Concentrations Of Dioxin-like Polychlorinated Biphenyls Research Articles

Concentrations and accumulation profiles of PCDDs, PCDFs and dioxin-like PCBs in adipose fat tissues of Korean women

Reports on residue levels and accumulation profiles of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in human adipose tissue are scarce in Korea. In this study, concentrations and accumulation features of PCDD/Fs and DL-PCBs were determined in the samples of adipose tissue collected from Korean women in 2007-2008. The total dioxin-like toxic equivalent (TEQ) concentrations (3.4-42 pg g(-1) lipid wt) in Korean adipose tissues were similar to those reported in European and other Asian countries. The relative contributions of individual compounds to total TEQs were as follows: non-ortho PCBs (mean: 45%) > PCDFs (28%) > PCDDs (24%) > mono-ortho PCBs (3%), a pattern similar to those reported for seafoods in Korea. The dominant PCDD/F congeners found in adipose tissues were OCDD and 2,3,4,7,8-PeCDF and dominant PCBs were 118, 156 and 105. No correlation was found between subject's age and concentrations of dioxin-like contaminants. Body mass index was not correlated with concentrations of PCDD/Fs and was negatively (p < 0.001) correlated with concentrations of DL-PCBs. The results of this study provide baseline information on PCDD/Fs and DL-PCBs in adipose tissues of the general population in Korea.

Distribution, source and risk assessment of polychlorinated biphenyls (PCBs) in urban soils of Beijing, China

The concentration of PCBs in urban soils of Beijing across six land types including business districts (BD), cultural and educational areas (CE), classical gardens (CG), public green (PG), residential areas (RA), and roadsides (RD) was investigated. The total concentrations of PCBs ranged from below method detection limit (M.D.L.) to 37.11 × 10 −3 mg kg −1 dry weight (mean: 11.70 × 10 −3 mg kg −1; median: 13.28 × 10 −3 mg kg −1), which was at a medium level compared with other cities around the world. In general, the levels of PCBs decreased from the center of Beijing city to the suburb, suggesting the increasing PCBs concentrations with the age of the urban area. For different types of land use, the highest level of PCBs was observed in CG soils which have the oldest age, and the homologue profiles were similar, which were predominated by lowly chlorinated congeners including di-, tri- and tetra-CBs. Principal component analysis indicated that local sources such as Aroclor 1016, 1242, and 1248 were important sources in addition to long-range transport of PCBs all over the world. Although the toxic equivalency (TEQ) concentrations of dioxin-like PCBs in all soil samples of Beijing were higher than those in other urban areas of China, they met the Canadian soil quality standard.

Reducing persistent organic pollutants while maintaining long chain omega-3 fatty acid in farmed Atlantic salmon using decontaminated fish oils for an entire production cycle

Oily fish are an important source of health promoting nutrients such as the very long chain marine omega-3 (VLC-n3) fatty acids and simultaneously a source of potentially hazardous contaminants. Fish oils that are used in fish feed are the main source for both contaminants and VLC-n3. Decontamination techniques have recently been developed to effectively remove persistent organic contaminants from fish oils. The aim of the present study was to assess the level of potentially hazardous contaminants and the health beneficial fatty acids in Atlantic salmon reared on novel decontaminated feeds. Atlantic salmon were fed for 18 months (an entire seawater production cycle) on diets based on decontaminated or non-treated (control) fish oils until market size (∼5 kg). The level of known notorious persistent organic pollutants (POPs, i.e. dioxins, dioxin-like polychlorinated biphenyls (DL-PCBs), non dioxin-like PCBs, poly brominated diphenyl ethers (PBDE), and organochlorine pesticides), as well as fatty acid composition were analysed in fish oils, the two diets, and Atlantic salmon fillet. The oil decontamination process was a two-step procedure using active carbon and short path distillation. The fillet levels of POPs in market size fish were reduced by 68–85% while the concentration of very long chain omega-3 fatty acids was reduced by 4–7%. No differences in biomarkers of dioxin-like component exposures, such as hepatic gene expression of CYP1A or AhR2B, CYP1A protein expression and 7-ethoxyresorufin O-deethylase (EROD) activity, were observed between salmon raised on normal or decontaminated feeds, thus indicating that the difference in POPs levels were of no biological significance to the fish. Atlantic salmon reared on decontaminated feeds had sum polychlorinated dibenzodioxins/furans (PCDD/Fs) and DL-PCB concentrations that were comparable with terrestrial food products such as beef, while the level of marine omega-3 fatty acids remained as high as for commercially farmed Atlantic salmon.

