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T A DelValls

Publications and source records attributed to T A DelValls.

15 recordsLinked to original sources
PubMed2006

Comparative sediment quality assessment in different littoral ecosystems from Spain (Gulf of Cadiz) and Brazil (Santos and São Vicente estuarine system).

The goal of this work was to establish comparisons among environmental degradation in different areas from Southern Spain (Gulf of Cádiz) and Brazil (Santos and São Vicente estuary), by using principal component analyses (PCA) to integrate sediment toxicity (amphipods mortality) and chemical-physical data (Zn, Cd, Pb, Cu, Ni, Co, V, PCBs, PAHs concentrations, OC and fines contents). The results of PCA extraction of Spanish data showed that Bay of Cádiz, CA-1 did not present contamination or degradation; CA-2 exhibited contamination by PCBs, however it was not related to the amphipods mortality. Ría of Huelva was the most impacted site, showing contamination caused principally by hydrocarbons, in HV-1 and HV-2, but heavy metals were also important contaminants at HV-1, HV-2 and HV-3. Algeciras Bay was considered as not degraded in GR-3 and -4, but in GR-3' high contamination by PAHs was found. In the Brazilian area, the most degraded sediments were found in the stations situated at the inner parts of the estuary (SSV-2, SSV-3, and SSV-4), followed by SSV-6, which is close to the Submarine Sewage Outfall of Santos - SSOS. Sediments from SSV-1 and SSV-5 did not present chemical contamination, organic contamination or significant amphipod mortality. The results of this investigation showed that both countries present environmental degradation related to PAHs: in Spain, at Ría of Huelva and Gudarranque river's estuary areas; and in Brasil, in the internal portion of the Santos and São Vicente estuary. The same situation is found for heavy metals, since all of the identified metals are related to toxicity in the studied areas, with few exceptions (V for both Brazil and Spain, and Cd and Co for Brazilian areas). The contamination by PCBs is more serious for Santos and São Vicente estuary than for the investigated areas in Gulf of Cádiz, where such compound did not relate to the toxicity.

Animals↗
PubMed2006

Liquid versus solid phase bioassays for dredged material toxicity assessment.

Since 1994 the results of the analyses of key chemical compounds (trace metals, polychlorinated biphenyls and polycyclic aromatic hydrocarbons) and the comparison with the corresponding sediment quality guidelines (SQGs) are used in decision-making for dredged material management in Spain. Nonetheless in the last decades a tiered testing approach is promoted for assessing the physical and chemical characteristics of dredged sediments and their potential biological effects in the environment. Bioassays have been used for sediment toxicity assessment in Spain but few or no experiences are reported on harbour sediments. We studied the incidence of toxicity in the 7 d bioassay using rotifers (Brachionus plicatilis) and the 48 h bioassay using sea urchin (Paracentrotus lividus) embryos over a series of experiments employing 22 different elutriates. The relative performance of this exposure phase was not comparable to data on the 10-d acute toxicity test using the burrowing amphipod Corophium volutator and the polychaete Arenicola marina, carried out on the whole sediments. These results evidence the importance of the exposure route and the test selected in decision-making, as the toxicity registered for the undiluted elutriates was largely due to the different solubility of sediment-bound contaminants. This work and other studies indicate that for many sediments, a complete battery of test is recommended together with physico-chemical analyses to decide whether dredged sediments are suitable for open water disposal or not.

Animals↗
PubMed2006

Comparing sediment quality in Spanish littoral areas affected by acute (Prestige, 2002) and chronic (Bay of Algeciras) oil spills.

The quality of sediments collected from two areas of the Spanish coast affected by different sources of contaminants has been compared in this study. The areas studied are the coast of Galicia affected by the oil spill from the tanker Prestige (November 2002) and the Gulf of Cádiz which suffers continuous inputs of contaminants from industries located in the area and from oil spills. Contamination by several chemicals (metals, PCBs and PAHs) that bind to sediments was analyzed, and two toxicity tests (Microtox) and amphipod 10-day bioassay) were conducted. PAHs were identified as the compounds responsible for the toxic effects. Results show differences between an acute impact related to the sinking of the tanker Prestige and the chronic impact associated with continuous oil spills associated with the maritime and industrial activities in the Bay of Algeciras, this being the most polluted part of the two coastal areas studied in this work.

Amphipoda↗
PubMed2005

Effect of sediment turbidity and color on light output measurement for Microtox Basic Solid-Phase Test.

