Horst Karl

Determination of polycyclic aromatic hydrocarbons in smoked fishery products from different smoking kilns

The levels of 13 polycyclic aromatic hydrocarbons (PAH) were determined by an HPLC method with fluorescence and UV detection and by a GC/MS technique in smoked fishery products from modern smoking kilns with external smoke generation and from traditional smoking kilns. The average benzo(a)pyrene (BaP) concentration of all 35 samples from commercial smoking kilns with external smoke generation was 0.1 μg/kg (wet weight) and the sum of the carcinogenic compounds determined in the study, i.e. benz(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenz(a,h)anthracene and indeno(1,2,3-c,d)pyrene did not exceed 4.5 μg/kg (wet weight). The BaP levels of the 27 smoked fish samples from traditional kilns ranged from 0.2 μg/kg to 4.1 μg/kg, with a mean value of 1.2 μg BaP/kg. The average concentration of the sum of the carcinogenic compounds was 9.0 μg/kg. Large variations were found in the content of the non-carcinogenic PAHs phenanthrene, anthracene, fluoranthene and pyrene in all samples from both types of smoking kilns.

Levels of dioxins in fish and fishery products on the German market

In 1995-1998 the contents of polychlorinated dibenzodioxins and dibenzofurans of 184 pooled fish samples were analysed. Sampling focused on fish and fishery products with a market share of more than 1% and covered all fishing grounds important for the supply of the German market. Investigation included 15 different fish species, shrimp, mussel and squid samples and various fishery products, typically on the German market. Generally lean fish species like cod, saithe or Alaska pollock were less contaminated on fresh weight basis than fat fish species like herring, Greenland halibut and sardine. In herring the dioxin content is related to the fishing ground. Low concentrations were found in North Sea herring, high concentrations measured in samples from the Baltic Sea. Dioxin contents in fishery products did not differ significantly from the raw fish samples. Results allow an estimation of the daily intake of dioxins and furans via fish consumption in Germany. Based on a daily fish consumption of 20 g the average intake of dioxins via fish is 6.2 pg WHO-PCDD/F-TEQs per person and day.

Temporal trends of PCDD, PCDF and PCB levels in muscle meat of herring from different fishing grounds of the Baltic Sea and actual data of different fish species from the Western Baltic Sea

To study the time trend of PCDD, PCDF and dl-PCB levels in the muscle of herring from the Western Baltic Sea, samples were collected in 2006 at the same fishing locations as in 1999. The results demonstrated no obvious change in contamination levels based on content in fat during the last 7 years. The site-dependent increase in WHO-PCDD/F-PCB-TEQ concentrations already found in 1999 in fishing grounds between the Skagerrak and the east of Bornholm could be confirmed by this study. In addition, an overview is given in this study on the actual WHO-TEQ concentrations in cod, eel, herring, sprat and some salmon landed at various fishing ports along the coast of Mecklenburg-Western Pomerania/Germany. All herring samples were found to be below the maximum levels and the concentrations in cod were below 1 ng WHO-TEQ kg(-1) wet weight (ww). The contaminant levels of 28 pooled eel samples varied considerably between 1.35 and 16.75 ng WHO-TEQ kg(-1) ww. The results are discussed in relation to the fat content and to the weight of the eels.

Levels of toxaphene indicator compounds in fish

Abstract Three toxaphene indicator compounds were determined in more than 100 samples of fish. The investigated fish included nearly all important fish species consumed in Germany. Highest residue concentrations were found in marine fish with high or moderate fat content, e.g. halibut, herring, redfish and mackerel. In fresh water species and marine fish with low fat content less contamination was found. A significant relationship between the fishing ground and the toxaphene residue could not established. Contamination levels of most species were related to the age (length) of the fish. The daily intake of total toxaphene in Germany was estimated at 2.8–5.6 ng/kg body weight.

Levels of chlordane compounds in fish muscle, -meal, -oil and -feed

Cis-, trans-, oxychlordane and trans-nonachlor were determined in the edible part of more than 140 fish samples of 15 different species and in fish meal, -oil and fish feed. The investigated fish included most of the important fish species consumed in Germany. Highest concentrations were found in muscle of marine fish with high or moderate fat content, but also in eel and farmed salmon. Marine fish with low fat content contained only traces of chlordane in the muscle tissue. A relationship between fishing ground and levels of chlordane could not be established. Contamination level of herring was related to the age (length) of the fish. Data are also given for contamination levels of fish meal, -oil and -feed.

