Search

Among the numerous PCB congeners, most of the dioxin-like PCBs (DL-PCBs) need to be characterized by hyphenated techniques. It has been shown in several instances that these congeners are well related to the total PCB content in fish. We examined datasets collected mainly in France, on freshwater and marine fish and sediments. A statistical model linking DL- and indicator PCBs was developed for a dataset composed of freshwater fishes, and proved to predict well DL-PCBs from indicator PCBs in all other fish sets, including marine ones. Type II error rates remained low in almost all fish sets. A similar correlation was observed in sediments. Non-dioxin-like PCBs elicit various adverse effects and represent 95% of the total PCBs. A European guideline for them is needed; the correlation between DL- and indicator PCBs could help develop this standard in the future. [Copyright &y& Elsevier]

Specimens of the mussel Perna perna were collected along Moroccan coasts to determine the concentrations of polycyclic aromatic hydrocarbons (PAHs) bioaccumulated in the tissues, and to measure benzo[ a ]pyrene hydroxylase (BPH) activity. Chemical analysis of PAHs show that the Mediterranean (Nador, Martil, Tanger) and central Atlantic coasts (from Rabat to Jorf Lihoudi) are those most contaminated (351 245 ng.g - 1 dry weight in Tanger). The mussel contaminants were of mixed origin for most of the locations with non negligible inputs of petrogenic origin in many of them. Baseline levels of PAHs were between 6 and 55 ng.g - 1 dry weight. BPH activity showed significant correlation (r s = 0.64, P [ABSTRACT FROM AUTHOR]

Biomarkers are now proposed for evaluation and control of the health of marine ecosystems (Narbonne et al. 1991; Labrot et al. 1996; Pellerin - Massicotte 1994; Mora et al. 1999). At present, they are extensively used in international programs of pollution monitoring (McCarthy and Shugart 1990; Narbonne et al. 1999). However, the ability of biological and biochemical parameters for the biomarker approach is closely related to the choice of sentinel species. Among marine organisms, mussels appeared to be one of the most appropriate candidates for use as sentinel species. These animals are suspension feeders, ubiquists, sedentary, bioaccumulators, able to survive in heavy contaminated areas and are easily handled (collection and caging). Research in this field has been carried out on these bivalves (Narbonne et al. 1991; Burgeot et al. 1996; Boucquené 1996; Najimi et al. 1997). But, these mollusks are strictly present in rocky substrate and they can't be used for pollution survey in sandy beach ecosystems. The aim of this work was to study a mollusk, Donax trunculus, as a sentinel species of sandy beaches. This mollusk, living in the sediment and largely distributed in West-African and West-European Atlantic and Mediterranean costs, exhibits the same characteristics as other mussels in that they are suspension feeders as well as potential bioaccumulators (Ansell, 1983). [ABSTRACT FROM AUTHOR]

The newt larvae (Pleurodeles waltl) stage 48-49 in the development table of Gallien and Durocher (1) were exposed for 30 days to sediment previously contaminated with individual 14 C-labeled polycyclic aromatic hydrocarbons (PAHs), including anthracene (Ant), phenanthrene (Phe), pyrene (Pyr), and benzo[ a ]pyrene (B a P). Toxicokinetic parameters (uptake and depuration rate constants) were measured. The rate of radioactivity release was measured under both contaminated (Experiment 1) and clean conditions (Experiment 2). The results confirmed that uptake and depuration rate constants were strongly related to physicochemical properties including the number of rings, molecular weight, octanol-water coefficient partition ( K OW ), and water solubility. The highest uptake rate was observed with a low-molecular-weight compound (Ant). Comparatively the uptake rates for Phe, Pyr, and B a P were 17%, 48%, and 95% respectively, all lower than that for Ant. The rank order of PAH depuration rate constants from P. waltl was Phe > Ant > Pyr > B a P under both clean and contaminated conditions. The results also indicate that the depuration rate constants seemed to depend on the PAHs' bioavailability potential and their initial concentration in larvae at the beginning of the depuration phase. Thus when the initial concentration of pollutants in the animal were very weak (example: B a P), the depuration rate constants were in the same range for Experiments 1 and 2. In contrast when the PAHs' initial bioconcentrations were relatively high like for Ant, Phe, and B a P, their elimination from the larvae remained from 1.5-fold to 2-fold faster under Experiment 1 than under Experiment 2. [ABSTRACT FROM AUTHOR]

Validates several biochemical parameters as biomarkers of pollution in the freshwater bivalve Corbicula fluminea. Exposure of the bivalve to trichloroethylene, toluene and cadmium chloride; Exhibition of oxidative stress and components of phase I metabolism; Conduction of discriminant analysis.

Investigates the presence of micropollutants in the Gironde estuary, France. Presence of metallic and organic pollutants; Examination of sediments as a source of pollutants for the biota; Estimation of Cd mobility.

Abstract: In the present study, Hediste diversicolor biotransformation and anti-oxidant responses to acute exposure to cadmium (Cd) and to the polycyclic aromatic hydrocarbons benzo[a]pyrene (B[a]P) were investigated. Worms were submitted to 0.2, 0.4 and 1μM of each contaminant and to their mixture during a period of test of 48h. Following biological responses were measured: (1) NADPH cytochrome c reductase (NADPH cyt c) activity, as phase I biotransformation parameter; (2) gluthathione-S-transferase (GST) activity as a phase II conjugation enzyme, (3) catalase activity as anti-oxidant response and (4) malondialdehyde accumulation (MDA) as lipid peroxydation marker. The cholinergic system was evaluated using the acetylcholinesterase activity (AChE). Exposure to the mixture resulted in low dose level additive effects on the investigated biomarkers. However, worms exposed to 1μM of the single compounds and to their mixture exhibited the highest MDA accumulation and the lowest enzymatic biomarkers activities suggesting severe toxicological effects. These data should be carefully considered in view of the biological effects of mixture pollutants and particularly in marine sediment ecosystems. [Copyright &y& Elsevier]

Abstract: Environmental pollutants with hormonal activity including bisphenol, diallyl phtalate and tetrabromodiphenyl ether, have the potential to alter gonadal development and reproduction in aquatic wildlife. Little is known about the biological impact of environmentally relevant concentrations in mussels. To investigate some aspects of their potential estrogenic action, mussels were continuously exposed during 3 weeks. Gonadal development and vitellogenin like protein levels were examined. Bisphenol (50μg/l) induced the expression of phospho-proteins in females and spawning in both sexes. Diallyl phthalate and tetrabromodiphenyl ether decreased phospho-protein levels in both sexes and induced spawning in males. Moreover, severe damaging effects on ovarian follicles and ovocytes were observed in both bisphenol A- and tetrabromodiphenyl ether-exposed female mussels. [Copyright &y& Elsevier]