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1.
The use of oil-based drilling muds has been discouraged in hydrocarbon exploration and production in the marine environment but these muds are presently being used to a considerable degree in the United Kingdom and Norwegian sectors of the North Sea. Field studies in the North Sea have demonstrated only localized impacts around individual drilling sites,1,2 even including those sites where ‘toxic’ diesel oils were employed as base fluids in drilling muds. Yet the question of disposal of cuttings contaminated with oil from drilling muds remains somewhat controversial. The induction of mixed-function oxygenases (MFO) has been validated on a number of occasions in the field as a sensitive index of low level hydrocarbon exposure (reviewed by Payne),3 including sites in the North Sea where diesel-based muds were used.4 The present study demonstrates that any potential for induction by hydrocarbon contaminated cuttings will probably be reduced by substitution of low-aromatic base oils for diesel in drilling mud formulations.  相似文献   

2.
Polycyclic aromatic hydrocarbons (PAHs) were identified and measured in surface seawater and in the tissues (gills and mantle) of indigenous black mussels, Mytilus galloprovincialis, collected from three coastal sites of Saronikos Gulf (Greece), a gulf that exhibits high levels of pollution. The total PAHs measured by spectrofluorometry in the surface seawater were found in the range of 425–459 ng L−1 at the most polluted sites 1 and 2 (Elefsis Bay–Salamis Island) and in the range of 103–124 ng L−1 at site 3 (Aegina Island). PAHs' sources in seawater were identified by application of specific PAH ratios, such as phenanthrene/anthracene and fluoranthene/pyrene. Levels of PAHs in soft tissues (gills and mantle) of indigenous mussels were much higher than those reported for seawater. Total PAH concentrations in mantle tissues were in the range of 1300–1800 ng g−1 dry weight (dw) tissue at sites 1 and 2 and approximately 380 ng g−1 dw at site 3. In gill tissues total PAH concentrations were in the range of 1480–2400 ng g−1 dw at sites 1 and 2 and approximately 430 ng g−1 dw at site 3. PAHs composition was dominated by two-, three- and four-ring compounds in seawater, where 17 different PAH compounds were identified and measured in mussel tissues. Mussels can be used as sentinel organisms to monitoring PAHs' contamination, since they concentrate PAHs from the surrounding water media and therefore making the chemical analysis simpler and less prone to error than that for water. In surface seawater possible weathering and photodegradation due to hot climates contribute to reduced PAHs concentrations.  相似文献   

3.
Newark Bay (NB) killifish (Fundulus heteroclitus) have been chronically exposed to environmental contaminants that activate the aryl hydrocarbon receptor (AHR) and are tolerant to toxic effects and CYP1A induction provoked by AHR ligands. Resistance to CYP1A induction could be due to an epigenetic mechanism such as DNA methylation. We measured in-ovo CYP1A catalytic activity (ethoxyresorufin-O-deethylase, EROD) in NB and reference site killifish embryos aqueously exposed to various concentrations of the de-methylating agent 5-azacytidine, 5-AC (5, 50 and 500 μ(micro)M) with or without 0.2 μ(micro)g/l of the CYP1A inducer 3,3′,4,4′,5 pentachlorobiphenyl (IUPAC PCB126). Neither PCB126 alone, nor PCB126 plus 5-AC, induced EROD above levels in vehicle treated Newark Bay fish. In reference site fish, the same PCB126 dose provoked a 7.4-fold EROD induction relative to controls. We conclude that Newark Bay killifish are resistant to CYP1A induction by co-planar PCBs during early embryological development and our data suggests that DNA methylation does not play a critical role in resistance to CYP1A induction in this model.  相似文献   

4.
Suspended matter (SM) and surface sediments were analysed for polycyclic aromatic hydrocarbons (PAH) throughout the Ob and Yenisei River estuaries and in the Kara Sea in order to evaluate the contamination of Arctic shelves by these two major Siberian rivers. PAH concentrations were extremely low, among the lowest measured up to now in the Arctic region. Particle-associated PAH were in many cases non-detectable. A total PAH maximum value of 3·2ngl − 1was found in surface waters. In surficial sediments, they spanned a range from 24 to 115ngg − 2in the Ob River, from 40 to 131ngg − 2in the Yenisei and from 16 to 94ngg − 2in the Kara Sea. Compositional features revealed a contribution of detrital material eroded from soils of the drainage basins and inputs from airborne pyrolytic PAH emitted at lower latitudes and from industrial complexes in Siberia. Particulate and sedimentary PAH distributions were highly variable both in type and concentration. The Ob and Yenisei estuaries are geographically large features where hydro-dynamical and sedimentary processes are complex. As a consequence, inhomogeneities—in the form of patch-structures—develop and make it difficult to resolve the fate of riverborne constituents based on ship measurements only. Remote sensing in conjunction with oceanographic observations may provide further guidance to study large river systems.  相似文献   

