bluuebunny/crossref_metadata_2025_split huggingface dataset:
Water quality of the river nile. III. Toxicity assessment of six industrial effluents polluting the river nile
Authors: Abdel‐Hamid Mohammad I. , Shaaban‐Dessouki Sami A. , Skulberg Olav M. 
Published: October 2006

AbstractSix different industrial effluents were chemically and physically characterized. Their toxicity was evaluated using biotests with Selenastrum capricornutum strain NIVA‐CHL1. The growth of the test alga showed either inhibition or stimulation. Two of the effluents were highly inhibitory with EC50 values ranging between 1 and 10% (v/v) effluent concentrations. Others showed low growth inhibitory effects (50% < EC50 < 100%). EC50 values derived from the growth parameters, algal dry weight, cell count, growth rate, and area under the growth curve were almost similar for those two effluents exhibiting highly inhibitory effects. The toxicity values, calculated from algal dry weight and cell count showed, a strong positive linear relationship (r = 0.97 at p < 0.0001). The potential toxicity of some effluents was partly related to their high content of heavy metals. Changes in mean cell volume of the test alga may be used as an indicator for the potential effects of toxic effluents on the overall cellular activities. The results emphasized the indispensable role of algal bioassays among the basis of relevant and quantitative information about the biological impacts of the investigated effluents on the receiving waters. © 1993 John Wiley & Sons, Inc.
Interactive toxic effect and bioconcentration between cadmium and chromium using continuous algal culture
Authors: Aoyama Isao , Okamura Hideo 
Published: October 2006

AbstractNumerous studies have been conducted on the effects of toxic chemicals using algal batch culture. On the other hand, continuous culture research has the advantage of allowing optimal cell growth. Few studies on the interactive toxic effect between chemicals have been carried out either with batch culture or with continuous culture. The purpose of this study is to find the relationship between interactive toxic effects and the bioconcentration of heavy metals using continuous algal culture. The green alga Chlorella ellipsoidea was used as a test organism. As test substances cadmium and chromium were used.The amount of heavy metals both in algae and in the medium was determined after the cells had been exposed to heavy metals for 10 days. The amount of Cd taken up in the cells and the growth inhibition rates caused by Cd increased as the concentration of Cd in the medium became higher. The inhibition rates rose drastically but the amount of Cd in the cells remained at almost the same level even if Cr was added. The bioconcentration factors of Cd were ca. 10,000 in all the cases tested, regardless of the presence of Cr. The amount of Cr in the cell exposed to Cr was low, while that amount and the growth inhibition rates for all the concentrations tested increased when Cd was added to the medium containing Cr. The bioconcentration factors of Cr reached 156,000 as the concentration of Cd in the medium increased. It seems that the toxicity of Cr was enhanced because the presence of Cd in the medium raised the amount of Cr in the cell. © 1993 John Wiley & Sons, Inc.
Biodegradation of pentachlorophenol by micromycetes. II. Ascomycetes, basidiomycetes, and yeasts
Authors: Steiman Regine , Benoit‐Guyod Jean‐Louis , Seigle‐Murandi Françoise , Sage Lucile , Toe Adama 
Published: October 2006

AbstractFollowing a previous study on the biodegradation of pentachlorophenol (PCP) (100 mg L−1) by Zygomycetes, other taxonomic groups (Ascomycetes, Basidiomycetes, and Yeasts) have been investigated in relation to their ability to produce extracellular phenoloxidases. Ascomycetes gave heterogeneous results since disappearance of PCP occurred both in phenoloxidases‐producing and non‐producing strains. Basidiomycetes were high producers of phenoloxidases and showed a moderate depletion of PCP. Yeasts degraded PCP very poorly and did not produce phenoloxidases. No correlation was found between phenoloxidases production and PCP depletion. © 1994 by John Wiley & Sons, Inc..
Semiautomated fluorometric analysis of nucleic acids in tissue homogenates
Authors: Nacci Diane , Cheer Sue , Jackim Eugene , Juinio Annette 
Published: October 2006

