Polychlorinated biphenyls (PCBs) and their congener-specific accumulation in edible fish from the Gulf of Gdansk, Baltic Sea.

Concentrations and composition profiles of polychlorinated biphenyls (PCBs) were investigated in composite samples of 10 species of edible fish from the Gulf of Gdansk, in the southern part of the Baltic Sea, Poland, to understand the status of contamination and possible human exposure risk. Apart from the total PCBs, planar non-ortho (IUPAC nos 77, 126, 169) and mono-ortho (nos 105, 114, 118, 123, 156, 157, 167, 189) chlorobiphenyls were also quantified and their dioxin-like toxicity assessed. The absolute total PCB concentrations in fish ranged from 43 to 490 ng g(-1) wet wt (910-11000 ng g(-1) lipids), while of TCDD TEQs of planar members were from 0.15 to 3.1 pg g(-1) wet wt (8.1-81 pg g(-1) lipids). The penta- and hexa-CBs usually comprised 70-80% of the total PCBs and were followed by hepta-, tetra- and tri-CBs, and for a specific site tri- and tetra-CBs comprised as much as 22%. Among the individual CB congeners, nos 118, 153 (+132) and 138 (+160 +163 +164) were the most abundant, while no. 110 comprised between 6.8 and 9.3% of the total PCBs in some species. Principal component analysis (PCA) was applied to examine the interdependences among CB congeners in the factor space. The PCA model and cluster analyses were further used to examine site- and species-specific differences and similarities of PCB composition, and the results are discussed. An assessed daily intake rate of TCDD TEQ of planar PCBs with the fishmeal of the Gulf of Gdansk in the 1990s was between 78 and 96 pg per capita or between 1.3 and 1.6 pg kg(-1) body weight.

Chlorinated cyclodiene pesticide residues in blue mussel, crab, and fish in the Gulf of Gdansk, Baltic Sea.

Chlordane components (CHLs) and their metabolites (heptachlor, cis-heptachlor epoxide, U82, MC4, trans-chlordane, MC5, cis-chlordane, MC7, oxychlordane, MC6- and trans- and cis-nonachlor) and aldrin, dieldrin, endrin, isodrin, endosulfan 1, endosulfan 2, and mirex were quantified in the soft tissues of blue mussel, a whole crab, and whole fishes collected from the spatially different sites in the Gulf of Gdansk. Six to twelve chlordane compounds and metabolites and dieldrin were detected in all organisms examined while aldrin, endrin, isodrin, endosulfans 1 and 2, and mirex were not found above the detection limit of the method. The lipid weight based concentrations in Baltic biota were relatively small and ranged from 12 to 150 and 7.6-77 ng/g, while between 0.16 and 6.8 and 0.10-6.6 ng/g in fresh tissue, respectively. The profile (%) of chlordane compounds was very similar between various fish species with trans-nonachlor (28 +/- 17), cis-chlordane (23 +/- 18), oxychlordane (13 +/- 7), and heptachlor epoxide (11 +/- 5) as major constituents and was totally different in crab with oxychlordane as the most dominating (>65%) compound. Blue mussel, lamprey, and three-spined stickleback exhibited a smallest ability to metabolize CHLs, and such fishes as cod, lesser sand-eel, sand-eel, pikeperch, perch, round goby, flounder, and herring showed a slightly better ability, while crab was able to effectively metabolize most of CHL compounds except trans-nonachlor. A value of the quotient of the trans-nonachlor to cis-chlordane concentrations (N/C quotient) was 1.0 in blue mussel, 3.1 in crab, and between 0.9 and 1.8 in fish. Both the small concentrations of CHLs in all organisms and the values of N/C quotients close to 1 imply on a long-range aerial transport through movement of the air masses from the remote regions of the northern hemisphere as a main source of this pesticide in the Gulf of Gdansk. The interdependences between the CHL profiles for various fish species and between different sampling sites were examined using the principal component analysis (PCA) method. Applying the PCA model the first four significant components explained 90% (43% + 23% + 15% + 8%) of the total variance in the data matrix.

Biochemical, neuropsychological, and neurological abnormalities following 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure.

