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1.
The polycyclic aromatic hydrocarbons fluoranthene and benzo(a)pyrene significantly reduced the feeding rate of mussels. For both compounds the tissue concentration resulting in a 50% reduction of the clearance rate (TEC50) was calculated. At high tissue concentrations both aromatic compounds reduced the tolerance of mussels to aerial exposure, whereas at low tissue concentrations an improved response was noticed. The activities of the antioxidant enzymes Superoxide dismutase (SOD) and catalase were elevated only at low tissue concentrations of fluoranthene and benzo(a)pyrene. At the highest measured tissue concentrations the activity of both enzymes was reduced, possibly due to a narcotic effect. The reproductive success rate of mussels appeared to be affected negatively by the investigated hydrocarbons. The results of a pilot experiment indicate that mussels can be used also for the testing of contaminated sediments.  相似文献   

2.
The possibility of using the pyrene metabolite 1-hydroxypyrene as a biomarker of polycyclic aromatic hydrocarbons (PAHs) exposure was investigated by exposure of the marine polychaete Nereis diversicolor to several PAHs in the laboratory. Animals were exposed to pyrene alone and to five different PAHs – phenanthrene, anthracene, pyrene, benzo[a]pyrene and benzo[k]flouranthene. After five days of exposure the concentrations of parent PAHs and 1-hydroxypyrene were identified using three different analytical methods, high-performance liquid chromatography with fluorescence detection (HPLC/F), synchronous fluorescence spectroscopy (SFS) and gas chromatography with mass spectrometric detection (GC/MS). The SFS measurements of 1-hydroxypyrene were validated by the more sensitive method HPLC/F. The positive correlation between total PAHs and 1-hydroxypyrene concentrations in the polychaete tissues observed in experiments, suggests the feasibility of 1-hydroxypyrene as a suitable biomarker for total PAH exposure assessment. Furthermore, the possibility of employment of the simple and rapid SFS method instead of HPLC/F for biomarker analysis has been confirmed by the positive and significant correlation between results achieved by these two analytical methods.  相似文献   

3.
Theoretical considerations allow the calculation of the potential significance of mixed-ligand solution complexes. It can be shown that the solution concentration, [MXY], of a chemical species, MXY, cannot represent more than 50% of a metal's total dissolved concentration, MT. For higher ligand number mixed-ligand complexes it is found that ([MX2y]+ [MXY2)/MT 0.75 and ([MX3y] + [MX2Y2 ] + [MXY3] /MT 0.875. In high average ligand number systems, mixed complexes, MXaYb, can dominate a metal's solution chemistry even when only one single-ligand type species, MXa + b, is important. Mixed-ligand complexes may dominate the chemistry of highly associated hydrothermal solutions.  相似文献   

4.
5.
建立了用固相萃取-高效液相色谱-荧光检测法测定海水中多环芳烃的方法,优化了色谱条件和萃取条件。除苊不能用荧光检测器检出外,其余15种多环芳烃的空白加标回收率在64.5%(苯并[g,h,i],茚并[1,2,3-cd]芘)~88.7%(苯并[a]蒽)之间,相对标准偏差(n=5)为4.9%(荧蒽,苯并[b]荧蒽)~11.1%(苯并[g,h,i],茚并[1,2,3-cd]芘),方法的检出限在0.72(蒽)~14.10 ng/L(荧蒽)之间,基本上达到了痕量分析的要求。利用该方法测得青岛湾表层海水中多环芳烃的浓度在0.125(苯并[k]荧蒽)~25.996 ng/L(萘)之间,但苯并[a]芘未检出。  相似文献   

6.
The potential of heterotrophs to degrade aromatic hydrocarbons derived from oil in water and sediments in the northern North Sea around the Brent, Beryl, Forties and Murchison oilfields and at a number of stations, from the Forties field to the Firth of Forth, was estimated using 1-14C naphthalene and 7, 10-14C benzo(a)pyrene. The degradation of uniformly labelled 14C mixed 1-amino acids was used as a measure of total heterotrophic activity. Results showed that microorganisms have the potential to degrade the smaller aromatic hydrocarbon molecules rapidly in the water column and in surface sediments. Close to the Beryl platform, where diesel-washed drill cuttings have been continuously dumped, the rate of input of hydrocarbons to the sediment has exceeded the rate of degradation. Mineralization of benzo(a)pyrene, estimated in the sediments only, was minimal. Close to production platforms the biodegradation rate of mixed 1-amino acids showed no increase comparable with that found for naphthalene, suggesting that existing microbial populations had not increased but adapted to degrade oil in water and sediments.  相似文献   