AbstractThis report describes a technique that was developed to provide an efficient and accurate estimation of RNA:DNA ratios. These ratios have been used as an instantaneous measure of recent growth of individual aquatic organisms where morphometrics are not appropriate (e.g., field‐collected species) or insufficiently sensitive (e.g., small life stages or species). In this semiautomated, sensitive method, ethidium bromide fluorescence was used to quantitate total nucleic acids in crude homogenates. Individual concentrations of RNA and DNA were determined by differences in fluorescence before and after elimination of RNA by digestion with RNase. Efficiency of the procedure was enhanced using a computer‐driven multiwell plate scanning system (CYTOFLUOR, Millipore CorporationReference to trade names does not imply endorsement.
) to measure fluorescence at timed intervals and perform data manipulations. Routinely, detection limits of 0.1 μg DNA and 0.4 μg RNA were achieved, allowing the analysis of small, individual organisms. Fluorescence results of split samples were comparable with those obtained using a standard spectro‐photometric method to quantitate nucleic acids. Coefficients of variation for replicate samples within an assay (1.6%) and for samples within replicate assays (5.6%) indicated good test reproducibility. Quantitative recoveries of nucleic acid standards spiked into tissue homogenates were generally high, averaging 91.0% for DNA and 119.0% for RNA. Factors affecting the fluorescence of ethidium bromide stained nucleic acids—e.g., nucleic acid source, crude homogenate components, and buffer composition—are discussed relative to assay performance. This method provides a rapid and reliable assessment of individual growth, an important sublethal toxicological end point, that is suitable for both laboratory and field studies. © 1994 by John Wiley & Sons, Inc..
Cytotoxicity of metals toward rainbow trout R1 cell line
Authors: Segner Helmut , Lenz Dietmar , Hanke Wilfried , Schüürmann Gerrit 
Published: October 2006

AbstractCultured fish cells are of potential use in the initial screening of the adverse effects of aquatic pollutants. In the present study, R1 cells, a fibroblast‐like cell line derived from liver tissue of rainbow trout (Oncorhynchus mykiss), were exposed to 13 metal salts. Cytotoxicity was assessed by the neutral red uptake inhibition test. The rank order of cytotoxicity for the cationic metals was silver > mercury > cadmium > zinc > copper > nickel > lead; for the anionic metal complexes it was arsenite > dichromate > chromate > arsenate > selenite > permanganate > selenate. Metal cytotoxicity toward R1 cells showed close correlation with the cytotoxicity values of metals toward the BF‐2 cell line from bluegill sunfish (r = 0.98). For the divalent cations, cytotoxicity correlated well with the physicochemical softness parameter σp (r = 0.93). Correlation coefficients between the in vitro toxicity of cationic metals and their in vivo LC50 data varied for different fish species, with r values from r = 0.64 to r = 0.92. The in vitro cytotoxicity of anionic metal complexes was not related with their acute in vivo toxicity. © 1994 by John Wiley & Sons, Inc..
Aquatic field studies in ecotoxicological assessment of hazardous substances
Authors: Kussatz Carola 
Published: October 2006

AbstractThe role of field tests for chemical management must not be overestimated. Results obtained from multi species tests in the field indisputably give valuable information on the fate of a substance that facilitates the assessment of results from laboratory tests provided the test design is orientated on the appropriate formulation of question.If those investigations are available, they are included in the assessment of substances. These may increase the uncertainty factor, but this can only be a critical case‐by‐case decision.The investigations, however, have to satisfy certain minimum requirements:

—examination of several test concentrations and untreated controls, proof of a dose–effect relationship, ability to derive the NOEC;

—exposure of several taxonomic groups over a longer period;

—analytical control of the test concentration during the experiment;

—equivalent development of controls, ability to repeat the experiments under different starting conditions; and

—use of aquatic ecological parameters as toxicological end points.

