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31.
In this study, we investigated the suppressive effect of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (DL-PCBs) transfer from the feed to the eggs of laying hens by using activated carbon as a feed additive. Four groups of six hens (White Leghorn egg-layers; age, 11 weeks) were housed as two control groups and two exposure groups for a period of 20 weeks. Two control groups were fed with either the basal feed “Control” or basal feed additing activated carbon “Control + C”. Another two exposure groups were fed with feed contaminated (about 6 ng TEQ kg−1 feed) by standard solutions of PCDDs/PCDFs and DL-PCBs “Exposure” alone and contaminated feed adding activated carbon “Exposure + C”. There was no significant effect on each groups for the growth rate, biochemical blood components, and egg production: these were around the standard levels for poultry in general. Moreover the results in this study showed the availability of activated carbon as a feed additive owing to the reduction in the risk of food pollution by PCDDs/PCDFs and DL-PCBs. The concentration in the eggs of the Exposure group gradually increased following the start of egg-laying but reached a steady state after about 1 month. In contrast, the concentration for the Exposure + C group was stationary and below the maximum EU level (6 pg TEQ g−1 fat). In comparison to the Exposure group, the Exposure + C group showed a significant decline in the percentage of bioaccumulation into the egg. This reduction due to activated carbon was also observed in the muscle and abdominal fat. The reductions were compound- and congener-dependent for DL-PCBs as follows: PCDDs/PCDFs, non-ortho-PCBs, and mono-ortho-PCBs were more than 90%, 80%, and 50%, respectively, irrespective of the type of tissues. Fat soluble vitamin concentrations in the eggs of the Exposure + C group showed lower trends than the Exposure group. The γ-tocopherol and α-tocopherol concentrations in eggs of Exposure + C group showed a significant reduction of about 40%. However, the addition of activated carbon into animal feed could obviate the remote potential for accidents causing unintentional food pollution with PCDDs/PCDFs and DL-PCBs. 相似文献
32.
Markku Korhonen Simo Salo Harri Kankaanpää Hannu Kiviranta Päivi Ruokojärvi Matti Verta 《Chemosphere》2013
Sediment trap material was collected during May–December in the period 1996–2008 in three coastal areas and four open sea stations in the Finnish territory of the Baltic Sea. The highest sedimentation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) with a typical source-related congener profile from chlorophenol production dominated by highly chlorinated dibenzofurans was found close to a historical source in the Kymijoki estuary. This was an order of magnitude higher than in other river estuaries and two orders of magnitude higher than in the open sea stations. The sedimentation of polychlorinated biphenyls (PCBs) was also higher in river estuaries than in other areas. No significant decrease over a 12 year period of monitoring was found in concentration or in sedimentation in the Kymijoki estuary. In the western Gulf of Finland, the Archipelago Sea and the Gulf of Bothnia, the dominating congeners, calculated as toxic equivalent (TEQ) in sedimentation were 1, 2, 3, 7, 8-PeCDD and 2, 3, 4, 7, 8-PeCDF, often reported as the main congeners in deposition. 相似文献
33.
Corsolini S Borghesi N Schiamone A Focardi S 《Environmental science and pollution research international》2007,14(6):421-429
Background, Aims and Scope Fish-eating seabirds are recognized to be at risk of accumulating toxic contaminants due to their high position in the trophic
web and to their low ability to metabolize xenobiotic compounds. Penguins are widely distributed in Antarctica and represent
an important fraction of the Antarctic biomass. They feed mainly on krill and, depending on krill availability, also on fish.
It has been reported that predators may be a sink for volatile and toxic chemicals and this may pose a serious environmental
problem. Polybrominated diphenyl ethers (PBDEs), polychlorinated dibenzo-dioxins (PCDDs),-furans (PCDFs), and-biphenyls (PCBs),
including non-ortho congeners, hexachlorobenzene (HCB) and p,p′-DDE, were quantified in three species of Antarctic Pygoscelids in order to evaluate their accumulation patterns. The potential
toxicity of twenty-two dioxin-like congeners was assessed and expressed as 2,3,7,8-tetraCDD equivalents (TEQs). Differences
between males and females were investigated.
Methods Blood samples of the Adélie penguin Pygoscelis adeliae, Chinstrap penguin Pygoscelis antarctica and Gentoo penguin Pygoscelis papua were collected at Admiralty Bay, King George Is (62°10′39″ S, 58°26′46″ W) in February 2004. Halogenated hydrocarbons were
identified and quantified using gas chromatography coupled with gas chromatography mass spectrometry analyses. Results are
expressed on a wet weight basis.
