ISSN:0730-7268    

DOI:10.1002/etc.5620061101

出版商:Wiley Periodicals, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe degradation of selected halogenated ethanes was studied in anoxic sediment‐water suspensions at 1 to 20% sediment concentrations. Batch kinetic experiments were used to quantify decay. Eh measurements of all suspensions were below ‐100 mV (vs SHE), indicating reduced environmental conditions. Hexachloroethane (HCA), 1,1,2,2‐tetrachloroethane (TTCA), 1,2‐diiodoethane (DIA) and 1,2‐dibromoethane (DBA) were degraded within minutes to days, but 1,2‐dichloroethane (DCA) remained in the system through 35 d, at which point the study was ended. The major route of transformation of these compounds in this system was vicinal dehalogenation. Rates of disappearance followed pseudo‐first‐order kinetics at low reactant concentrations and high sediment concentration. The order of reactivity in the same sediment sample followed the sequence, HCA ⋍

ISSN:0730-7268    

DOI:10.1002/etc.5620061102

出版商:Wiley Periodicals, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe phytotoxicity of herbicidal triazines has been analyzed as a function of a number of physicochemical molecular properties by the PLS (partial least squares in latent variables) method for the purpose of generating QSAR‐type models. The analysis was carried out on an initial set of 20 chemicals; the PLS models were able to explain percentages of the variance of the activity up to 91%. In each model the variance of the phytotoxicity was mainly explained in terms of four out of the eight considered descriptors: practically all information needed for modelling the biological activity was contained into descriptors related to the mobility of triazines and, in particular, to their partitioning among phases of different chemical composition and polarity. No relevance was found for such descriptors as molecular weight, redox properties, and ionization constant

ISSN:0730-7268    

DOI:10.1002/etc.5620061103

出版商:Wiley Periodicals, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe uptake of bromacil, dichlorobenzonitrile (DCBN), nitrobenzene (NB) and dinitrobenzene (DNB) was studied in isolated barley roots and mature soybean plants. The uptake rate constants for soybean plants were in the order of DCBN = bromacil

ISSN:0730-7268    

DOI:10.1002/etc.5620061104

出版商:Wiley Periodicals, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractSeveral conjugated metabolites were found to accumulate in the gall bladder bile of trout (Salmo gairdneri) exposed to No. 2 fuel oil, but no free metabolites could be detected. GC‐MS analysis of the major resolved components resulted in the identification of at least eight metabolites, present as alcohols. Single‐ion monitoring MS indicated the predominance of a fragment at m/e 152, and1H‐NMR spectroscopy provided information on the average structure of the mixture of hydrolyzed metabolites. The study demonstrated that focusing on specific two‐ and three‐ring conjugated metabolites in the gall bladder bile of fish can provide a simple and rapid investigative tool for the monitoring and assessment of petroleum and fuel oil

ISSN:0730-7268    

DOI:10.1002/etc.5620061105

出版商:Wiley Periodicals, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractPairs of adult mallards (Anas platyrhynchos) were fed a control diet or a diet containing 1, 2, 4 or 8 ppm selenium in the form of seleno‐DL‐methionine. Ducklings from these pairs were fed an untreated diet from hatching through 6 d of age, at which time their avoidance of a fright stimulus was tested. Selenium had no effect on the ducklings' response to the fright stimu

ISSN:0730-7268    

DOI:10.1002/etc.5620061106

出版商:Wiley Periodicals, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe uptake and distribution of cadmium in rainbow trout (Salmo gairdneri) was studied after 1 week of exposure to109Cd in water and after a subsequent 14‐week period in clean water. The major target organs, that is, gills, kidney, liver and intestine, were analyzed for109Cd content and the subcellular distribution of cadmium determined. A successive redistribution of cadmium from the gills and intestine to the liver and kidney was observed. Sephadex G‐75 chromatography of the organs revealed that most of the cadmium was found in the metallothionein‐containing peak and that the amount of cadmium in this peak increased over time after the exposure. Ion‐exchange chromatography on fast protein, polypeptide and polynucleotide liquid chromatography of the metallothionein‐containing peaks revealed that109Cd eluted together with copper and polaro‐graphic activity. There was no evidence that other low‐molecular‐weight cadmium‐binding proteins were present in the organs. These results indicate that the metallothionein in rainbow trout binds cadmium after the fish are exposed to t

