvants n'interférant pas sur les mesures et ces solvants, chlorés et fluorés, sont généralement toxiques ou représentent un danger pour l'environnement. Par la suite, nous avons étudié l'extraction liquide-solide au soxtec avec un dosage des hydrocarbures par gravimétrie. Cette méthode a permis d'obtenir des rendements supérieurs à 80% mais avec une répétabilité relativement faible. Cela est essentiellement dû au séchage des extraits qui peut entrainer la perte des composes les plus volatils. Enfin, nous avons développé une méthode de dosage basée sur la séparation des hydrocarbures en familles chimiques par chromatographie sur couche mince couplée à la détection en UV et en fluorescence. Grâce à l'exaltation de la fluorescence émise par la berbérine, en présence de composes à structure partiellement saturée, nous avons pu doser ces composés dans des dérivés pétroliers. Nous avons également dosé les composés aromatiques, en UV et en fluorescence. Les résultats que nous avons obtenus sont similaires à ceux obtenus par d'autres techniques (CLHP, gravimétrie, Iatroscan). Ainsi, cette méthode de dosage se présente comme une alternative intéressante à l'IRTF pour la détection et la quantification des hydrocarbures extraits d'échantillons solides ou aqueux, d'autant plus qu'elle ne restreint pas le choix des solvants
Thesis
Les sols industriels ayant des contaminations multiples (HAP, ETM) posent des problèmes pour leur traitement car les techniques disponibles (ex. biopile, désorption thermique) ne diminuent pas l'ensemble de la pollution et modifient les propriétés physico-chimiques et biologiques du sol. La phytoremédiation peut être une technique alternative de traitement. Les objectifs de ce travail étaient (i) de caractériser les propriétés biologiques de sols contaminés ou traités par biopile ou par désorption thermique, (i) d'évaluer l'effet de la mycorhization et de la fertilisation sur la capacité de la luzerne à croître sur des sols avant et après remédiation (ii) d?étudier la dynamique des polluants dans la rhizosphère de plantes mycorhizées ou non et de caractériser les communautés microbiennes. Les sols étudiés proviennent de sites industriels contaminés en HAP et dans une moindre mesure en ETM. Des cultures de luzerne inoculée ou non par un champignon MA et/ou fertilisée ont montré que la survie et la croissance de la plante étaient dépendantes de la mycorhization. Les teneurs et la disponibilité des HAP dans la rhizosphère ont diminué en présence de plante tandis que le champignon MA, qui n'a pas d'effet sur la teneur en HAP. Différentes techniques (dénombrement, PCR-TTGE, PCR en temps réel) ont montré l'impact de la remédiation sur la microflore bactérienne et fongique du sol. Les résultats indiquent la nécessité de prendre en compte les caractéristiques physicochimiques et biologiques des sols contaminés et des sols traités. L'association plante-champignons MA sont certainement déterminants pour la remédiation et la restauration des propriétés de ces sols.
Thesis
Notre travail de thèse a porté sur les modalités de dépôts de PGE et HAP sur le fourrage à partir d'un bio-accumulateur (ray-grass). Les cinétiques du dépôt de PGE et HAP sur les plants de ray-grass exposé en bordure d'autoroute ont montré que l'essentiel de la contamination s'effectue durant les premières semaines d'exposition, et aussi que ces contaminants restent fixés au ray-grass au moins cinq semaines après son retrait de l'autoroute. L'étude de l'influence des conditions du trafic a montré un faible impact de l'autoroute sur la contamination du ray-grass en PGE et HAP par rapport à une route nationale, suggérant que le dépôt de PGE et HAP sur le ray-grass est beaucoup plus lié aux propriétés de leurs émissions par les véhicules que par le nombre de véhicules. La spatialisation de l'exposition du fourrage en PGE et HAP à l'échelle parcellaire a révélé une diminution significative des concentrations de Pd, Rh et HAP du ray-grass avec l'éloignement de la source d'émission
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Road-deposited sediment and its adsorbed pollutants have been regarded as significant sources of urban diffuse pollution. In this study, the solid-phase concentrations (mg/g), surface load (mg/m(2)) and chemical fractionation of zinc (Zn), copper (Cu) and cadmium (Cd) were determined. Geo-accumulation (Igeo) and ecological risk (RI) indexes were employed for metal risk assessment. Results show that the highest solid-phase concentrations of Zn and Cu were usually found at an industrial area. However, Cd had the highest solid-phase concentrations at a rural area, followed by a commercial area. The surface loads of Zn and Cu decreased along the city centre to city border gradient. However, Cd was distributed irregularly. In terms of chemical fractionation, the predominant components of Zn and Cd were identified in the unstable exchangeable fractions, indicating high potential ecological risks to the aquatic environments. Cu posed a comparably low risk due to the high proportions of the stable components of residual and oxidisable fractions. According to a two-dimensional hierarchical cluster analysis, Zn and Cu surface loads were dominantly influenced by the antecedent dry-weather period; Cd contents were strongly land-use type dependent. In addition, the enrichment capability was ranked as Zn > Cu > Cd determined by Igeo index. The sampling site dependent potential ecological risk was determined as rural area (R) > commercial city centre (W) > federal highway (B) > industrial area (I) > main road (S) > secondary road (A) by the RI index.