Results and Discussion HCB, p,p′-DDE and ΣPCBs were higher in Adélie penguins (6.7±6.1, 8.2±3.3 and 9.8±3.8 ng/g, respectively) than in Chinstrap and Gentoo
penguins, both of which showed values in the same order of magnitude, but approximately 40% lower than Adélie penguins. Hexa-CBs
ranged 35–45% of the residue. Low-chlorinated PCBs (nos. 70+76+95+56+60+101) accounted for 40–60% in the three species. PCB101
made up 15% of the residue in Adélie penguins. PBDEs were 291±477, 107±104 and 116±108 pg/g in Adélie, Chinstrap and Gentoo
penguins, respectively; the most abundant congeners were BDE47 in Adélie and Chinstrap penguins and BDE17 in Gentoo penguins.
PCDDs were 22±32, 6.5±7.4 and 18±23 pg/g in Adélie, Chinstrap and Gentoo penguins, respectively. PCDFs were higher in Adélie
penguins and lower in Chinstrap penguins. PCDDs/Fs and PBDEs were higher in males than in females of Gentoo and Chinstrap
penguins; differences in concentrations were likely related to the partial detoxification that occurs in females during egg
formation. Of the four non-ortho PCBs measured, PCB126 occurred at the highest concentrations and contributed the majority of the non-ortho PCB-TEQ in Gentoo and Chinstrap penguins. The highest TEQs were found in the Gentoo penguin and due mainly to PCDDs and non-ortho PCBs.
Conclusions POP concentrations in penguins were lower than those found in seabird species from other areas of the world. Different chemical
accumulation patterns were observed in relation to species and sex; the Adélie penguin showed the highest POP levels. Dissimilar
ecological or metabolic features may be involved; the diverse timing of reproduction steps can be responsible for those differences;
moreover, Adélie penguins feed on krill (a fatty resource) more abundantly than the other two species during the rearing period.
Recommendation and Outlook The South Shetland Islands might be subjected to a higher chemical impact with respect to the rest of Antarctica, due to their
being near South America. Because penguins are fish-eating birds showing low detoxifying capacities and key-species in Antarctic
ecosystems, further studies on their xenobiotic metabolism should be carried out. 相似文献
34.
LI Xiao-dong ZHANG Ji YAN Jian-hu CEN Kef RYAN Shawn P GULLETT Brian K LEE Chunwai 《环境科学学报(英文版)》2007,19(1):117-122
The effect of sulfur dioxide (SO2) on the formation of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) has been studied in an entrained-flow reactor (EFR) under simulated waste combustion conditions. A chlorination model based on conditional probability was employed to evaluate the homologue patterns of PCDDs and PCDFs. Results revealed that the presence of SO2 did not alter the formation pathway although SO2 suppressed PCDD/F formation. The prediction model of PCDF showed good agreement with the experimental data (R--0.95), whereas the prediction for PCDDs did not correlate well with the experimental data. This may be explained because potential chlorination pathways play a significant role in PCDF formation, whereas PCDDs are mainly formed through condensation reactions. Furthermore, the result indicated that the steric hindrance during formation has more effects on PCDD than on PCDF due to the symmetric molecular structures of PCDDs. 相似文献
35.
Presently, in Japan there are no limitations on the emission of PCDDs or PCDFs, but in order to study the feasibility of dry type air pollution control, a pilot plant was constructed in 1988 and the removal efficiencies for PCDDs, acid gas and heavy metals were measured.At the same time PCDDs concentration was compared with that of a previously installed electrostatic precipitator (ESP) plus wet scrubber line.In this paper, the following two items are reported.
- 1. (1) The difference in the amounts of PCDDs and PCDFs produced due to differences in gas temperature and retention time in ESP and fabric filter (FF).
- 2. (2) Removal efficiencies of PCDDs and PCDFs of fabric filter.
36.
Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/DFs) were detected in waterfowl such as common cormorants, tufted ducks, and their prey, namely fish and bivalves from Lake Shinji, Japan. The concentration of total PCDDs/DFs-TEQ was found to be higher in the muscle tissues of common cormorants than in those of tufted ducks. The results of hierarchical cluster analysis implied that the residue distribution pattern of PCDD/DF homologues was considerably different between these two species. Furthermore, biomagnification factors (BMFs) were estimated from bivalves as prey to tufted duck muscles as target organs. Despite the highest concentrations of 1,3,6,8- and 1,3,7,9-TeCDD in tufted ducks and their prey, however, the BMFs of these isomers were calculated to be lower than those of the toxic 2,3,7,8-substituted PCDDs/DFs. On the other hand, log BMF of toxic 2,3,7,8-substituted PCDDs/DFs were significantly higher for lower chlorinated isomers than those of the higher chlorinated isomers. The biota-sediment accumulation factors (BSAFs) of PCDDs/DFs were also estimated using shijimi clam and fish samples against sediment from Lake Shinji. The average BSAFs were estimated and ranged from 4.0×10−3 to 2.2×10−1 and 2.0×10−4 to 2.0×10−1 for bivalve and fish samples, respectively. Based on calculated BMFs and BSAFs, the total PCDD/DF-TEQ levels in the tufted duck were estimated to have been lowest (2.0 pg TEQ/g dry weight basis) in 1947 and highest (9.8 pg TEQ/g) in 1971. 相似文献
37.
