摘要:

AbstractBy hanging blue rayon, an adsorbent specific for chemicals with polycyclic aromatic structures, in seawater for one day, the mutagenicity and the benzo(a)pyrene pollution of the water were monitored. Mussels living in the sites of water sampling were also subjected to the blue rayon extraction process and assayed. The mutagenicity was evaluated by the Salmonella/microsome reversion assay of Ames, with the use of a recently developed sensitive strain YG1024. The monitoring was performed in the Seto Inland Sea at 5 sites near Okayama, in the year 1991–1992. All the water and mussel samples gave positive benzo(a)pyrene contents and many of them showed positive mutagenicity (as assayed with metabolic activation). The mutagenicity and the benzo(a)pyrene contents were found to be significantly correlated both for the water samples and for the mussel samples. In contrast, there were no correlations between the water and the mussel samples regarding either the mutagenicity or benzo(a)pyrene contents. This lack of correlations may be attributed to the fact that the water samples gave results for a one‐day exposure whereas the mussel samples gave those of a long‐term exposure. This simple technique has advantages over the conventional sampling method in terms of easy handling, high sensitivity, and feasibility of monitoring distant sites. ©by John Wiley&Son

ISSN:1053-4725    

DOI:10.1002/tox.2530100302

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

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 ofEscherichia 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

ISSN:1053-4725    

DOI:10.1002/tox.2530100303

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractAmong several bioassays, theScenedesmus subspicatuschlorophyll fluorescence test and thePhotobacterium phosphoreumbioluminescence assay were selected to examine their applicability for toxicity evaluation of changes in coke plant effluent quality. In addition to the ecotoxicological parameters, a chemical analysis of dissolved organic carbon (DOC), ammonia‐N, and nitrate‐N was performed.It was demonstrated that the toxicity values obtained from the bioassays give a first indication on potential hazard and successful treatment. Decreasing toxicity values went along with decreasing DOC or ammonia‐N values, but the sensitivity toward DOC reduction was higher. Sensitivity toward pure compounds was assessed by comparing the EC50values of the luminescent bacteria assay with the corresponding EC50values of the algal bioassay. The data showed a poor correlation between the two bioassays. ©by John Wiley&Son

ISSN:1053-4725    

DOI:10.1002/tox.2530100304

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractTo evaluate toxicity of xenobiotics on microflora of soils and sediments, reduction of tetrazolium dye [2‐p‐iodophenyl‐3‐p‐nitrophenyl‐5‐phenyltetrazolium chloride (INT) or 2,3,5 triphenyltetrazolium chloride (TTC)] by dehydrogenase activities is commonly used, but many questions are posed about the biological relevance of this test.In this work, INT was chosen to evaluate the influence of some experimental factors on reductase activity. INT adsorption to soil, concentration of INT, and sterilization methods were tested on different soils and sediments to determine bioavailability of INT, saturation concentration, and intensity of chemical reduction.INT adsorption shown dramatic variations vs type of soil, from 0 to 100%, and was particularly linked with cation exchange capacity.Formaldehyde seems to be the best method with irradiation to determine abiotic reduction, particularly with sediments.However, it must be stressed that the tetrazolium reduction in microbial systems can be carried out by other enzymatic systems than malate dehydrogenase. INT is an excellent substrate of membrane hydrogenases found in numerous anaerobic bacteria. This was observed with experiments conducted withRhodobacter capsulatusin our laboratory. ©by John W

ISSN:1053-4725    

DOI:10.1002/tox.2530100305

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractA semiquantitative direct sediment toxicity testing procedure using the Sediment‐Chromotest was developed. This procedure has advantages over many other toxicity bioassays. It is simple, quick, and reliable, and does not require special instrumentation.The direct sediment toxicity testing procedure involves the use of serial dilutions of solid phase suspensions mixed with stressed bacteria (Escherichia coli) and a cocktail containing the specific inducer for the chromogenic enzyme and other essential factors. The assay is based on the ability of toxicants to inhibit the de novo synthesis of an inducible enzyme, beta‐galactosidase. The amount of de novo synthesized enzyme is determined by a colorimetric reaction.This new procedure measures the presence of bioavailable toxicants in sediments, suspended sediments, soils, and other solid wastes directly without extraction and concentration. ©by John Wiley&Sons,

