| 1. |
- Mangano, M. C., et al.
(författare)
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The aquaculture supply chain in the time of covid-19 pandemic : Vulnerability, resilience, solutions and priorities at the global scale
- 2022
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Ingår i: Environmental Science and Policy. - : Elsevier. - 1462-9011 .- 1873-6416. ; 127, s. 98-110
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Tidskriftsartikel (refereegranskat)abstract
- The COVID-19 global pandemic has had severe, unpredictable and synchronous impacts on all levels of perishable food supply chains (PFSC), across multiple sectors and spatial scales. Aquaculture plays a vital and rapidly expanding role in food security, in some cases overtaking wild caught fisheries in the production of high quality animal protein in this PFSC. We performed a rapid global assessment to evaluate the effects of the COVID19 pandemic and related emerging control measures on the aquaculture supply chain. Socio-economic effects of the pandemic were analysed by surveying the perceptions of stakeholders, who were asked to describe potential supply-side disruption, vulnerabilities and resilience patterns along the production pipeline with four main supply chain components: a) hatchery, b) production/processing, c) distribution/logistics and d) market. We also assessed different farming strategies, comparing land-vs. sea-based systems; extensive vs. intensive methods; and with and without integrated multi-trophic aquaculture, IMTA. In addition to evaluating levels and sources of economic distress, interviewees were asked to identify mitigation solutions adopted at local / internal (i.e., farm site) scales, and to express their preference on national / external scale mitigation measures among a set of a priori options. Survey responses identified the potential causes of disruption, ripple effects, sources of food insecurity, and socio-economic conflicts. They also pointed to various levels of mitigation strategies. The collated evidence represents a first baseline useful to address future disaster-driven responses, to reinforce the resilience of the sector and to facilitate the design reconstruction plans and mitigation measures, such as financial aid strategies.
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| 2. |
- Sarà, G., et al.
(författare)
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The Synergistic Impacts of Anthropogenic Stressors and COVID-19 on Aquaculture : A Current Global Perspective
- 2022
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Ingår i: Reviews in Fisheries Science & Aquaculture. - : Informa UK Limited. - 2330-8249 .- 2330-8257. ; 30:1, s. 123-135
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Tidskriftsartikel (refereegranskat)abstract
- The rapid, global spread of COVID-19, and the measures intended to limit or slow its propagation, are having major impacts on diverse sectors of society. Notably, these impacts are occurring in the context of other anthropogenic-driven threats including global climate change. Both anthropogenic stressors and the COVID-19 pandemic represent significant economic challenges to aquaculture systems across the globe, threatening the supply chain of one of the most important sources of animal protein, with potential disproportionate impacts on vulnerable communities. A web survey was conducted in 47 countries in the midst of the COVID-19 pandemic to assess how aquaculture activities have been affected by the pandemic, and to explore how these impacts compare to those from climate change. A positive correlation between the effects of the two categories of drivers was detected, but analysis suggests that the pandemic and the anthropogenic stressors affect different parts of the supply chain. The immediate measurable reported losses varied with aquaculture typology (land vs. marine, and intensive vs. extensive). A comparably lower impact on farmers reporting the use of integrated multitrophic aquaculture (IMTA) methods suggests that IMTA might enhance resilience to multiple stressors by providing different market options under the COVID-19 pandemic. Results emphasize the importance of assessing detrimental effects of COVID-19 under a multiple stressor lens, focusing on areas that have already locally experienced economic loss due to anthropogenic stressors in the last decade. Holistic policies that simultaneously address other ongoing anthropogenic stressors, rather than focusing solely on the acute impacts of COVID-19, are needed to maximize the long-term resilience of the aquaculture sector.
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| 3. |
- Amin, M. A., et al.