38.
Levels of PCDDs and PCDFs in products and effluent from the Swedish pulp and paper industry and chloralkali process 总被引:1,自引:0,他引:1
Within the Swedish Dioxin Survey various samples from the pulp and paper industry and the chloralkali process have been analyzed by congener specific analytical methods. In addition to the generally discussed “bleaching pattern” of the tetrachlorinated congeners, these samples also contained higher chlorinated congeners like hexa-CDDs, hepta-CDFs, octa-CDD and octa-CDF. Consequently it is recommended that samples from the pulp industry should be analyzed for all PCDDs and PCDFs (tetra- through octa-). Counted as Nordic Toxic Equivalents (NTEQ), the recycled pulp samples had the highest contamination level followed by TMP, unbleached sulfite and bleached softwood and hardwood. In addition to the bleaching process, various chemicals used in the pulping, bleaching and wastewater treatment can contribute to the contamination. 相似文献
39.
Levels of PCDDs, PCDFs and non-ortho PCBs in serum samples of non-exposed individuals living in Madrid (Spain) 总被引:1,自引:0,他引:1
In an attempt to evaluate the background levels of PCDDs, PCDFs and non-ortho PCBs in people living in Madrid (Spain), blood serum samples had been analyzed PCDD, PCDF and coplanar PCB levels from non exposed individuals are reported in this study. Average levels found were 515.29 ppt for total PCDDs, 66.73 ppt for total PCDFs and 85.47 ppt for non-ortho PCBs on a lipid weight basis Calculated I-TEQ values were 8.78 ppt for PCDDs, 6.96 for PCDFs and 7.03 for coplanar PCBs on a lipid weight basis. 相似文献
40.
Wolfgang K?rner 《Umweltwissenschaften und Schadstoff-Forschung》2005,17(2):115-121
Zusammenfassung
Ziel und Absicht Der derzeitige Kenntnisstand zu Quellen, Verbleib in der Umwelt, Exposition des Menschen und gesundheitlicher Bewertung von
dioxin?hnlichen polychlorierten Biphenylen (PCB) und nicht dioxin?hnlichen PCB wird mit Fokus auf den deutschsprachigen Raum
dargestellt und zusammengefasst.
Methoden Grundlage für den aktuellen Kenntnisstand sind die Vortr?ge und Diskussionsergebnisse eines zweit?gigen bundesweiten Statuskolloquiums.
Die Bedeutung der dioxin?hnlichen PCB wird insbesondere in Relation zu den polychlorlerten Dibenzo-p-dioxinen (PCDD) und Dibenzofuranen
(PCDF) betrachtet. Dazu dient in erster Linie ein Vergleich der Toxizit?ts?quivalentkonzentrationen (TEQ) beider Stoffgruppen
in den betrachteten Umweltmatrices.
Ergebnisse und Schlussfolgerungen In vielen Umweltmedien sind die TEQ-Werte der dioxin?hnlichen PCB ?hnlich hoch wie die PCDD/PCDF-Gehalte, in den meisten Lebensmitteln
tierischen Ursprungs sogar h?her. In den meisten Medien hat das nichtortho substituierte PCB 126 aufgrund seines hohen Toxizit?ts?quivalenzfaktors
von 0,1 den mit Abstand h?chsten Beitrag zum PCB-TEQ. Für die gro?fl?chige Umweltbelastung mit PCB ist offensichtlich der
atmosph?rische (Fern) Transport wesentlich. Für den Eintritt der dioxin?hnlichen, PCB in terrestrische Nahrungsketten ist
der Transfer Atmosph?re-Pflanze wahrscheinlich der entscheidende Schritt.
Empfehlungen und Ausblick Trotz des Rückgangs der Umweltbelastung mit PCB und PCDD/PCDF überschreitet ein erheblicher Teil der Bev?lkerung in Deutschland
und anderen europ?ischen Staaten gegenw?rtig noch die duldbare Aufnahme an, dioxin?hnlichen Substanzen. Aber auch aufgrund
einer aktuellen toxikologischen Neubewertung der nicht-dioxin?hnlichen PCB muss die Verminderung der PCB-Exposition weiter
betrieben werden.
OnlineFirst: 11. April 2005 相似文献