خيارات البحث
النتائج 4151 - 4160 من 7,292
Accumulation of metallic trace elements in Reynoutria japonica: a risk assessment for plant biomass valorization النص الكامل
2022
Lerch, Sylvain | Sirguey, Catherine | Michelot-Antalik, Alice | Jurjanz, Stefan
Sustainable solutions aiming at limiting Reynoutria japonica invasion consist of frequent removal of its aerial biomass. The aims of this study were to measure the accumulation of metallic trace elements (MTE) in R. japonica, and to assess the eco-toxicological risk related to the valorization of the produced biomass. R. japonica fragmented rhizomes were regenerated in pots for 41 days on a control soil (CTL) or a moderately MTE-contaminated soil (POL, 3.6 mg Cd kg⁻¹ DM). Growth traits were recorded, as well as MTE bioconcentration (BCF) and translocation factors (TF) from soil to plant organs. Whatever the MTE and plant organs, BCF remained below one (mean Cd-BCF for stem and leaf: 0.07 and 0.29 for CTL and POL, respectively), conversely to TF (until 2.2 for Cd and Ni in POL soil). When grown on the POL soil, R. japonica stem and leaf Cd content was close to the EU maximum regulatory limit for organic amendments or animal feed. Model simulations suggested that liver and kidney Cd concentrations would exceed the regulatory limit in food when adult cattle or sheep constantly ingest R. japonica grown on the POL soil over 200 to 800 days. The results of the present study will be useful to help managers in selecting efficient and safe solutions for the control of R. japonica invasion.
اظهر المزيد [+] اقل [-]Assessment for combined phytoremediation and biomass production on a moderately contaminated soil النص الكامل
2022
Hostyn, Guillaume | Schwartz, Christophe | Côme, Jean-Marie | Ouvrard, Stéphanie
Once previous industrial activity has ceased, brownfields are found in urban and suburban environments and managed in different ways ranging from being left untouched to total reconversion. These situations apply to large surface areas often impacted by residual diffuse pollution. Though significant and preventing any sensitive use, residual contamination does not necessarily require treatment. Moreover, conventional treatments show their technical and economic limits in these situations and gentle remediation options such as phytomanagement might appear more relevant to the management of those sites. Thus, these sites face up two major issues: managing moderate contamination levels and providing an alternative use of economic interest. This work proposes to assess a management strategy associating the phytoremediation of organic pollution along with the production of biomass for energy generation production. A 16-week controlled growth experiment was conducted on a soil substrate moderately impacted by multiple pollution (trace elements, mainly Zn and Pb, and hydrocarbons), by associating rhizodegradation with Medicago sativa or biomass production with Robinia pseudoacacia or Alnus incana in monocultures. The effect of a microbial inoculum amendment on the performances of these treatments was also evaluated. Results showed total hydrocarbons (TH), and to a lesser extent polycyclic aromatic hydrocarbons (PAH), concentrations decreased over time, whatever the plant cover. Good biomass production yields were achieved for both tree species in comparison with the control sample, even though R. pseudoacacia seemed to perform better. Furthermore, the quality of the biomass produced was in conformity with the thresholds set by the legislation concerning its use as a renewable energy source.