Depletion study of PCDD/Fs and dioxin-like PCBs concentrations in contaminated home-produced eggs: Preliminary study

Dioxins (PCDD/Fs) and polychlorinated biphenyls (PCBs) are ubiquitous environmental contaminants. The contamination of food products with dioxins and PCBs is a well studied issue, because food is generally considered the major source of dioxin intake for humans. In Italy, the Regional Monitoring Plan (part of the national residue monitoring plan) used in the field for 2009 has also included the control of environmental pollutants in small egg producers. Following an irregular result, 12 laying hens were transferred into a laboratory controlled environment. Eggs were collected for 60 days and they were weekly analysed for the evaluation of dioxins, dioxin-like PCBs (DL-PCBs), and non-dioxin-like PCBs (NDL-PCBs, six congeners) levels. The dioxins and PCBs contents were determined, according to EPA methods, by gas chromatography ic determination coupled with high resolution mass spectrometry (HRGC-HRMS). The content of PCDD/Fs, DL-PCBs and NDL-PCBs was evaluated weekly by mean from week to week. The concentration of dioxins was lower than DL-PCBs (2.5 pg TEQ g −1 of fat against 4.5 pg TEQ g −1 of fat), but we observed the same depletion trend for both pollutants. On the opposite, NDL-PCBs had a different course: we noted there was an increase between weeks 6 and 7, but the mean levels remained very low (about 20 ng g −1 of fat). The dioxins, and sum of dioxin and DL-PCBs concentration were below the fixed European limits (i.e. 3 pg TEQ g −1 of fat for dioxins and 6 pg TEQ g −1 of fat for sum of dioxins and DL-PCBs), beginning from the 3rd week of trial.

Atmospheric distribution of polychlorinated dibenzo- p-dioxins, dibenzofurans and dioxin-like polychlorinated biphenyls around a steel plant Area, Northeast China

Air monitoring of polychlorinated dibenzo- p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (PCBs) was carried out in June 2008 and January 2009 to investigate the concentrations, profiles and estimating potential inhalation risks to the local residents around a steel plant area in northeast China. The air concentrations and WHO-TEQs of PCDD/Fs ranged 94–4944 fg m −3 (average 1352 fg m −3) and 3–247 fg m −3 (average 81 fg m −3), respectively. The WHO-TEQ concentrations of dioxin-like PCBs ranged 1–18 fg m −3 (average 5 fg m −3), contributing to 3.6–26% of the total TEQ. Higher PCDD/F concentrations were observed in the winter, whereas higher dioxin-like PCB concentrations were found in the summer. The seasonal trend can be related to the significant correlation between the concentrations of dioxins and the reciprocal of temperature (positive for PCDD/Fs, P < 0.01; negative for dioxin-like PCBs, P = 0.05). A significant positive correlation ( P < 0.0001) was found between the concentration of total suspended particulate (TSP) and PCDD/F concentrations, but not for PCB congeners. Although the steel plant sites showed higher dioxin levels than the residential and background areas, the PCDD/F levels in the atmosphere of the steel plant area was at a relatively low level. The results from this study provides further aid in evaluating the impact of steel plants as PCDD/Fs emission sources to the ambient air in China.