ISSN:1053-4725    

DOI:10.1002/tox.2530100306

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

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'sStandard Methods, 1989) and SBR treated domestic sewage have been developed for SBR treated combined sewage:\documentclass{article}\pagestyle{empty}\begin{document}$$ \log \,{\rm TC = 0}{\rm .798}\left({{\rm log}P} \right) + 3.921 $$\end{document}where TC is total coliforms/100 mL andPis the coliphages/100 mL, and\documentclass{article}\pagestyle{empty}\begin{document}$$ \log \,{\rm FC = 0}{\rm .850}\left({{\rm log}P} \right) + 3.501 $$\end{document}where FC is fecal coliforms/100 mL andPis 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&S

ISSN:1053-4725    

DOI:10.1002/tox.2530100307

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractField studies were conducted along an urban/industrial river to investigate the potential relationship between anthropogenic contaminants, including those related to oil refining, and fish health. The channel catfish,Ictalurus punctatus, served as the benthic sentinel species for these studies. At least 15 aromatic hydrocarbons known to be associated with oil refining and/or other industrial activities were detected at impacted stations including known carcinogens and mutagens [e.g., anthracene and benzo(a)pyrene]. At an appropriate reference station, no anthropogenic contaminants were identified in the waters and only 2 were observed in the sediments. Catfish collected from the reference station were significantly heavier, longer, and had higher relative weights. Morphological deformities such as clubbed, split, and missing barbels were observed on 37.8% of the fish collected from the impacted stations, while none were observed on fish from the reference station. Livers of catfish collected from the impacted stations exhibited a variety of histological changes consistent with contaminant exposure including vacuolated hepatocytes, pigment deposits, and other hepatoxic changes. These sublethal changes appear to be associated with chemical contamination and represent compromised health of individual organisms and, potentially, populations. ©by John Wiley&Sons, Inc

ISSN:1053-4725    

DOI:10.1002/tox.2530100308

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractRainbow trout hepatocytes were used as anin vitrobioassay to assess the genotoxic potential of single chemicals and marine sediment extracts. Freshly prepared trout hepatocytes were exposed to either benzo[a]pyrene, N‐methyl‐N′‐nitro‐N‐nitrosoguanidine, β‐naphtoflavone, or organic extracts of marine sediments for 24 h at 15°C. Genotoxicity was assayed using the nick translation assay, which makes use of a nonradioactive nucleotide (biotin‐dUTP), and the DNA alkaline precipitation assay followed by fluorometric detection of DNA strands. Exposure to benzo[a]pyrene or methyl‐N′‐nitro‐N‐nitrosoguanidine, known indirect‐and direct‐acting genotoxins respectively, produced genotoxicity to rainbow trout hepatocytes with both assays. β‐Naphtoflavone displayed genotoxic activity in trout hepatocytes. Sediment extracts and reference sediment extracts displayed high toxicity and genotoxicity to trout hepatocytes. Chemical analyses showed that these sediments contained significant amounts of organochlorine pesticides, polychlorinated biphenyls, and polycyclic aromatic hydrocarbons. Cell toxicity was correlated with total levels of organochlorine pesticides and polychlorinated biphenyls but not total levels of polycyclic aromatic hydrocarbons. No positive correlation was found with the nick translation assay between total levels of chemicals and genotoxicity in marine sediments. Genotoxicity obtained with the alkaline precipitation assay was correlated with levels of the organochlorine pesticide DDT. However, more tests would be required to further substantiate possible links with other specific c

ISSN:1053-4725    

DOI:10.1002/tox.2530100309

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

ISSN:1053-4725    

DOI:10.1002/tox.2530100301

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY