ISSN:0730-7268    

DOI:10.1002/etc.5620040401

出版商:Wiley Periodicals, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractA soil column study was conducted to characterize the movement of permethrin [3‐phenoxybenzyl(1RS)‐cis, trans‐3‐(2,2‐dichlorovinyl)‐2,2‐dimethylcyclopropanecarboxylate], fenvalerate [(RS)‐α‐cyano‐3‐phenoxybenzyl(RS)‐2‐(4‐chlorophenyl)‐3‐methylbutyrate], toxaphene (chlorinated camphene), trifluralin (α,α,α ‐trifluoro‐2,6‐dinitro‐N,N‐dipropyl‐p‐toluidine) and metribuzin [4‐amino‐6‐tert‐butyl‐3‐(methylthio)‐as‐triazin‐5(4H)‐one] in soil as affected by fertilizer anhydrous NH3application at 0, 50 and 150 kg N/ha. The soil columns were leached with three pore volumes of water and segmented. Under the saturated flow conditions used in the study, the insecticides were essentially immobile in the columns receiving no anhydrous NH3. About 5% permethrin was found 5 to 10 cm below the zone of application and about 9% fenvalerate and 16% toxaphene were found 5 to 20 cm below the zone of application in the soil columns receiving the highest level of anhydrous NH3. No appreciable amounts (<0.5%) of the insecticides occurred in the column leachates. There was no apparent enhancement of the mobility of the herbicides trifluralin and metribuzin due to anhydrous NH3application. Extensive disappearance of trifluralin occurred at all anhydrous NH3levels, and the disappearance of metribuzin increased with increasing anhydrous NH3application. The observed enhanced leaching of the insecticides appears to support the hypothesis that soil

ISSN:0730-7268    

DOI:10.1002/etc.5620040402

出版商:Wiley Periodicals, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractThe in vivo fate and metabolism of a model aromatic amine (o‐toluidine) were determined for mussels(Mytilus edulis)and oysters(Crassostrea gigas). o‐Toluidine was found to be relatively nontoxic and was rapidly turned over in mollusc tissues. The biotransformation ofo‐toluidine andN‐acetyl‐o‐toluidine was determined by the extraction and analysis of eliminated metabolites. The metabolism of [14C]o‐toluidine in both bivalve species resulted in the formation of 2‐nitrosotoluene,N‐methyl‐o‐toluidine andN‐formyl‐o‐toluidine. Small amounts ofN‐hydroxy‐o‐toluidine were detected in experiments withM. edulis.Mussels were found to be capable ofN‐deacetylation but oysters were not. The total extent ofo‐toluidine andN‐acetyl‐o‐toluidine biotransformation in mussels from pristine waters was found to be greater than in mussels from contaminated waters.The formation ofN‐oxidized metabolites is toxicologically important because this pathway constitutes the route of activation for mutagenic and carcinogenic aromatic amines. The formation of anN‐formyl metabolite by these bivalves is also interesting, as this detoxication pathway has not been previously reported for marine invertebrates. The lack of carbon oxidizing pathways in these bivalves may be of limited toxicological significance because of their ability to utiliz

ISSN:0730-7268    

DOI:10.1002/etc.5620040403

出版商:Wiley Periodicals, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractConcentrations of airborne particulate lead in an indoor pistol range far exceeded the recently revised Occupational Safety and Health Administration target standard of 50 μg/m3, often by two or three orders of magnitude. A substantial fraction (40 to 50%) of the lead occurred on respirable‐size particles (diameter ≤ 2 μm). Significantly elevated levels of Sb, Cu, As and Ba also resulted from the firing of .38 and .45 caliber pistols. The high levels of respirable, toxic elements observed indicate a potentially serious exposure for users and, in particular, the operators of such facil

ISSN:0730-7268    

DOI:10.1002/etc.5620040404

出版商:Wiley Periodicals, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractThe influence of lugworms (Arenicola cristataStimpson) and seagrass (Thalassia testudinumKoenig) on Kepone® (chlordecone) distribution in sediment/water systems was examined. Radiolabeled Kepone was introduced into continuous‐flow sediment/water systems, and the dissolved and sorbed concentrations of Kepone were quantified. Lugworm activity decreased the Kepone concentration in the water and increased its concentration in the sediment. The presence of seagrasses did not appreciably affect the concentration of Kepone in the water. Bioturbation appeared to be the prime factor in the transport of Kepone from water to sedime

ISSN:0730-7268    

DOI:10.1002/etc.5620040405

出版商:Wiley Periodicals, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractDissolved organic carbon (DOC) in water sorbs or binds organic xenobiotics, reducing the amount of compound that is “freely dissolved” and therefore the amount bioavailable toPontoporeia hoyi.The apparent biological uptake rate constant for each compound is proportional to the inverse of the Aldrich humic acid concentration as a source of DOC. The log of the DOC concentration required to reduce the apparent uptake rate constant by 50% correlates well with the log of the partition coefficient to DOC determined by reverse‐phase methodology for partition coefficients as low as 104. Further, the partitioning to DOC determined by reverse‐phase methodology and from the toxicokinetics inP. hoyiyields partition coefficients similar to those of Aldrich humics measured as DOC and DOC from Lake Michigan interstitial waters. The partition coefficients determined by the two methods correlate well and only vary by a constant bias of a factor of approximately 3. Thus the partition coefficient determined by reverse‐phase methodology can be used to predict the bioavailable concentration of organic compounds in water containing DOC f