Contamination levels and congener distribution of PCDDs, PCDFs and dioxin-like PCBs in buffalo’s milk from Caserta province (Italy)

An extraordinary plan of official control was carried out in 2008 in Campania (Italy) with the aim to monitor polychlorinated dibenzo- p-dioxins (PCDDs), dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) levels in buffalo milk and to detect the contaminated farms, most of which are located in Caserta province. For these companies has been ordered seizure and execution of additional analyses has been requested in farms falling in the nearness, within a distance of 3 km, for a total of 304 farms examined. Moreover, all non-compliant farms were subjected to a periodic sampling in order to monitor trends in the levels of contamination. In this paper the distribution and the concentrations of 17 PCDD/Fs and 12 dioxin-like PCBs in 460 samples of buffalo milk collected in the province of Caserta (Italy) are presented. The range of WHO-TEQ values for the PCDD/Fs in milk was 0.17 pg TEQ g −1 fat and 87.0 pg TEQ g −1 fat with a mean value 3.63 pg TEQ g −1 fat and medium value 2.25 pg TEQ g −1 fat. The concentrations of dioxin-like PCBs in the analysed samples ranged from 0.21 pg TEQ g −1 fat to 15.9 pg TEQ g −1 fat and the WHO-TEQ values of sum of PCDDs, PCDFs and dl-PCBs ranged from 0.45 pg TEQ g −1 fat to 103.0 pg TEQ g −1 fat. The geo-referencing analysis allowed to individuate a restricted area of the region object of the present study where is located the majority of the non-compliant farms. The study of the congeners distribution has finally suggested that the likely cause of contamination is to be attributed to the illegal burning of waste.

Polychlorinated dibenzo-p-dioxin, polychlorinated dibenzofurans and polychlorinated biphenyls in farmed fish, water, sediment, and feed

This investigation was undertaken to determine the levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dizenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (DL-PCBs) in farmed grouper tissues and environmental medium samples, including sediment, water, and feed. The water concentrations of DL-PCBs were low at 4.33–7.63 pg/L, and those of PCDD/Fs were 0.399–0.794 pg/L. The concentrations of PCDD/Fs in sediment samples were 21.4–35.3 pg/g, and those of PCBs were 54.7–100 pg/g. To identify changes in PCDD/Fs and PCBs levels in fish throughout growth, the tissue samples from hatchlings, 2-month, 15-month, 24-month, and 36-month-old orange spotted grouper (Epinephelus coioides) were analyzed. In grouper tissue samples, the total toxicity equivalent (TEQ) of the total PCBs were 0.129–0.745 pg World Health Organization- toxicity equivalent (WHO-TEQ/g) wet weight (w.w.), while total PCDD/Fs TEQ were 0.022–0.073 pg WHO-TEQ/g w.w¨ The DL-PCBs were contributed more to the TEQ than PCDD/Fs in all fish tissue samples. Both PCDD/F and DL-PCB concentrations increase as grouper age increased. Results of this study demonstrate that PCDD/Fs and PCBs accumulate in fish tissues, and diet is the main source of PCDD/Fs and PCBs accumulations.

Contamination and Congener Profiles of Polychlorinated Biphenyls from different agricultural top soils in a county of the Tailake Region, China

Hundred topsoil (0–20 cm) samples under different land use types were collected from a county in the Tailake Region, China and analyzed for 18 polychlorinated biphenyls (PCBs) including five dioxin-like PCBs. The mean concentration of total PCBs (ΣPCBs) for all sites was 1.071 μg kg −1 dry weight (dw) with a range of 0.016 μg kg −1 to 4.050 μg kg −1, and the concentration of total Dioxin-like PCBs (ΣDioxin-like PCBs) was 0.352 μg kg −1 about 33% of ΣPCBs. The concentration of ΣPCBs in paddy field (PF) soils with a mean of 1.637 μg kg −1 was higher than that in vegetable soil with a mean of 0.882 μg kg −1, but the concentration of Dioxin-like PCBs in PF soil was lower than that in commercial vegetable production soil. The concentration of heavier weighted molecular PCB congeners (≥penta-PCBs) in vegetable soil accounted for 98% of ΣPCBs, while that in Paddy field soil for 65% of ΣPCBs.

