Ejercicio interlaboratorio de bioensayos marinos para la evaluación de la calidad ambiental de sedimentos costeros. IV. Ensayo de toxicidad sobre sedimento con crustáceos anfípodos

9 páginas, 2 figuras, 3 tablas.[EN] Interlaboratory variability was studied for the bioassay using crustacean amphipods. Nine series of data were obtained from different laboratories using four different species (Ampelisca brevicornis, Corophium volutator, Corophium multisetosum and Microdeutopus gryllotalpa), all previously used for sediment toxicity assessment in Spain. Results were studied for interlaboratory variability and according to different confounding factors. The coefficients of variation were similar to those previously reported for this bioassay and sample classification was homogeneous among the laboratories that successfully completed the exercise. No significant tendencies related to test species were identified and it seems that the factor most critically affecting test results and the classification of samples is storage time before testing.[ES] Se estudió la precisión interlaboratorio del bioensayo con crustáceos anfípodos. Se recogieron nueve series de datos procedentes de distintos laboratorios europeos y de cuatro especies distintas (Ampelisca brevicornis, Corophium volutator, Corophium multisetosum y Microdeutopus gryllotalpa), todas ellas usadas previamente para la caracterización de la toxicidad de sedimentos en España. Esos resultados se estudiaron para evaluar la variabilidad interlaboratorio de acuerdo a las diferentes especies y los distintos tiempos de almacenamiento de las muestras antes del ensayo. Los resultados mostraron coeficientes de variación similares a los encontrados en estudios previos y permitieron una clasificación homogénea de las muestras entre los laboratorios que completaron el ejercicio con éxito. No se identificaron tendencias significativas debidas al uso de distintas especies y, al parecer, el factor que puede afectar más críticamente la clasificación de las muestras y, por lo tanto, el uso de los resultados para la toma de decisiones, es el tiempo de almacenamiento de los sedimentos previamente al desarrollo del ensayo.This study was carried out under a joint research project between CEDEX and the University of Cádiz. Part of the work was funded by the Spanish Ministry of Science and Technology REN2002_01699/TECNO). The first author was supported by a grant (FPI) from the Spanish Ministry of Education and Science.Peer reviewe

Metarhizium anisopliae Pathogenesis of Mosquito Larvae: A Verdict of Accidental Death

Metarhizium anisopliae, a fungal pathogen of terrestrial arthropods, kills the aquatic larvae of Aedes aegypti, the vector of dengue and yellow fever. The fungus kills without adhering to the host cuticle. Ingested conidia also fail to germinate and are expelled in fecal pellets. This study investigates the mechanism by which this fungus adapted to terrestrial hosts kills aquatic mosquito larvae. Genes associated with the M. anisopliae early pathogenic response (proteinases Pr1 and Pr2, and adhesins, Mad1 and Mad2) are upregulated in the presence of larvae, but the established infection process observed in terrestrial hosts does not progress and insecticidal destruxins were not detected. Protease inhibitors reduce larval mortality indicating the importance of proteases in the host interaction. The Ae. aegypti immune response to M. anisopliae appears limited, whilst the oxidative stress response gene encoding for thiol peroxidase is upregulated. Cecropin and Hsp70 genes are downregulated as larval death occurs, and insect mortality appears to be linked to autolysis through caspase activity regulated by Hsp70 and inhibited, in infected larvae, by protease inhibitors. Evidence is presented that a traditional host-pathogen response does not occur as the species have not evolved to interact. M. anisopliae retains pre-formed pathogenic determinants which mediate host mortality, but unlike true aquatic fungal pathogens, does not recognise and colonise the larval host

Dietary intake of polychlorinated dibenzo-p-dioxins and furans, adiposity and obesity status