(författare)
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Synthesis of Cyano-Benzylidene Xanthene Synthons Using a Diprotic Brønsted Acid Catalyst, and Their Application as Efficient Inhibitors of Aluminum Corrosion in Alkaline Solutions
- 2022
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Ingår i: Molecules. - : MDPI AG. - 1420-3049. ; 27:17
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Tidskriftsartikel (refereegranskat)abstract
- Novel cyano-benzylidene xanthene derivatives were synthesized using one-pot and condensation reactions. A diprotic Brønsted acid (i.e., oxalic acid) was used as an effective catalyst for the promotion of the synthesis process of the new starting xanthene–aldehyde compound. Different xanthene concentrations (ca. 0.1–2.0 mM) were applied as corrosion inhibitors to control the alkaline uniform corrosion of aluminum. Measurements were conducted in 1.0 M NaOH solution using Tafel extrapolation and linear polarization resistance (LPR) methods. The investigated xanthenes acted as mixed-type inhibitors that primarily affect the anodic process. Their inhibition efficiency values were enhanced with inhibitor concentration, and varied according to their chemical structures. At a concentration of 2.0 mM, the best-performing studied xanthene derivative recorded maximum inhibition efficiency values of 98.9% (calculated via the Tafel extrapolation method) and 98.4% (estimated via the LPR method). Scanning electron microscopy (SEM) was used to examine the morphology of the corroded and inhibited aluminum surfaces, revealing strong inhibitory action of each studied compound. High-resolution X-ray photoelectron spectroscopy (XPS) profiles validated the inhibitor compounds’ adsorption on the Al surface. Density functional theory (DFT) and Monte Carlo simulations were applied to investigate the distinction of the anticorrosive behavior among the studied xanthenes toward the Al (111) surface. The non-planarity of xanthenes and the presence of the nitrile group were the key players in the adsorption process. A match between the experimental and theoretical findings was evidenced. © 2022 by the authors.
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| 4. |
- Mersal, G. A. M., et al.
(författare)
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Study of half metallic ferromagnetism and thermoelectric properties of spinel chalcogenides BaCr2X4 (X 1/4 S, Se, Te) for spintronic and energy harvesting
- 2022
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Ingår i: Journal of Materials Research and Technology-Jmr&T. - : Elsevier BV. - 2238-7854. ; 18:May–June 2022, s. 2831-2841
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Tidskriftsartikel (refereegranskat)abstract
- The control of spin degree of freedom in electronics open new horizons to manipulate, transfer, and storage data at fasters speed. For this the structural, electronic, and magnetic characteristics of BaCr2X4 (X 1/4 S, Se, Te) spinels are addressed comprehensively. The more energy release in ferromagnetic states than antiferromagnetic states, and formation energy verified thermal stability in FM states. The Curie temperature, and spin polarization density have been reported for room temperature ferromagnetism. The detail and nature of ferromagnetism have illustrated by band structures, density of states, hybridization, double exchange mechanism, crystal field energy, exchange energies and exchange constants. The transfer of magnetic moment from Cr sites to other nonmagnetic sites (Ba, X)
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| 5. |
- Amin, Mohammed A., et al.
(författare)
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Elemental Variability of PM2.5 Aerosols in Historical and Modern Areas of Jeddah, Saudi Arabia
- 2022
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Ingår i: Atmosphere. - : MDPI AG. - 2073-4433. ; 13:12
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Tidskriftsartikel (refereegranskat)abstract
- Air particulate matter with a diameter of 2.5 µm (PM2.5) were assembled for a whole year from the historical Jeddah district. Additional PM2.5 aerosols were collected during the autumn and winter seasons from another newly constructed district in Jeddah city (Alnaeem). The annual concentration of the total mass of the PM2.5 aerosols from the historical Jeddah site was found to be 43 ± 6 µg/m3. In addition, the average of the total mass concentration at the Alnaeem site was 61 ± 14 µg/m3. These values were greater than the annual mass concentration of the air quality standards of the European Commission (25 µg/m3) and the World Health Organization (10 µg/m3). The elemental analysis of the collected fine atmospheric aerosols was achieved by energy dispersive X-ray fluorescence (EDXRF) with three secondary targets (CaF2, Ge, and Mo). Quantitative elemental analyses of twenty-two (22) elements were achieved starting from the low atomic number element (Na) up to the high atomic number element (Pb). Although the historical Jeddah site is not well organized, the elemental concentrations and total mass concentrations were lower than those of the other site. The statistical analyses including enrichment factors, correlation analysis, and the principal component analysis revealed more information about the source identification of the PM2.5 aerosols collected from both locations. It was recognized that the elements Al, Si, K, Ca, Ti, Mn, Fe, Rb, and Sr originated from a natural source. On the other hand, the elements Ta, Br, Pb, Sc, Ni, Cu, Zn, and S originated from anthropogenic sources. Finally, the elements Na, Cl, and Br came mainly from the sea spray source.
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| 6. |
- Amin, Mohammed A., et al.
