Jacek Tronczynski

Polyaromatic hydrocarbon (PAH) distributions in the Seine River and its estuary

Dissolved and particulate PAHs were quantified throughout the Seine River and its estuary. Samples were collected in October 1993, covering a salinity gradient of 0.2‰ to 34.8‰. Two mooring stations were occupied at the river mouth to ascertain the influence of tidal cycles on the dispersal of riverborne PAHs. Total particulate PAH concentrations ranged from 2 to 687 ng l−1 (or 1 to 14 μg g−1). Concentrations were correlated to the suspended matter load and distributions could be explained by estuarine mixing. PAH levels decreased from ebb to flood tides. PAH concentrations in the dissolved phase (4 to 36 ng l−1) were, in general, an order of magnitude lower than in the particulate phase. The partition coefficient of individual PAHs (Koc) were comparable to those previously reported for the Rhone River suspensions.

Herbicide contamination of Mediterranean estuarine waters: Results from a MED POL pilot survey☆

Abstract The reported data offers the first extensive evidence that significant concentrations of some herbicides persist in marine systems. In the areas studied (the Ebro delta on the Eastern Coast of Spain, the Rhone delta in the South of France, the River Po, Italy/the Northern Adriatic Sea, the Thermaikos and Amvrakikos Gulfs in Greece and the Nile delta in Egypt) the most commonly encountered herbicides were atrazine, simazine, alachlor, metolachlor and molinate. In general, aqueous concentrations encountered in the riverine inputs were comparable to (or below) those reported for rivers in other regions of the World. Concentrations generally declined from freshwater locations through estuaries to marine waters. The distributions of some herbicides (e.g. the triazines) in sediments endorsed the environmental persistence of these compounds. In contrast to the other areas studied, no herbicides were detected in samples from a preliminary survey of the Nile delta.

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.

PCDD/F, PBDE, and nonylphenol contamination in a semi-enclosed bay (Masan Bay, South Korea) and a Mediterranean lagoon (Thau, France).

Chemical contamination of the coastal marine environment by polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) was assessed along with emerging contaminants such as polybrominated diphenyl ethers (PBDEs) in an industrially well-developed country (France) and a fast-developing country (Korea). Other chemicals, i.e. nonylphenol (NP) and 5 beta(H)-cholestan-3beta-ol (coprostanol) were determined to trace industrial waste and/or domestic inputs. These compounds were analyzed in coastal sediments and mussels in two enclosed coastal water bodies: Masan Bay (South Korea) and Thau lagoon (France). The overall levels of target organic contaminants were higher in Masan Bay than in Thau lagoon. The mean concentrations of 17 PCDD/Fs, 13 PBDEs, NP and coprostanol in Masan Bay sediments were, respectively, 1.3, 11, 248 and 291 ng g(-1) dry weight (d.w.); in Thau lagoon sediments they were, respectively, 0.39, not detectable (nd), 23 and 395 ng g(-1)d.w. Mean concentrations in mussels (coprostanol and cholestanol were not measured) were 0.0093, 13, 140 ng g(-1)d.w. in Masan Bay and 0.016, 0.94, 38 ng g(-1)d.w. in Thau lagoon. Principal component analysis of the contaminants and chemical tracers indicates possible point sources of pollution for Masan Bay and Thau lagoon. This study highlights a growing pollution problem in Asia and in particular a tremendous uptrend in Korea, in comparison to more controlled discharges and releases in Western Europe.

Monitoring of trace-levels of herbicides and their degradation products in the river Rhône, France, by gas chromatography-mass spectrometry

Sampling of 5 liters of river Rhone water in each of seven stations located at the Camargue region took place in November 1990 during an oceanographic cruise (Dypole 7) organized within the French scientific programme GDR-ICO (Groupement De Recherche, Interface Continent Ocean, CNRS). After sampling was completed, water samples were filtered through fiberglass filters and two fractions corresponding to dissolved and particulate matter were obtained. Dichloromethane was used for the liquid-liquid extraction of chlorotriazines dissolved in water with further quantitation by selected ion monitoring (SIM) gas chromatography-mass spectrometry (GC-MS). Concentrations of atrazine in the range of 12–30 ng/l and 1 ng/l in the dissolved and suspended phase, respectively, were found. Such levels were compared with previously reported data from other rivers and have been related with the distribution coefficients Koc. An estimation of the loss of applied atrazine in the Rhone basin is also reported.

Differential biomagnification of PCB, PBDE, Hg and Radiocesium in the food web of the European hake from the NW Mediterranean

Consumption of marine organisms represents one of the main exposure sources of contaminants for human populations. To obtain a global view of the contamination in commercial fish in the NW Mediterranean Sea, we analysed four types of priority contaminants (PCBs, PBDEs, Hg and (137)Cs) in the European hake, Merluccius merluccius, from the Gulf of Lions in relation with organisms trophic level (δ(15)N). All contaminants presented a significant increase in concentration in hake muscle with trophic level. However, obvious differences between contaminants were evidenced. Biomagnification factors (BMF and FWMF) along the hake food web were higher for Hg and CB-153 than for BDE-47 and (137)Cs, and increase in contaminant concentration with trophic level occurred at different rates depending on contaminants. Such differences of biomagnification patterns can be related to physico-chemical properties of the different contaminants.

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.

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.

Mutagenicity and genotoxicity of suspended particulate matter in the Seine river estuary

Highly mutagenic compounds such as some PAHs have been identified in surface waters and sediments of the Seine river estuary. Suspended particulate matter (SPM) represents a dynamic medium that may contribute to the exposure of aquatic organisms to toxic compounds in the water column of the estuary. In order to investigate major sources of mutagenic contaminants along the estuary, water samples were taken at 25 m downstream of the outlet of an industrial wastewater-treatment plant (WWTP). SPM samples were analyzed for their genotoxicity with two short-term tests, the Salmonella typhimurium mutagenicity assay (TA98+S9 mix) and the comet assay in the human HepG2 cell line. Sampling sites receiving effluents from a chemical dye industry and WWTP showed the highest mutagenic potencies, followed by petrochemical industries, petroleum refinery and pulp and paper mills. These data indicate that frame-shift mutagens are present in the Seine river estuary. Furthermore, the comet assay revealed the presence of compounds that were genotoxic for human hepatocytes (HepG2 cells). We also observed a high level of mutagenic potency in the sediment of the lower estuary (3 × 10⁴ revertants/g). The source of mutagenic and genotoxic compounds seems to be associated with various types of effluents discharged in the Seine river estuary. Both test systems resulted in the same assessment of the genotoxicity of particulate matter, except for three of the 14 samples, underlying the complementarity of bioassays.

Photodechlorination of chlorobiphenyls by sodium methyl siliconate

Abstract Sodium methyl siliconate is unreactive with 4-chlorobiphenyl in aqueous methanol in the dark, but the reaction to give biphenyl (85 %) occurs rapidly when stimulated by ultraviolet light (300 nm). In the absence of siliconate photolysis of 4-chlorobiphenyl for 10 h at 300 nm gave less than 5 % cleavage of the bond. Deuterium labelling experiments and the inhibitory effects of oxygen were consistent with a single electron transfer (SET)-hydrogen abstraction mechanism. Dechlorination of polychlorobiphenyls, PCBs, by the above model proceeds with regioselectivity similar to that of nucleophilic aromatic substitution of polyhaloarenes.