822 research outputs found
Chlorinated hydrocarbons in the environment – monitoring and effect monitoring
Thousands of chemicals are traded on the market, but only in a few cases is full information available on their distribution and their effects on man and the environment. In addition to real time monitoring of chemicals, it is, thus, necessary to establish an environmental specimen bank (ESB) for the retrospective monitoring of chem¬icals in the future. The base of ESB are representative bioindicators of systematically collected biological and environmental samples. As a result of extremely low storage temperature (T = < - 150°C) it is guaranteed that the samples are not subject to chemical changes during the long-term storage.
Furthermore we need in addition an effect monitoring, using in vitro testing like for example P 450 1A1 enzyme expression.В настоящее время на рынке присутствует огромное количество химических веществ, но только в некоторых случаях доступна полная информация об их распространенности и воздействиях, оказываемых ими на человека. В дополнение к мониторингу химических веществ, проводимому в реальном времени, необходимо создать банк образцов химических веществ, присутствующих в окружающей среде для проведения в будущем ретроспективного мониторинга. Основой такого банка данных могут стать репрезентативные биоиндикаторы
систематически собираемых биологических образцов и образцов, присутствующих в окружающей среде. Поскольку температура хранения образцов в банке крайне низкая ( Т< - 150°C) существует гарантия того, что образцы не будут подвергаться химическим изменениям во время длительного хранения. Но помимо прочего, нам необходим эффективный мониторинг, где бы использовались in vitro тест - системы, например, для определения экспрессии энзима 450 1А1
INFLUENCE OF LINEAR ALKYLBENZENE SULFONATE (LAS) AS ORGANIC COSOLVENT ON LEACHING BEHAVIOR OF PCDD/FS FROM FLY-ASH AND SOIL
The leaching of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) was measured in soil and standard fly ash column eluted with pure water and linear alkylbenzene sulfonate (LAS)- water. The data obtained were used to evaluate the leachability of PCDD/Fs from waste dump like incineration residual slag and fly ash deposition. The leaching rate was shown to be increased significantly by using LAS water. The leachate contents of PCDD/Fs were above their known water solubility. Concentration of PCDD/Fs in the leachates as well as the relative leaching (calculated on the fly ash content) increased with increasing chlorinating degree and decreasing water solubility. LAS above the critical micelle concentration (CMC) probably enhances PCDD/Fs solubility
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Environmental and health aspects of CIS-module production, use and disposal
Copper indium diselenide (CIS) is one of the most promising compounds in thin film technology. Since there is scant information available about environmental and health hazards, a study was initiated to characterize risks associated with the production, use and disposal of thin film photovoltaic modules. Data available from literature and developers of this technology contribute to an assessment of potential risks during production. In laboratory experiments the release of hazardous materials during operation caused by accidents or false handling and after disposal are simulated. In biological experiments the possible impact on living matter is established. These experiments comprise toxicity tests with aquatic organisms and rats representing mammals
Polycyclic aromatic hydrocarbons bioaccessibility in seafood: Culinary practices effects on dietary exposure
This work aimed to determine the effect of culinary practices on the contamination level and bioaccessibility of polycyclic aromatic hydrocarbons (PAHs) in seafood. The selected farmed seafood species (marine shrimp, clams and seaweed) were commercially available in Portugal. The mean concentrations of PAHs varied between 0.23 and 51.8 µg kg-1, with the lowest value being observed in raw shrimp and the highest in dried seaweed. The number of compounds detected in seaweed and clams (naphthalene, acenaphthene, fluorene, phenanthrene, benzo(b)fluoranthene and benzo(j)fluoranthene) were higher than in shrimp (fluorene and pyrene). Among the PAHs measured, fluorene was the predominant one. There was a significant interaction effect between species and culinary treatment (p < 0.05), thus boiled and dried seaweed samples presented the lowest and the highest levels of fluorene (0.13 and 1.8 µg kg-1), respectively. The daily intake of PAHs decreased with bioaccessibility, varying from 22% for benzo(k)fluoranthene (in raw clam) to 84% for phenanthrene (in steamed clam). According to the potency equivalent concentrations, screening values and bioaccessibility of PAHs, the consumption of marine shrimp, clam and seaweed is considered as safe for consumers.This work received financial support from European (FEDER funds through COMPETE) and Portuguese funds (Fundação para a Ciência e Tecnologia Project UID/QUI/50006/2013). The Portuguese Foundation for Science and Technology supported the Ph.D. Grant of ALM (SFRH/BD/103569/2014) as well as the post-doc Grant of P.A. (SFRH/BPD/100728/2014) and the IF2014 contract of AM.info:eu-repo/semantics/publishedVersio
Multiproxy analysis of a new terrestrial and a marine Cretaceous–Paleogene (K–Pg) boundary site from New Zealand
Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Geochimica et Cosmochimica Acta 75 (2011): 657-672, doi:10.1016/j.gca.2010.10.016.An integrated study of palynology, Mössbauer spectroscopy, mineralogy and osmium
isotopes has led to the detection of the first K-Pg boundary clay layer in a Southern
Hemisphere terrestrial setting. The K-Pg boundary layer was independently identified at
centimetre resolution by all the above mentioned methods at the marine K-Pg boundary site of
mid-Waipara and the terrestrial site of Compressor Creek (Greymouth coal field), New
Zealand. Mössbauer spectroscopy shows an anomaly of Fe-containing particles in both K-Pg
boundary sections: jarosite at mid-Waipara and goethite at Compressor Creek. This anomaly
coincides with a turnover in vegetation indicated by an interval dominated by fern spores and
extinction of key pollen species in both sections. In addition to the terrestrial floristic changes,
the mid-Waipara section reveals a turnover in the dinoflagellate assemblages and the
appearance of global earliest Danian index species. Geochemical data reveal relatively small
iridium enrichments in the boundary layers of 321 pg/g at mid-Waipara and 176 pg/g at
Compressor Creek. Unradiogenic 187Os/188Os values of the boundary clay reveal the presence
of a significant extraterrestrial component. We interpret the accumulation of Fe nano-phases
at the boundary as originating from both the impactor and the crystalline basement target
rock. The goethite and jarosite are interpreted as secondary phases formed by weathering and
diagenesis. The primary phases were probably controlled by the initial composition of the
vapor plume and condensation kinetics rather than condensation thermodynamics. This
investigation indicates that identification of Fe in nano-phases by Mössbauer spectroscopy is
an accurate and cost-effective method for identifying impact event horizons and it efficiently
complements widely used biostratigraphic and geochemical methods.V. Vajda acknowledges the
financial support provided by the Swedish Royal Academy of Sciences through the Knut &
Alice Wallenbergs Foundation and from the Crafoord Foundation. P.S. Willumsen
acknowledges financial support from the Carlsberg Foundation no.2008_01_0404
Modeling the formation of the K-P boundary layer
Accepted versio
Semiconducting Metal Oxide Based Sensors for Selective Gas Pollutant Detection
A review of some papers published in the last fifty years that focus on the semiconducting metal oxide (SMO) based sensors for the selective and sensitive detection of various environmental pollutants is presented
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