Independently of these requirements, the necessity of validation does in principle exist. © 1994 by John Wiley & Sons, Inc..
Inhibition of the biological self‐purification by chlorophenols, sodium dodecyl sulfate, and the complexing agents ethylenediaminetetraacetic acid and nitrilotriacetic acid
Authors: Weßler Adelheid , Obst Ursula 
Published: October 2006

AbstractThe determination of enzymatic activities in surface water allows the control of the biological selfpurification as well as being an indicator for microbial degradation of xenobiotics. As for this matter it is a good instrument for controlling alterations in the ecosystem. Inhibition of enzymatic activities (esterases, β‐glucosidases, and alanin‐aminopeptidases) were analyzed using linear dilution of the water under test, then correlating the resulting enzyme activities of each dilution step and the concentration of the sample. Because of the complex matrix of surface water, chemical analysis of inhibiting substances has been and still is very difficult. A characterization of these substances is therefore only possible by pretreatment of the samples. In order to simulate definite inhibition effects, surface water was spiked with 2‐chlorophenol and 4‐chlorophenol, as well as with the surfactant sodium dodecyl sulfate and the complex agents ethylenediaminetetraacetic acid and nitrilotriacetic acid. The simulated inhibition effects on the enzyme activities were characterized closely by an additional pretreatment of the water under test. The elimination of the inhibiting substances by adsorption on water‐insoluble polyvinylpyrrolidone or activated carbon and the reduction of the inhibitory effect on the enzyme activities were investigated. The oxidation of inhibiting chemicals using stripping or treatment with H2O2 was also found to be a reliable method to diminish the inhibitory effects on the enzymatic activities. © 1994 by John Wiley & Sons, Inc..
Comparison of standard most probable number method with three alternate tests for detection of bacteriological water quality indicators
Authors: Ramteke Pramod W. 
Published: October 2006

AbstractThe standard most probable number (MPN) method for the detection of total and fecal coliforms was compared with three simple microbial tests: H2S paper strip test, Presence‐absence (P‐A) test for coliforms using MacConkey broth (PA‐TC), and P‐A test for fecal streptococci using KF streptococcal broth (PA‐FS) in 187 samples of water from three districts of Indian state of Jammu and Kashmir: Doda, Udhampur, and Jammu. All three tests were comparable with the standard MPN method. However, the PA‐FS and H2S tests were found more sensitive in the detection of indicator organisms. Four hundred and fifty eight cultures obtained from positive tests were identified in order to evaluate the specificities of tests used in detection of coliform indicators. The low incidence of recovery of Escherichia coli (16–34%) for the standard MPN method places doubt on the validity of its application in tropical areas. In view of this, the need for relaxed standards of water quality in tropical areas is discussed. From the results reported here it appears that the combination of the PA‐FS and H2S test could be used as a suitable multiple test to assess the microbiological quality of drinking water in India and other tropical countries. © by John Wiley & Sons, Inc.
Coliphages as a rapid indicator of sequencing batch reactor (SBR) treatment performance
Authors: Sim T. S. , Ng W. J. , Ong S. L. , Ng K. Y. , Ramasamy M. , Tan K. N. 
Published: October 2006

AbstractGenerally, conventional tests for total and fecal coliforms take from 1 to 4 days before the results are available. In contrast, the coliphage method is a simple, rapid, economical, and reliable method that has been used as an additional indicator of potential pathogens whereby coliform numbers present in natural waters can be estimated within 6–24 h. In this pilot‐scale study, besides demonstrating that the 6‐h coliphage test may be used to evaluate sequencing batch reactor (SBR) treatment efficiency (up to 99% removal), predictions of coliform numbers were made by enumeration of the coliphages. Coliform–coliphage correlationships similar to that for natural water (as proposed by the American Public Health Association's Standard Methods, 1989) and SBR treated domestic sewage have been developed for SBR treated combined sewage:

where TC is total coliforms/100 mL and P is the coliphages/100 mL, and

where FC is fecal coliforms/100 mL and P is coliphages/100 mL. Comparison between the logarithm of coliphages after 24 h incubation with the logarithm of coliphages after 6 h incubation yielded correlation coefficients of at least 0.91 suggesting that the 6 h coliphage detection test is sufficient for use as a rapid test and may be correlated to coliform numbers in sewage. © by John Wiley & Sons, Inc.
Cyst‐based toxicity tests. IX. The potential of Thamnocephalus platyurus as test species in comparison with Streptocephalus proboscideus (crustacea: Branchiopoda: Anostraca)
Authors: Centeno Maria Dulce F. , Persoone Guido , Goyvaerts Marie Pierre 
Published: October 2006