7.
苯并(a)芘对紫菜(Porphyra)的致突变效应   总被引:1,自引:0,他引:1  
  相似文献   

8.
To investigate the biological impact of polycyclic aromatic hydrocarbons (PAHs) on reproductive system, scallops Chlamys farreri were continuously exposed to benzo[a]pyrene (BaP) (0.5, 3, 10 μg L?1) during 15 days. DNA damage and histological alterations were examined in female gonad. DNA strand break levels significantly increased after 12 h exposure, and remained high and significantly different from control values until the end of the exposure. In the ovaries of the scallops exposed to 10 μg L?1 BaP for ten days, histological analysis showed that the cytoplasts of the oocytes in the outer layer of the ovaries became sparse, and the nuclear membranes were obscure. Damaging effects on ovaries and oocytes were more severe after 15 days exposure. Degenerating oocytes increased and the connective tissue of the ovary envelops became loose. Electron microscopic examination revealed ultrastructural aspects of degenerating oocyte and degenerated oocyte after 15 days exposure.  相似文献   

9.
Addition of a heavy oil to a Spartina salt marsh in the autumn resulted in high concentrations of polycyclic aromatic hydrocarbons in sediment and benthic animals. The highest concentrations of phenanthrene, chrysene and fluoranthene in the sediment were 112, 105 and 75 ng/g sediment, respectively. These concentrations rapidly decreased during the 20 week period following the spill. The times for these hydrocarbons to decrease to 50% of their highest values, i.e. half-life, were approximately 100, 70 and 30 days in sediment, mussels and oysters, respectively. Benthic macrofauna species showed three responses to oil addition which included no change, an increase, or a decrease in the population. No changes were noted in populations of fiddler crabs (Uca pugnax), oysters (Crassostrea virginica), and mussels (Modiolus demissus). Mud snails (Nassarius obsoleta) increased in density after the spill due to immigration of adult snails from untreated areas to scavenge on animals killed by the oil. Many of the adult periwinkles (Littorina irrorata) were killed by the oil. In the spring, juvenile periwinkles recolonised to oiled areas as a result of larvae settling.  相似文献   

10.
The metabolism at specific sites on carcinogenic hydrocarbons such as benzo[a]pyrene (BP) is responsible for activation to the ultimate mutagens and carcinogens, and patterns of metabolism can thus influence the biological effect of such compounds. Marine fish are known to efficiently metabolize BP at the benzo-ring, forming high percentages of the 9,10-dihydrodiol (DHD) and 7,8-DHD, the latter including the penultimate carcinogen.1,2 Hydrocarbon-induced cytochrome P-450 in fish is responsible for initiating metabolism on the benzo-ring, but epoxide hydrolase (EH) activity is required for DHD formation.3,4 Both factors could influence formation of the DHD leading to the ultimate carcinogenic diol-epoxide. In the present study, patterns of BP metabolism were evaluated in a number of individual scup Stenotomus chrysops sampled from local Woods Hole waters, and a correlation is described between variation in the DHD formation and EH activity in these feral fish.  相似文献   

11.
Macoma inquinata, a detritus feeding clam, was exposed for 60 days to coarse-grained, and Abarenicola pacifica, a burrowing polychaete, to fine-grained, sediment. Each sediment contained 14-C-labelled phenanthrene, chrysene or benzo(a)pyrene. Over 70% of the chrysene and benzo(a)pyrene, but only 8% of the phenanthrene, remained in the coarse sediment during the exposure. Essentially all of the chrysene and benzo(a)pyrene and 70% of the phenanthrene remained in the fine sediment. The concentrations of chrysene and benzo(a)pyrene in the clams rose steadily, reaching levels 11·6 and 5·2 times as high as those in the sediment. The tissue phenanthrene concentration rose for 3 days, then fell to one-eighth of the initial concentration. The concentrations of each of the aromatic hydrocarbons in Abarenicola tissue increased for 2 weeks to four to six times the sediment levels. The tissue concentration of chrysene remained constant thereafter, but the levels of phenanthrene and benzo(a)pyrene fell to three-quarters of their peak values. No intermediate degradation products of any of the hydrocarbons were identified in extracts of sediment from either exposure system, or in solvent extracts of tissue or of tissue digestates.Significant 14C-activity, associated with non-solvent extractable compounds, remained in tissue digestates of individuals of both species exposed to phenanthrene.  相似文献   