اظهر المزيد [+] اقل [-]An ex ante life cycle assessment of wheat with high biological nitrification inhibition capacity النص الكامل
2022
Leon, Ai | Guntur V., Subbarao | Kishii, Masahiro | Matsumoto, Naruo | Kruseman, Gideon
It is essential to increase food production to meet the projected population increase while reducing environmental loads. Biological nitrification inhibition (BNI)-enabled wheat genetic stocks are under development through chromosome engineering by transferring chromosomal regions carrying the BNI trait from a wild relative (Leymus racemosus (Lam.) Tzvelev) into elite wheat varieties; field evaluation of these newly developed BNI-wheat varieties has started. Ten years from now, BNI-enabled elite wheat varieties are expected to be deployed in wheat production systems. This study aims to evaluate the impacts of introducing these novel genetic solutions on life cycle greenhouse gas (LC-GHG) emissions, nitrogen (N) fertilizer application rates and N-use efficiency (NUE). Scenarios were developed based on evidence of nitrification inhibition and nitrous oxide (N₂O) emission reduction by BNI crops and by synthetic nitrification inhibitors (SNIs), as both BNI-wheat and SNIs slow the nitrification process. Scenarios including BNI-wheat will inhibit nitrification by 30% by 2030 and 40% by 2050. It was assumed that N fertilizer application rates can potentially be reduced, as N losses through N₂O emissions, leaching and runoff are expected to be lower. The results show that the impacts from BNI-wheat with 40% nitrification inhibition by 2050 are assessed to be positive: a 15.0% reduction in N fertilization, a 15.9% reduction in LC-GHG emissions, and a 16.7% improvement in NUE at the farm level. An increase in ammonia volatilization had little influence on the reduction in LC-GHG emissions. The GHG emissions associated with N fertilizer production and soil N₂O emissions can be reduced between 7.3 and 9.5% across the wheat-harvested area worldwide by BNI-wheat with 30% and 40% nitrification inhibition, respectively. However, the present study recommends further technological developments (e.g. further developments in BNI-wheat and the development of more powerful SNIs) to reduce environmental impacts while improving wheat production to meet the increasing worldwide demand.
اظهر المزيد [+] اقل [-]Lab-scale investigation of the ability of Polar Organic Chemical Integrative Sampler to catch short pesticide contamination peaks النص الكامل
2022
Bernard, Marion | Boutry, Sebastien | Tapie, Nathalie | Budzinski, Héléne | Mazzella, Nicolas
In this lab-scale study, the POCIS capacity to integrate short contamination peaks of variable intensity and duration was evaluated. POCIS were immersed for 14 days in tanks filled with tap water and spiked at different concentrations with 12 pesticides of various polarities (log Kₒw = 1.1–4.7) and classes (herbicides, fungicides, and insecticides). Concentrations were kept relatively constant at 1 μg L⁻¹ and 5 μg L⁻¹, respectively, in two “background” exposure tanks. Three contamination peaks of increasing intensity and decreasing duration were simulated (10 μg L⁻¹ for 24 h, 40 μg L⁻¹ for 6 h, and 60 μg L⁻¹ for 1 h). This lab-scale study demonstrated that ten moderately polar compounds (2 < log Kₒw < 4) showed a linear uptake, as observed in previous studies, while a non-linear model fits the data of the two most polar pesticides (log Kₒw < 2). Depending on chemical polarity, some compounds exhibited a “burst effect” or “lag effect” during the first 3 days of exposure. After 14 days of exposure, contamination peaks appeared integrated for seven compounds, showing the ability of POCIS to catch very short pollution events and to provide acceptable time-weighted average concentration estimates under laboratory-controlled conditions.
اظهر المزيد [+] اقل [-]Development of an exposure protocol for toxicity test (FEET) for a marine species: the European sea bass (Dicentrarchus labrax) النص الكامل
2022
Soloperto, Sofia | Aroua, Salima | Jozet-Alves, Christelle | Minier, Christophe | Halm-Lemeille, Marie-Pierre
Regulatory assessment of the effects of chemicals requires the availability of validated tests representing different environments and organisms. In this context, developing new tests is particularly needed for marine species from temperate environments. It is also important to evaluate effects that are generally poorly characterized and seldom included in regulatory tests. In this study, we designed an exposure protocol using European sea bass (Dicentrarchus labrax) larvae. We examined classical toxicological values (LCx) as well as behavioral responses. By comparing different hatching and breeding strategies, we defined the optimal conditions of exposure as non-agitated conditions in 24- or 48-well microplates. Our exposure protocol was then tested with 3,4-dichloroaniline (3,4-DCA), a recommended reference molecule. Based on our results, the 96 h LC₅₀ for 3,4-DCA corresponded to 2.04 mg/L while the 168 h LC₅₀ to 0.79 mg/L. Behavioral analyses showed no effect of 3,4-DCA at low concentration (0.25 mg/L). In conclusion, the present work established the basis for a new test which includes behavioral analysis and shows that the use of sea bass is suitable to early-life stage toxicity tests.