AbstractThe potential of the larvae of the freshwater anostracan crustacean Thamnocephalus platyurus has been evaluated as an alternative to those of the related species Streptocephalus proboscideus, used so far as the test organism in the standard Streptoxkit F test. In line with the former cyst‐based toxicity test method, the hatching of dried T. platyurus eggs, the molting of larvae, and the sensitivity of the latter to toxicants were assessed. The acute toxicity of 10 pure chemicals, 4 solid waste leachates, and 5 sediment pore waters to T. platyurus nauplii was determined according to the standard Streptoxkit F test protocol. Hatching success and reliability of T. platyurus cysts proved better than that of S. proboscideus cysts after 20 h incubation in standard conditions; the hatching percentage after 24 h was slightly improved by diluting the Environmental Protection Agency medium to 1:8 with deionized water. The sensitivity of T. platyurus nauplii to pure toxicants and wastes was at least equal to, and in many cases even higher than, that of S. proboscideus larvae. Generally, precision of the toxicity tests with T. platyurus was better than that of the S. proboscideus assay, especially for the pure chemicals tested. Consequently, the standard operational testing protocol of the Streptoxkit F has been slightly modified with replacement of S. proboscideus by T. platyurus as a test species. The Streptoxkit F has consequently been renamed to Thamnotoxkit F for use in cost‐effective routine acute toxicity testing of chemicals and wastes. © by John Wiley & Sons, Inc.
Use of four microbial tests to assess the ecotoxicological hazard of contaminated sediments
Authors: Ross Philippe E. , Henebry Michael S. 
Published: October 2006

AbstractThree single‐species bioassays (Microtox, Selenastrum capricornutum, and Panagrellus redivivus) and a test using microbial communities developed on artificial substrates were used in a series of in situ and laboratory tests evaluating the ecotoxicological hazard of contaminated sediments at two sites on Lake Michigan: Waukegan (Illinois) Harbor and The Chicago Area Confined Disposal Facility Study. In the single‐species tests, exposure to elutriates of contaminated sediments significantly inhibited bacterial luminescence, algal photosynthesis, and nematode survival and growth at polluted stations, while elutriates from control stations did not. The battery of three tests is a promising screening tool for in‐place pollutants.Protozoan species richness and protozoan phototroph abundance were inhibited by elutriates from contaminated sites, but the abundance of heterotrophic protozoans was enhanced by sediment elutriates from some stations. Microbial community photosynthesis was significantly inhibited by most sediment elutriates, while community respiration was often stimulated; thus, functional responses paralleled the structural changes. Overall, the results of the microbial community tests were consistent with expected patterns of toxicity at the two sites on Lake Michigan.In general, single‐species test results agreed with the community bioassays. Although community tests may be more realistic than single‐species bioassays in predicting the impact of sediment contamination on actual ecosystems, caution must be exercised in interpreting the results.
Statistical concerns in the design and analysis of multispecies microcosm and mesocosm experiments
Authors: Smith Eric P. , Mercante Donald 
Published: October 2006

AbstractMicrocosm and mesocosm experiments are useful in the environmental analysis of the effects of toxicants on ecological communities. While there has been much interest in the biological approaches to microcosm design, there seems to have been little thought given to statistical issues in the design of these experiments. Here, some statistical design issues are considered. Some criteria are proposed, and optimal or near optimal designs suggested. Of particular interest is the choice of doses in the experiment, choices that allow for tests with high power and also provide good estimates of effect levels and other parameters. Also, some analytical techniques recently suggested for the analysis of community data are criticized and alternate methods suggested.
Relationships among the biological properties, distribution, and regulation of production by planktonic cyanobacteria
Authors: Reynolds C. S. 
Published: October 2006

AbstractInterrelationships between the morphological and physiological properties of selected cyanobacterial species distinguished in the laboratory are used to simulate their population dynamics against realistic scales of environmental variability. Differences in performances are shown to correlate well with the ambient conditions found in the various types of lakes in which cyanobacteria are typically distributed.
Bacterial indicators to estimate the health hazards associated with the use of swimming pools
Authors: Seyfried Patricia L. 
Published: October 2006