5.
Polycyclic aromatic hydrocarbon (PAH) bioaccumulation by the polychaete worm Streblospio benedicti (Webster) was measured under exposure to PAH-contaminated sediments in the field and for 28 d in the laboratory. Streblospio benedicti collected from field sediments contaminated at 2.94, 1.07, and l.52 μg g−1 fluoranthene (FLU), benz[a]anthracene (BAA), and benzo[a]pyrene (BAP), bioaccumulated those PAHs at 1.53, 0.215, and 0.332 μg g−1, while worms isolated from less contaminated field sediments (0.399, 0.228, 0.288 μg g−1 FLU, BAA, and BAP) had FLU, BAA, and BAP body burdens of 0.543, 0.236, and 0.083 μg g−1. Worms incubated for 28 d in PAH-spiked sediments (1.52, 0.991, 0.504 μg g−1 FLU, BAA, and BAP) bioaccumulated those PAHs at 0.382, 0.966, and 0.602 μg g−1, respectively. Data normalization to organism lipid and sediment organic carbon (biota-sediment accumulation factors [BSAFs] strongly suggest that Streblospio PAH bioaccumulation was directly related to percent sediment organic carbon, but BSAFs were substantially lower than predicted by equilibrium partitioning theory. BSAFs decreased with increasing PAH log Kow, in worms collected from field sediments, but in spiked sediments BSAFs increased with increasing PAH hydrophobicity. This disparity may have been caused by insufficient spiked-sediment equilibration time (1.5h) in the case of the laboratory test sediments.  相似文献   

6.
Coastal marine sediment, air and seawater samples were collected at six sampling stations in the Eastern Mediterranean Sea distant from pollutant point sources. All sediment samples were analyzed to determine polycyclic aromatic hydrocarbon (PAH), black carbon (BC) and organic carbon (OC) contents. The PAH contents of gaseous and seawater samples of the study were determined in order to evaluate the role of air–sea exchange as PAH nonpoint source to the marine sediments. The average concentration of the total PAHs (∑PAHs) in the sediments varied from 2.2 to 1056.2 ng g−1 dry weight. The average BC and OC contents varied from 0.3 to 5.6 and from 2.9 to 21.4 mg g−1 dry weight, respectively. ∑PAH concentration in the marine atmosphere varied from 20.0 to 83.2 ng m−3. Air–water exchange flux (FA–W) estimation has indicated air transport as a significant source of PAHs to pristine marine sediments of Eastern Mediterranean. In addition, the significant correlation between the PAHs and the organic and soot carbon content further suggests the importance of atmospheric input of PAHs to the sediments.  相似文献   

7.
We have proposed a time-weighted measurement using blue rayon that selectively adsorbs and concentrates polycyclic aromatic hydrocarbons (PAH), e.g. benzo(a)pyrene (BaP). Though the method was demonstrated to be a convenient way to monitor PAH, the amount adsorbed to the blue rayon depends on the intensity of water stream and the level of PAH. The intensity of water stream was measured by ‘plaster ball’ method, while TWA of PAH in water was measured by a portable sampler using solid phase extraction cartridge. A level of BaP measured by the original blue rayon technique was corrected in this way by the water stream intensity, which correlated well with the TWA of BaP measured by the portable sampler. The improved blue rayon hanging method was applied to several field sites in the Seto Inland Sea of Japan. TWA of BaP ranged from 0.08 to 3.78 ngl−1. These results showed the possibility that the method could be used to evaluate pollution in aquatic environment.  相似文献   