Presented herein are the results of follow-up examinations of 13 workers performed in 1996--30 yr following 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) intoxication in a herbicide production plant. In these workers, the current mean plasma level of 2,3,7,8-TCDD, measured by high-resolution gas chromatography/high-resolution mass spectrometry, was 256 pg/gm lipid (range = 14-760 pg/gm lipid). This mean value corresponded to an estimated concentration of approximately 5,000 pg/gm plasma fat that existed about 30 years ago. Such a mean plasma level indicates that this group was one of the most heavily exposed groups to 2,3,7,8-TCDD described in the literature. Patients with persistent chloracne had significantly higher plasma levels of 2,3,7,8-TCDD than persons without chloracne. A significant, positive correlation was found between plasma levels of 2,3,7,8-TCDD in 1996 and levels of cholesterol and plasma lipids that existed since 1974. During 1996, there was a significant positive correlation between 2,3,7,8-TCDD and levels of beta-lipoproteins, cholesterol, and triglycerides. Also in 1996, significant correlations were found between neuropsychological variables and plasma levels of 2,3,7,8-TCDD. Other significant correlations were observed between neuropsychological variables and (1) the highest levels of triglycerides (i.e., since the year 1989), (2) levels of triglycerides in 1996, (3) levels of cholesterol at the first examination (i.e., 1969-1970), (4) highest level of cholesterol since the year 1969, and (5) cholesterol levels in 1996. Such correlations are biologically plausible, and they provide evidence of impaired cognitive performance (i.e., memory first), with a concurrent increase of plasma lipid levels. Abnormal electromyography, electroencephalography, and visual evoked potentials were observed in 23%, 54%, and 31 %, respectively, of former workers. Abnormal electroencephalography findings occurred more frequently in workers who had 2,3,7,8-TCDD blood levels that exceeded 200 pg/gm plasma fat than in workers with 2,3,7,8-TCDD values lower than 200 pg/gm plasma fat (p < .025). Frequency of polyneuropathic EMG abnormalities decreased from 38% in the 1970s to 23% in 1996. Improvement of conduction velocity in the tibial nerve was statistically significant (p < .05).

[Residues of chlordane in fish in the Gulf of Gdansk]. / Pozostalosci chlordanu w rybach w Zatoce Gdanskiej.

Concentrations, composition and spatial variations of the residues of the pesticide Chlordane were determined in several species of fish caught in Gulf of Gdansk. The residues of Chlordane (cis-i trans-chlordane, cis-i trans-nonachlor, oxychlordane, heptachlor, heptachlor epoxide, MC4, MC5, MC6, MC7, U82 and U83) were found in all fish examined, however, the concentrations noted were low, i.e. from 0.40 to 12 ng/g wet weight. Among the Chlordane constituents and metabolites determined trans-naonachlor, cis-chlordane, oxychlordan, heptachlor epoxide, cis-nonachlor, MC5, MC6 and trans-chlordane were dominated, and MC4, MC7, U82 and U83 were minor compounds. No heptachlor residues were found in fish examined. A small concentrations and specific composition of the residues of Chlordane and its metabolites determined in fish from the Gulf of Gdansk do indicate on a distant sources of pollution with that pesticide--mainly transported and deposited via the atmosphere.

Exposure of populations to dioxins and related compounds.

The present situation with respect to the exposure of the general human population to PCDDs, PCDFs and (dioxin-like) PCBs and specific issues that should be taken into consideration for a risk assessment of these exposures have been summarized. The information is based on studies performed in The Netherlands and Germany in the last 10 years. Additional data have been collected through a literature search and through many contacts with researchers and national authorities. The most important route for human exposure to PCDDs, PCDFs and (dioxin-like) PCBs is food consumption contributing over 90% of total exposure, with products of animal origin and fish making the greatest contribution to this exposure. The dietary intake of PCDDs and PCDFs by the general population of industrialized countries is on average 1-3 picograms of (i)-TEQ per kilogram body weight per day. If the contribution of dioxin-like PCBs are also considered, the daily TEQ intake can be a factor of two to three higher. Special consumption habits and consumption of highly contaminated foodstuffs may lead to lower and higher TEQ intakes. In general, TEQ intake increases during childhood and stabilizes in adults of about 20 years of age. However, when normalized by body weight exposure is found to decrease with childhood age due to increasing body weight. Exposure has been shown to have fallen over time in all countries where data are available. Countries that started to implement measures to reduce dioxin emissions in the late 1980s, such as The Netherlands, United Kingdom and Germany, clearly show decreasing PCDD/PCDF and PCB levels in food and consequently a significantly lower dietary intake of these compounds by almost a factor of 2 within the past 7 years.

Discrimination and thermal degradation of toxaphene compounds in capillary gas chromatography when using split/splitless and on-column injection.