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Environmental air pollution encompasses various particulate matters (PMs). The increased ambient PM from industrialization and urbanization is highly associated with morbidity and mortality worldwide, presenting one of the most severe environmental pollution problems. This article focuses on the correlation between PM and skin diseases, along with related immunological mechanisms. Recent epidemiological studies on the cutaneous impacts of PM showed that PM affects the development and exacerbation of skin diseases. PM induces oxidative stress via production of reactive oxygen species and secretion of pro-inflammatory cytokines such as TNF-α, IL-1α, and IL-8. In addition, the increased production of ROS such as superoxide and hydroxyl radical by PM exposure increases MMPs including MMP-1, MMP-2, and MMP-9, resulting in the degradation of collagen. These processes lead to the increased inflammatory skin diseases and skin aging. In addition, environmental cigarette smoke, which is well known as an oxidizing agent, is closely related with androgenetic alopecia (AGA). Also, ultrafine particles (UFPs) including black carbon and polycyclic aromatic hydrocarbons (PAHs) enhance the incidence of skin cancer. Overall, increased PM levels are highly associated with the development of various skin diseases via the regulation of oxidative stress and inflammatory cytokines. Therefore, anti-oxidant and anti-inflammatory drugs may be useful for treating PM-induced skin diseases.
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The experiment studied on the rhizosphere effect in phytoremediation of the petroleum polluted soil by three kinds of grasses which were Pannicum, Eleusine indica (L.) Gaerth and Tall Fescue. After a period of 150 d, this pot experiment show that the three kinds of plants rhizosphere accelerated the degradation of petroleum in different degrees. The results show that the plant roots improved the soil moisture which increased 5% compared with unplanted control soil. The dehydrogenase activity is 0.61-1.20 times higher. The number of microorganisms in the rhizosphere increased three orders of magnitude. The abduction of plant rhizosphere environment and the coercion of petroleum changed the distribution and activity of microorganisms. The petroleum degradation rates in the rhizosphere are 22.1%-30.3% higher than in the unplanted control soil. The effect of rhizosphere degeneration changed the component of petroleum obviously. It strengthened the degeneration degree of normal hydrocarbons that had low and moderate carbon. The plant rhizosphere environment is favorable to degenerate the high-carbon hydrocarbons into the low-carbon hydrocarbons. At the same time the peak area ratios of Pr/nC17, Ph/nC18 and Pr/Ph have been enhanced 0.99, 2.69 and 1.25 respectively. It accelerated the isomerization of normal hydrocarbons.
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Taking tomato 'Zhongza 105' as test material, the influences of sodium naphthalene acetate (SNA) on growth and physiological characteristics of tomato seedlings under suboptimal temperature and light condition were investigated. The results showed that the dry mass, vigorous seedling index, root activity, total nitrogen content, net photosynthesis rate (Pn) of tomato seedlings were significantly decreased by suboptimum temperature and light treatment. In addition, the catalase activity and zeatin riboside (ZR) concentration were also reduced. However, the superoxide dismutase, peroxidase activity and the content of abscisic acid (ABA) were increased. Compared with treatment of the same volume distilled water on tomato seedlings under suboptimum temperature and light condition, the dry mass of whole plant and vigorous seedling index of tomato seedlings were significantly increased by 16.4% and 22.9%, as the total N contents in roots and leaves and Pn were also increased by 8.5%, 28.5%and 37.0%, respectively, with the treatment of root application of 10 mg·L-1 SNA. Besides protective enzyme activity and the root activity were improved, the indole acetic acid (IAA) and ZR concentration of tomato were raised, and ABA concentration was reduced. The results indicated that root application of certain concentration of SNA could promote the growth of tomato seedlings by increasing the tomato root activity, protective enzymes activity, Pn and regulating endogenous hormone concentration under suboptimum temperature and light condition. ©, 2015, Editorial Board of Chinese Journal of Applied Ecology. All right reserved.
