Bartrons M.,University of Wisconsin - Madison |
Bartrons M.,CSIC - Center for Advanced Studies of Blanes |
Grimalt J.O.,Jordi Girona |
Catalan J.,CSIC - Center for Advanced Studies of Blanes
Limnetica | Year: 2012
Persistent organic pollutants (POPs) are toxic substances that are usually produced for use in agricultural, industrial, and domestic applications. Because of their long-range atmospheric transport capacity, POPs are distributed worldwide. The global distillation theory predicts that there will be a temperature-dependent partitioning of these low volatility compounds in the environment. Concentration patterns of POPs in agreement with the theory have been observed for different environmental compartments, such as lake sediments and mosses, and along altitudinal and latitudinal gradients. However, concentration patterns in lake fish do not exactly match the expected results, indicating that further investigation into the bioaccumulation processes in food webs is required. Here, we briefly review the state of the question of POPs bioaccumulation in high mountain lake food webs and present some hypotheses concerning processes worthy of investigation. © Asociacion Iberica de Limnologia, Madrid. Spain.
Cirpka O.A.,University of Tubingen |
Rolle M.,University of Tubingen |
Rolle M.,Stanford University |
Chiogna G.,University of Trento |
And 2 more authors.
Journal of Contaminant Hydrology | Year: 2012
We study plumes originating from continuous sources that require a dissolved reaction partner for their degradation. The length of such plumes is typically controlled by transverse mixing. While analytical expressions have been derived for homogeneous flow fields, incomplete characterization of the hydraulic conductivity field causes uncertainty in predicting plume lengths in heterogeneous domains. In this context, we analyze the effects of three sources of uncertainty: (i) The uncertainty of the effective mixing rate along the plume fringes due to spatially varying flow focusing, (ii) the uncertainty of the volumetric discharge through (and thus total mass flux leaving) the source area, and (iii) different parameterizations of the Darcy-scale transverse dispersion coefficient. The first two are directly related to heterogeneity of hydraulic conductivity. In this paper, we derive semi-analytical expressions for the probability distribution of plume lengths at different levels of complexity. The results are compared to numerical Monte Carlo simulations. Uncertainties in mixing and in the source strength result in a statistical distribution of possible plume lengths. For unconditional random hydraulic conductivity fields, plume lengths may vary by more than one order of magnitude even for moderate degrees of heterogeneity. Our results show that the uncertainty of volumetric flux through the source is the most relevant contribution to the variance of the plume length. The choice of different parameterizations for the local dispersion coefficient leads to differences in the mean estimated plume length. © 2012 Elsevier B.V.
Bru M.,Jaume I University |
Alfonso I.,Jordi Girona |
Bolte M.,Goethe University Frankfurt |
Burguete M.I.,Jaume I University |
Luis S.V.,Jaume I University
Chemical Communications | Year: 2011
An anionic dicarboxylate is able to template the formation of geometrically disfavoured macrocycles from a dynamic covalent mixture of open chain oligoimines. © 2011 The Royal Society of Chemistry.
Rodrigues A.C.M.,University of Aveiro |
Gravato C.,University of Aveiro |
Quintaneiro C.,University of Aveiro |
Barata C.,Jordi Girona |
And 2 more authors.
Environmental Pollution | Year: 2015
Integrative studies focused on sub-organismal responses to pyrethroid exposure are important to understand life history responses. In this study, the ecotoxicological effects of esfenvalerate (ESF) on Chironomus riparius were assessed using five biochemical biomarkers related to neurophysiological function (acetylcholinesterase) and oxidative stress (catalase; glutathione-S-transferase; total glutathione and lipid peroxidation). In addition, effects on cellular energy allocation were assessed and all results were compared with organismal level responses (larval growth, emergence and sex ratio). Exposure to sub-lethal concentrations of ESF caused the failure of C. riparius antioxidant defenses (inhibition of catalase activity and decreased levels of total glutathione), which was reflected as oxidative damage. C. riparius energy budget was decreased by exposure to ESF due to an increased energy consumption. Life cycle tests showed that exposure to ESF impaired C. riparius developmental rates and increased male:female ratios, thereby confirming its toxicity and potential population level effects at environmentally relevant concentrations. © 2015 Elsevier Ltd. All rights reserved.
Campo J.,University of Valencia |
Perez F.,Jordi Girona |
Masia A.,University of Valencia |
Pico Y.,University of Valencia |
And 3 more authors.
Science of the Total Environment | Year: 2015
The occurrence and sources of 21 perfluoroalkyl substances (PFASs: C4-C14, C16, C18 carboxylate, C4, C6-C8 and C10 sulfonates and C8 sulfonamide) were determined in water, sediment, and biota of the Llobregat River basin (NE Spain). Analytes were extracted by solid phase extraction (SPE) and determined by liquid chromatography triple quadrupole mass spectrometer (LC-QqQ-MS). All samples were contaminated with at least one PFAS, being the most frequently found perfluorobutanoate (PFBA), perfluorooctanoate (PFOA) and perfluorooctane sulfonate (L-PFOS). In general, mean PFAS concentrations measured in sediments (0.01-3.67ngg-1) and biota (0.79-431μgkg-1) samples were higher than those found in water (0.01-233ngL-1). L-PFOS presented very high levels in biota and water, particularly in the Anoia River where a maximum concentration of 2.71μgL-1 was related to important industrial activities. However, this pollution does not extend down the Llobregat River according to cumulated values. None of the hazard quotients (HQ) calculated indicate potential risk for the different tropic levels considered (algae, Daphnia sp. and fish). According to Maximum Allowable Concentration (MAC) proposed by the European Commission (L-PFOS) and to Provisional Health Advisory (PHA) values (PFOA, L-PFOS) established by the United States Environmental Protection Agency (US EPA), only two water samples exceeded PHA concentration for L-PFOS. © 2014 Elsevier B.V.