Technical toxaphene and a 22-component Reference Mixture were analyzed using capillary gas chromatography with split/splitless injection (SSL) and on-column injection (OC). In both techniques, electron-capture, negative ionization mass spectrometry (ECNI-MS) was used for detection of chlorobornanes, chlorocamphenes and related compounds. Significant discrimination of highly chlorinated congeners was observed as a result of incomplete transfer of these compounds from the vaporizer to the analytical column when using SSL. This resulted in a much lower response for nona- and decachloro congeners than when using OC. In addition, several toxaphene components, especially the chlorobornanes with gem dichloro substitution on the six-member carbon ring, undergo thermal degradation when using SSL. Some of these congeners are major components of technical toxaphene, but generally are not present, except at low concentrations, in environmental and biological samples. Therefore, technical toxaphene may be discriminated and/or degraded differently than toxaphene compounds in environmental samples when using SSL. This results in significant bias of the quantitative data when using the technical material as a reference. OC suffers much less from these deficiencies and, therefore, is a preferable technique for toxaphene analysis.

Organochlorine compounds in the Gulf of Bothnia: sediment and benthic species.

Surface sediment, amphipods (Monoporeia affinis), isopods (Saduria entomon) and fourhorn sculpins (Oncocottus quadricornis) were collected at two coastal stations in the Gulf of Bothnia, one in the Bothnian Bay and the other in the Bothnian Sea. The objective was to study the concentrations, composition profiles, bioaccumulation features and spatial differences of organochlorine compounds such as hexachlorocyclohexanes (HCHs), DDTs, hexachlorobenzene (HCBz), chlordanes (CHLs), dieldrin, Mirex and polychlorinated biphenyls (PCBs). All groups of compounds were found in every sample investigated, with the exception of Mirex that was not detected in the sediment samples. The concentrations for e.g. PCBs and CHLs ranged from 700 to 2400 and 70 to 400 ng/g lipid in the specimens. For the corresponding sediments the results were 9.0-9.3 ng/g dw for PCBs and 0.54-0.57 ng/g dw for CHLs, respectively. Bioaccumulation differences between the species with regard to both degree of and type of compound were observed. The highest accumulation potential was found for the cyclodiene compounds including CHLs and Mirex in isopod. Finally, there were only small concentration and bioaccumulation differences between the two stations.

Search for chlorobornanes in river sediments and in influents and effluents.

In 1997, we collected nine river sediment samples, including one duplicate, from above and below three pulp and paper mills on the Wisconsin River in Wisconsin, USA, and one mill on Beaver Dam Creek in Ontario, Canada. We also obtained twenty split sediment samples from the Wisconsin River that were collected by the US EPA in collaboration with Indiana University. Finally, we collected influent and effluent samples from eight pulp and paper related industries in the US and Canada. We analyzed all sediment and water samples for hexa- through decachlorobornanes. We did not detect any chlorobornanes in most of the sediments. When chlorobornanes were detected, the concentration in sediments below pulp mills were similar to or less than in those from above the same mills. Chlorobornanes could not be detected in any of the influent or effluent samples. Thus, pulp and paper mills and relate facilities are not a source of chlorobornanes.

Rapid anaerobic degradation of toxaphene in sewage sludge.

We studied the degradation of technical toxaphene in anaerobic sewage sludge from a municipal waste water treatment plant. Chlorobornanes, chlorocamphenes and related compounds were rapidly degraded, with degradation rates in the order of decachloro>nonachloro>octochloro>heptachloro approximately = hexachloro compounds. The half-lives of individual congeners ranged from <1 day to several days. We also studied the degradation of technical toxaphene in previously sterilized sludge (control), and found it was slower than in the anaerobic sludge. The chlorobornanes that degraded most rapidly in the non-sterilized anaerobic sludge were those with gem chloro substitution on the 6-member carbon-ring, including the toxic congeners, Toxicant A and B. Non-gem chloro substituted congeners, like the biologically persistent P26 and P50, also degraded, but less rapidly. Toxaphene degradation in sewage sludge proceeded primarily via reductive dechlorination, leading to HxSed, HpSed, TC2 and other persistent metabolites. Enantioselective determinations indicated little, if any, enantioselectivity in the formation and/or degradation of these compounds. The isomer and enantiomer profiles of the hexa-, hepta-, and octachlorobornanes are similar to those observed in sediment from the Baltic Sea, suggesting that technical toxaphene is the source of these compounds and that its composition was changed via similar anaerobic degradation pathways.

Persistent health effects of dioxin contamination in herbicide production.