(författare)
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Non-Covalent Functionalization of Graphene Oxide-Supported 2-Picolyamine-Based Zinc(II) Complexes as Novel Electrocatalysts for Hydrogen Production
- 2022
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Ingår i: Catalysts. - : MDPI AG. - 2073-4344. ; 12:4
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Tidskriftsartikel (refereegranskat)abstract
- Three mononuclear 2-picolylamine-containing zinc(III) complexes viz [(2-PA)2ZnCl]2(ZnCl4)] (Zn1), [(2-PA)2Zn(H2O)](NO3)2] (Zn2) and [Zn(2-PA)2(OH)]NO3] (Zn3) were synthesized and fully characterized. Spectral and X-ray structural characteristics showed that the Zn1 complex has a square-pyramidal coordination environment around a zinc(II) core. The hydroxide complex Zn3 was non-covalently functionalized with few layers of graphene oxide (GO) sheets, formed by exfoliation of GO in water. The resulting Zn3/GO hybrid material was characterized by FT-IR, TGA-DSC, SEM-EDX and X-ray powder diffraction. The way of interaction of Zn3 with GO has been established through density functional theory (DFT) calculations. Both experimental and theoretical findings indicate that, on the surface of GO, the complex Zn3 forms a complete double-sided adsorption layer. Zn3 and its hybrid form Zn3/GO have been individually investigated as electrocatalysts for the hydrogen evolution reaction. The hybrid heterogenized form Zn3/GO was supported on glassy carbon (GC) with variable loading densities of Zn3 (0.2, 0.4 and 0.8 mg cm−2) to form electrodes. These electrodes have been tested as molecular electrocatalysts for the hydrogen evolution reaction (HER) using linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) in 0.1 M KOH. Results showed that both GC-Zn3 and GC-Zn3/GO catalysts for the HER are highly active, and with increase of the catalyst’s loading density, this catalytic activity enhances. The high catalytic activity of HER with a low onset potential of −140 mV vs. RHE and a high exchange current density of 0.22 mA cm−2 is achieved with the highest loading density of Zn3 (0.8 mg cm−2). To achieve a current density of 10 mA cm−2, an overpotential of 240 mV was needed.
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| 7. |
- Shaltout, Abdallah A., et al.
(författare)
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Elemental Composition of PM2.5 Aerosol in a Residential–Industrial Area of a Mediterranean Megacity
- 2020
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Ingår i: Archives of Environmental Contamination and Toxicology. - : Springer Science and Business Media LLC. - 0090-4341 .- 1432-0703. ; 78, s. 68-78
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Tidskriftsartikel (refereegranskat)abstract
- Very little is known about the elemental composition and possible sources of fine aerosol particles from Mediterranean megacities. Fine aerosol particles were collected at a residential-industrial area in Greater Cairo, Egypt, during the period from October 2010 to May 2011. The elemental compositions of the collected samples were quantified by using a homemade energy dispersive x-ray fluorescence spectrometer, whereas black carbon was quantified by a black smoke detector. Fifteen elements have been quantified. Of these constituents, Ca, C, Cl, S, and Fe had the highest concentrations: greater than 1µgm−3. The overall mean mass concentration of the collected samples equals 70µgm−3; this value exceeds the European Union annual Air Quality Standard levels. The individual elemental concentrations of the fine particles were found to be dominated by elements linked to mineral dust. Most of the monthly variations of elemental concentrations can be attributed to seasonal meteorological conditions. Other possible sources were vehicle-exhaust and industrial activities. The results pinpoint the problem of identifying different sources when one source, in this case, the nearby deserts, is dominant. The results from this study contribute to the growing knowledge of concentrations, composition, and possible sources of ambient fine particulate matter. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.
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| 8. |
- Shaltout, Abdallah, et al.
(författare)
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Spectroscopic investigation of PM2.5 collected at industrial, residential and traffic sites in Taif, Saudi Arabia
- 2015
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Ingår i: Journal of Aerosol Science. - : Elsevier BV. - 0021-8502. ; 79, s. 97-108
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Tidskriftsartikel (refereegranskat)abstract
- The present work aims at detecting and characterizing the semiquione free radicals and inorganic composition of atmospheric aerosol particles, PM2.5, collected at three different sites (industrial, residential, and traffic dominated) in Taif city, Saudi Arabia, during 2011/2012. PM2.5 particles have been collected on polycarbonate filters in a collection cartridge in a cyclone. The duration of the collection was 24 h at an air flow of 3 L min−1. The average PM2.5 mass concentration was 37±22 μg/m3, 57±22 μg/m3 and 50±31 μg/m3 at the residential, industrial and traffic sites, respectively. These values are higher than the target value for air quality standards of European Union (25 μg/m3). Energy dispersive X-ray fluorescence (EDXRF) and electron paramagnetic resonance (EPR) spectroscopic techniques were chosen for sample analysis. Fourteen elements were quantified by EDXRF: Si, S, Cl, K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Rb, Sr and Pb. The measured concentrations of the potentially hazardous trace elements As, Cu, Sb, Cr, Mn, Ni and Pb were either below the detection limit or below the limits defined by international guidelines and national standards of ambient air quality. Furthermore, electron paramagnetic resonance (EPR) technique was used for testing and identifying paramagnetic species in the PM2.5 particles. The EPR spectra of PM2.5 from the three sites have a g-value in the range from 2.0033 to 2.235 which is characteristic for semiquinone radicals. The PM2.5 samples showed three EPR signals indicate the presence of semiquinone radical anion.