Dioxin and dioxin-like PCB levels in cod-liver and -muscle from different fishing grounds of the North- and Baltic Sea and the North Atlantic

The contaminant levels of dioxins, dioxin-like PCBs and non dioxin-like PCBs were determined in pooled samples of cod liver and corresponding cod muscle from different fishing grounds of the North- and Baltic Sea and from East Greenland. The dependence of the contaminant concentrations was studied on cod of three different sizes caught at the same fishing ground. Samples were taken during different research trips at 11 fishing grounds of the Baltic Sea, and 3 fishing grounds of the North Sea and of East Greenland in 2006 and 2007, respectively. Cod liver from the Baltic- and the North Sea were highly contaminated. Mean concentrations were 93 and 83xa0ng WHO-TEQ/kgxa0wetxa0weight (w.w.), respectively. Cod livers from East Greenland had only low contaminant levels of 3.4xa0ng WHO-TEQ/kgxa0w.w. Highest concentrations were found in livers from the Bay of Kiel. Within the same fishing area the concentrations increased with the size of the cod. The WHO-TEQ amounts of the cod fillets were below 1xa0ng WHO-TEQ/kgxa0w.w. and thus within the commonly observed low range for lean fish.ZusammenfassungEs wurden die Gehalte von Dioxinen, von dioxinähnlichen PCBs und nicht dioxinähnlichen PCBs in Kabeljau- bzw. Dorschleberproben aus verschiedenen Fanggebieten der Ostsee, Nordsee und des Nordatlantik erfasst. Zudem wurden Untersuchungen zur Belastung der Lebern und der zugehörigen Fische in Abhängigkeit von der Größe (Alter) der Fische durchgeführt. Auf mehreren Fischerei-Forschungsreisen wurden an elf Fangplätzen in der Ostsee und je drei Fanggebieten in der Nordsee und vor Ostgrönland Kabeljauleberproben und dazu gehörige Muskelfleischproben gesammelt. Insgesamt waren die untersuchten Dorschlebern aus der Ostsee und der Nordsee sehr hoch mit Dioxinen und Dioxin-ähnlichen PCB belastet. Die mittleren Gehalte der Lebern aus der Ostsee und aus der Nordsee waren mit 93 bzw. 83xa0ng WHO-TEQ/kg Frischgewicht (FG) nahezu identisch. Die Kabeljaulebern von Fischen aus Ostgrönland waren dagegen mit 3,4xa0ng WHO-TEQ/kg FG deutlich geringer kontaminiert. Die höchsten Gehalte wurden in Lebern von Fischen aus der Kieler Bucht gemessen. Die WHO-TEQ-Gehalte der Dorschfilets blieben weit unter 1xa0ng/kg FG und damit in dem für Magerfische üblichen niedrigen Bereich. Die Untersuchungsergebnisse zur Abhängigkeit der Belastung von der Größe zeigen eine eindeutige Zunahme der Gesamtbelastung mit der Länge der Fische sowohl in den Lebern als auch im Muskel, d. h. innerhalb eines Fanges nimmt die Belastung mit der Größe der Fische zu.

Levels of toxaphene indicator compounds in fish meal, fish oil and fish feed

Three toxaphene indicator compounds were determined in fish oil and fish meal of different origin and raw material as well as in feed containing fish oil and fish meal. Fish oil and fish meal from South America contained no or only traces of the indicator congeners. The sum of the three compounds varied in fish oils from Europe between 13 micrograms/kg fat (sand eel oil) and 206 micrograms/kg fat (cod oil). Varying concentrations were also determined in European fish meal and in feed. Toxaphene indicator compounds were as well detected in trout and salmon fed with toxaphene residues containing feed. Results indicate that feed can contribute to toxaphene contamination of farmed salmon from Europe.

