ISSN:0730-7268    

DOI:10.1002/etc.5620060701

出版商:Wiley Periodicals, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractA model is presented describing the kinetics of uptake and release of nonmetabolizing organic chemicals by fish from water. The model contains three parameters: a bioconcentration factor which is specific to the chemical (and can be characterized by the octanol/water partition coefficient and fish lipid content), a water‐phase resistance term and a lipid‐phase resistance term which are specific to the fish. These parameters can be estimated from uptake‐clearance experiments. Part of the water‐phase resistance term can be attributed to gill ventilation rate as estimated from gill uptake efficiencies and part is an “internal” resistance. Procedures are suggested for scaling these parameters to different fish sizes. The dependence of these resistances, and uptake and clearance rate constants, on chemical hydrophobicity is discussed and

ISSN:0730-7268    

DOI:10.1002/etc.5620060702

出版商:Wiley Periodicals, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractMicrobial enzyme activity,Ceriodaphniasurvival and reproduction, and metal concentrations were used as indicators of water and sediment quality along Whitewood Creek, South Dakota. Whitewood Creek receives point and nonpoint sources of metals from the Homestake Mine and City of Deadwood. Several significant correlations were observed between various microbial enzyme activity profiles. Stream concentrations of copper were significantly correlated with glucosidase or galactosidase activity. High correlations were also observed between galactosidase activity and both total cyanide and total dissolved solids.Ceriodaphniastream profile responses were significantly correlated with chromium and nickel concentrations, but not with microbial activity test parameters. Biological test responses appeared to be associated with metal inputs, supporting the use of the bioindicator test approach in stream profile assessments of macrofauna and nutrient cycles.

ISSN:0730-7268    

DOI:10.1002/etc.5620060703

出版商:Wiley Periodicals, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractA multivariate statistical method and a heuristic method were employed to examine the structural features associated with the persistence or degradation of 287 chemicals tested with the standard biochemical oxygen demand (BOD) procedure. The data base consisted of 196 “degradable” chemicals with a half‐life of less than 15 d (e.g., Theoretical BODs (ThOD)>16%) and 91 “persistent” chemicals with a half‐life of more than 15 d. The multivariate statistical analysis consisted of (1) calculating 54 molecular connectivity indices, five physicochemical properties and eight principal components from the molecular connectivity indices, (2) clustering the chemicals on the basis of the principal components and one of the physicochemical properties,Kowand (3) discriminating between persistent and degradable chemicals using the molecular connectivity indices and the physicochemical properties as discriminating variables within each cluster. The heuristic approach used the results of the multivariate analyses and the literature on biodegradation to identify a series of structural features associated with degradable and persistent chemicals.The best iteration of the multivariate technique correctly predicted 85% of the degradable chemicals and 94% of the persistent chemicals. In contrast, the heuristic approach correctly predicted 91% of the degradable chemicals and 96% of the persistent chemicals. Twelve structural features or chemical classes were associated with degradable chemicals and 16 structural features were associated with persistent chemicals. The analysis is presented as a potential technique for rapidly assessing the relative degradability of discrete organic chemicals. The structural features identified are offered as tentative hypotheses to be examined with a larger and more diver

ISSN:0730-7268    

DOI:10.1002/etc.5620060704

出版商:Wiley Periodicals, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractFluoride levels were measured in Arctic char (Salvelinus alpinus) living near Narsaq. The Narsaq River is unpolluted, but has naturally high levels of fluoride—varying from about 2 mg/L in summer to 10 to 20 mg/L in winter. The river has a relatively large population of Arctic char which appears unaffected by the high fluoride level. Stationary char accumulate fluoride in muscles (16.6 mg/kg) and bones (1,150 mg/kg), while char caught in the estuary have concentrations similar to char from reference areas (6.5 mg/kg in muscle, 439 mg/kg in bone). It is concluded that Arctic char accumulate fluoride when living in the high‐fluoride freshwater environment, but that concentrations return to normal in anadromous char during the 1 to 2 summer months annually spent at