Persistent organic pollutants in breast milk of mothers residing around an open dumping site in Kolkata, India: Specific dioxin-like PCB levels and fish as a potential source

Concentrations of persistent organic pollutants (POPs) such as polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) and organochlorine pesticides were measured in human breast milk collected from mothers residing near an open dumping site and a reference site in Kolkata, India during 2004–2005. POPs were detected in all the human milk samples analyzed, suggesting that residents of Kolkata are widely exposed to these contaminants. Concentrations of dioxin-like PCBs in the samples from the dumping site were significantly higher than in the reference site samples, whereas no such difference was found for PCDDs and PCDFs. In addition, significantly higher concentrations of total PCBs were also observed in the samples from the dumping site than the reference site. Interestingly, concentrations of total and dioxin-like PCBs in the breast milk of mothers from the dumping site significantly increased with the number of years of residence near the dumping site. These results indicate that significant pollution sources of PCBs are present in the dumping site of Kolkata and the residents living around are exposed to relatively higher levels of PCBs. When the residue levels of dioxins and related compounds in fish collected from ponds near the Kolkata dumping site and the reference site were measured, it was found that dioxin-like PCB and TEQ levels in fish from the dumping site were notably higher than those from the reference site. This result indicates that fish is a potential source of PCBs for residents living near the Kolkata dumping site.

Accumulation of polychlorinated biphenyls and organochlorine pesticide in pet cats and dogs: Assessment of toxicological status

PCB and DDT concentrations were determined in the adipose tissue of cats and dogs from Southern Italy. In cats p,p′-DDE was the most abundant DDT component (95.0%), while in dogs these compounds were absent, except in two specimens. PCB concentrations were higher in cats (199.02 ng g − 1 lipid weight) than in dogs (41.61 ng g − 1 lipid weight). Also there were inter-specific differences in the contribution of the different congeners to PCBs, although PCB 138, PCB 153 and PCB 180 were the most representative congeners in both species. Animals from one location, Taranto City, had significantly elevated concentrations of dioxin-like PCBs compared to the other locations. Consequently the estimated mean 2,3,7,8-tetrachlorodibenzo- p-dioxin toxic equivalents (TEQs) of coplanar PCBs were higher in these animals (cats: 0.65 pg g − 1 lipid weight; dogs 0.29 pg g − 1 lipid weight) than in the other ones (cats: 0.12 pg g − 1 lipid weight; dogs: 0.001 pg g − 1 lipid weight).

민물 붕어 (Crucian carp)에 축적된 Dioxin, Furan 및 DL-PCBs 농도

Concentrations of dioxins, furans and dioxin-like polychlorinated biphenyls (DL-PCBs) were determined in crucian carp collected from eight locations mainly along the Nakdong River during 2004. Total dioxin concentrations which include concentrations of dioxins, furans and DL-PCBs ranged from 0.053 to 0.614 pg WHO-TEQ wet wt. with a mean of pg WHO-TEQ wet wt. The proportions of dioxins, furans and DL-PCBs to total dioxin TEQ were 4%, 12% and 84%, respectively. The results suggest that concentrations of dioxin-like polychlorinated biphenyls should be determined when total dioxin TEQ accumulated in freshwater fish is investigated.