A total of 159 cases of chloracne reported in 1969-1975 in TCDD-contaminated production of the herbicide 2,4,5-T have been followed for mortality and morbidity up to 1996 when blood and urine tests were performed on 50 survivors of these exposed chemical workers and matched controls. In exposed, the most frequent cause of sick leave was chloracne which persisted in 32%. Neurological symptoms were reported frequently (44% sleep disturbance, 32% headache, 30% neuralgia). BSR, leucocytes, gamma-GT, SGOT, and SGPT were significantly higher in exposed than in controls. The effects of exposure (P= 0.002) and alcohol (P= 0.002) on gamma-GT were found to be independent of each other. Comparisons within the chloracne cohort showed significantly exposed TCDD per gram blood lipid in patients with a history of liver disease (mean 801 pg/g) than without (mean 407 pg/g). Other congeners were not found elevated but some higher chlorinated furans and PCBs were found reduced in patients with liver disease. In multiple regression analysis with the factors age, alcohol, and log TCDD, the effects of TCDD and its interaction with age were found significant, indicative of chronic liver damage after high TCDD exposure at a young age. The prevalence of neurological symptoms and signs of chronic liver disease were related to TCDD in blood and abnormal poryphyrins in urine. In 48% coproporphyrin I > III ratio was elevated, this group showing increased TCDD (mean 719 pg/g). These results contribute to the evidence that chloracne is not the only chronic disease which can be related to TCDD exposure, even 23 years after exposure and despite high intersubject variability of TCDD half-life and other exposures.

[Dieldrin, aldrin, endrin, isodrin, endosulfan 1 and 2 on fish in the Gulf of Gdansk]. / Dieldryna, aldryna, endryna, izodryna, endosulfan 1 i 2 w rybach w Zatoce Gdanskiej.

The residues of dieldrin, aldrin, endrin, isodrin, endosulfan 1 and 2 has been determined in a several species of fish caught in the Gulf of Gdansk in 1992. The method of measurement was capillary gas chromatograph and low resolution mass spectrometry (HRGC/LRMS) after a nondestructive extraction and clean-up step with a further fractionation of the extract on Florisil column. Apart from dieldrin no other cyclodiene pesticides studied were found in fishes in detectable amounts, and for dieldrin concentrations ranged from 0.84 to 6.6 ng/g wet weight.

[DDT and it metabolites in fish in the Gulf of Gdansk]. / DDT i jego metabolity w rybach w Zatoce Gdanskiej.

The residues of DDT and its metabolites (DDTs; p,p'-DDT, o,p'-DDT, p,p'-DDD, o,p'-DDD, p,p'-DDE, o,p'-DDE i p,p'-DDMU) has been determined in ten species of edible fish caught in the Gulf of Gdansk in 1992. The method of measurement was capillary gas chromatography and low resolution mass spectrometry (HRGC/LRMS) after a nondestructive extraction and clean-up step with a further fractionation of the extract on Florisil column. All fish examined contained detectable residues of DDTs, and the concentrations ranged from 28 to 310 ng/g wet weight. o,p'-DDT accounted from 0.4 to 2.5% to DDTs content. The residue concentration of DDTs in herring (110 ng/g wet weight and 1100 ng/g lipid weight) in 1992 was threefold lower than in the years 1979-1983 and fourteen fold lower than in 1969-1973.

PCDD, PCDF, and PCB in farm-raised catfish from southeast United States--concentrations, sources, and CYP1A induction.

Nine catfish fillets, three catfish nuggets, two feed samples, and one pond sediment were analyzed for PCDD, PCDF, and PCB. Farm-raised catfish from Mississippi, Alabama, and Arkansas contained significant levels of 2,3,7,8-substituted PCDD and PCDF. In addition, a large number of non-2,3,7,8-substituted congeners were present in all samples. The catfish fillets and catfish nuggets also contained high concentrations of dioxin-like PCB, as well as a number of non-dioxin-like PCB. The TEQ based on PCDD and PCDF ranged from 9.5 to 43.0 pg/g lipid and the TEQ based on PCB ranged from 0.45 to 4.9 pg/g lipid for all catfish samples. The dioxin-like PCB contributed 4-16% to the total TEQ (PCDD/PCDF/PCB) for the catfish samples. The major source for the PCDD, PCDF, and PCB appears to be from feed and not from pond sediment. Immunoreactive CYP1A protein was elevated 2.5 fold in the pond-raised catfish compared to the aquarium-raised one. The results of this study suggest that the PCDD/PCDF are more important than the PCB in the CYP1A induction.

