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Izquierdo M.,British Geological Survey | Querol X.,CSIC - Institute of Environmental Assessment And Water Research
International Journal of Coal Geology | Year: 2012

Coal-based power generation produces over 750. Mt of coal ash per year globally, but under 50% of world production is utilised. Large amounts of fly ash are either stored temporarily in stockpiles, disposed of in ash landfills or lagooned. Coal ash is viewed as a major potential source of release of many environmentally sensitive elements to the environment. This paper encompasses over 90 publications on coal fly ash and demonstrates that a large number of elements are tightly bound to fly ash and may not be easily released to the environment, regardless of the nature of the ash. This review provides an extensive look at the extent to which major and trace elements are leached from coal fly ash. It also gives an insight into the factors underlying the leachability of elements and addresses the causes of the mobility. The mode of occurrence of a given element in the parent coal was found to play an important role in the leaching behaviour of fly ash. The amount of calcium in fly ash exerts a dominant influence on the pH of the ash-water system. The mobility of most elements contained in ash is markedly pH sensitive. The alkalinity of fly ash attenuates the release of a large number of elements of concern such as Cd, Co, Cu, Hg, Ni, Pb, Sn or Zn among others, but at the same time, it enhances the release of oxyanionic species such as As, B, Cr, Mo, Sb, Se, V and W. The precipitation of secondary phases such as ettringite may capture and bind several pollutants such ash As, B, Cr, Sb, Se and V. © 2011 Elsevier B.V.

Postigo C.,CSIC - Institute of Environmental Assessment And Water Research | Richardson S.D.,University of South Carolina
Journal of Hazardous Materials | Year: 2014

Pharmaceuticals are emerging contaminants of concern and are widespread in the environment. While the levels of these substances in finished drinking waters are generally considered too low for human health concern, there are now concerns about their disinfection by-products (DBPs) that can form during drinking water treatment, which in some cases have been proven to be more toxic than the parent compounds. The present manuscript reviews the transformation products of pharmaceuticals generated in water during different disinfection processes, i.e. chlorination, ozonation, chloramination, chlorine dioxide, UV, and UV/hydrogen peroxide, and the main reaction pathways taking place. Most of the findings considered for this review come from controlled laboratory studies involving reactions of pharmaceuticals with these oxidants used in drinking water treatment. © 2014 Elsevier B.V.

Joshi R.S.,Molecular Biology Institute of Barcelona | Pina B.,CSIC - Institute of Environmental Assessment And Water Research | Roca J.,Molecular Biology Institute of Barcelona
Nucleic Acids Research | Year: 2012

The extent to which the DNA relaxation activities of eukaryotic topoisomerases (topo I and topo II) are redundant during gene transcription is unclear. Although both enzymes can often substitute for each other in vivo, studies in vitro had revealed that the DNA cross-inversion mechanism of topo II relaxes chromatin more efficiently than the DNA strand-rotation mechanism of topo I. Here, we show that the inactivation of topo II in budding yeast produces an abrupt decrease of virtually all polyA+ RNA transcripts of length above ∼3 kb, irrespective of their function. This reduction is not related to transcription initiation but to the stall of RNA polymerase II (Pol II) during elongation. This reduction does not occur in topo I mutants; and it is not avoided by overproducing yeast topo I or bacterial topo I, which relaxes (-) DNA supercoils. It is rescued by catalytically active topo II or a GyrBA enzyme, which relaxes (+) DNA supercoils. These findings demonstrate that DNA relaxation activities of topo I and topo II are not interchangeable in vivo. Apparently, only topo II relaxes efficiently the (+) DNA supercoils that stall the advancement of Pol II in long genes. A mechanistic model is proposed. © 2012 The Author(s).

Tobias A.,CSIC - Institute of Environmental Assessment And Water Research
Environmental health : a global access science source | Year: 2014

Periods of high temperature have been widely found to be associated with excess mortality but with variable relationships in different cities. How these specifics depend on climatic and other characteristics of cities is not well understood. We assess summer temperature-mortality relationships using data from 50 provincial capitals in Spain, during the period 1990-2004. Poisson time series regression analyses were applied to daily temperature and mortality data, adjusting for potential confounding seasonal factors. Associations of heat with mortality were summarised for each city as the risk increments at the 99th compared to the 90th percentiles of the whole-year temperature distributions, as predicted from spline curves. Risk increments averaged 14.6% between both centiles, or 3.3% per 1 Celsius degree. Although risk increments varied substantially between cities, the range of temperature from the 90th to 99th centile was the only characteristic independently significantly associated with them. The heat increment did not depend on other city climatic, socio-demographic and geographic determinants. Cities in Spain are partially adapted to high mean summer temperatures but not to high variation in summer temperatures.