Polychlorinated dibenzo- p-dioxins, dibenzofurans and biphenyls in crucian carp ( Carassius auratus) from rivers in Korea during 2000–2004

Concentrations of polychlorinated dibenzo- p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were analyzed in freshwater fish (crucian carp) taken from 16 locations in nine rivers and a wetland in Korea, during 2000–2004. Dioxin-like polychlorinated biphenyls (DL-PCBs) were also analyzed in the same samples but over shorter period (2002–2004). Concentrations on a wet weight basis for 3 years (2002–2004) ranged from below the detection limit (DL) to 0.36 pg TEQ g −1 wet wt. for PCDDs, below the DL to 2.0 for PCDFs, and from 0.02 to 1.9 for DL-PCBs, with a mean of 0.07, 0.33 and 0.83 pg TEQ g −1 wet wt., respectively. The proportions of PCDDs, PCDFs and DL-PCBs in the total dioxin TEQ for 2002–2004 were 7%, 26% and 67%, respectively. While the temporal trend showed a significant decrease in PCDDs/DFs concentrations over the 5-year study period, DL-PCBs did not show significant change in concentration over the 3-year period. The results suggest that DL-PCBs concentrations should be determined when total dioxin TEQ is analyzed in freshwater fish.

Removal of dioxins and dioxin-like PCBs from fish oil by countercurrent supercritical CO 2 extraction and activated carbon treatment

It has been known that fish oils are prone to contamination by polychlorinated dibenzo- p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (DL-PCBs). In this study, the removal of contaminants from fish oil by countercurrent supercritical CO 2 extraction (CC-SCE) and activated carbon treatment was investigated. Fish oil was treated by CC-SCE at 70 °C and 30 MPa and with a CO 2/oil ratio of 72; this resulted in a 93% reduction in the sum of PCDDs, PCDFs and DL-PCBs concentration level by and 85% reduction in toxic equivalency (TEQ). CC-SCE uses 40% less CO 2 and yields 30% more refined oil than semi-batch-type processes. Subsequent treatment by activated carbon reduced the concentration level by 94% and TEQ by 93%. CC-SCE is effective for the removal of DL-PCBs, whereas activated carbon treatment is effective for the removal of PCDD/Fs. These results reveal that the combination of CC-SCE and activated carbon treatment is applicable to the removal of PCDD/Fs and DL-PCBs from fish oil.

Interspecies variability of Dioxin-like PCBs accumulation in five plants from the modern Yellow River delta

To investigate the interspecies variance of Dioxin-like polychlorinated biphenyls (DL-PCBs) in the plants from modern Yellow River delta, the concentrations of 12 DL-PCBs congeners were examined in five plant species and their associated soils. The DL-PCBs concentrations in plants (2.32–287.60 ng/kg dry weight) were low compared to most published literature, and the concentrations and ratios of DL-PCBs congeners in plants varied greatly among species. The properties of plants and PCBs were then studied to explore the factors affecting the interspecies variance of DL-PCBs accumulation. The plants with the smallest variance of morphological and physiological characteristics ( Imperata cylindrical var. Major and Phragmites australis (Cav.) Trin. ex Steud) had the most similar accumulation patterns of DL-PCBs among the species tested. As the octanol–air partitioning coefficient ( K oa) of the DL-PCBs increased, interspecies variance decreased on the whole plant level. Interestingly, the correlation between the DL-PCBs concentrations in plants and log K oa of congeners was found to be significant for annual plants, but for perennial plants it was not significant. Thus the patterns of uptake of DL-PCBs are different between annual and perennial plants.

Levels, distributions and profiles of polychlorinated biphenyls in surface soils of Dalian, China

Surface soil (0–5 cm) samples from 14 sampling sites including rural and urban areas of Dalian, a coastal city in Liaoning Province, China, were collected and analyzed for 84 polychlorinated biphenyls (PCBs). Total 57 PCB congeners were identified and mean concentration of total PCBs among all the sites was 2.8 μg kg −1 dry weight (dw) with a range of 1.3 (rural site) to 4.8 μg kg −1 dw (urban site). For the urban sites, total PCB concentrations in the soil samples collected in industrial area are highest, followed by those from business/residential sites and the garden sites, but the differences are not significant. Higher percentage of lighter weighted molecular PCBs were found in the rural site than urban sites in Dalian, possibly indicating the “urban fractionation effect”. Total seven dioxin-like PCBs (CB-77, 81, 105, 114, 118, 123, and 126) have been found in Dalian soils and the mean concentration (in μg kg −1 dw) among all the sites of CB-105 (0.17) is higher than any other dioxin-like PCBs, followed by that for CB-81 (0.14) and for 118 (0.06). No significant correlation relationship between the concentrations of dioxin-like PCBs and those of total PCBs was found. The toxic equivalency (TEQ) concentrations (in ng kg −1 dw) of these seven dioxin-like PCBs in 14 soil samples range from 0.006 7 to 4.885 7 (with a mean 1.372 7) for humans and mammals, from 0.001 7 to 0.37 7 (with a mean 0.14 7) for fish, and from 0.01 7 to 31.47 7 (with a mean 17.23 7) for birds.