اظهر المزيد [+] اقل [-]Essential and non-essential trace element concentrations in muscle and liver of a pregnant Munk’s pygmy devil ray (Mobula munkiana) and its embryo النص الكامل
2022
During gestation, essential and non-essential trace elements are transferred from the pregnant females to embryos. This study aimed to determine and compare the concentrations of seven essential trace elements (Fe, Zn, Se, Cu, Mn, Cr, Co) and six non-essential trace elements (As, Cd, V, U, Tl, Ag) in the muscle and the liver of a Munk’s pygmy devil ray pregnant female, Mobula munkiana, and its embryo. Transfer evidence of essential and non-essential trace elements was detected in M. munkiana tissues. Arsenic was found in elevated concentrations in the pregnant female and the embryo tissues. Elevated levels of Cd, V, U, and Ag were found in the pregnant female liver, but were minimal in the embryo tissue. This is the first study to investigate maternal transfer of essential and non-essential trace elements in these species and their reproductive strategy.
اظهر المزيد [+] اقل [-]Factors driving sediment compositional change in the distal area of the Ria de Vigo (NW Spain): oceanographic processes vs. paleopollution النص الكامل
2022
Virginia Alves Martins, Maria | Cazelli, Lucas | Yhasnara, Missilene | da CristineSilva, Layla | Barros Saibro, Murilo | Bobco, Fabia Emanuela Rafaloski | Rubio, Belen | Ferreira, Bruna | Castelo, Wellen Fernanda Louzada | Santos, José Francisco | Ribeiro, Sara | Frontalini, Fabrizio | Martínez-Colón, Michael | Pereira, Egberto | Antonioli, Luzia | Geraldes, Mauro | Rocha, Fernando | Sousa, Silvia Helena Mello e | Manuel Alveirinho Dias, João
We analyze potential Late Holocene metal contamination along a sediment core collected in the distal zone of Ria de Vigo (North Spain). Statistical treatment of the dataset based on a multiproxy approach enabled us to identify and disentangle factors influencing the depositional processes and the preservation of the records of this activity in the area over the last ≈3000 years BP. Some layers of the analyzed core have significant enrichment in Cu and a moderate enrichment in Ag, Mo, As, Sb, S, Zn, Ni, Sn, Cd, Cr, Co, Pb, and Li. The enrichment of these elements in some layers of this core may be related to mining activities that have taken place since classical times in the region. Successive phases of pollution were identified along the core KSGX24 related to the Late Bronze Age (≈3000–2450 years BP), Iron Age (≈2450–1850 years BP), Roman times (≈1850–1550 years BP), Middle Ages (≈1250–500 years BP), and industrial and modern (≈250–0 years BP) anthropic activities. The protection of the Cies Islands, the erosive and transport capacity of the rivers in the region, oscillations of the oceanographic and climatic regime, atmospheric contamination, and diagenetic sedimentary processes might have contributed to the accumulation and preservation of this record in the distal region of the Ria de Vigo. The studied core shows that the industrial and preindustrial anthropic impacts caused an environmental liability and contributed to the presence of moderate to heavy pollution of various metals in surface and subsurface sediment layers in the distal sector of the Ria de Vigo, which could be a hazard to biota.