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Various types of polycyclic aromatic compounds (PACs) in diesel exhaust particles are thought to contribute to carcinogenesis in mammals. Although the carcinogenicity, mutagenicity and tumour-initiating activity of these compounds have been evaluated, their tumour-promoting activity is unclear. In the present study, to determine the tumour-inducing activity of PACs, including previously known mutagenic compounds in atmospheric environments, a transformation assay for promoting activity mediated by the release of contact inhibition was conducted for six polycyclic aromatic hydrocarbons (PAHs), seven oxygenated PAHs (oxy-PAHs) and seven nitrated PAHs (nitro-PAHs) using mouse embryonic fibroblast cells transfected with the v-Ha-ras gene (Bhas 42 cells). Of these, two PAHs [benzo[k]fluoranthene (B[k]FA) and benzo[b]fluoranthene (B[b]FA)], one oxy-PAH [6H-benzo[cd]pyren-6-one (BPO)] and two nitro-PAHs (3-nitro-7H-benz[de]anthracen-7-one and 6-nitrochrysene) were found to exhibit particularly powerful tumour-promoting activity (≥10 foci following exposure to <100nM). In addition, clear mRNA expression of CYP1A1, which is associated with aryl hydrocarbon receptor (AhR)-mediated activation, was observed following the exposure of cells to two PAHs (B[k]FA and B[b]FA) and three oxy-PAHs (1,2-naphthoquinone, 11H-benzo[b]fluoren-11-one and BPO). Further, an HO-1 antioxidant response activation was observed following exposure to B[k]FA, B[b]FA and BPO, suggesting that the induction of tumour-promoting activity in these compounds is correlated with the dysfunction of signal transduction via AhR-mediated responses and/or oxidative stress responses.
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Nine zucchini cultivars (Cucurbita pepo subspecies ovifera and pepo) were grown in soil containing a mixture of dioxins and dioxin-like compounds. Plants of subspecies pepo accumulated polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) in their aerial parts at higher concentrations than did plants of subspecies ovifera. In all cultivars, the accumulation of PCDDs and PCDFs in the aerial parts decreased with increasing hydrophobicity, whereas for PCBs, a negative correlation was observed in only two cultivars. The other seven cultivars selectively accumulated ortho-chlorinated biphenyls. Our results contribute to the understanding of the mechanisms underlying these phenomena, which should help in the development of efficient methods for phytoremediation of hydrophobic contaminants. (C) Pesticide Science Society of Japan
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Derived compounds leakage of petroleum by pipelines, overflowing of reservoirs, carrier vehicles accident and petroleum depots that burned in wars are most siginificant sources of environmental pollution by petroleum hydrocarbonsThe fate of spilled petroleum after releasing to environment is very variable, and different factors for controlling the situation are effective. Physical and chemical properties of these compounds, rate of concentration variation related chemical reactions or microbial degradation, environmental conditions such as temperature, light, oxygen and solubility rate in water can be considered. Nowadays, applying methods in accordance with environmental criteria expanding vastly and one of well-studied technique for cleanup of petroleum compounds is utilization of native plants. In current study, uptake of total petroleum hydrocarbons (TPH) by Fetsuca and Geranium with aim of TPH reduction from gas oil polluted soil was evaluated. Results indicated that Fetscua is capable of TPH uptake. Moreover, TPH content in Fetsuca were more than Geranium. With respect to results of this study, both plants can be potential candidate for TPH uptake from soil, where rate of uptake by Fetsuca is higher than Geranium.
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Soil samples contaminated with spent motor engine oil collected from Abakaliki auto-mechanic site were analyzed to determine the concentration of polycyclic aromatic hydrocarbon (PAH) components which are often targets in environmental check. Identification and quantification of the PAH components was accomplished using a gas chromatographic system (6890 series and 6890 plus) equipped with a quadrupole Mass Spectrometer (Agilent 5975 MSD) after ultrasonic extraction of the sample and clean up of the extract. The results showed that out of the sixteen USEPA target PAHs (EPA-16) assayed, only six were detected in varying concentrations in mg/kg. These include Phenanthrene with concentration range of 0.0172 ± 0.01 to 0.0193 ± 0.02, fluorene (0.0189 ± 0.01), benzo[a]anthracene (0.0162 ± 0.05), chrysene (0.0209 ± 0.02), benzo[b]fluoranthrene (0.0453 ± 0.02) and benzo[k]fluoranthrene (0.0389 ± 0.1). The concentration of total PAH components detected in the samples ranged from 0.0184 ± 0.02 to 0.1385 ± 0.2 mg/kg. Implications of PAHs on health were discussed. ©JASEM