AbstractA total of 200 swimming pools, including one wading pool, were monitored for specific bacteria to select the most appropriate water quality indicators for a proposed prospective epidemiological survey of swimming pools. The organisms included in the study were fecal coliforms, fecal streptococci, Pseudomonas aeruginosa, Staphylococcus aureus, Acinetobacter spp., and total plate counts of aerobic heterotrophic bacteria. The results indicated that fecal coliforms, fecal streptococci, and Acinetobacter spp. have limited use as water quality parameters because of their naturally low densities in pools. Total plate counts, P. aeruginosa, and S. aureus appeared to be the indicators of choice because they were either present in large numbers, were opportunistic pathogens, or had a varied susceptibility to chlorine. The study showed that P. aeruginosa has an added advantage as an indicator because it can be typed using serological and genotyping methods.
Acute toxicity of six metals to the Rotifer Brachionus calyciflorus, with comparisons to other freshwater organisms
Authors: Couillard Yves , Ross Philippe , Pinel‐Alloul Bernadette 
Published: October 2006

AbstractThere are several advantages to the use of planktonic rotifers as freshwater bioassay organisms, yet few studies report toxicological data for these taxa. The goal of the present study was to evaluate the 24‐h acute toxicity responses of Brachionus calycifiorus to six heavy metals, and to compare metal tolerance of this species to published results for other aquatic organisms. Metal toxicity to B. calyciflorus, in decreasing order, was Hg > Cu > Cd > Zn > Fe > Mn. This order follows the theoretical ranking by affinity for anionic radicals based on Lewis acid‐base classification. While not quite as sensitive as Daphnia magna, B. calyciflorus is potentially useful as a bioassay species because it is easy to culture and manipulate, and is widely distributed in alkaline waters of eastern North America.
Genotoxicity of 22 pesticides in microtitration SOS chromotest
Authors: Xu Hao H. , Schurr Karl M. 
Published: October 2006

AbstractThe authors adapted microtitration techniques to the SOS Chromotest, and thereby established a simple and reliable modified genotoxicity test: the Microtitration SOS Chromotest. This test employs microtitration techniques and photometric analysis with numerical readout. These data are integrated into the computerized data processing program Statistical Analysis System to obtain genotoxicity and toxicity results of a chemical or chemical mixture within 16 h.In order to test the applicability of the new system, the genotoxicity and toxicity of 22 pesticides were studied. A two‐sample t test was employed to determine the level of significance (p < 0.05). Nine of the pesticides were found to induce the SOS response in Escherichia coli cells. Their relative degrees of induction based on SOS inducing potency values are as follows: captafol > captan > folpet > dinoseb > ferbam > linuron > alachlor > phosmet > cacodylic acid. The addition of rat liver S9 mix does not transform the nongenotoxic pesticides tested into genotoxic forms but significantly decreases the inducing ability of most positive pesticides.The Microtitration SOS Chromotest is rapid and efficient in providing evidence for decision‐making related to cleanup of chemical spills and discharges where time is a critical factor. This method maintains its high accuracy and sensitivity compared with conventionally used assays. The studies of pesticide genotoxicity using this test confirm the applicability, reliability, and sensitivity of the Microtitration SOS Chromotest as a simple, efficient, and rapid genotoxicity prescreening system as well as an excellent research tool for genotoxic mechanism studies.
Use of Microtox® andCeriodaphniabioassays in wastewater fractionation
Authors: Mazidji C. N. , Koopman B. , Bitton G. , Voiland G. , Logue C. 
Published: October 2006

AbstractCollection system and nonchlorinated secondary effluent samples from a large municipal wastewater system were fractionated using a scheme that included filration, EDTA treatment, C18solid‐phase extraction columns, and air stripping. Microtox required less time thanCeriodaphnia dubiabioassay for determining the toxicity of the numerous test samples generated by the fractionation procedure. Its usefulness was limited to collection system samples, however. Secondary effluent samples, which caused significant mortality ofC. dubia, were nontoxic to Microtox. Diazinon was tentatively identified as one of the causative toxicants present. Its LC50toC. dubia(0.5 μg/L) is within the range of concentrations detected (0.1–0.6 μg/L), whereas the EC50of diazinon to Microtox is much higher (> 18,000 μg/L).