In this work, sediment samples collected from several Spanish harbours were tested with two toxicity procedures, designed for solid samples: the Microtox Basic Solid-Phase Test (BSPT) and a modified procedure of the previous test protocol (mBSPT). According to the BSPT procedure, after initial light readings, pure bacteria were exposed to sediment suspension dilutions and light production was directly measured on suspended sediments without any further manipulation. As measurements are likely to be affected by sediment turbidity and color, a variation in initial light measurement has been here suggested, in order to consider the sample effect at all time readings during the test. Firstly, when sediment suspensions at different concentrations were added to bacteria suspension, immediately the initial light output drastically decayed by more than 50% in signal difference, resulting in a false inhibition, as effect of sample turbidity/color. This effect was more evident at high EC50 values, when slightly or not toxic samples were assessed. Secondly, the comparison of the EC50 obtained with both procedures, demonstrated that the mBSPT produced higher EC50 values (less toxic) than those obtained with the standard procedure. The mBSPT procedure resulted rapid and effective and it could be applied simultaneously with BSPT, in order to better evaluate the toxicity.

Algorithms↗
PubMed2005

Linking sediment chemical and biological guidelines for characterization of dredged material.

Dredged material management in Spain and possible options for the different categories is discussed according to chemical sediment quality guidelines. Also an approach using an integrated assessment that includes biological end points as part of a tiered testing schema is discussed for future implementation in Spanish recommendations. To establish the feasibility of using both kinds of guidelines, an example of the utility and validity of the approach that links both chemical and biological guidelines proposed for the management of dredged material characterization processes data from a particular case study associated with a port in the north of Spain are discussed. The use of both kinds of methodologies, together with the necessity of assessing the bioavailability of some contaminants, has been shown as a powerful tool for the best selection of different disposal options of dredged material in the case study described.

Biological Availability↗
PubMed2004

Sediment quality in the Guadalquivir estuary: lethal effects associated with the Aznalcóllar mining spill.

Monitoring from 1998 to 2001 has assessed the impact of the Aznalcóllar mining spill on the sediment quality in the Guadalquivir estuary. Chemical analysis has been completed with biological effects measured in different organisms. The toxicity of sediments obtained from dilutions of toxic mud and from environmental stations affected by the accidental spill was tested using the amphipod Ampelisca brevicornis and the clam Scrobicularia plana. The results obtained show that amphipods are more sensitive to the accidental spill than the clams. A dilution of clean sediment by more than 1.8% of toxic mud produced 100% mortality of amphipods. In GR2 station is detected toxicity to amphipods but not to clams. The rest of the environmental stations show no toxicity. Toxicity to amphipods in GR2 station decreased along time (from 50% to 60% of mortality in 1998 to 10 to 15% in 2001) and it can be associated with a recovery of the areas impacted by the accidental spill.

Accidents↗
PubMed2004

Sediment quality in the Guadalquivir estuary: sublethal effects associated with the Aznalcóllar mining spill.

As a complementary assessment of the impact of the Aznalcóllar mining spill on the Guadalquivir estuary two different sediment toxicity tests using fish (Solea senegalensis) and clams (Scrobicularia plana) were performed. The histopathological alterations by recording lesions at 15 and 30 days in fish to the gills, liver, gut and kidney and at 14 days in clams to the gills and gut were used to determine the adverse effects associated with the contaminants bound to sediments. The lesions measured at different tissues in both organisms show that the enrichment of heavy metals from the mining spill stressed some areas in the ecosystem of the estuary. The comparison of these effects with those lethal effects detected in the same samples using a multivariate analysis approach permits to identify the adverse effects associated with the accidental spill on the estuary. The incidence of the impact, located in specific areas of the estuary show an acute effect related to the spill.

Accidents↗
PubMed2002

Influence of the Aznalcóllar mining spill on the vertical distribution of heavy metals in sediments from the Guadalquivir estuary (SW Spain).

The Natural Park of Doñana and the Guadalquivir estuary were impacted by the release of 6 million cubic meters of acid waste after the mine-tailing spill in Aznalcóllar (Andalusia, SW, Spain). Here is presented the monitoring of the accidental spill on vertical distribution of heavy metals in the estuarine sediments. The total concentration of six metals (Fe, Mn, Zn, Cd, Pb, Cu), their chemical speciation and the organic carbon concentration were analyzed in sediment vertical profiles. The results obtained determine background levels similar to previously reported in the area. The analysis catalogues the impact of the accident on the estuary as acute and mainly associated with high concentrations of Zn and Cd. The recent enrichment in Zn and Cd and their geochemical association with the more mobile fractions of the sediment determine an environmental risk associated with the acute impact and detected in some of the areas of the estuary.

Accidents, Occupational↗
PubMed1998

Evaluation of heavy metal sediment toxicity in littoral ecosystems using juveniles of the fish Sparus aurata.