اظهر المزيد [+] اقل [-]Heavy metal tolerant endophytic fungi Aspergillus welwitschiae improves growth, ceasing metal uptake and strengthening antioxidant system in Glycine max L النص الكامل
2022
Husna | Hussain, Anwar | Shah, Mohib | Hamayun, Muhammad | Qadir, Muhammad | Iqbāl, Amjad
In modern agricultural practice, heavy metal (HM) contamination is one of the main abiotic stress threatening sustainable agriculture, crop productivity, and disturb natural soil microbiota. Different reclamation techniques are used to restore the contaminated site; however, they are either costly or unable to remove contaminant when concentration is very low. In such circumstances, bioremediation is used as a novel technique involving microbes for soil restoration. In the current project, Aspergillus welwitschiae(Bk) efficiently endure metal stress (i.e., Cr-VI and As-V in the form of K₂Cr₂O₇ and Na₃AsO₄) up to 1200 μg/mL and enhanced the production of phytohormones, i.e., 54.83 μg/mL of indole acetic acid (IAA) compared to control 15.56 μg/mL, solubilized inorganic phosphate, and produced stress-related metabolites. The isolate Bk was able to enhance growth of soybean by showing higher root shoot length and fresh/dry weight under stress (p<0.05). Besides, the strain strengthened the antioxidant system of the host increasing enzymatic antioxidants, i.e., catalases (CAT) by 1.58 and 1.11 fold, ascorbic acid oxidase (AAO) by 6.75 and 7.94 fold, peroxidase activity (POD) by 1.12 and 1.37 fold, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) by 1.42 and 1.25 fold at 50 μg/mL of chromate and arsenate. Thus, actively scavenging the reactive oxygen species (ROS) produced results in lower ROS accumulation and high ROS scavenging. On the other hand, the isolates cut down Cr and As uptake by approximately 50% at 50 μg/mL from the medium while bio-transforming it, thereby stabilizing it and assisting the host to resume normal growth, thus avoiding phytotoxicity. It is evident from the current study that A. welwitschiae may potentially be used as a bioremediating agent for reclamation of Cr- and As-contaminated soil.
اظهر المزيد [+] اقل [-]Climate change and COVID-19: shared challenges, divergent perspectives, and proposed collaborative solutions النص الكامل
2022
Wahaj, Zujaja | Alam, Mahmudul | Al-Amin, Abul Quasem
Pandemics leave their mark quickly. This is true for all pandemics, including COVID-19. Its multifarious presence has wreaked havoc on people's physical, economic, and social life since late 2019. Despite the need for social science to save lives, it is also critical to ensure future generations are protected. COVID-19 appeared as the world grappled with the epidemic of climate change. This study suggests policymakers and practitioners address climate change and COVID-19 together. This article offers a narrative review of both pandemics' impacts. Scopus and Web of Science were sought databases. The findings are reported analytically using important works of contemporary social theorists. The analysis focuses on three interconnected themes: technology advancements have harmed vulnerable people; pandemics have macro- and micro-dimensions; and structural disparities. To conclude, we believe that collaborative effort is the key to combating COVID-19 and climate change, while understanding the lessons learnt from the industrialised world. Finally, policymakers can decrease the impact of global catastrophes by addressing many socioeconomic concerns concurrently.
اظهر المزيد [+] اقل [-]Freely dissolved organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) along the Indus River Pakistan: spatial pattern and risk assessment النص الكامل
2022
Sohail, Muhammad | Ali Musstjab Akber Shah Eqani, Syed | Bokhari, Habib | Zaffar Hashmi, Muhammad | Ali, Nadeem | Alamdar, Ambreen | Podgorski, Joel E. | Adelman, Dave | Lohmann, Rainer
Freely dissolved OCPs and PCBs were measured by using polyethylene passive samplers at 15 sites during 2014 throughout the stretch of the Indus River to investigate the spatial pattern and risk assess. Levels (pg/L) of dissolved ∑OCPs and ∑PCBs ranged from 34 to 1600 and from 3 to 230. Among the detected OCPs, dissolved DDTs (p,p′-DDE, followed by p,p′-DDT) predominated with levels of 0.48 to 220 pg/L. The order of occurrence for other studied OCPs was as follows: HCB, endosulfans, chlordanes, and HCHs. Spatially, dissolved (pg/L) ∑OCPs varied (p < 0.05) as the following: surface water of the alluvial riverine zone (ARZ) showed the highest levels (114) followed by the frozen mountain zone (FMZ) (52.9), low-lying zone (LLZ) (28.73), and wet mountain zone (WMZ) (14.43), respectively. However, our zone-wise PCB data did not exhibit significant differences (p > 0.05). Principal component analysis/multilinear regression results showed pesticide usage in the crop/orchard fields and health sector, electric and electronic materials, and widespread industrial activities as the main source of OCPs and PCBs along the Indus River. Our results showed that OCPs and PCBs contaminated water intake, playing an important role towards the considerable cancer/non-cancer risk (HI and CR values) along the Indus River Flood-Plain.
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