8.
The incidence of hepatoma, epidermal and other forms of cancerous growths in fish is well documented (Halver, 1967; Matsushima & Sugimura, 1976; Dawe et al., 1964). In fish, as in mammals, cancer may be a result of metabolically activated carcinogens. In mammals the primary enzyme system involved in the activation of environmental carcinogens is the cytochrome P-450 linked mixed-function oxidase (MFO). The hepatic microsomes of the species offish studied contain variable levels of cytochrome P-450. Liver microsomes of the trout Salmo trutta lacustris are surprisingly active in metabolising benzo-[a]pyrene (BP) and other compounds preferentially metabolised by polycyclic aromatic hydrocarbon (PAH)-specific cytochrome P-450. This finding may be significant, because it is apparent that the detrimental effects of PAHs require metabolic activation.We have studied the production of reactive intermediates of BP by following their binding to DNA and by measuring the specific nucleotide-BP metabolite complexes by chromatography. Untreated S. trutta liver microsomes catalyse the production of reactive intermediates of BP which bind to nucleotides of DNA at a rate that is 3–4 times higher than that catalysed by control rat liver microsomes. The most prominent DNA-BP metabolite adducts produced by trout liver microsomes are the nucleoside adduct of BP-7, 8-diol-9,10-epoxide and 9-OH-BP-4,5-oxide and other phenol oxides. In contrast to the trout, another fish species, roach (Rutilus rutilus), has extremely low activity. Although the in vitro binding of BP to DNA is not strictly correlated to in vivo binding or biological effects, our results show that reactive intermediates are formed by trout liver and thus the prerequisite for chemical carcinogenesis or mutagenesis is ful filled. This is further supported by the fact that in Ames's test, trout liver preparations produce mutagenic products from promutagens.  相似文献   

9.
In 1993 collections of marine mussels (Mytilus galloprovincialis) were deployed 1 m from the water surface at six sites in San Diego Bay for 88 days. A similar mussel deployment was conducted in 1995, except the animals were deployed 1 m off the bottom and only for 32 days. After recovery from the sites, tissue was extracted with dichloromethane and the solvent extracts analyzed for chemical contaminant content and the ability to produce CYP1A1 induction in a transgenic cell line (TV101L cells). The cells used in the assay (P450 RGS) are stably transfected with a plasmid containing firefly luciferase linked to human CYP1A1 promoter sequences. Induction (fold increase compared to control) was determined by luminometry 16 h after application of small volumes (2–10 μl) of solvent extracts to cultured cells. Small mussels deployed in the Naval Station (NAV) in 1993 exhibited very high bioaccumulation of polycyclic aromatic hydrocarbons (PAHs; 52 μg/g) and polychlorinated biphenyls (PCBs), in addition to very strong induction of CYP1A1 measured by reporter gene system (RGS) responses. Large mussels deployed at the NAV station in 1993 and intermediate-sized animals placed at three stations within the NAV station in 1995 accumulated 13–29 μg PAH/g and exhibited relatively high RGS responses. Correlation of RGS responses for all mussel samples to the measured PAH concentrations was 0.85 (r2). When the concentrations of seven specific PAHs found in the samples are converted to benzo[a]pyrene equivalents, from previously derived toxic equivalency factors (TEFs) for this test system, and compared to measured RGS responses, the correlations are approximately 0.9. The results of these studies indicate that the RGS biomarker can be used as a screening tool for detection of CYP1A1-inducing compounds in tissues, and an estimate of potential human health or ecological risk from ingestion of contaminated organisms. Positive RGS responses can be followed by detailed chemical analyses of PAHs and coplanar PCBs using the same extract.  相似文献   

10.
This study was undertaken to determine the potential for trophic transfer of polycyclic aromatic hydrocarbon (PAH) metabolites from infaunal organisms to bottom-feeding fish. Winter flounder, Pseudopleuronectes americanus, were given single oral doses of ground polychaetes (Nereis virens), either treated with pure [14C]henzo[a]pyrene (BaP) or containing a mixture of naturally produced radiolabeled BaP and BaP metabolites. Fish were sacrificed 24 h after feeding and total accumulated radioactivity and metabolite class profiles determined in major organs. Metabolites produced by worms were absorbed by flounder, although as a percentage of dose given they were less available than parent BaP. Comparison of metabolite profiles in the worm diet and in target organs in the fish indicated that metabolites accumulated through the diet can be further modified by the prey organism and can lead to the formation of bound residues. These results demonstrate that PAH metabolites in the diet are available for accumulation. Furthermore, metabolites absorbed appear to be susceptible to metabolic alteration by consumer organisms.  相似文献   