Biosensor immunoassay for the screening of dioxin-like polychlorinated biphenyls in retail fish

Dioxin-like polychlorinated biphenyls (DL-PCBs) often make up the majority of the toxic equivalent (TEQ) contribution of dioxins found in fish samples. For the purpose of making risk assessments, it is therefore important to develop screening methods for determining TEQ concentrations of DL-PCBs in retail fish. We have developed a rapid biosensor immunoassay (BIA) for DL-PCBs that uses a surface plasmon resonance sensor (Biacore 3000). The BIA is highly specific for 2,3′,4,4′,5-pentachlorobiphenyl (PCB 118) that is generally the most abundant DL-PCB isomer found in fish. The fish extracts were first cleaned up on a multilayer silica gel column followed by an alumina column, then subjected to the assay. The quantitative limit of the assay was 1 ng PCB 118 per gram of tested sample. Dilution and recovery tests using purified fish extracts suggested that the matrix effect was minimized in the assay by diluting the analyzed samples. The assay results for retail fish samples ( n = 7) agreed well with those obtained by an enzyme-linked immunoassay (ELISA) using the same monoclonal antibody: ELISA has been already validated for determining DL-PCBs in fish samples, so BIA performs well in this analysis. Finally, BIA results for the TEQ concentrations of DL-PCBs in retail fish samples ( n = 10) correlated well with those obtained by high-resolution gas chromatography coupled to high-resolution mass spectrometry ( r = 0.89). Our method is therefore useful for screening retail fish to determine the TEQ concentrations of DL-PCBs.

Congener‐specific characterization and sources of polychlorinated dibenzo‐p‐dioxins, dibenzofurans and dioxin‐like polychlorinated biphenyls in marine sediments from industrialized bays of Korea

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (DLPCBs) were determined in 122 coastal sediments from heavily industrialized areas in Korea. Toxic equivalent (TEQ) concentrations of PCDD and PCDF (PCDD/F) and DLPCB ranged from 0.44 to 38.5 pg/g dry weight and from 0.01 to 38.4 pg/ g dry weight, respectively. Overall PCDD/F and DLPCB concentrations were elevated in estuarine and inner bay locations close to industrial complexes, indicating that these contaminants derived from local discharges. Concentrations of PCDD/F measured in the present study were comparable to those in industrialized areas of other countries. Nonparametric multidimensional scaling ordination and congener-specific characterization showed that combustion processes occurring in industrial complexes, including the steel industry, are the major source of PCDD/Fs in Korean coastal waters. There were no significant correlations among PCDD/ Fs, DLPCBs, and total organic carbon; however, there was moderate correlation between PCDD/Fs and DLPCBs in some coastal bays, suggesting that these chemicals have similar sources and movements in these locations.

Levels of PCDDs, PCDFs and dioxin-like PCBs in raw cow’s milk collected in France in 2006

Polychlorinated dibenzo- p-dioxins and dibenzofurans (PCDD/Fs) as well as polychlorinated biphenyls (PCBs) are widespread environmental contaminants. A French national survey was carried out in April 2006 to assess the concentrations of PCDD/Fs and dioxin-like PCBs (DL-PCBs) in raw cow’s milk. A random sampling scheme stratified by region was applied to collect 239 raw milk samples from 93 plants belonging to 17 dairy companies. Compared to a previous survey led in 1998 analyzing half-skimmed drinking milk in France, the PCDD/Fs level was cut by half, with an average concentration of 0.33 pg toxic equivalent (TEQ)/g fat in 2006. The mean DL-PCBs concentration was 0.57 pg TEQ/g fat and subsequently the sum of PCDD/Fs and DL-PCBs was 0.90 pg/g fat, values below the thresholds defined by the European Union regulations.

