ISSN:0730-7268    

DOI:10.1002/etc.5620141201

出版商:Wiley Periodicals, Inc.    

年代:1995

数据来源: WILEY

ISSN:0730-7268    

DOI:10.1002/etc.5620141202

出版商:Wiley Periodicals, Inc.    

年代:1995

数据来源: WILEY

摘要:

AbstractThe metabolism of 10 different congeners of polychlorinated biphenyls (PCBs) was tested in cell cultures of 12 different plant species. The rate of metabolism was determined through comparison with cells inactivated by treatment with perchloric acid. The metabolism of defined PCB congeners was strongly dependent on the plant species. In particular, two Fabaceae species exhibited high capacities for metabolizing different congeners. Except for PCB 15 (4,4′‐dichlorobiphenyl), it was shown that a lower chlorination grade is associated with higher metabolism rates. Also, it was shown that substitution and molecular configuration play an important role in the metabolism of PCBs in plants. In studies with14C‐PCB 1 (2‐chlorobiphenyl) in soybean cultures, one dihydroxylated and six different monohydroxylated compounds were detected after acid hydrolysis of polar metabolites (conjugates). Hydrolysis of metabolites of14C‐PCB 52 (2,2′,5,5′‐tetrachlorobiphenyl) in wheat cell cultures yielded four monohydroxylated and three dihydroxyla

ISSN:0730-7268    

DOI:10.1002/etc.5620141203

出版商:Wiley Periodicals, Inc.    

年代:1995

数据来源: WILEY

摘要:

AbstractIn the present survey zebra mussels were used as biomonitors to evaluate concentrations of nine organotin compounds (OTs) in Dutch fresh waters. To this end mussels were sampled at 56 locations throughout the country at the end of the summer of 1992. Variations in OT concentrations in zebra mussels were studied at two locations near potato crops that were sprayed with triphenyltin (TPT) in order to estimate the integration period over which body concentrations reflect the environmental quality. Apparent depuration half‐life times in the field were calculated to be 100 to 200 d for TPT, which indicates that body burdens represent the TPT water quality over a long period of time. Results from the survey showed that OTs are still ubiquitously present in the freshwater environment in The Netherlands. Despite the implementation of legislation restricting the use of tributyltin (TBT), very high TBT body concentrations can still be found. The TPT was found in very high concentrations in mussels near sources of this fungicide. It was also discovered at remote locations. Possibly the presence of TPT there is due to transport via the air. The degradation products of TBT and TPT, the di‐ and mono‐, ‐butyl‐ and ‐phenyltins, were also detected in nearly all mussels analyzed. Tricyclohexyltin (TCT) and fenbutatinoxide (FBTO), which are much less used organotin pesticides, were identified only in a few cases and do not appear to pose real environmental threats. Statistical analysis by means of principal component analysis was found to be a useful tool for evaluating the sources of OTs monitored by the ze

ISSN:0730-7268    

DOI:10.1002/etc.5620141204

出版商:Wiley Periodicals, Inc.    

年代:1995

数据来源: WILEY

摘要:

AbstractThe chemical form or species of metal present in a growth system is crucial to the toxicity of that metal. A growth medium is described in which the free metal concentration of either Zn or Cd is known. A method using a cation exchange resin as a buffer to maintain free metal ion concentrations during microbial growth is discussed. Using a buffered system, free concentrations of 3.4 μg Cd L−1and 57 μg Zn L−1reduced the growth rate of a sensitive isolate ofRhizobium leguminosarumbiovartrifolii.The results demonstrate that to assess the true toxicity of Cd and Zn, thefreeion concentration must be considered and that small free concentrations must be buf

ISSN:0730-7268    

DOI:10.1002/etc.5620141205

出版商:Wiley Periodicals, Inc.    

年代:1995

数据来源: WILEY

摘要:

AbstractA comparison of the environmental fate of [14C]trichloroethylene ([14C]TCE) in vegetated and nonvegetated soils from a contaminated field site indicated increased mineralization (14CO2production) in soils containing vegetation. Mineralization in soils containingLespedeza cuneata(Dumont),Pinus taeda(L.),Solidagosp. (all collected from a former chlorinated solvent disposal site), andGlycine max, germinated from commercially available seeds, accounted for>26% of the total recovered radioactivity compared with approximately 15% for nonvegetated soil and<9% for control (sterile) soil. Uptake of14C into plant tissues ranged from 1 to 21% total for leaves (or needles), stems, and roots and appeared to be related to plant species and water use during the experiment. The higher mineralization rates for [14C]TCE in the vegetated soils compared with nonvegetated soils indicates that the rhizosphere provides a favorable environment for microbial degradation of organic compounds. Therefore, vegetation may play an important role in enhancing biological remediation of contaminated surface soils in situ.