11.
This paper reports a rapid and facile procedure for obtaining of DNA from small, whole aquatic organisms (fathead minnow, Pimephales promelas) as well as from the liver of another species (bluegill sunfish, Lepomis macrochirus) and the subsequent estimation of its double strandedness. DNA was isolated from various tissues by homogenization in a basic pH solution containing detergent followed by differential extraction using organic solvents. Additional purification was accomplished by molecular sieve chromatography. Under defined alkaline unwinding conditions, the amount of double-stranded and single-stranded DNA was determined using the bisbenzimidazole dye Hoechst 33258. The technique was used to detect the occurrence of strand breaks in DNA of fathead minnows chemically exposed to benzo[a]pyrene.  相似文献   

12.
Indices of hepatic mixed function oxidase (MFO) activity in winter flounder (Pseudopleuronectes americanus) were measured at approximately monthly intervals from November 1983 to October 1985. Benzo[a]pyrene hydroxylase and ethoxyresorufin O-deethylase activities and cytochromes P450 and b5 were generally, but not significantly, higher in males than in females. The MFO activity varied seasonally, reaching a maximum during or shortly after spawning. Variation in MFO enzyme activity between sexes was never greater than 2-fold at any time, and within sex, no greater than 6-fold during the seasonal cycle. This variability is less than that caused by exposure to environmentally realistic levels of some pollutants; measurements of MFO activity in this species might therefore be used to indicate environmental contamination.  相似文献   

13.
The degree of induction of hepatic mixed function oxidase (MFO) enzymes in fish is modulated by environmental conditions. This study was designed to investigate the influence of water temperature, presence or absence of food, and exposure to benzo(a]pyrene (BaP) on the inductive response of bluegill sunfish (Lepomis macrochirus). The results show an increase in 7-ethoxyresorufin O-deethylase (EROD) activity with an increase in acclimation temperature and dose. This activity appears to be associated with a very small fraction of the total cytochrome P-450 induced. Major changes were observed in the 53- and 57-kilodaltons (kDa) electrophoretic bands.  相似文献   

14.
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15.
Turbot (Scophthalmus maximus) and mussel (Mytilus edulis) microsomes were incubated with DNA to examine if microsomal in vitro metabolism of BaP could result in DNA adducts detected by 32P-postlabelling. Turbot DNA was incubated with benzo[a]pyrene (BaP), NADPH and microsomal activating systems prepared from either livers of unexposed turbot, turbot exposed to BaP or β-naphthoflavone (ß-NF) or digestive glands from mussels. The β-NF activating system generated the highest levels of DNA adducts detected in this study (451.7 adducts per 108 nucleotides) and were distributed in three discrete adduct TLC spots, one of which (97% of the total adducts) co-migrated with the 32P-postlabelled BaP 7,8-diol, 9,10-epoxide-N2-guanine adduct. Fewer adducts (P <0.05) were generated by BaP-induced microsomes (9.4–30.6 adducts per 108 nucleotides) but levels were higher (P <0.05) than those generated from untreated fish (3.5 adducts per 108 nucleotides). Co-incubation with 500 μM α-naphthoflavone (α-NF) resulted in 97–99% inhibition in adduct formation implicating cytochrome P450-dependent (CYP) bioactivation however there was some evidence for carry over of BaP in the liver microsomal preparations from BaP injected fish. In contrast to the fish activating systems, no DNA adducts were observed when mussel microsomes were incubated with BaP, DNA and NADPH.  相似文献   

16.
Benzo(a)pyrene (BaP) and polychlorinated biphenyls (PCBs) often co-exist in contaminated environments. Polychlorobiphenylols (OH-PCBs), formed by CYP-dependent monooxygenation of PCBs, are potent inhibitors of the glucuronidation of hydroxylated BaP metabolites. We hypothesized that OH-PCBs could drive the biotransformation of (−)BaP-7,8-dihydrodiol (BaP-7, 8-D) away from detoxication and towards formation of the reactive metabolite. A mixture of five OH-PCBs with 4–6 Cl atoms was infused into isolated, perfused, biliary intact livers (n=3 fish) removed from 3-methylcholanthrene-induced channel catfish. Controls (n=3) were infused with vehicle. Subsequently, [3H]-BaP-7, 8-D was infused into each liver and bile was collected for 1 h. The livers were taken for analysis of metabolites and DNA adducts. Induction status was confirmed by EROD assay. Bile was analyzed for metabolites. It was found that preinfusion of the mixture of OH-PCBs reduced the extent of glucuronidation of BaP-7, 8-D and increased the formation of DNA adducts 5-fold over controls. GSH conjugates, tetrols and triols were increased in the OH-PCB-infused fish, providing further support for our hypothesis that if the glucuronidation were inhibited, CYP-dependent activation would increase. These studies suggest a mechanism for synergy of toxicity of PAH and PCBs.  相似文献   