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| 9. |
- Badawi, Ali, et al.
(författare)
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Exploring the structural and optical properties of FeS filled graphene/PVA blend for environmental-friendly applications
- 2021
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Ingår i: Journal of Polymer Research. - : Springer Science and Business Media LLC. - 1022-9760 .- 1572-8935. ; 28
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Tidskriftsartikel (refereegranskat)abstract
- In this study, the role of iron sulfide (FeS) content on the structural and optical properties of graphene/polyvinyl alcohol (Gr/PVA) blend has been examined for environmental-friendly applications. Gr/PVA blend filled with FeS (0 to 10 wt%) were equipped using the casting technique. The prepared samples were studied via a scanning electron microscope, X-ray diffractometer, FT-IR and UV–visible-NIR spectrophotometers. XRD analysis shows that the crystallinity increases with increasing FeS concentration in the host Gr/PVA blend. UV–visible-NIR analysis shows that the direct optical bandgap of composite blends shrinks from 5.37 to 4.68eV as FeS content is increased to 10 wt%. Also, it confirms that the refractive index and optical conductivity of Gr/PVA blend could be significantly enhanced via FeS filling. FeS filled Gr/PVA blends are recommended eco-friendly applications.
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| 10. |
- Eladawy, A., et al.
(författare)
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Characterization of the northern Red Sea's oceanic features with remote sensing data and outputs from a global circulation model
- 2017
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Ingår i: Oceanologia. - : Elsevier BV. - 0078-3234. ; 59:3, s. 213-237
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Tidskriftsartikel (refereegranskat)abstract
- Sea surface temperature (SST) and surface wind ( SW) are considered the most important components in air-sea interactions. This study examines the relationships between SST, SW and various oceanic variables in the northern Red Sea (NRS) during the period of 2000-2014. The current study is the first attempt to identify the SST fronts and their relationship with the dominant circulation patterns. SST fronts are mapped using the Cayula and Cornillon algorithms. The analysis is performed with available remote sensing and reanalyzed data together with 1/12 degrees HYbrid Coordinate Ocean Model (HYCOM) outputs. Seasonal-trend decomposition procedure based on loess (STL) is applied for trend analysis, and Principal Component Analysis (PCA) is run for the atmospheric parameters. The SST, SW speed and Chlorophyll-a (Chl-a) changes show insignificant trends during the period of 2000-2014. Meridional SST fronts are more significant during the month of January, and fronts that are perpendicular to the sea's axis occur from February to May. Distinct monthly and spatial variations are present in all the examined parameters, although these variations are less pronounced for the wind direction. The SST is mainly controlled by the air temperature and sea level pressure. Significant correlations exist between the SST and the studied parameters (alongshore wind stress rather than the cross-shore wind stress, surface circulation, MLD, and Chl-a). Surface winds generally flow southeastward parallel to the Red Sea's axis explaining that alongshore wind stress is highly correlated with the studied parameters. (C) 2017 Institute of Oceanology of the Polish Academy of Sciences. Production and hosting by Elsevier Sp. z o. o.
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| 11. |
- Mohamed, B., et al.
