Fast and low cost analysis of dioxin and dioxin-like compounds in marine matrices: final report

0info:eu-repo/semantics/publishe

AhR transcriptional activity in serum of Inuits across Greenlandic districts

<p>Abstract</p> <p>Background</p> <p>Human exposure to lipophilic persistent organic pollutants (POPs) including polychlorinated dibenzo-<it>p</it>-dioxins/furans (PCDDs/PCDFs), polychlorinated biphenyls (PCBs) and organochlorine pesticide is ubiquitous. The individual is exposed to a complex mixture of POPs being life-long beginning during critical developmental windows. Exposure to POPs elicits a number of species- and tissue-specific toxic responses, many of which involve the aryl hydrocarbon receptor (AhR). The aim of this study was to compare the actual level of integrated AhR transcriptional activity in the lipophilic serum fraction containing the actual POP mixture among Inuits from different districts in Greenland, and to evaluate whether the AhR transactivity is correlated to the bio-accumulated POPs and/or lifestyle factors.</p> <p>Methods</p> <p>The study included 357 serum samples from the Greenlandic districts: Nuuk and Sisimiut (South West Coast), Qaanaaq (North Coast) and Tasiilaq (East Coast). The bio-accumulated serum POPs were extracted by ethanol: hexane and clean-up on Florisil columns. Effects of the serum extract on the AhR transactivity was determined using the Hepa 1.12cR mouse hepatoma cell line carrying an AhR-luciferase reporter gene, and the data was evaluated for possible association to the serum levels of 14 PCB congeners, 10 organochlorine pesticide residues and/or lifestyle factors.</p> <p>Results</p> <p>In total 85% of the Inuit samples elicited agonistic AhR transactivity in a district dependent pattern. The median level of the AhR-TCDD equivalent (AhR-TEQ) of the separate genders was similar in the different districts. For the combined data the order of the median AhR-TEQ was Tasiilaq > Nuuk ≥ Sisimiut > Qaanaaq possibly being related to the different composition of POPs. In overall, the AhR transactivity was inversely correlated to the levels of sum POPs, age and/or intake of marine food.</p> <p>Conclusion</p> <p>i) We observed that the proportion of dioxin like (DL) compounds in the POP mixture was the dominating factor affecting the level of serum AhR transcriptional activity even at very high level of non DL-PCBs; ii) The inverse association between the integrated serum AhR transactivity and sum of POPs might be explained by the higher level of compounds antagonizing the AhR function probably due to selective POP bioaccumulation in the food chain.</p

Validation of the analysis of the 15+1 European-priority polycyclic aromatic hydrocarbons by donnor-acceptor complex chromatography and high-performance liquid chromatography-ultraviolet/fluorescence detection

The European Commission recommends to monitor the 16 polycyclic aromatic hydrocarbons (PAHs) possessing both genotoxic and carcinogenic properties. Since robust analytical methods specific for this set of European PAH are lacking, a new method for their analysis in food is proposed. The donnor-acceptor complex chromatography (DACC) is used as clean-up step and high-performance liquid chromatography-ultraviolet/fluorescence detection (HPLC-UV/FLD) is used for detection and quantification. The method has been validated for analysis of PAH in oil and in dried plants and bears very good results for all compounds.</p

Dioxin and dioxin-like activity in sediments of the Belgian coastal area

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Étude du gonflement des sols pour des projets de tunnels

Cette communication porte sur l’étude du gonflement d’une marne « intacte » réalisée à l’aide d’un œdomètre flexible. Le dispositif utilisé autorise une certaine déformation latérale de l’éprouvette lors du gonflement et permet la mesure de la pression de gonflement exercée dans cette direction. La variation de la rigidité de l’œdomètre flexible permet d’étudier l’influence de la déformation du sol sur le gonflement et de reproduire les conditions rencontrées lors de la construction de tunnels flexibles dans des sols gonflants. Les essais réalisés montrent que la rigidité de l’anneau œdométrique ainsi que la stratification de l’éprouvette affectent sensiblement le gonflement

Dioxin and dioxin-like activity in sediments of the Belgian Coastal Area (Southern North Sea)

Dioxin and dioxin-like activity in sediments of the North Sea, along the Belgian coast, was assessed with the bioassay CALUX (Chemically Activated LUciferase gene eXpression). Crude extracts of the samples as well as the dioxin fraction (PCDD/Fs) obtained after a thorough clean-up procedure were analyzed with the CALUX method. When analyzing the cleaned extract, a general low contamination level is observed (around 0.1 pg CALUX-TEQ/g sediment), except at the mouth of the two main rivers—the Yser and the Scheldt—where concentrations measured are about 100 times higher (10–42 pg CALUX-TEQ/g sediment). Much higher potencies are measured for the crude extracts compared to the cleaned ones. In the crude extracts, the highest dioxin-like activities were again observed at the mouth and outflow of the two rivers (600–7200 pg CALUX-TEQ/g sediment). These activities are at least two orders of magnitude higher than the ones found at the coastal and sea stations (1.3–45 pg CALUX-TEQ/g sediment). The difference in activity between cleaned and crude sediment extracts is due to the presence of dioxin-like compounds such as, for example, non-ortho and mono-ortho polychlorinated biphenyls and polybrominated dioxins, but also to PAHs. The percentage of five major PAHs in the crude samples at the river mouths, when using the average activities in those samples, varies between 25% and 50%

Supercritical fluid extraction of polychlorinated dibenzo-p-dioxins from fly ash: the importance of fly ash origin and composition on extraction efficiency

Supercritical fluid extraction (SFE) of polychlorinated dibenzo-p-dioxins (dioxins) from by ash samples, collected at different municipal waste incinerators, was investigated using supercritical CO2 and compared to the classical Soxhlet extraction. Results were correlated to fly ash composition, which is strongly related to the fume purification system used in the incinerators. Fly ash collected at the bottom of the electrostatic precipitator is composed of dust coming from the combustion unit, but also of lime and eventually of activated charcoal injected in the fumes for acids and pollutants removal. When only lime is used for the fume purification, SFE of dioxins from fly ash leads to better results than Soxhlet extraction. The use of a binary cosolvent (trifluoroacetic acid in toluene) greatly increases the percentage recovery. When activated charcoal is used in conjunction with lime for the fume purification, SFE under classical extraction conditions is not powerful enough to extract dioxins, which are strongly adsorbed to the residual activated charcoal. (C) 1998 Elsevier Science B.V. All rights reserved