Introduction: The principal source of exposure to Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo-p-furans (PCDD/Fs) in humans comes from food intake. PCDD/Fs, are a family of potential endocrine disruptors and have been associated with different chronic diseases such as diabetes and hypertension. However, studies assessing the relationship between dietary exposure to PCDD/Fs and adiposity or obesity status in a middle-aged population are limited. Objective: To assess cross-sectionally and longitudinally the associations between estimated dietary intake (DI) of PCDD/Fs and body mass index (BMI), waist circumference, and the prevalence/incidence of obesity and abdominal obesity in a middle-aged population. Methods: In 5899 participants aged 55-75 years (48% women) living with overweight/obesity from the PREDIMED-plus cohort, PCDD/Fs DI was estimated using a 143-item validated food-frequency questionnaire, and the levels of food PCDD/F expressed as Toxic Equivalents (TEQ). Consequently, cross-sectional and prospective associations between baseline PCDD/Fs DI (in pgTEQ/week) and adiposity or obesity status were assessed at baseline and after 1-year follow-up using multivariable cox, logistic or linear regression models. Results: Compared to participants in the first PCDD/F DI tertile, those in the highest tertile presented a higher BMI (β-coefficient [confidence interval]) (0.43kg/m2 [0.22; 0.64]; P-trend <0.001), a higher waist circumference (1.11 cm [0.55; 1.66]; P-trend <0.001), and a higher prevalence of obesity and abdominal obesity (1.05 [1.01; 1.09] and 1.02 [1.00; 1.03]; P-trend = 0.09 and 0.027, respectively). In the prospective analysis, participants in the top PCDD/F DI baseline tertile showed an increase in waist circumference compared with those in the first tertile after 1-year of follow-up (β-coefficient 0.37 cm [0.06; 0.70]; P-trend = 0.015). Conclusion: Higher DI of PCDD/Fs was positively associated with adiposity parameters and obesity status at baseline and with changes in waist circumference after 1-year of follow-up in subjects living with overweight/obesity. Further large prospective studies using a different population with longer follow-up periods are warranted in the future to strengthen our results. Keywords: Abdominal obesity; Adiposity; Endocrine disrupting chemicals; Obesity; Polychlorinated dibenzo-p-furans (PCDD/F)

Laboratory scale simulation of CO2 leakages from marine stable geological storage: metal accumulation and biological effects on the benthic organism Ruditapes philippinarum

Trabajo presentado en el 6th SETAC World Congress (2012), celebrado en Berlín del 20 al 24 de mayo de 2012.Nowadays, the injection and storage of CO2 in marine geological stable formations is proposed as one of the potential strategies to decrease the atmospheric CO2 concentrations in order to avoid the abrupt and irreversible repercussions of climate change. Nevertheless, practical implementation of this technical option could produce significant impacts on marine ecosystems due to possible CO2 leakages that may occur during the injection and sequestration procedure. This study aims to quantify the possible effects of variation in sediment pH derived from CO2 leakages on metal bioaccumulation. To this end, a lab scale experiment involving direct release of CO2 was conducted using the model benthic organism, Ruditapes philippinarum. Bivalves were exposed during 10 days to sediment samples under established pH conditions (8.0-6.0). Survival, burrowing activity and metal accumulation (Fe, Co, Pb, Mn, Al, Zn, Cu, Hg and As) on whole body were employed as endpoint. After 10 days of exposure, 100% mortality was observed at pH 6.0. Non significant differences for mortality rate were found in 7.0 and 6. 5 treatments with regard to the control (7.9). Burrowing activity was affected by pH, decreasing the activity at low pH levels. In general, metal concentrations in clam tissues were affected by pH.Peer Reviewe

Influence of sediment acidification on the bioaccumulation of metals in Ruditapes philippinarum

