ISSN:0730-7268    

DOI:10.1002/etc.5620040101

出版商:Wiley Periodicals, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractStructure‐activity models, which were developed to predict bioconcentration of organic chemicals in freshwater fish, were tested for use with several marine species (Cyprinodon variegatus, Lagodon rhomboides, Crassostrea virginica, Mytilus edulis). Significant linear relationships existed between the bioconcentration factor (BCF) for each marine species tested and the log of the octanol/water partition coefficient (P). The results suggest that freshwater models can be used to predict the BCF of a chemical in marine species, since the slopes of the freshwater models were within the 95% confidence intervals for marine models. Models derived from data on freshwater species were used to calculate BCF values for each of the marine species. The calculated BCF values were compared with the measured BCF values for each marine species and those measured for the fathead minnow (Pimephales promelas). The data indicate that the log BCF can be estimated for the marine species using freshwater models to within one order of magnitude for a minimum of 71% of the chemicals having a range of 3,000,000 in the partition coefficient (1.61 to 6.50 in logP). It appears that models based on data from freshwater species offer the same precision in estimation of BCF values for marine species as for freshwater fish. Good agreement existed between measured and calculated BCF values for bothL. rhomboidesandM. edulis, whereas the data forC. virginicawere more variable and those forC. variegatuswere the most variable. Tests indicated that, generally, calculated BCF values overestimate the measured BCF values. Significant linear relationships existed between measured BCF values forP. promelasand each marine species, exceptM. eduli

ISSN:0730-7268    

DOI:10.1002/etc.5620040102

出版商:Wiley Periodicals, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractThe bottom sediment of an earthen water reservoir was found to cause elevated somatic mutation frequencies in the stamen hair system ofTradescantiaand a decrease in the transient chlorophyll fluorescence yield in leaves ofTradescantiaandZea mays.The mutation frequencies varied only slightly over time, and remained elevated for 91 d of chronic treatment when compared with controls. Chemodynamic modeling indicates that chemicals, including mutagens, can be transferred effectively from reservoir bottom sediment to water.

ISSN:0730-7268    

DOI:10.1002/etc.5620040103

出版商:Wiley Periodicals, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractThe ability to degrade [14C]‐naphthalene was transferred fromBacillus megateriumtoB. subtilisby extractingB. megateriumDNA and introducing it intoB. subtilisusing the protoplast‐polyethylene glycol method. Naphthalene degradation was indicated by the accumulation of water soluble14C activity and the presence of a unique solvent‐extractable metabolite on TLC analysis. In addition, resistance to dibenzofuran,p‐chlorobiphenyl, and naphthalene (as demonstrated by lack of growth inhibition by these compounds) was transferred by the same technique.B. megateriumATCC 13368 and derivatives conditioned to the presence of each of these three chemicals were used as DNA donors.B. subtilistransformants showed greater resistance to the chemical to which the DNA donorB. megateriumhad been cond

ISSN:0730-7268    

DOI:10.1002/etc.5620040104

出版商:Wiley Periodicals, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractCoal liquefaction compounds could, through accidental release, enter aquatic environments. Experiments were conducted to determine the kinetics, degree of bioconcentration and stability of two of these compounds at the first level of the aquatic food web. We exposed the freshwater phytoplankterScenedesmus quadricaudato sublethal concentrations of14C‐labeled phenol and aniline. Both accumulation and elimination occurred within a few hours and followed hyperbolic kinetics. Results indicate that substantial quantities of accumulated compounds remain as the parent compound (22% for phenol and 52% for aniline) for up to 24 h and could be available to animals higher in the food web. Bioconcentration factors [(nm parent compound/cm3phytoplankton) ÷ (nm parent compound/cm3water)] were 3.5 for phenol and 91 for anili

ISSN:0730-7268    

DOI:10.1002/etc.5620040105

出版商:Wiley Periodicals, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractDesorption kinetics of picloram (4‐amino‐3,5,6‐trichloropicolinic acid) was studied as a function of incubation time in seven soils incubated for up to 300 d in the presence of picloram. The amount of picloram readily released from the soil decreased significantly with incubation time. A two‐step sorption‐desorption mechanism was used to model the observed behavior that can be described in terms of external and internal sorption sites. Desorption from external sites is relatively fast, taking place in less than 5 h, whereas desorption from internal sites can take up to 300 h to reach equilibrium. The amount of picloram sorbed to internal sites increases with residence time in the soil. Implications of this study for the transport of picloram under field conditions and for models describing transport are

ISSN:0730-7268    

DOI:10.1002/etc.5620040106

出版商:Wiley Periodicals, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractToxicity and sorption of five azo and triphenylmethane dyes to freshwater microbiota were determined to assess, in part, the risks that these dyes may pose to the aquatic environment. The toxicities of Basic Violet 1, Basic Violet 2, Basic Violet 3, Basic Green 4 and Tropaeolin 0 were established by determining the percent survival of microbiota when dyes were incorporated into plating media. Basic Violet 3 was the most toxic, with a mean survival rate of 20.7 ± 6.57% at a dye concentration of 5.0 mg/L. Tropaeolin 0 was the least toxic, with a survival rate of 92.0 ± 9.57%. Survival increased with decreasing dye concentration. Sorption of the dyes to viable cells required from 8 to 24 h to reach equilibrium. Partition coefficients were higher for viable cells than for heat‐killed cells, suggesting that a metabolic process may be involved in sorption of these dyes or that autoclaving the cells reduces the organisms' cation exchange capacit