ISSN:0730-7268    

DOI:10.1002/etc.5620060705

出版商:Wiley Periodicals, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe microbial mineralization of six polycyclic aromatic hydrocarbons (PAHs), containing two to five fused benzene rings, and hexadecane were investigated in sediment: water microcosms which modeled degradation in two freshwater and one estuarine ecosystem. A ranking of the PAHs by order of mineralization rates along with calculated half‐lives (range in weeks) are as follows: naphthalene (2.4‐4.4) ≥ hexadecane (2.2‐4.2)>phenanthrene (4‐18)>2‐methylnaphthalene (14‐20)>pyrene (34‐>90) ≥ 3‐methylcholanthrene (87‐>200) ≥ benzo[a]pyrene (200‐>300). PAH residues persisted from two to over four times longer in a pristine ecosystem than in an ecosystem chronically exposed to low levels of petroleum hydrocarbons. The mineralization of higher‐molecular‐weight PAHs (>four rings) totaled 0.2 to 6.5% after 8 wk. Relative differences in PAH mineralization among the ecosystems were related to hexadecane mineralization rates, the occurrence and concentration of aromatic hydrocarbon residues in sediments, and elevated populations of hydrocarbon‐degrading microorganisms. Total heterotrophic microbial populations were not good indicators of PAH mineralization rates. Chemical analyses of residues in the microcosms detected the presence of extractable polar metabolites in water and sediments which accounted for

ISSN:0730-7268    

DOI:10.1002/etc.5620060706

出版商:Wiley Periodicals, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractA two‐compartment open model using plasma and seasonally variable lipid compartments was developed and validated for several organochlorines in herring gulls (Larus argentatus). Plasma clearance rate constants (k′pc,L·kg−1·d−1), plasma: whole‐body lipid partition coefficients (Kpf) and compartment sizes for lipid and plasma were obtained for juvenile gulls injected i.p. with a mixture ofp,p′‐DDD,p,p′‐DDE, hexachlorobenzene, oxychlordane, γ‐hexachlorocyclohexane,trans‐chlordane, octachlorostyrene, dieldrin, mirex and photomirex. Concentrations in plasma were determined at 11 time points during the 239‐d study, and whole‐body contaminant burdens and lipid weights were determined at 3 time points. MeanKpfforp,p′‐DDD andp,p′‐DDE (0.0038 ± 0.0002) was different from that of the other organochlorines (0.0058 ± 0.0005,n= 7). The latter values were close to the expected fraction lipid in plasma, indicating a simple thermodynamic partitioning between lipid pools in adipose tissue and plasma. Plasma clearance rate constants ranged from approximately 0.04 L·kg−1·d−1for slowly clearing organochlorines such asp,p′‐DDE and mirex to 500 L·kg−1·d−1for rapidly clearing γ‐hexachlorocyclohexane andtrans‐chlordane. Simulations using these parameters and lipid weight regimes for individual experimental birds tracked observed plasma concentrations and final body burdens closely. Simulated whole‐body half‐lives of organochlorines in wil

ISSN:0730-7268    

DOI:10.1002/etc.5620060707

出版商:Wiley Periodicals, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe toxicities of chemicals found in bleached kraft pulp mill effluent were assessed using a sea urchin sperm toxicity test. Sperm of the purple sea urchin,Strongylocentrotus purpuratus, were preincubated with 12 individual compounds, including resin acids, unsaturated fatty acids, their chlorinated derivatives and chlorinated guaiacols. Sperm were then coincubated with eggs and inhibition of fertilization and the effects on sperm motility were assessed. Resin acids, which are highly toxic to juvenile salmonids in freshwater, were less toxic in seawater (EC50s ranging from 2 to more than 20 mg/L). Unsaturated linoleic and linolenic fatty acids inhibited fertilization at lower concentrations (EC50s of 0.28 to 1.07 mg/L) than resin acids, although they are less toxic than resin acids to freshwater fishes. Oleic acid was not significantly toxic up to 75 mg/L. Chlorinated derivatives showed increasing toxicity with increasing chlorination, and chlorinated resin acids were more toxic than their unchlorinated parent compound. Dichlorostearic acid was the most toxic compound tested, with an EC50 of 0.057 mg/L. All compounds except fatty acids inhibited sperm motility.These results indicate that some of the major constituents of pulp mill effluent exhibit very different levels of toxicity in seawater using a sea urchin sperm cell toxicity test as compared to freshwater bioassays using juvenile salmonids. In addition, mechanisms of action on the sperm appear to differ among the compounds. Accurate quantification of the compounds in effluent as well as the potential effect of the effluent on other marine organisms remains to be determined.

ISSN:0730-7268    

DOI:10.1002/etc.5620060708

出版商:Wiley Periodicals, Inc.    

年代:1987

数据来源: WILEY