10 páginas, 3 figuras, 1 tabla.Background, aim and scope: The influence of pH (range 6.5–8.5) on the uptake of Zn, Cd, Pb, Cu, Ni, Cr, Hg, and As by juveniles of the clam Ruditapes philippinarum was examined in order to understand whether variation in sediment pH has significant repercussions on metal bioaccumulation. Materials and methods: Clams were exposed to sediments collected in three locations in the Gulf of Cadiz (Huelva, Guadalquivir and Bay of Cadiz) and to contaminated particles derived from an accidental mining spill in Spain. Results: With a notable exception of metal Cd, the concentration of metals within clams significantly increased (p < 0.1) when sediment pH was lowered by one or two units. Moreover, the magnitude of this effect was dependent on the type of sediment contamination. Discussion: Lower pH increases metal solubility and reduces or invert the metal sorption of metals to sediments. Increases in free metal ions in water favors metal uptake by clams, hence pH is an important factor controlling the mobility of these metals within sediments and their subsequent bioaccumulation within biota. Although sediment-water exchange of Cd can increase with acidification, this excess may be counterbalanced by the presence of ligands in seawater preventing the uptake by organism. Besides chlorines, Cd has also an affinity with carbonates and other ligands present in sea water. These Cd-carbonate complexes may reduce the bioavailable to organisms. Conclusions: These results highlight the potential implications of sediment acidification, either due to the storage excess of organic matter or to the forced capture of CO2, on the increasing metal availability to benthic organisms.The described work was partially supported by grants funded by the Spanish Ministry of Science and Innovation (CTM2008-06344-C03-02/TECNO and CTM2008-06344-C03-03/TECNO) and by grant P08-RNM-3924 funded by ‘Junta de Andalucía’. Dra. Inmaculada Riba (Ramon y Cajal contract) thanks the Spanish Science and Innovation program ‘Jose Castillejo’ for supporting her stay at IPIMAR. Judit Kalman also thanks the I3P program for funding her research at ICMAN/CSIC.Peer reviewe

Ejercicio interlaboratorio de bioensayos marinos para la evaluación de la calidad ambiental de sedimentos costeros. V. Ensayo de toxicidad sobre sedimento con juveniles

8 páginas, 1 figura, 3 tablas.[EN] Several species of bivalves and procedures have been used to characterize sediment toxicity. Here we report the results of an interlaboratory exercise that included three different laboratories to evaluate the use of the bioassay using the commercial clam Ruditapes philippinarum. Six different dredged sediments were studied using two different endpoints: lethality after two different exposure periods (7 and 14 days) and burrowing activity after 48 h of exposure. The lethal endpoint was only sensitive to characterize samples with high metallic concentration and following the 14-day exposure period. The burrowing activity showed very variable results that evidence the unsuitability of this endpoint for dredged material characterization. According to these results, a new design is recommended for the test using juvenile bivalves if it is to be used to characterize sediment samples on a regulatory context especially if sediments are not affected by metallic contamination.[ES] Este estudio resume los resultados del ejercicio interlaboratorio realizado en tres laboratorios para evaluar el uso del ensayo con la almeja comercial de Manila Ruditapes philippinarum. Seis muestras de sedimentos dragados se estudiaron mediante dos medidas finales distintas: mortalidad tras dos periodos de exposición distintos (7 y 14 días) y la medida subletal que estudia el porcentaje de organismos enterrados tras 48 h desde el inicio de la exposición. La medida de la letalidad fue sólo sensible tras el periodo más largo de exposición y la contaminación metálica más elevada. La actividad de enterramiento mostró resultados muy variables y altamente dependientes del operador responsable. De acuerdo con estos resultados se recomienda la revisión del protocolo para mejorar su uso en la gestión de dragados portuarios especialmente si se trata de zonas no afectadas por contaminación metálica.Este trabajo fue financiado parcialmente por el Ministerio de Ciencia y Tecnología (REN2002_01699/TECNO). El diseño de los ensayos de toxicidad para la caracterización de material de dragado se realizó mediante un proyecto conjunto entre el CEDEX y la Universidad de Cádiz (2001 y 2003). MC Casado fue financiada por el Ministerio Español de Educación y Ciencia en el programa de Formación de Personal Investigador (FPI).Peer reviewe

