79 research outputs found

    Seasonal inputs of polyethoxylated compounds to a Mediterranean coastal lagoon through surface watercourses

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    Synthetic surfactants are among the chemicals that are produced and consumed in the largest volumes in the world (more than 10 million tons per year), due to their variety of applications, mainly as key ingredients in detergents and cleaners but also as additives in paints, pesticides, personal care products, etc. In spite of the high removal efficiences of surfactant residues in sewage treatment plants (STP), significant amounts of these chemicals reach aquatic ecosystems via direct discharges of treated or non-treated wastewaters, or indirect discharges through rivers, where they are present dissolved or associated with particulate material. Therefore, particular attention has been given to the environmental analysis of anionic and non-ionic surfactants (90% of the overall production. Our main objective in this work was to detect the presence and compare the distribution of the most world-wide used non-ionic (alcohol polyethoxylates, AEOs, and nonylphenol polyethoxylates, NPEOs) surfactants, and an important group of nonionic synthetic water-soluble polymers of ethylene oxide, polyethylene glycols (PEGs), which are also used in a wide range of applications (e.g., antifreeze agents, cosmetics) as well as the main precursors / degradation products of AEOs, in waters and sediments from Mar Menor Lagoon (SE Spain). Under our knowledge, some of the data shown here are among the first even reported on the environmental distribution of PEGs in aquatic systems

    SORPTION OF LINEAR ALKYLBENZENE SULFONATES AND SULFOPHENYLCARBOXYLIC ACIDS ON MARINE SEDIMENTS

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    The sorption of linear alkylbenzene sulfonates (LAS) and of their main biodegradation intermediates, sulfophenylcarboxylic acids (SPC) has been characterized in marine sediments. The required equilibrium time for undecylbenzene sulfonate (C11LAS) sorption is 12 h, and 24 h for sulfophenyl undecanoic acid (C11SPC). C11LAS sorption decreases with temperature due to the exothermic character of this process. C11SPC sorption is less complete and less homogeneous than for C11LAS. The alkylic or carboxylic chain length (C10-C13) is correlated positively with the partition coefficient, and the effect of the carboxylic group is more significant than that of the additional methylene group. Sorption of LAS and SPC homologues (C10-C13) are reversible processes. Desorption of SPC homologues is almost complete, but the desorption percentage of LAS homologue decreases with alkylic chain length. Small fractions of sorbed LAS homologues could take longer to be desorbed than the times covered by this study.This research has been supported by the Environmental and Climate Program of the European Commission PRISTINE (Contract ENV4-CT97-494) from Waste Water Cluster and by the Spanish Inter-Ministerial Science and Technology Commission “BALAS” project (CICYT, REN2001-2980-C02-01/HID)

    Distribution of anionic and nonionic surfactants in a sewage-impacted Mediterranean coastal lagoon: Inputs and seasonal variations

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    In this work we have monitored the seasonal inputs, occurrence and distribution of the world’s most widely used surfactants (linear alkylbenzene sulfonates, LAS, nonylphenol polyethoxylates, NPEOs, and alcohol polyethoxylates, AEOs) in Mar Menor lagoon (SE Spain) and its main tributary (El Albujón) for the first time. Concentration of target compounds was determined in both surface waters and sediments after solid phase extraction and pressurized liquid extraction, respectively, followed by liquid chromatography-mass spectrometry (LC-MS). There were significant differences in surfactant fluxes from El Albujón towards Mar Menor depending on the season and the day of the week, with maximum estimated annual inputs being detected for LAS (406 kg) and their metabolites, sulfophenyl carboxylic acids (482 kg). Average concentrations of surfactants in the lagoon were between 44 and 1665 µg/kg in sediment, and between 0.3 and 63 µg/L in water. These levels were significantly higher for samples collected near the shore than for those measured inside the lagoon itself. Overall, the occurrence and distribution of surfactants in the system could be explained due to a combination of different sources (surface and groundwater inputs, treated and untreated wastewater effluents, towns, ports, etc.) and simultaneous in-situ physicochemical and biological processes, with an special emphasis on degradation during warmer months.En prensa3,258

    Factor analysis of linear alkylbenzene sulphonate (LAS) vertical distribution in coastal sediments of Cadiz Bay (southwest Spain)

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    El comportamiento del alquilbenceno lineal sulfonato (LAS) en los sistemas costeros no se conoce con precisión, y este conocimiento es aun menor si nos restringimos al compartimento sedimentario. En este trabajo se aplica un análisis factorial a los resultados obtenidos para distintas variables determinadas en tres estaciones, tanto en sedimento como en agua intersticial, con el objetivo de evaluar sus interrelaciones con el LAS. Las variables analizadas presentan dos modos principales de distribución con la profundidad en el compartimento sedimentario: lineal y/o exponencial. En casi todos los casos, el LAS se asocia a ambos modos de distribución, lo que indica que su concentración sufre una disminución con la profundidad, pero se produce de forma especialmente acusada en la capa superficial.Very little is known concerning the behaviour of linear alkylbenzene sulphonate (LAS) in coastal systems, and even less when we consider the sedimentary field only. In the present study, a factor analysis is applied to the results obtained for different variables at three stations, both in the sediment and in interstitial water, with the aim of evaluating their relationship with LAS. The variables analysed have two main types of distribution in the sedimentary area in relation to depth: linear and/or exponential. LAS is, in most cases, associated with both types of distribution, indicating that its concentration decreases with depth, especially in the surface layer.Instituto Español de Oceanografí