Concentrations and biomagnification of 17 chlordane compounds and other organochlorines in harbour porpoise (Phocoena phocoena) and herring from the southern Baltic Sea.

Four species of harbour porpoise (Phocoena phocoena) and one herring (Clupea harengus) sample from the southern Baltic Sea were analysed in an attempt to study the concentration and biomagnification of 17 chlordane related compounds (CHLs) including 12 components present in technical chlordane, the toxic metabolites oxychlordane and cis-hepatchlorepoxide and the photoconversion products photoheptachlor and two photo-cis-chlordanes. The concentration and biomagnification ability of CHLs were also compared to other organochlorines such as HCHs (hexachlorocyclohexanes), hexachlorobenzene, DDTs, dieldrin, mirex and PCBs (polychlorinated biphenyls). Of the CHLs analysed, 16 were detected in porpoise and 15 in herring including the photoconversion products. In both species the highest concentrations were found for PCBs and DDTs. The concentration of PCBs and CHLs in porpoise varied from 5700-16,000 and 470-1250 ng/g lipid, and in herring from 1300 and 49 ng/g lipid, respectively. The biomagnification factor (BMF: concentration in organism/concentration in food; all lipid normalized) in porpoise was found to be high for CHLs followed by dieldrin and lowest for HCHs. Among the CHLs, a big variation of BMF (BMF range approximately 1-50) was found e.g., the nonachlorinated compounds biomagnified to the highest degree followed by cis-heptachlorepoxide, photoheptachlor and oxychlordane.

PCDD and PCDF contamination in catfish feed from Arkansas, USA.

One combined catfish feed sample from Arkansas, USA, and its eight ingredients were analyzed for PCDDs and PCDFs. One of the ingredients, soybean meal, was highly contaminated by PCDDs, especially the toxic 2,3,7,8-substituted congeners, e.g., 7.3 pg/g dry weight or 370 pg/g lipid for the 2,3,7,8-tetra CDD. The I-TEQ value for the soybean meal was 11.4 pg/g dry weight or 576 pg/g fat. The corresponding values for the combined catfish feed concentrations were approximately 3 times lower. The congener pattern, the congener profile and the ratio sigma PCDDs/sigma PCDFs for the soybean meal were quite unique. We are not aware of any environmental sample or technical product with similar characteristics. As a result, natural formation of the PCDDs found in the soybean meal cannot be ruled out.

Concentrations, biomagnification and spatial variation of organochlorine compounds in a pelagic food web in the northern part of the Baltic Sea.

Zooplankton, mysis (Mysis sp.) and herring (Clupea harengus) were collected at two pelagic locations in the northern part of the Baltic Sea, one in Bothnian Bay (BB) and the other in the Bothnian Sea (BS), in order to investigate concentrations, composition profiles, biomagnification features and spatial differences of organochlorine contaminants. Compounds included in this study are hexachlorocyclohexanes (HCHs), DDTs, hexachlorobenzene (HCBz), chlordanes (CHLs), dieldrin, mirex and polychlorinated biphenyls (PCBs). All groups of compound were detected in every sample investigated, with the exception of mirex that was detected only in the herring samples. The concentrations of organochlorine compounds in all samples ranged, e.g. from 250 to 1500 ng/g lipid for PCBs and from 6 to 150 ng/g lipid for CHLs. The biomagnification factor (BMF) is calculated as the concentration of the compounds in the organism divided by the concentration in food normalised to lipids. In the zooplankton-mysis-herring food web, large variations in BMFs between the different compound groups were observed. The highest BMFs were obtained for the CHLs followed by the DDTs and the lowest for the HCHs. Nonachlorinated CHLs had the highest BMFs within the group of CHLs and for the DDTs p,p'-DDT had a higher biomagnification potential than its metabolites p,p'-DDE and p,p'-DDD. Finally, concentration and biomagnification differences between the two stations were observed. The herring in the southernmost station (BS) displayed approximately two- to sixfold higher biomagnification than the herring from the north (BB).

Concentrations and spatial variations of cyclodienes and other organochlorines in herring and perch from the Baltic Sea.