Evaluación de la calidad del sedimento en puertos españoles mediante un bioensayo con algas verdes

9 páginas, 4 figuras, 2 tablas.[EN] Coastal zones are under environmental pressure due to human activities, and ports are the areas that probably present the highest levels of contaminants in their sediments. In the present study we have combined chemical data and biological effects to determine the sediment quality of six Spanish ports. Trace metals and organic contaminants have been analyzed, and an acute bioassay was carried out in sediment elutriate using the unicellular green alga Dunaliella tertiolecta. The toxicological parameter employed was EC50, which was estimated after exposure to different concentrations of elutriates during 72 h. The development of this alga may be affected when there is a xenobiotic in the environment, and growth inhibition can be quantified and linked to the levels of contaminants in the sediment in order to determine its quality. The results showed that the metals (Cd, Cr, Hg, and Zn) and organic contaminants (PAHs and PCBs) bound to the sediments reduced the normal growth of the alga, but no alterations were detected due to the presence of Cu. The main disadvantage observed was the hormesis produced by the presence of high levels of organic material in the sediment that might hide the toxicity of xenobiotics.[ES] En la actualidad las áreas costeras están sometidas a una presión ambiental por parte de las actividades humanas y los puertos son las zonas que probablemente presentan los mayores niveles de contaminantes en sus sedimentos. En el presente estudio se han combinado datos químicos y efectos biológicos para determinar la calidad ambiental de los sedimentos de seis puertos españoles. Se llevó a cabo el análisis de metales traza y contaminantes orgánicos además de un ensayo de toxicidad con la microalga marina Dunaliella tertiolecta. El parámetro toxicológico utilizado fue el EC50, calculado a partir de una exposición a distintas concentraciones de lixiviado de sedimento durante 72 h. El desarrollo de este alga verde puede verse afectado con la presencia ambiental de xenobióticos de forma que la inhibición del crecimiento de la población puede ser cuantificada y relacionada con los niveles de contaminantes en el sedimento con el fin de determinar su calidad. Los resultados demostraron que tanto la presencia de metales (Cd, Cr, Hg y Zn) como de contaminantes orgánicos (PAHs y PCBs) en el sedimento afectaron al crecimiento normal del alga mientras que no se detectaron alteraciones por la presencia de Cu. La principal desventaja observada fue el fenómeno de hormesis que ocurre con concentraciones elevadas de materia orgánica en el sedimento enmascarando la toxicidad de los xenobióticos.Este trabajo fue financiado parcialmente por los proyectos PET2006_0685_00, PET2006_0685_01 y PHB2005-0100-PC del Ministerio de Innovación y Ciencia de España. C Morales-Caselles y Á Rico fueron financiadas por el Ministerio Español de Educación y Ciencia en el programa ARGO.Peer reviewe

Risk Assessment of a Coastal Ecosystem from SW Spain Exposed to CO₂ Enrichment Conditions

The Weight-of-Evidence (WOE) approach uses multiple lines of evidence to analyze the adverse effects associated with CO2 enrichment in two stations from the Gulf of Cádiz (Spain) with different contamination degrees. Sediment contamination and metal (loid) mobility, toxicity, ecological integrity, and bioaccumulation from the samples exposed to different acidification scenarios (pH gradient from 8.0 to 6.0) were used in the WOE. The experiments were conducted under laboratory conditions using a CO2-bubbling system. Different integration approaches such as multivariate analyses were used to evaluate the results. The results indicated that the adverse biological effects under pH 6.5 were related to the mobility of dissolved elements (As, Fe, Cu, Ni, and Zn). Furthermore, the pH reduction was correlated to the increase of bioaccumulation of As, Cr, Cu, Fe, and Ni in the tissues of mussels at pH 7.0. The noncontaminated sediment showed environmental degradation related to the acidification at pH values of 7.0; whereas the sediment moderately contaminated showed both environmental risks, caused by acidification and the presence and the increase of the bioavailability of contaminants. The WOE approach supposes an effective tool to identify and distinguish the causes of adverse effects related to the enrichment of CO2 in marine environments

Biological responses on C. maenas caused by sediment properties and pH interactions during CO2 leakage events from sub-seabed injection and storage.