The toxicity of sediments from two littoral ecosystems of the Gulf of Cadiz was tested using juveniles of the fish Sparus aurata (seabream). Concentrations of total carbon and nitrogen, organic carbon, 14 heavy metals (Fe, Mn, Cu, Zn, Pb, Cd, Ag, Hg, As, Sn, V, Ni, Co, Cr), and the surfactant linear alkyl benzenesulfonate (LAS) in the sediments were measured. Chemical analysis was performed in the stations to determine the degree and nature of contamination. Four different endpoints were selected in the toxicity test: survival, superficial alteration, hematocrit analysis, and histological damage. After 14 days, survival, superficial alteration, and hematocrit analysis did not reveal effects of the different sediments tested. The histological and cellular damage revealed a more sensitive response to measured chemicals in sediments and they were found to be a powerful tool to evaluate sediment toxicity effects. Semiquantitative evaluation of the histological damage demonstrated correlation with sediment concentrations of some of the heavy metals (Cr, Cd, Pb, Ag, Cu) and the surfactant (LAS). Data derived from chemical concentrations and toxicity tests were assembled by multivariate statistical techniques (principal components analysis) to identify the ranges of chemical concentrations associated with an adverse effect. The results obtained, as suggested by site-specific sediment quality values, were the following: Cr>/=90.2; Cd>/=1.24; Pb>/=52.5; Ag>/=0.68; Cu>/=71.2; LAS>/=8.7 mg kg-1 of dry sediment. These results are mainly in concordance with studies performed in other areas of the world and therefore support wide application of the method.

Animals↗
PubMedDate not supplied

Simulating a heavy metal spill under estuarine conditions: effects on the clam Scrobicularia plana.

We describe the effect of heavy metals Zn, Cd, Pb and Cu on the induction of methallothioneins on the clam Scrobicularia plana along a salinity gradient simulated under laboratory conditions. The clams were exposed to constant heavy metal concentrations in a dynamic estuary simulator during a 15-day assay to investigate possible induction of metal-binding proteins in them. The concentration of heavy metals in water was analysed. Clams were analysed for methallothionein concentrations. The speciation of Zn, Cd, Pb and Cu along the salinity gradient was modelled. Zn showed the highest concentrations and its prevalent species was the free ion. Intersite differences have been observed in methallothionein concentration and related to the salinity gradient. It seems that synthesis of methallothioneins is the result of physiological forces acting in concert with the changes in the chemical speciation of metals, owing to the trace metals uptake is controlled by means of an interaction of physiology and physicochemistry.

Animals↗
PubMedDate not supplied

Bioavailability of heavy metals bound to sediments affected by a mining spill using Solea senegalensis and Scrobicularia plana.

After the Aznalcóllar mining spill (April, 1998) different ecosystems along the Guadiamar river and the Guadalquivir estuary were impacted by high concentrations of metals. The concentration of metals Zn, Cd, Pb, Cu and As has been detected as a good tracer of the pathway of the toxic spill. Different individuals of the fish Solea senegalensis and the clam Scrobicularia plana were exposed to contaminated sediments after the accidental spill in the south-west Spain. The induction of metallothioneins in fish and the bioaccumulation of metals in clams were determined in different tissues to determine the biological adverse effect associated with the heavy metals from the spill. A relationship between the enrichment of metals in the tissues and the induction of metallothioneins was determined for those assays performed using contaminated sediments. The bioaccumulation of metals indicates that the risk associated with the spill should be continuously evaluated to establish the sublethal effects related to the accident.

Animals↗
PubMedDate not supplied

Toxicokinetics of heavy metals from a mining spill using Carcinus maenas.

The knowledge of the reproduction and growth background related to the shore crab Carcinus maenas promotes the use of this crab as a model crustacean to asses the potential for endocrine disruption in crustaceans. In addition, an enzyme linked inmunosorbent assay (ELISA), sensitive to the shore crab vitellogenin in serial hemolymph samples allows determination of the extent of disruption of the process of vitellogenesis in female crabs and its likely impact on reproductive output. Intermoult females Carcinus maenas were exposed to concentrations of Cd: 3 microgl(-1), Cu: 15 microgl(-1) and Zn: 700 microgl(-1) determined at the Guadalquivir estuary after the Aznalcóllar mining spill, during 21 days. Crab hemolymph samples, were taken every seven days, and analyzed through an ELISA for Carcinus maenas vitellogenin. Vitellogenin concentration along the time was fitted to a first order kinetic approach. Results showed a good correlation among experimental values and estimated ones. Metal exposure resulted in an increase in vitellogenin concentration in hemolymph, especially for cadmium.

Animals↗