ISSN:0730-7268    

DOI:10.1002/etc.5620040406

出版商:Wiley Periodicals, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractSorption of hydrophobic organic chemicals in natural sediment suspensions was found to frequently require extended time periods (days to weeks) for complete equilibration. Sorption dynamics could be described by a two‐compartment model that distinguished rapid or “labile” exchange (requiring at most a few hours to achieve) from highly retarded or “nonlabile” sorption requiring days to weeks to occur. In general, one‐half or less of the total sorption was labile. For highly hydrophobic chemicals and high solid concentrations, the labile fraction decreased to 0.1 or less in some systems. The kinetic exchange constant for nonlabile sorption varied inversely with the sorption equilibrium constant. That is, the more highly sorbed chemicals sorbed more slowly. For some sediments, air‐drying to facilitate sample transport or storage was found to result in formation of highly stable aggregates that severely altered sorbent availability to hydrophobic chemicals. An understanding of sorption dynamics is important in describing the fate of highly sorbed pollutants in aq

ISSN:0730-7268    

DOI:10.1002/etc.5620040407

出版商:Wiley Periodicals, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractProcess analysis and a mathematical model were used to evaluate and predict the fate of 3,4‐dichloroaniline (DCA) in 40‐m3outdoor ponds. Six ponds were treated with DCA: three with a nominal concentration of 450 μg/L and three with a nominal concentration of 45 μg/L. These concentrations were maintained in the water by repeated applications during a period of 28 d. The predicted fate of DCA was compared with its observed fate.The dominant loss process was predicted to be direct phototransformation. Using the mathematical model SOLAR and an empirical correction for cloud cover, the rate constant for this process was calculated to be 0.12 to 0.20 d−1. Observed absorbance data for pond water were used to estimate the rate of indirect phototransformation to be 0.01 to 0.02 d−1. Evaporation, hydrolysis and biodegradation were predicted to be of minor importance. The partition coefficient of DCA between wet sediment and water was predicted to be near unity for the range of observed pH values. From this it was calculated that only 3% of the compound would be sorbed and that, therefore, this process could be neglected.The observed rate of loss of dissolved DCA from the ponds was 0.11 to 0.17 d−1, in good agreement with the predicted overall rate of loss, i.e., 0.13 to 0.22 d−1. It is concluded that the mathematical model SOLAR provided a reliable tool for predicting the rate of direct phototransformation of organic compounds in n

ISSN:0730-7268    

DOI:10.1002/etc.5620040408

出版商:Wiley Periodicals, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractThe effects of 3,4,‐dichloroaniline (DCA) on survival, growth and reproduction of the planktonic crustaceanDaphnia magnawere evaluated in the laboratory using a procedure based on Organization for Economic Cooperation and Development guidelines. Effects on reproduction, the most sensitive of the measured biological responses, occurred at a concentration of 20 μg/L but not at 10 μg/L or at lower concentrations. These, and similar results reported elsewhere, were used to calculate the maximum acceptable toxicant concentration (MATC) forD. magna.In acute toxicity tests withD. magnaandD. longispinathe 48‐h EC50 values were 290 and 440 μg/L, respectively. An estimate of the MATC forD. longispinawas then obtained by multiplication of the MATC forD. magnaby the ratio of the 48‐h EC50 values for the two species.A field experiment was carried out to compare the chronic toxicity of DCA in the laboratory with effects on populations of zooplankton and communities of macroinvertebrates in outdoor ponds. Three ponds were treated with DCA at a nominal concentration of 45 μg/L and three at 450 μg/L. These concentrations were maintained in the water for 28 d. Three untreated ponds were used as controls. Population densities of the dominant species of zooplankton were monitored before, during and after treatment with DCA. Samples of the macroinvertebrate communities were taken immediately after the end of treatment. Birth, death and growth rates ofD. longispinapopulations were monitored using Perspex cylinders to confine samples of adults in situ for periods of 24 h.Population densities ofD. longispinawere significantly affected (p≤ 0.05) by both treatment levels. There were no adverse effects on the population densities of two species of copepods and no changes were observed in the structure of macroinvertebrate communities. It was concluded that the Cladocera were much more susceptible to DCA than were other groups of invertebrates in the outdoor ponds.Birth and growth rates ofD. longispinapopulations were highly sensitive to the effects of DCA. They were depressed when concentrations of DCA were maintained at a level greater than the MATC and increased rapidly when concentrations decreased below this level. Thus, the MATC, derived from the results of toxicity tests, provided an accurate estimate of threshold concentrations affecting field populations ofD

ISSN:0730-7268    

DOI:10.1002/etc.5620040409

出版商:Wiley Periodicals, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractTwo laboratory test units (plastic flower pots and intact soil‐core microcosms) were compared for their accuracy in predicting crop yield and element uptake in field plots. All three test units were amended with four treatment levels of unweathered, acidic fly ash (0, 100, 400 and 700 t/ha), fertilized with alfalfa meal and planted in late June with equivalent rates of Saranac alfalfa(Medicago sativa), Climax timothy(Phleum praetense)and Clintford oats(Avena sativa).Microcosms were more accurate than pots in predicting the dose‐response yield curve for alfalfa/timothy grown in field plots. The hypothesis of parallelism between regression equations for alfalfa yield was rejected for pots versus field plots, but was not rejected for microcosms versus field plots. Neither of the two laboratory units accurately predicted the dose‐response curves for oat grain or total oat yield. Pots were only slightly more accurate than microcosms in predicting the enrichment ratios (ERs) for alfalfa uptake of elements from field plots, based on statistical analysis of the distributions of In‐ER ratios for 22 elements. The extra rooting depth of the 60‐cm microcosms may provide more accurate yield data for long tap‐rooted species like alfalfa, as well as permit a second year of accurate data on crop yield and ele

ISSN:0730-7268    

DOI:10.1002/etc.5620040410

出版商:Wiley Periodicals, Inc.    

年代:1985

数据来源: WILEY