Trabajo presentado en el 10th Iberian Congress on Environmental Contamination and Toxicology y el 7th Iberoamerican Congress on Environmental Contamination and Toxicology (CICTA 2015), celebrados en Vila Real (Portugal) del 14 al 17 de julio de 2015.CO2 capture and storage in sub-seabed geological formations is proposed as one of the potential options to mitigate the abrupt and irreversible consequences of climate change. However, possible CO2 leakages could occur during the injection and sequestration procedure, provoking significant repercussions on marine environment. In this study, we investigate the toxicity effects of acidification derived from possible CO2 leakage events on the European green crab, Carcinus maenas. To this end, a lab-scale experiment involving direct release of CO2 through marine sediment was conducted at expected scenarios of pH values for this kind of events. Crabs were exposed for 10 days to sediments collected from two different coastal areas, one with relatively uncontaminated sediments (RSP) and the other with known contaminated sediments (MZ and ML), under the pre-established pH conditions (8.0-6.1). End points measured were: survival rate, histopathological damages and metal accumulation (Fe, Mn, Cu, Zn, As, Cr, Cd and Pb) in gills and hepatopancreas. Significant associations were observed between pH and the histological damage. Organic matter and organic carbon content as well as Fe, Mn, Cr, Pb, Cd and PAHs concentrations in sediment presented significant correlation coefficients with the damage to gills and hepatopancreas and metal accumulation in both tissues. The results obtained in this study revealed the importance of sediment properties in the biological effects caused by possible CO2 leakage events derived from the implementation of this mitigation option. However, a clear pattern was not observed between metal accumulation in tissues and pH reduction. Animal ́s avoidance behaviour and tolerance degree to acidification may are confounding factors to assess metal bioaccumulation. Further research to find a suitable organism battery, which allows us to predict the possible consequences on human health derived from metal bioaccumulation associated to high CO2 conditions, is required.N

Laboratory simulation of CO2 leakages during injection and storage in sub-seabed geological formations: metal accumulation and toxicity in the model benthic organisms Hediste diversicolor and Ruditapes philippinarum

Trabajo presentado en el 6th Bilateral Seminar Italy-Japan (BIMAT 2014, "Physical and Chemical Impacts on Marine Organisms Supporting Blue Growth in meaningful mutual symbiosis with the marine environment"), celebrado en Palermo el 19 y 20 de noviembre de 2014.The CO2 capture and storage in sub-seabed geological formations is proposed as one of thc potential options to decrease the atmospheric CO2 concentrations. However, possible CO2 leakages could occur during the injection and sequestration procedure, provoking significant repercussions on marine environment. We investiga te, the effe ts of acidification derived from CO2 leakage in the benthic model organisms Hediste diversicolor and Ruditapes philippinarurn. To this end, to independent lab scale experiments involving direct release of CO2 were conducted at possible expected scenarios of pH values between 8.0 and 6.1. Individuals of both species were independently exposed during 10 days lo seawater with sediment samples collected in two different coastal areas, one relatively uncontaminated sediment as reference (RSP) and the other with known contaminated sediment (ML). Survival rate and metal accumulation (Fe, Al, Mn, Cu and Zn) on whole body were employed as endpoint. Furthermore, burrowing activity and histopathological damages were quantified for R. philippinarum. Highly significant associations were observed between pH and the biological effects measured in R philippinarum, exccpt for metal concentrations in tissues. However, for H. diversicolor, mortality was only significant at the lowest pH level in the contaminated sediment andan increase in metal uptake by worms exposed to the contaminated sediment was observed in line with the r duction of pH, Those findings may indicate that bivalves are more vulnerable than polychaetes when they are subjected to possible acidification scenarios caused by C02 leakages.N