Dentz M.,CSIC - Institute of Environmental Assessment And Water Research
Advances in Water Resources | Year: 2012

We study concentration statistics for tracer transport in the flow through a heterogeneous porous medium. Spatial heterogeneity and temporal variability cause fluctuations in spatial characteristics of the tracer distribution such as the center of mass velocity v(t) and the spreading rate D e(t), which leads to fluctuations in the concentration. These fluctuations can be quantified statistically by the one-point probability density function (PDF) of concentration and by its simplest characteristics, the concentration mean and variance. We focus on the impact of variability in the center of mass velocity and treat D e(t) as deterministic. The fluctuating v(t) is modeled as a Gaussian stochastic process. Based on this stochastic description, we derive explicit expressions for the concentration variance and the full one-point concentration PDF. Their behavior is mainly controlled by the ratio of the spatial variance of the tracer distribution κ e(t) in single realizations and the variance κ m(t) of the plume centroids between realizations. We explore the behavior of concentration variance and PDF for two velocity correlation models, one that leads to a diffusive increase of centroid variance κ m(t) and one that yields an asymptotically constant κ m(t). The obtained results give insight into the dynamics of concentration statistics in heterogeneous media and the mechanisms by which they are controlled. © 2011 Elsevier Ltd.

Babin P.J.,University of Bordeaux 1 | Goizet C.,University of Bordeaux 1 | Goizet C.,Bordeaux University Hospital Center | Raldua D.,CSIC - Institute of Environmental Assessment And Water Research
Progress in Neurobiology | Year: 2014

Motor neuron diseases (MNDs) are an etiologically heterogeneous group of disorders of neurodegenerative origin, which result in degeneration of lower (LMNs) and/or upper motor neurons (UMNs). Neurodegenerative MNDs include pure hereditary spastic paraplegia (HSP), which involves specific degeneration of UMNs, leading to progressive spasticity of the lower limbs. In contrast, spinal muscular atrophy (SMA) involves the specific degeneration of LMNs, with symmetrical muscle weakness and atrophy. Amyotrophic lateral sclerosis (ALS), the most common adult-onset MND, is characterized by the degeneration of both UMNs and LMNs, leading to progressive muscle weakness, atrophy, and spasticity. A review of the comparative neuroanatomy of the human and zebrafish motor systems showed that, while the zebrafish was a homologous model for LMN disorders, such as SMA, it was only partially relevant in the case of UMN disorders, due to the absence of corticospinal and rubrospinal tracts in its central nervous system. Even considering the limitation of this model to fully reproduce the human UMN disorders, zebrafish offer an excellent alternative vertebrate model for the molecular and genetic dissection of MND mechanisms. Its advantages include the conservation of genome and physiological processes and applicable in vivo tools, including easy imaging, loss or gain of function methods, behavioral tests to examine changes in motor activity, and the ease of simultaneous chemical/drug testing on large numbers of animals. This facilitates the assessment of the environmental origin of MNDs, alone or in combination with genetic traits and putative modifier genes. Positive hits obtained by phenotype-based small-molecule screening using zebrafish may potentially be effective drugs for treatment of human MNDs. © 2014 The Authors.

Negreira N.,CSIC - Institute of Environmental Assessment And Water Research | Lopez de Alda M.,CSIC - Institute of Environmental Assessment And Water Research | Barcelo D.,CSIC - Institute of Environmental Assessment And Water Research
Journal of Chromatography A | Year: 2013