Herring (Clupea harengus) and perch (Perca fluviatilis) were collected in the northern and southern Baltic Sea and analyzed for the presence of the cyclodiene pesticides chlordane (CHL), heptachlor, aldrin, dieldrin, endrin, isodrin, endosulfan and mirex, as well as other organochlorine contaminants, hexachlorocyclohexanes (HCHs), DDTs, hexachlorobenzene (HCBz) and polychlorinated biphenyls (PCBs) in order to investigate concentrations, accumulation and differences in geographical distribution. In the northern part of the Baltic Sea, Gulf of Bothnia, herring were collected at two pelagic stations, one in the Bothnian Bay (BB) and the other in the Bothnian Sea (BS), respectively; perch were collected at four coastal locations along the Swedish coast. All these locations were selected to represent background areas except one in the vicinity of an industrialised and contaminated area. Both specimens were also caught in the southern part of the Baltic Sea, in the Gulf of Gdansk (GG), Poland, a potentially highly polluted area. From the eight cyclodiene pesticides analyzed, three were detected in herring and perch samples, including 12 different CHL-related compounds, dieldrin and mirex. To our knowledge, it is the first time that mirex has been detected in samples from the Baltic Sea. Neither heptachlor, aldrin, endrin, isodrin nor endosulfan were found. However, HCHs, DDTs, HCBz and PCBs were found in every sample investigated, and the concentrations ranged e.g. for the cyclodiene chemicals dieldrin and CHL-related compounds from 30 to 170 ng/g lipid and for PCBs from 360 to 5400 ng/g lipid, both fish species included. Differences in contamination burden between the sites can be seen, e.g. for herring the BB and GG locals were similar, and generally lower than BS for all chemicals except that of DDT where GG was the highest. For the perch samples the industrialised location had markedly higher concentrations of HCBz and PCBs than the other locations. This species also identifies GG as the most DDT contaminated site among the three studied areas.

Dialysis with semipermeable membranes as an efficient lipid removal method in the analysis of bioaccumulative chemicals.

Herein is a procedure described using a semipermeable membrane (SPM) for enrichment of organic chemicals from lipid-containing samples. Dialysis with SPMs in an organic solvent can separate organochlorine contaminants such as non-, mono-, and di-o-PCBs, PCDDs, PCDFs, PCDTs, PCNs, pesticides, and PAHs from lipids. The method is nondestructive and more than 20 g of lipid can be dialyzed in a single membrane with acceptable recoveries of the internal standards, nearly independent of amount and type of lipid dialyzed. The lipid removal process shows good consistency between subsamples, and the lipid content can be reduced by 90-99%, depending on species and amount lipid. Neither triglycerides nor phospholipids were obtained in the dialysate fraction. The utility and reliability of the method is displayed by good precision for 72 PCBs and 27 organochlorine pesticides in the concentration range 0.05-50 micrograms/sample for triplicate subsamples, by the consistency in PCDD/F levels compared to a classic analytical procedure, and by the analysis of the above listed chemicals in approximately 200 biological samples of a wide variety of types. This technique can also be used as an enrichment device for contaminants when huge amounts of lipids are extracted for toxicological studies. Moreover, it is possible to use SPM to cleanup other samples from molecules with relatively high masses, e.g. sediments, soil, compost, and tar materials.

Concentrations and biomagnification of polychlorinated naphthalenes in black cormorants Phalacrocorax carbo sinensis from the Gulf of Gdansk, Baltic Sea.

Black cormorants, Phalacrocorax carbo sinensis (the breast muscles and liver) originating from the colony near Katy Rybackie on the south coast of the Gulf of Gdansk, Baltic Sea, were collected in 1992 and analysed for polychlorinated naphthalenes. PCNs were determined employing a multi-residue procedure including a non-destructive wide-bore open-tube extraction step, cleanup using semipermeable polyethylene membrane, HPLC fractionation of planar compounds on activated carbon column and final separation and identification and quantification with HRGC/HRMS. Tetra- to hepta-CNs were found in all samples examined, and penta- and next tetra-CNs were dominating homologue groups. Dominating members in the fingerprint of PCNs in black cormorants were 1,3,5,7-T4CN (no. 42); 1,2,3,5,7-/1,2,4,6,7-P5CN (no. 52/60); 1,2,4,6,8-P5CN (no. 61); 1,2,3,4,6,7-/1,2,3,5,6,7-H6CN (no. 66/67); 1,2,4,6-/1,2,4,7-/1,2,5,7-T4CN (no. 33/34); 1,2,4,5,7-P5CN (no. 58); and 1,2,4,7,8-P5CN (no. 62). When related to potential food items, black cormorants biomagnify in their body many PCNs and the congeners no. 42 and 66/67 show highest biomagnification factor (BMF) values.