17.
Polycyclic aromatic hydrocarbons (PAH) were measured in sediment cores from 13 locations in South-Western Barents Sea as part of a detailed study of the Norwegian seabed under the MAREANO program. The generally low PAH levels found, an average around 200 ng g−1 dry weight for sum PAH, indicate low inputs of petroleum hydrocarbons to the marine environment in the area. Differences in PAH composition and various PAH ratios indicate a natural, mostly petrogenic origin of PAH in sediments from the open sea locations, while the fjord locations show higher pyrogenic PAH contents with an increase towards upper sediment layers, indicating low inputs from human activities. Petrogenic PAH levels increase in deeper sediments at open sea locations, also when normalised to total organic carbon (TOC) contents, suggesting natural leakages of oil-related hydrocarbons in the area.  相似文献   

18.
Bivalve molluscs have been used as monitors of marine pollution because they concentrate xenobiotics of many kinds in their tissues. Marine pollutants often produce stress responses such as reduced scope for growth, lysosomal destabilization, altered immune responsiveness and other sequelae. The ability of bivalves to metabolize organic compounds via mixed-function oxygenases (MFO) was demonstrated by the epoxidation of aldrin1 and benzo[a]pyrene (BP);2 this work has been corroborated and extended in many subsequent studies. Biotransformation of BP and other environmental procarcinogens can generate either activated or detoxified metabolites. In this paper the BP metabolites produced by digestive gland homogenates of the clam (Mercenaria mercenaria) and the oyster (Crassostrea virginica) are described. Control bivalves produced the proximate carcinogen (BP 7,8-dihydrodiol), as well as various minimally reactive BP diols and monohydroxylated metabolites. Seven days after injection of the potent inducer of mammalian MFO, Aroclor 1254, BP 7,8-diol production was augmented in Mercenaria, and atypical quinones and phenols were seen in both species. However, in the Ames bacterial mutagenicity assay, homogenates from Aroclor-treated clams failed to activate benzo[a]pyrene. The biological significance of BP metabolism in bivalves is unknown; however, it may prove to be a useful index of pollution.  相似文献   

19.
Bivalve and gastropod molluscs readily accumulate polynuclear aromatic (PNAH) and other hydrocarbons from the environment and are widely used in environmental monitoring programmes.1 The response of the cytochrome P-450 monooxygenase or mixed function oxidase (MFO) system to organic xenobiotics is of interest from the comparative viewpoint and in biological effects monitoring.2 We have studied the bivalves Mytilus edulis (mussel) and Cardium edule (cockle) and the gastropod Littorina littorea (periwinkle) exposed to hydrocarbons, experimentally or naturally in the field. The general trend of response in digestive gland microsomes was an increase in cytochrome P-450 content and NADPH-cytochrome c reductase (NADPH-CYTCRED) activity but no increase in benzo[a]pyrene hydrolyase (BPH) activity. Sex and seasonal interactions were evident. We conclude that aspects of the responses may be peculiar to the Mollusc and that NADPH-CTYCRED possibly offers potential for this phylogenetic group as a specific indicator of biological impact by organic pollution.  相似文献   

20.
Polycyclic aromatic hydrocarbon (PAH) distributions and sources are characterized in 96 sediment samples from 24 210Pb-dated cores collected at locations in the greater Puget Sound. The highest PAH concentrations are found within a few kilometers of several sources including industrial facilities in northern Puget Sound, urban areas in central Puget Sound, and river systems draining coal-bearing strata. Regional patterns of combustion-derived PAH in surficial sediments indicate little atmospheric or waterborne exchange of PAH between different regions of the Sound. Significant subsurface maxima in combustion-derived PAH concentrations (210Pb dated at the 1950s) occur only in sediment cores collected near urban centers. Perylene apparently derives from erosion of a terrestrial source with little or no evidence of in situ production at depth in sediment cores. Coal fragments are carriers of a characteristic suite of alkylated phenanthrene, chrysene, and picene derivatives concentrated near river mouths in central and southern Puget Sound.  相似文献   

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