A fully automated on-line solid-phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) method has been developed for the determination of 13 cytostatics and 4 metabolites in aqueous matrices, including groundwater, surface water, and raw and treated wastewater. On-line SPE is performed by loading 5mL of water sample at pH 2 through a PLRP-s cartridge. MS/MS is performed with an electrospray (ESI) interface operating in the positive ion mode and registering two selected reaction monitoring (SRM) transitions per compound. Quantification is carried out by the isotope dilution method using 15 different isotope-labelled compounds, specific for the target analytes, as internal standards (IS). The main advantages of the method are high sensitivity, with limits of determination in groundwater, surface water, and raw and treated wastewater below 5ngL-1 for all compounds except for gemcitabine (6.9-9.3ngL-1), temozolomide (26-50ngL-1), imatinib (80-180ngL-1) and etoposide (38-65ngL-1), repeatability, with relative standard deviations (RSDs) in most cases below 15%, and selectivity and reliability of results. The method is also fairly simple and fast, with an analysis time per sample (excluding the manual steps, i.e., sample filtration, pH adjustment, and addition of IS) of 40min. Application of the method to influent wastewater samples collected daily during eight consecutive days from a wastewater treatment plant (WWTP) from Catalonia showed the presence of methotrexate, ifosfamide, capecitabine, tamoxifen and 6(α)-hydroxypaclitaxel but at fairly low concentrations (up to 43ngL-1). © 2013 Elsevier B.V.

Cristale J.,CSIC - Institute of Environmental Assessment And Water Research | Lacorte S.,CSIC - Institute of Environmental Assessment And Water Research
Journal of Chromatography A | Year: 2013

This study presents a multiresidue method for simultaneous extraction, clean-up and analysis of priority and emerging flame retardants in sediment, sewage sludge and dust. Studied compounds included eight polybrominated diphenyl ethers congeners, nine new brominated flame retardants and ten organophosphorus flame retardants. The analytical method was based on ultrasound-assisted extraction with ethyl acetate/cyclohexane (5:2, v/v), clean-up with Florisil cartridges and analysis by gas chromatography coupled to tandem mass spectrometry (GC-EI-MS/MS). Method development and validation protocol included spiked samples, certified reference material (for dust), and participation in an interlaboratory calibration. The method proved to be efficient and robust for extraction and determination of three families of flame retardants families in the studied solid matrices. The method was applied to river sediment, sewage sludge and dust samples, and allowed detection of 24 among the 27 studied flame retardants. Organophosphate esters, BDE-209 and decabromodiphenyl ethane were the most ubiquitous contaminants detected. © 2013 Elsevier B.V.

Zhang X.,CSIC - Institute of Environmental Assessment And Water Research | Tauler R.,CSIC - Institute of Environmental Assessment And Water Research
Analytica Chimica Acta | Year: 2013

The application of the MCR-ALS method is demonstrated on two simulated remote sensing spectroscopic images and on one experimental reference remote sensing spectroscopic image obtained by the Airborn Visible/Infrared Imaging Spectrometer (AVIRIS). By application of MCR-ALS, the spectra signatures of the pure constituents present in the image and their concentration distribution at a pixel level are estimated. Results obtained by MCR-ALS are compared to those obtained by other methods frequently used in the remote sensing spectroscopic imaging field like VCA and MVSA. In the case of the analysis of the experimental data set, the resolved pure spectra signatures were compared to reference spectra from USGS library for their identification. In all cases, results were also evaluated for the presence of rotational ambiguities using the MCR-BANDS method. The obtained results confirmed that the MCR-ALS method can be successfully used for remote sensing hyperspectral image resolution purposes. However, the amount of rotation ambiguity still present in the solutions obtained by this and other resolution methods (like VCA or MVSA) can still be large and it should be evaluated with care, trying to reduce its effects by selecting the more appropriate constraints. Only in this way it is possible to increase the reliability of the solutions provided by these methods and decrease the uncertainties associated to their use. © 2012 Elsevier B.V.

Galban-Malagon C.,CSIC - Institute of Environmental Assessment And Water Research
Nature communications | Year: 2012

Semivolatile persistent organic pollutants have the potential to reach remote environments, such as the Arctic Ocean, through atmospheric transport and deposition. Here we show that this transport of polychlorinated biphenyls to the Arctic Ocean is strongly retarded by the oceanic biological pump. A simultaneous sampling of atmospheric, seawater and plankton samples was performed in July 2007 in the Greenland Current and Atlantic sector of the Arctic Ocean. The atmospheric concentrations declined during atmospheric transport over the Greenland Current with estimated half-lives of 1-4 days. These short half-lives can be explained by the high air-to-water net diffusive flux, which is similar in magnitude to the estimated settling fluxes in the water column. Therefore, the decrease of atmospheric concentrations is due to sequestration of atmospheric polychlorinated biphenyls by enhanced air-water diffusive fluxes driven by phytoplankton uptake and organic carbon settling fluxes (biological pump).

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