(författare)
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Inter-Annual Variability and Trends of Sea Level and Sea Surface Temperature in the Mediterranean Sea over the Last 25 Years
- 2019
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Ingår i: Pure and Applied Geophysics. - : Springer Science and Business Media LLC. - 0033-4553 .- 1420-9136. ; 176:8, s. 3787-3810
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Tidskriftsartikel (refereegranskat)abstract
- Sea level and sea surface temperature inter-annual variability and trends in the Mediterranean Sea were investigated during the period 1993-2017. These were carried out using gridded absolute dynamic topography from satellite altimetry, tide gauge (TG) time series from 25 stations and gridded sea surface temperature (SST) from advanced very-high-resolution radiometer (AVHRR) data. The coastal TG data were used to verify the satellite derived sea level. Moreover, the contributions of atmospheric pressure and North Atlantic Oscillation (NAO) to sea level changes were also examined. The results revealed that the Mediterranean Sea exhibits inter-annual spatiotemporal coherent variability in both sea level and SST. The spatial variability in sea level is more significant over the Adriatic and Aegean Seas, most of the Levantine basin, and along the Tunisian shelf. Marked spatial variability in SST occurs over the central part of the Mediterranean Sea with maximum amplitude in the Tyrrhenian Sea. The highest temporal variability of sea level and SST was found in 2010 and 2003, respectively. The inter-annual variability of sea level and SST accounts for about 32% and 3% of the total variance of sea level and SST, respectively. An analysis of sea level anomaly reveled large negative values during the extended winter of 2011-2012, which may be attributed to the strong positive phase of NAO index. Satellite altimetry indicated a significant positive sea level trend of 2.7 +/- 0.41 mm/year together with a significant warming of 0.036 +/- 0.003 degrees C/year over the whole Mediterranean Sea for the period 1993-2017.
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| 12. |
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| 13. |
- Shaltout, A. A., et al.
(författare)
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Environmental and health risks of potentially toxic elements in ambient PM10in Jeddah, Saudi Arabia
- 2024
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Ingår i: INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY. - 1735-1472 .- 1735-2630.
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Tidskriftsartikel (refereegranskat)abstract
- Source apportionment and environmental and risk assessments of ambient PM10 collected from three locations in Jeddah, Saudi Arabia, were investigated. These estimations were based on the concentrations of ambient PM10 mass and potentially toxic elements. The annual ambient PM10 concentration, 120 +/- 40, 180 +/- 170, and 150 +/- 230 mu g/m(3) at three locations respectively, exceeds the Saudi Arabia annual air quality limit (80 mu g/m(3)). The highest 24-h PM10 concentrations were measured at a location influenced by traffic and industries (1800 mu g/m(3)) and at a seaside location (2000 mu g/m(3)) while the lowest 24-h PM10 concentration was measured at a university campus site (50 mu g/m(3)). The elements As, Cd, Ce, Co, Cr, Mn, Mo, Ni, Pb, Sb, Se, Sn, Te, V, and Zn were included in the source apportionment analysis using positive matrix factorization. The major sources identified were crustal material and windblown dust (27-28%), a mix of natural and anthropogenic sources (20-26%), combustion and traffic (18-21%), industrial activities (14-20%), and heavy metal industry (11-15%). Several environmental risk indices show a serious environmental pollution problem in Jeddah city due to the high concentrations of ambient PM10 and their elemental content. A non-carcinogenic health risk assessment showed that Cd and Mn constituted a risk for children and adults and inhalation was the main pathway for exposure. No carcinogenic risks were found but Cd, Co, and Ni had CR values above the safe limit of 10(-6).
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| 14. |
- Shaltout, A. A., et al.
(författare)
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Temporal and Spatial Variations of Potentially Toxic Elements in PM10 Collected in Jeddah City, Saudi Arabia
- 2023
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Ingår i: Archives of Environmental Contamination and Toxicology. - 0090-4341. ; 85:4, s. 451-65
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Tidskriftsartikel (refereegranskat)abstract
- Air pollution causes environmental and health problems around the world. In this study, ambient particulate matter with an aerodynamic diameter equal to or less than 10 microns (PM10) has been collected at three different locations in Jeddah city, Saudi Arabia. The locations are characterized by differences in terms of traffic, residential intensity, industrial, and non-road mobile machinery activities. The monthly and annual mass concentration of the PM10 exceeds the recommended annual limit of the World Health Organization (15 & mu;g/m(3)) and the European air quality standard (40 & mu;g/m(3)) at the three locations. The collected PM10 samples as well as a certified reference material of atmospheric particulates (NIST 1678a) were digested in aqua regia using microwave digestion. The quantitative elemental analysis was carried out using inductively coupled plasma mass spectrometry. The variations of the elemental concentration in terms of workdays, weekends, seasons, and annual were determined at the three locations. The spatial and temporal elemental variations were found to be different between the three sites, pointing to local influences that should be further evaluated. The concentration of Cd was found to be high and may cause health problems.
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| 15. |
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