12.
Freshly prepared homogenates were used to assess the relative ability of winter flounder (Pseudopleuronectes americanus) liver and intestinal mucosal cells to metabolize the polycyclic aromatic hydrocarbon (PAH) benzo[a]pyrene (BaP) and its proximate carcinogenic metabolite, BaP-7,8-dihydrodiol (7,8-Diol). Data obtained from homogenates prepared from fish previously fed β-naphthoflavone (BNF) indicated that both tissues had similar abilities to metabolize either BaP or 7,8-Diol on a per gram of protein basis. Metabolite profiles produced indicate that water-soluble metabolite formation is favored at low doses. These findings support the hypothesis that the intestine plays an important role in first-pass metabolism of dietary carcinogens in the winter flounder.  相似文献   

13.
14.
Breaking wave loads on coastal structures depend primarily on the type of wave breaking at the instant of impact. When a wave breaks on a vertical wall with an almost vertical front face called the “perfect breaking”, the greatest impact forces are produced. The correct prediction of impact forces from perfect breaking of waves on seawalls and breakwaters is closely dependent on the accurate determination of their configurations at breaking. The present study is concerned with the determination of the geometrical properties of perfect breaking waves on composite-type breakwaters by employing artificial neural networks. Using a set of laboratory data, the breaker crest height, hb, breaker height, Hb, and water depth in front of the wall, dw, from perfect breaking of waves on composite breakwaters are predicted using the artificial neural network technique and the results are compared with those obtained from linear and multi-linear regression models. The comparisons of the predicted results from the present models with measured data show that the hb, Hb and dw values, which represent the geometry of waves breaking directly on composite breakwaters, can be predicted more accurately by artificial neural networks compared to linear and multi-linear regressions.  相似文献   

15.
Induction of cytochrome P4501A in fish is a well-known indicator of exposure to polycyclic aromatic hydrocarbons (PAHs) and determination of PAH metabolites in bile by fixed wavelength fluorescence (FF) or synchronous fluorescence spectroscopy (SFS), has become an useful method in monitoring programs. In this work the relationship between cytochrome P4501A (EROD activity) and levels of biliary PAH metabolites was measured in the European eel Anguilla anguilla, in both field and laboratory conditions: organisms were sampled on a seasonal basis from the Orbetello lagoon (Tuscany) to characterize the natural variability of these biological parameters, while in laboratory eels were intraperitoneally injected with benzo[a]pyrene to investigate temporal and dose-dependent induction patterns. Results showed that induction of cytochrome P450 and accumulation of PAHs metabolites in bile are not necessarily correlated either in field, or in laboratory investigations; different seasonal changes were measured in natural conditions and slight variations in dose and time response patterns were also obtained in laboratory exposures.  相似文献   

16.
This paper considers the currently available approaches to constructing numerical models describing the dependence of parameters of the atmospheric boundary layer on waving parameters (dynamic boundary layer). The models proposed in [1, 2] are characterized by detailed numerical algorithms, numerical calculations, and comparisons of the resistance coefficient C d as functions of the parameters of the waving surface, the state of which is given by the model two-dimensional wave spectrum as represented in [3]. For the same spectrum, the calculation results obtained by different models are shown to yield estimates for the value of C d with a more than twofold discrepancy; however, the trends in the dependence of C d on wave age and wind strength are close to one another and to observational data. Possible shortcomings of both approaches are analyzed, and ways to eliminate them are proposed. The requirements for setting special experiments needed to verify theoretical models of the dynamic boundary layer are discussed.  相似文献   