ISSN:0730-7268    

DOI:10.1002/etc.5620040107

出版商:Wiley Periodicals, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractThe bioconcentration of four synthetic pyrethroid insecticides (cis‐ andtrans‐cypermethrin, deltamethrin, fenvalerate andcis‐ andtrans‐permethrin) by larvae of the midgeChironomus tentanswas studied in sand, silt and clay sediments and water (sediment/water ratio, 1:5). Larvae were exposed for 24 h in sediment and for 48 h in water above sediment that contained 12 to 640 ng/g14C‐labeled cypermethrin and 5 and 50 ng/g of the other compounds. Depuration of radioactivity following transfer to clean sand/water systems was monitored for 96 h. Bioconcentration factors for larvae held in sand ranged from 135 fortrans‐permethrin to 316 for deltamethrin. Larvae in water above sand accumulated 5‐ to 15‐fold greater concentrations of each pyrethroid than did larvae held in water above silt or clay sediments. The lower bioavailability of each compound to larvae in water above silt and clay was attributed to greater sorption to suspended particulates and to dissolved organic carbon in these systems than in relatively particulate‐free sand/water systems. The accumulation of pyrethroids by larvae in silt and clay sediments was best accounted for by the uptake of the dissolved portion of each compound in pore water. Depuration of the four pyrethroids byChironomuslarvae was rapid, with an overall half‐life for radioactivity of 27 ± 8 h. Exposure for 24 h in sediments containing 5 ng/g concentrations of each pyrethroid had little effect on the behavior of the larvae, but at higher concentrations the animals were immobilized, although many survived following transfer to de

ISSN:0730-7268    

DOI:10.1002/etc.5620040108

出版商:Wiley Periodicals, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractA comparison was made of the sensitivity of fish,Daphniaand algae to the toxic effects of copper and acridine. A series of toxicity tests was conducted with these organisms, and the following biological endpoints determined: LC50s for fish, LC50s and effects on reproduction ofDaphniaand 50% inhibition of the growth rate of algae. The 96‐h LC50s for bluegill(Lepomis macrochirus)andDaphnia magnaexposed to copper were 2.2 and 0.13 mg/L, respectively. A chronic exposure to 0.03 mg/L of copper for 14 d significantly decreased reproduction inDaphnia.Exposure to 0.4 and 0.2 mg/L copper inhibited the growth rate ofSelenastrum capricornutumandChlorella vulgaris, respectively, by 50%. The 96‐h LC50s for fathead minnows(Pimephales promelas)andD. magnaexposed to acridine were 2.3 and 3.1 mg/L, respectively. A chronic exposure to 1.25 mg/L acridine for 14 d significantly inhibited reproduction inDaphnia, and an exposure to 0.9 mg/L inhibited the growth rate ofS. capricornutumby 50%. Based on the biological endpoints determined in these tests,Daphniawere more sensitive to copper than were fish or algae. In contrast, the most sensitive biological endpoint in tests with acridine was the inhibition of algal growth. Comparison of these test results indicates that short‐term toxicity tests used for screening toxicants for possible environmental effects should include both plant and animal sp

ISSN:0730-7268    

DOI:10.1002/etc.5620040109

出版商:Wiley Periodicals, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractVarious laboratory methods and mathematical models are being developed to assess the hazards of chemicals to aquatic environments. Although the approach is generally accepted, many of the methods and models have not been validated by comparison with field observations. In this study we compared predictions of the fate and biological effects of a reference compound, pentachlorophenol (PCP), with observations in experimental outdoor ponds. PCP was repeatedly applied to the subsurface water of three ponds with the aim of maintaining an average concentration of 50 to 100 μg/L in the water for a period of 30 d. At this dosage level chronic toxicity to some organisms was expected.Evaporation, sorption, hydrolysis, biodegradation and indirect phototransformation of PCP were expected to be of minor importance under the environmental conditions encountered in the ponds. The partition coefficient of PCP between water and wet sediment was predicted to be near unity and the dominant loss process to be direct phototransformation. The rate of this process was calculated using the SOLAR mathematical model. Data used for this calculation were the light absorption spectrum of PCP, the quantum yield for the light‐activated reaction, depth and light attenuation of pond water, season and latitude. After correcting for cloud cover, the calculated rate constant was 0.23 to 0.46 d−1. In good agreement with the calculations, the observed rate of loss was 0.15 to 0.34 d−1, and there was no evidence of accumulation in sediment.The results of chronic toxicity tests with various species of fish, two species of snail and the planktonic crustaceanDaphnia magnaStraus were consistent with field observations. Chronic toxicity to filamentous algae (Charasp. andEnteromorphasp.) was observed in the field, and their death and decay were responsible for depression of dissolved oxygen concentrations and fish deaths. Direct effects on filamentous algae and the indirect effects caused by their death and decay could not be predicted in the absence of relevant laborator

ISSN:0730-7268    

DOI:10.1002/etc.5620040110

出版商:Wiley Periodicals, Inc.    

年代:1985

数据来源: WILEY