Polychlorinated dibenzo-p-dioxins, dibenzofurans and biphenyls in fish from the Netherlands: concentrations, profiles and comparison with DR CALUX® bioassay results

Fish from Dutch markets were analysed for concentrations of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) and compared with the new European maximum residue levels (MRLs), set in 2006. In a first study on 11 different fish and shellfish from various locations, concentrations of PCDD/Fs were nearly all below the MRL for PCDD/Fs [4 pg toxic equivalents (TEQ) per gram wet weight (ww)] and nearly all below 8 pg total TEQ/g ww, the new MRL for the sum of PCDD/Fs and DL-PCBs. Some samples exceeded the total TEQ MRL, such as anchovy, tuna and sea bass. Furthermore, 20 (out of 39) wild eel samples exceeded the specific MRL for eel (12 pg total TEQ/g ww), as the study revealed PCDD/F TEQ levels of 0.2-7.9 pg TEQ/g ww and total TEQ values of 0.9 to 52 pg/g ww. TEQ levels in farmed and imported eel were lower and complied with the MRLs. Smoking eel, a popular tradition in the Netherlands, only had marginal effects on PCDD/F and DL-PCB concentrations. Owing to volatilization, concentrations of lower-chlorinated PCBs were reduced to below the limit of quantification after smoking. DL-PCBs contributed 61-97% to the total TEQ in all eel samples. This also holds for other fish and shellfish (except shrimps): DL-PCB contributed (on average) from 53 (herring) to 83% (tuna) to the total TEQ. Principal-component analysis revealed distinctive congener profiles for PCDD/Fs and non-ortho PCBs for mussels, pikeperch, herring and various Mediterranean fish. The application of new TCDD toxic equivalency factors (TEFs) set by the World Health Organization in 2006 (to replace the 1997 TEFs) resulted in lower TEQ values, mainly owing to a decreased mono-ortho PCB contribution. This decrease is most pronounced for eel, owing to the relative high mono-ortho PCB concentrations in eel. Consequently, a larger number of samples would comply with the MRLs when the new TEFs are applied. The DR CALUX(R) assay may be used for screening total TEQ levels in eel, in combination with gas chromatography-high resolution mass spectrometry confirmation of suspected samples. An almost 1:1 correlation was found when the 1997 TEFs were applied, but, surprisingly, a 1.4-fold overestimation occurred with application of the 2006 TEFs.

PCB contamination in farmed and wild sea bass (Dicentrarchus labrax L.) from a coastal wetland area in central Italy

Food consumption is by far the main exposure route for polychlorinated biphenyls (PCBs) for the general population, and fish and fishery products seem to be the main contributors to the total dietary intake of these pollutants. In recent years some investigations have suggested that farmed fish may be more significantly contaminated than wild fish, because of polluted feed. This study measured the levels of PCBs in wild and farmed sea bass (Dicentrarchus labrax L.), one of the most valuable and popular fish in the Italian diet, and assessed the exposure to these pollutants through fish intake. Concentrations of summation operator (Sigma59PCBs) and dioxin-like PCBs (DL-PCBs), as toxic equivalency (TEQ), in fish samples, ranged from 2.2 to 32ngg(-1) and from 0.1 to 4.0pg TEQ((2006) DL-PCBs)g(-1) whole weight, respectively. Farmed sea bass were as average two times more contaminated. Even if the concentrations of DL-PCBs were below the regulation limits, intake of these compounds from nine fish meals per month can in itself exceed the WHO Provisional Tolerable Monthly Intake (PTMI).