17.
Petroleum hydrocarbons were investigated in Mytilus edulis and Macoma balthica at six intertidal sites in Port Valdez, Alaska after three to five years of oil terminal operation. Information about the concentrations of total hydrocarbons, unresolved complex mixture, normal alkanes, isoprenoids, olefins, hopanes and polycyclic aromatic hyrocarbons shows that petroleum accumulation in these bivalve mollusks is greatest at the Valdez municipal boat harbor and a crude oil terminal which has been permitted to discharge 170 kg oil day−1. Accumulation two- to ten-fold less were observed at 3 km from the terminal and boat harbor. The temporal trends in petroleum hydrocarbon concentrations in M. edulis and M. balthica reflect the effects of selective retention and depuration of different hydrocarbon classes as well as variation in hydrocarbon sources. It is not clear whether the petroleum concentrations in Port Valdez bivalves had reached steady state by 1982, the final sampling time reported here.  相似文献   

18.
The fate of saturated and aromatic hydrocarbons discharged into the coastal Baltic Sea environment from the TSESIS oil spill has been studied in the acute and postacute (one year) phases of the spill. Periodic samples of Mytilus edulis (mussels) from eight littoral zone stations and Macoma balthica from nine soft bottom stations were obtained as well as sediment trap samples and surface sediment samples. Glass capillary gas chromatography and gas chromatographic mass spectrometry were used as the analytical tools to determine saturated and aromatic hydrocarbon composition and concentrations in these samples.Sediment trap samples indicated that sizable quantities of chemically and microbially weathered oil were sedimented, and available for benthic uptake shortly after the spill. After initial uptake of sedimented oil (500 to 1000 μ/g dry weight), Macoma populations appear to have begun slow depuration through the first winter after the spill, but TSESIS oil was again introduced to the benthic stations studied during the following summer. Mytilus populations in the region were severely impacted by the oil. Initial depuration of spilled oil during the first month was rapid and nearly complete at all but the most heavily impacted stations one year after the spill. The post-spill depuration of assimilated hydrocarbons was characterised by a relative retention of alkylated dibenzothiophenes and alkylated phenanthrenes compared to their unsubstituted parent compounds and compared with the entire homologous naphthalene series.These data suggest that petroleum hydrocarbons from the TSESIS spill have become a chronic source of degraded saturated and aromatic hydrocarbons to the soft bottom benthic communities. Petroleum hydrocarbons in the benthic environment from this spill appear to reside in the difficulty sampled and mobile flucculent layer at the sediment/water interface and may affect epifaunal communities for an extended period of time.  相似文献   

19.
The hydrolysis of silicic acid, Si(OH)4, was studied in a simplified seawater medium (0.6 M Na(Cl)) at 25°C. The measurements were performed as potentiometric titrations (hydrogen electrode) in which OH? was generated coulometrically. The total concentration of Si(OH)4, B, and log[H+] were varied within the limits 0.00075 ? B ? 0.008 M and 2.5 ? -log[H+] ? 11.7, respectively. Within these ranges the formation of SiO(OH)3? and SiO2(OH)22? with formation constants log β?11(Si(OH)4 ? SiO(OH)3? + H+) = ?9.472 ±0.002 and log β?21(Si(OH)4 ? SiO2(OH)22? + 2H+) = ?22.07 ± 0.01 was established. With B > 0.003 M polysilicate complexes are formed, however, with -log[H+] ? 10.7 their formation does not significantly affect the evaluated formation constants. Data were analyzed with the least squares computer program LETAGROPVRID.  相似文献   

20.
An analytical method for the determination of polycyclic aromatic h hydrocarbons (PAHs) and substituted benzotriazoles in clams was developed using a combination of silica gel and Sephadex chromatography to isolate these compounds from large concentrations of polyolefinic hydrocarbons. The concentrations of total hydrocarbons, PAHs and substituted benzotriazoles were measured in hard shell clams (Mercenaria mercenaria) purchased from Rhode Island seafood stores. The levels of total hydrocarbons, PAHs and substituted benzotriazoles in these clams were generally higher than the concentrations found in clams collected from a lower Narragansett Bay control location. The significance of these findings on the health of consumers is unknown at this time because human health standards or alert levels for these compounds in seafoods have not been established. However, this study illustrates that contaminants entering Narragansett Bay from a variety of sources may eventually make their way to commercial outlets.  相似文献   

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