    Environmentally friendly analysis of emerging contaminants by pressurized hot water extraction-stir bar sorptive extraction-derivatization and gas chromatography-mass spectrometry

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    This work describes the development, optimiza- tion, and validation of a new method for the simultaneous determination of a wide range of pharmaceuticals (beta- blockers, lipid regulators ... ) and personal care products (fragrances, UV filters, phthalates ... ) in both aqueous and solid environmental matrices. Target compounds were extracted from sediments using pressurized hot water ex- traction followed by stir bar sorptive extraction. The first stage was performed at 1,500 psi during three static extrac- tion cycles of 5 min each after optimizing the extraction temperature (50 – 150 °C) and addition of organic modifiers (% methanol) to water, the extraction solvent. Next, aqueous extracts and water samples were processed using polydime- thylsiloxane bars. Several parameters were optimized for this technique, including extraction and desorption time, ionic strength, presence of organic modifiers, and pH. Fi- nally, analytes were extracted from the bars by ultrasonic irradiation using a reduced amount of solvent (0.2 mL) prior to derivatization and gas chromatography – mass spectrome- try analysis. The optimized protocol uses minimal amounts of organic solvents (<10 mL/sample) and time ( ≈ 8 h/sam- ple) compared to previous ex isting methodologies. Low standard deviation (usually below 10 %) and limits of de- tection (sub-ppb) vouch for the applicability of the method- ology for the analysis of target compounds at trace levels. Once developed, the method was applied to determin

    Primary care randomized clinical trial: manual therapy effectiveness in comparison with TENS in patients with neck pain

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    This study investigated effectiveness of manual therapy (MT) with transcutaneous electrical nerve stimulation (TENS) to reduce pain intensity in patients with mechanical neck disorder (MND). A randomized multi-centered controlled clinical trial was performed in 12 Primary Care Physiotherapy Units in Madrid Region. Ninety patients were included with diagnoses of subacute or chronic MND without neurological damage, 47 patients received MT and 43 TENS. The primary outcome was pain intensity measured in millimeters using the Visual Analogue Scale (VAS). Also disability, quality of life, adverse effects and sociodemographic and prognosis variables were measured. Three evaluations were performed (before, when the procedure ?nished and six months after). Seventy-one patients (79%) completed the follow-up measurement at six months. In more than half of the treated patients the procedure had a clinically relevant ?short term? result after having ended the intervention, when either MT or TENS was used. The success rate decreased to one-third of the patients 6 months after the intervention. No differences can be found in the reduction of pain, in the decrease of disability nor in the quality of life between both therapies. Both analyzed physiotherapy techniques produce a short-term pain reduction that is clinically relevant.Ministerio de SanidadInstituto de Salud Carlos II

    Genetic Ancestry, Race, and Severity of Acutely Decompensated Cirrhosis in Latin America

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    Background & Aims: Genetic ancestry or racial differences in health outcomes exist in diseases associated with systemic inflammation (eg, COVID-19). This study aimed to investigate the association of genetic ancestry and race with acute-on-chronic liver failure (ACLF), which is characterized by acute systemic inflammation, multi-organ failure, and high risk of short-term death. / Methods: This prospective cohort study analyzed a comprehensive set of data, including genetic ancestry and race among several others, in 1274 patients with acutely decompensated cirrhosis who were nonelectively admitted to 44 hospitals from 7 Latin American countries. / Results: Three hundred ninety-five patients (31.0%) had ACLF of any grade at enrollment. Patients with ACLF had a higher median percentage of Native American genetic ancestry and lower median percentage of European ancestry than patients without ACLF (22.6% vs 12.9% and 53.4% vs 59.6%, respectively). The median percentage of African genetic ancestry was low among patients with ACLF and among those without ACLF. In terms of race, a higher percentage of patients with ACLF than patients without ACLF were Native American and a lower percentage of patients with ACLF than patients without ACLF were European American or African American. In multivariable analyses that adjusted for differences in sociodemographic and clinical characteristics, the odds ratio for ACLF at enrollment was 1.08 (95% CI, 1.03–1.13) with Native American genetic ancestry and 2.57 (95% CI, 1.84–3.58) for Native American race vs European American race. / Conclusions: In a large cohort of Latin American patients with acutely decompensated cirrhosis, increasing percentages of Native American ancestry and Native American race were factors independently associated with ACLF at enrollment

    Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine

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    [This corrects the article DOI: 10.1186/s13054-016-1208-6.]
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