Trace metals and polycyclic aromatic hydrocarbons in the Eastern Mediterranean sediments: Concentration ranges as a tool for quality control of large data collections.

Assessing the status of marine pollution at regional and sub-regional scales requires the use of comparable and harmonized data provided by multiple institutions, located in several countries. Standardized data management and quality control are crucial for supporting a coherent evaluation of marine pollution. Taking the Eastern Mediterranean Sea as a case study, we propose an approach to improve the quality control procedures used for sediment pollution data, thus supporting a harmonized environmental assessment. The regional ranges of contaminant concentrations in sediments were identified based on an in-depth literature review, and the lowest measured concentrations were evaluated to determine the "background concentrations" of chemical substances not yet targeted in the Mediterranean Sea. In addition, to verify the suitability of the approach for validating large data collections provided by multiple sources, the determined ranges were used to validate a regional dataset available through EMODnet data infrastructure.

Modeling of PCB trophic transfer in the Gulf of Lions; 3D coupled model application.

3D coupled modeling approach is used for the PCB dispersion assessment in the Gulf of Lion and its transfer to zooplankton via biogeochemical processes. PCB budgets and fluxes between the different species of PCB: dissolved, particulate, biosorbed on plankton, assimilated by zooplankton, which are governed by different processes: adsorption/desorption, bacteria and plankton mortality, zooplankton excretion, grazing, mineralization, volatilization have been estimated. Model outputs were compared with the available in situ data. It was found that the Rhone River outflows play an important role in the organism contamination in the coastal zone, whereas the atmospheric depositions are rather more important in the offshore zones. The transfer of the available contaminant to bacteria and phytoplankton species is mainly related to the biomass present in the water column. Absorption fluxes (grazing) to zooplankton are rather higher than the passive sorption fluxes, which are themselves also linked to the sorption coefficient.

Historical records of mercury, lead, and polycyclic aromatic hydrocarbons depositions in a dated sediment core from the Eastern Mediterranean.

Depth profiles of mercury, lead and its stable isotopes, and polycyclic aromatic hydrocarbons were determined in a dated sediment core from the Levantine basin. Sedimentary records show that preindustrial fluxes and levels of Hg, Pb, and PAHs remained generally constant in the region before 1850. An almost concurrent uniform increase of both metals and PAHs deposition occurring at the beginning of the Industrial Revolution suggests coal combustion as a main source of these contaminants in the Levantine basin after the 1850s. However, none of the contaminant profiles indicates a decline after 1950-60, the characteristic period of coal use reduction. The modern fluxes of Hg and Pb reveal a 3- to 5-fold increase over preindustrial loads, while the contemporaneous flux of PAHs rises by 4-7 times. On the whole, records in the Eastern Mediterranean suggest atmospheric inputs from relatively distant sources, likely from Central and Eastern Europe.

Occurrence of priority and emerging organic compounds in fishes from the Rhone River (France).

The main objective of this study was to collect new data on the occurrence, levels of priority and emerging organic compounds in freshwater fish sampled in the Rhone River. The 34 studied contaminants included alkylphenols, bisphenol A, polybromodiphenylethers (PBDE), perfluorinated compounds, hexabromocyclododecanes (HBCD), hexachlorobenzene and hexachlorobutadiene (HCBD). About 50 fish samples (individual specimens or pooled fish) were collected from three sites located upstream and downstream of the Lyon metropolitan area in the Rhone River (France). Four species were caught at each site, namely: the barbel (Barbus barbus), the common bream (Abramis brama), the white bream (Blicca bjoerkna) and the chub (Squalius cephalus). Some contaminants were quantified in all the 32 fish samples analysed: 4-nonylphenol, α-HBCD, the six PBDE congeners (28, 47, 99, 100, 153, 154), perfluorooctanesulfonate (PFOS) and perfluorodecanoic acid. Twenty three of the 32 samples had a concentration of PFOS above the Environmental Quality Standards (EQS) (up to six times higher than the EQS), and all the 32 samples had concentrations of PBDE above the EQS (up to 4,000 times higher, with the sum of six PBDE varying from 4.5 to 182 ng/g dry weight). Clearly, the interest to consider PFOS and HBCD as new priority substances is confirmed. In contrast, the pertinence of a priority status for HCBD, which was never quantified in our study, might have to be reconsidered in the future.

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in marine mussels from French coasts: levels, patterns and temporal trends from 1981 to 2005.

The levels and temporal trends of toxic polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were determined in archived marine mussels collected between 1981 and 2005 from selected sites along French coasts. The geographical distribution and levels of PCDD/Fs generally reflect regional inputs of these contaminants: the highest concentrations were determined in samples from the Seine river estuary (English Channel) and Toulon area (Mediterranean coast); the lowest levels were determined in Corsica (Mediterranean Sea). PCDD/F isomeric composition showed a fairly homogeneous distribution pattern throughout the various sampling sites. This pattern, dominated by 2,3,7,8-TCDF and OCDD, can be considered as typical for the study species. However, on a more local scale, some differences in isomeric composition in mussels were identified in relation to local source characteristics. The time trend study showed a pronounced decrease in PCDD/F concentrations over the 24-year period at most sites, except Toulon on the Mediterranean Sea, where the decrease was not significant. This overall decrease probably reflects the general drop in PCDD/F emissions in Europe since 1980. However, high concentrations were determined in mussels collected in recent years (1999, 2001 and 2005) from the mouth of the Seine river. These concentrations are related to particular hydrological conditions, and intensive sediment dredging due to a new port construction at the mouth of the estuary. The results presented in this paper provide reference data on the contamination of shellfish by persistent organic pollutants in the marine environment.

PCDD/F and PCB multi-media ambient concentrations, congener patterns and occurrence in a Mediterranean coastal lagoon (Etang de Thau, France).

Ambient concentrations, congener patterns and multi-media distribution of PCDD/Fs and PCBs were determined in air, water, sediment and mussels in a semi-enclosed marine ecosystem (Thau lagoon, France). Sigma2,3,7,8-PCDD/F and sigma7ICES PCB air concentrations (0.2-1.4 and 31-57 pg m(-3), respectively) were typical of rural areas. Concentrations in the water column were very low for PCDD/Fs (163-476 fg L(-1)) and low for PCBs (138-708 pg L(-1)). PCDD/F and PCB concentrations found in surface sediment (0.15-1.6 and 2.5-33 ng g(-1) d.w., respectively) and mussel (13-21 pg g(-1) d.w. and 10-39 ng g(-1) d.w., respectively) were medium levels. PCDD/F congener patterns observed in air, water particulate phase and sediments were similar suggesting direct coupling among these compartments and atmospheric inputs of PCDD/Fs into the lagoon. Conversely, for the same set of samples, similar patterns were not observed for PCBs in the mentioned compartments.