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J M Forja

Publications and source records attributed to J M Forja.

11 recordsLinked to original sources
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↗
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↗
PubMed2003

The behaviour of heavy metals from the Guadalquivir estuary after the Aznalcóllar mining spill: field and laboratory surveys.

The spill at 'Los Frailes' caused a large input of metals into the riverine, estuarine and coastal ecosystems. Metal behaviour in natural waters can be studied both by performing field measurements, and by undertaking laboratory simulation experiments. Here is described the behaviour of the heavy metals Zn, Cd, Pb and Cu in the Guadalquivir estuary using incubation experiments and the results compared to those obtained during field assessments. If the toxic waste water had been discharged untreated into the environment, it could have raised the heavy metal concentrations in the estuary water to high values, such as 20.65 microM for Zn and 40 x 10(-3) microM for Cd. These values are several times higher than those obtained in samples collected in the area during the monitoring of the early impact. The metals present a non-conservative behaviour, with a high loss to waters of low salinity values.

Ecosystem↗
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↗
PubMed2002

Evaluating the heavy metal contamination in sediments from the guadalquivir estuary after the Aznalcóllar mining spill (SW Spain): a multivariate analysis approach.

The Doñana National Park is one of the most important Natural Reserves in west Europe. The park and the Guadalquivir estuary were impacted by the release of 5 million cubic meters of acid waste from the processing of pyrite ore. Here are presented a multivariate analysis approach to evaluate the extension and the magnitude of the accidental spill on the estuarine sediments. Sediments were used to analyze 6 different metals (Fe, Mn, Zn, Cd, Pb, Cu). Also the concentration of the metals in the different geochemical sediment fractions were determined as a means of assessing the potential impact of the acid water from the mine. The analysis of the results obtained permits to establish that the impact of the accident was acute on the ecosystem due to the set up of a treatment plan in June 1998 and to the high hydrodynamic of the estuary that absorb the early impact. Chronic contamination by Cu was also detected during the monitoring of the impact of the accident in the estuary but this did not appear to be related to the accidental spill. Because the likelihood of long term adverse effects from the heavy metal contamination of estuarine sediments, further ecotoxicological evaluations should be carried out for the estuary and the park using an integrated approach.

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↗