ISSN:0730-7268    

DOI:10.1002/etc.5620061107

出版商:Wiley Periodicals, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractConcentrations of Roundup® herbicide of up to 10 times those encountered in the environment immediately after aerial application (2.78 mg/L) did not affect 24–h seawater survival; nor did plasma sodium concentration, hematocrit or growth in 10‐d exposures with yearling coho salmon (Oncorhynchus kisutch). Similarly, no abnormal responses were noted when a 10‐d freshwater recovery period was provided between the herbicide and seawater exposures. These results indicate that the application of Roundup at the manufacturer's recommended use‐rates for forestry management will not adversely affect the ability of coho salmon smolts to adapt to seawater and to osmoregulate

ISSN:0730-7268    

DOI:10.1002/etc.5620061108

出版商:Wiley Periodicals, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractErosion and leaching of abandoned deposits of lead‐mine tailings in southeast Missouri have resulted in the heavy metal contamination of surface waters, sediments and aquatic biota. We examined how cover materials added to stabilize tailings deposits might influence the mobilization of metals in mine tailings leachates by monitoring metal bioaccumulation and toxic effects in aquatic invertebrates (Orconectes nais, Hexagenia limbataandChironomus riparius) exposed to leachates from test plots of tailings that had been given various cover treatments. Bioaccumulation of lead and cadmium increased significantly, and survival, growth and development were impaired in one or more invertebrate taxa during chronic (10–120 d) exposures to leachates from cover treatments of vegetation and organic mulches. Metal bioaccumulation and toxicity were greatest in a maple leaf cover treatment. Leachate from the leaf treatment had high metal concentrations because of the formation of metal/organic complexes. Lesser responses were observed in treatments of seed + fertilizer, bluegrass sod and dried sewage sludge, all of which resulted in the establishment of varying amounts of vegetative cover on the tailings. Bioaccumulation of lead, but not cadmium, was significantly correlated with the dissolved metal concentrations in the leachates. Toxic effects on invertebrate survival, growth and development were significantly correlated with the metal concentrations in leachate samples and, for lead, with body burdens in invertebrates. The results indicated that leachates from mine tailings deposits can adversely affect aquatic invertebrates, and that cover materials that release organic complexing agents can increase the mobilization of toxic metals in leachates. Vegetative cover would probably reduce future runoff and erosion from tailings deposits, but conditions similar to those in this study may favor the mobilization of metals from tailings already present in riparian habitats and stream sedime

ISSN:0730-7268    

DOI:10.1002/etc.5620061109

出版商:Wiley Periodicals, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe toxicity of pentachlorophenol (PCP) toSelenastrum capricornutumwas examined in three different culture media: a hard and a soft form of Freeman's reference water and the algal assay bottle test (AABT) medium (a soft water). The 96‐h growth potentials of the media were equal (28–29 mg/L dry wt.) but 96‐h EC50s ranged sevenfold: 0.11 mg/L (AABT), 0.15 mg/L (Freeman's soft water) and 0.76 mg/L (Freeman's hard water). Culture media equilibrium pH and 96‐h EC50 were strongly correlated (r= 1.00). Evidence is presented that supports the hypothesis that the toxicity of PCP, a weak acid, is due primarily to the concentration of the undissociated

ISSN:0730-7268    

DOI:10.1002/etc.5620061110

出版商:Wiley Periodicals, Inc.    

年代:1987

数据来源: WILEY