Dioxins and dioxin-like PCBs in fish and fishery products on the German market

Abstract:Concentrations of polychlorinated dibenzodioxins, dibenzofurans and dioxin-like PCBs in the edible part of fish and in fishery products were studied to gain an overview on actual contaminant levels on the German market.The investigation focused mainly on fish species with higher fat content and was orientated to cover all important fishing grounds for the supply of the German market. Pooled samples of 32 different fish species, 5 crustacean and mussel species and some typical products were analysed. Fish with low and moderate fat content kept on average below 1 ng Sum WHO-PCDD/FPCB-TEQ ng kg−1 wet weight and fish with high fat content (>10%) ranged between 1 to 3 ng kg−1 w.w.. A dependence of the WHO-TEQ concentrations in the muscle meat to the fishing ground was observed for several species. Ocean perch and Greenland halibut from the northern North Sea and fatty fish species from the Baltic Sea and the English Channel south of Great Britain had higher contaminant concentrations compared to corresponding fishes from other fishing grounds. The temporal trends of dioxin concentrations in mackerel and ocean perch are discussed.Zusammenfassung:Die vorliegende Studie gibt einen aktuellen Überblick zur Belastungssituation von Fischen und Fischereierzeugnissen auf dem deutschen Markt mit polychlorierten Dibenzodioxinen, Dibenzofuranen und dioxinähnlichen PCB. Untersucht wurden vor allem Fische mit höheren Fettgehalten unter Berücksichtigung der für den deutschen Markt wichtigen Fanggebiete.Insgesamt wurden 32 Fischarten, 5 Krebs- und Weichtierarten und verschiedene typische Produkte analysiert. Die Gesamtgehalte (WHO-TEQ) in Fischen mit niedrigen und mittleren Fettgehalten lagen im Allgemeinen unter 1 ng WHO-PCDD/FPCB-TEQ kg−1 Frischgewicht, Fische mit höheren Fettgehalten (>10%) lagen bei 1 – 3 ng kg−1. Bei einigen Fischarten konnte eine Abhängigkeit der Gehalte vom Fanggebiet nachgewiesen werden. Rotbarsch und Schwarzer Heilbutt aus dem Fanggebiet Tampen (nördliche Nordsee), sowie Fettfische aus der Ostsee und dem Seegebiet südlich von Großbritannien waren höher belastet als aus anderen Fanggebieten. Mögliche Veränderungen der Dioxinbelastungen im Vergleich zu den Untersuchungsergebnissen der Jahre 1995/97 werden am Beispiel Makrele und Rotbarsch diskutiert.

Organochlorine residues in the edible part of eels of different origins.

ZusammenfassungIn 54 geräucherten und unbehandelten Aalproben aus 11 Ländern wurden die Gehalte der chlororganischen Pesticide Aldrin, Endrin, Hexachlorbenzol;α-,β-HCH, Lindan, Heptachlor, Octachlorstyrol, pp′-DDT, pp′-DDD, pp′-DDE, sowie die Gehalte der PCB-Kongenere 28, 52, 101, 138, 153 und 180 gaschromatographisch ermittelt. Wildaale, insbesondere aus den Ostsee-Anrainerstaaten, zeigten im Vergleich zu Zuchtaalen leicht erhöhte Werte. Alle Gehalte lagen jedoch weit unter den gesetzlich festgelegten Grenzwerten. Im Mittel wurden die erlaubten Höchstmengen nur zu 1–5% ausgeschöpft.AbstractFifty-four eel samples from 11 different countries were analysed by capillary gas chromatography for levels of the pesticides aldrin, endrin, hexachlorobenzene,α- andβ-BHC, lindane, heptachlor, octachlorostyrene, pp′-DDT, pp′-DDD, pp′-DDE, and for the levels of the PCB congeners 28, 52, 101, 138, 153, and 180. Wild eels, especially from the Baltic Sea area, had elevated contents compared to farmed eels. The mean contamination level reached only 1–5% of the allowable values given by German directives and never exceeded the official limits.

Factors influencing the intake of dioxins and dioxin-like PCBs via fish consumption in Germany

This study discusses the various factors which influence the intake of dioxins and dioxin-like PCBs (dl-PCBs) via fish consumption to support the requirements for additional information for an adequate estimation of consumer’s exposure. Growing consumer preferences towards lean and aquaculture species have to be considered in future. The varying dioxin and dl-PCB levels of herring in relation to the geographical origin and the fishing season and their consequences for the estimation of the exposition are discussed. The levels in herring from different fishing grounds can vary by a factor of 8 between 0.43 and 3.04xa0ng WHO–PCDD/F–PCB–TEQ2005/kgxa0wet weight. Increasing lipid content of the muscle meat during the feeding cycle of herring and mackerel leads to a “dilution effect” of contaminants based on lipid weight. Changes in the composition of feed for carnivorous species reduced the dioxin levels in farmed salmon and trout considerably between 1997 and 2004. Hence only recently taken data collections should be used for exposure estimation. Furthermore processing and household preparation can change the contaminant levels and should be taken into account.