ISSN:0730-7268    

DOI:10.1002/etc.5620141206

出版商:Wiley Periodicals, Inc.    

年代:1995

数据来源: WILEY

摘要:

AbstractThe main purpose of this study was to monitor exposure to lead and cadmium in wild birds in Murcia, a southeastern region of Spain on the Mediterranean coast. This region lies on one of the African‐European flyways. Samples of liver, kidney, brain, bone, and whole blood from several species of wild birds were obtained during 1993. We found a clear relationship between cadmium and lead concentrations in birds and their feedings habits. Vultures (Gyps fulvus) had the highest concentrations of lead (mean 40 μg/dl in blood), and seagulls (Larus argentatusandLarus ridibundus) the highest concentrations of cadmium (mean 4.43 μg/g in kidney). Insectivores had high concentrations of both metals, and diurnal and nocturnal raptors showed the lowest tissue concentrations. The finding that tissue and blood concentrations were generally not elevated suggests environmental (rather than acute) exposure. Birds from more industrialized areas of the region studied here had higher concentrations of both lead and cadm

ISSN:0730-7268    

DOI:10.1002/etc.5620141207

出版商:Wiley Periodicals, Inc.    

年代:1995

数据来源: WILEY

摘要:

AbstractA bioassay‐directed chemical fractionation methodology was used to identify the principal mutagenic compounds in an organic solvent extract of coal‐tar‐contaminated sediment from Sydney Harbour, Nova Scotia. Biological assays withSalmonella typhimuriumbacteria with the addition of oxidative metabolism indicated that the majority of the mutagenic activity observed in the sediment extract was associated with the higher molecular mass polycyclic aromatic hydrocarbons (PAHs). A normal phase high‐performance liquid chromatography (HPLC) technique was developed to separate the PAH‐rich solvent extracts into fractions containing isomeric PAHs of a single benzologue class. These fractions were analyzed by probe mass spectrometry and gas chromatography‐mass spectrometry (GC‐MS), and subjected to biological assays using strain YG1025 with the addition of oxidative metabolism (4% and 10% S9). Fractions containing compounds of molecular weights 252, 276, 278, and 302 amu exhibited mutagenic activities of 930 + 125, 510 + 100, 250 + 40, and 370 + 140 rev/mg sediment, respectively. The molecular weight 252 and 276 amu fractions were further analyzed using reversed‐phase HPLC and GC‐MS to identify the individual PAHs responsible for the observed biological activity. High molecular mass PAHs including benzo[a]pyrene, benzo[ghi]perylene, indeno[1,2,3‐cd]pyrene, and compounds of molecular weight 302 amu were found to be responsible for the majority of the mutagenic activity displayed by this complex en

ISSN:0730-7268    

DOI:10.1002/etc.5620141208

出版商:Wiley Periodicals, Inc.    

年代:1995

数据来源: WILEY

摘要:

AbstractEstimation models for Henry's law constant (H), water solubility (Sw), vapor pressure (Pv), and octanol/water partition coefficient (Kow) of nonelectrolytes are derived from basic thermodynamic equations. The resultant regression equations require only two molecular descriptors, which are available from chemical structure through semiempirical quantum chemical calculations: free energy of solvation (δGs), and molecular contact surface area (CSA). Results are presented for a set of 17 benzenes with experimental data taken from literature, yielding squared correlation coefficientsr2adj(adjusted for degrees of freedom) between 0.83 and 0.95. The discussion includes limitations from currently available continuum solvation models to calculate δGs, aspects of potential error compensation, and the suitability of this approach to understand macroscopic compound properties in terms of calculated quantities that represent distinct types of intermolecular interaction

ISSN:0730-7268    

DOI:10.1002/etc.5620141209

出版商:Wiley Periodicals, Inc.    

年代:1995

数据来源: WILEY

摘要:

AbstractThe triple‐layer model was used to model the adsorption behavior of Cu(II), Pb(II), and Zn(II) onto goethite as a function of pH, total dissolved metal (Me) concentration, surface area, and ionic strength. A single reaction involving adsorption of Me2+onto negative surface sites as an inner‐sphere complex proved successful in describing adsorption of all three metals under the experimental conditions. The calibrated model was validated by comparing model predictions to independent data reported in the literature. A linear‐free‐energy relationship between the intrinsic surface complexation and the first‐hydrolysis equilibrium constants was determined and was used to predict the intrinsic surface complexation constants for Co(II) and Hg(II). The triple‐layer model, using the predicted constants, quantitatively described the adsorption of Co(II), but significantly over‐predicted the extent of Hg(I

ISSN:0730-7268    

DOI:10.1002/etc.5620141210

出版商:Wiley Periodicals, Inc.    

年代:1995

数据来源: WILEY