摘要:

AbstractThe sodium borohydride reduction of 3,4‐dichloro‐5‐hydroxy‐2(5H)‐furanone (mucochloric acid) resulted in the formation of 3,4‐dichloro‐2(5H)‐furanone and 4‐chloro‐2(5H)‐furanone formed in relative amounts of 98 and 2%, respectively. Mucochloric acid and 3,4‐dichloro‐2(5H)‐furanone were assayed together againstSalmonella typhimurium(TA100). Mucochloric acid was consistently more mutagenic than 3,4‐dichloro‐2(5H)‐furanone by a factor ranging from 36 to 49 times as established from three determinations of relative mutagenicity. Thus, the hydroxyl group substituted at the 5 position is concluded to have a marked influence on the mutagenicit

ISSN:0730-7268    

DOI:10.1002/etc.5620090601

出版商:Wiley Periodicals, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractIn situ microcosms of a winter plankton community were exposed for 21 d to 0 0, 0 1, 0 5 and 1 0 mg/L of the herbicide simazine, approximating persistent levels found after application in other systems Physical‐chemical parameters, phytoplankton, bacteria and zooplankton were quantifiedSimazine induced decreases in dissolved oxygen and pH, but induced increases in nitrate and am monia levels compared to control microcosms Phytoplankton were differentially affected by simazine Sensitive taxa includedTrachelomonas, Glenodiniumand diatoms Others, such asDinobryonand small coccoids, were not significantly affected Bacteria data were variable and did not exhibit changes related to phytoplankton densities or simazineRotifers dominated the zooplankton and were also differentially affected by simazine The dominant species,Kellicottia bostomensis, exhibited a positive response to simazine, as didKeratella cochlearis, due to lesser mortality in higher concentrations of simazinePolyarthra vulgariswas unaffected, butSynchaeta pectinatawas impaired by simazine at day 21 Zooplankton (primarily rotifers) may have fed on heterotrophic cells more than on autotrophic cells, and may have been more closely associated with the detrital food chain than the autotrophic food cha

ISSN:0730-7268    

DOI:10.1002/etc.5620090602

出版商:Wiley Periodicals, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractResting cell suspensions of the camphor‐grown soil organismPseudomonas putidaPpG‐786, ATCC culture 29607, dehalogenate 1,1,2‐trichloroethane by two pathways under aerobic conditions. The dominant pathway (85%) is oxidative (kox, 4 × 10−19L/org/sec) and leads in sequence to chloroacetic acid and glyoxylic acid. A competitive reductive pathway (15%) (kred, 0.7 × 10−19L/org/sec) occurs simultaneously and yields vinyl chloride exclusively. Glucose‐grown cells are ineffective in these reactions, and carbon monoxide completely inhibits these transformations. These findings implicate cytochrome P‐450 cam as the responsible enzyme in vivo. Overall rates of conversion of 1,1,2‐trichloroethane by the organism and the isolated enzyme correspond to those obtained previously with ethylene dibromide.The results suggest that reductive microbial dehalogenation can occur in the environment even under a

ISSN:0730-7268    

DOI:10.1002/etc.5620090603

出版商:Wiley Periodicals, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractThe uptake of five chlorinated benzenes and three polychlorinated biphenyls by guppies (Poecilia reticulata) from a sediment suspension has been investigated. To examine the availability of these chemicals, the uptake from water has been compared to that from a sediment suspension. In the two experiments, i.e., with and without sediment being present, the total amount of the test compounds was the same. The only difference was that the chemicals were purely dissolved in the water in one system and partly sorbed on the sediment in the other.For all five chlorobenzenes bioconcentration factors are found to be reduced when fish are exposed in a sediment suspension. The reduction increased with increasing hydrophobicity of the compounds. A relationship is found between the amount sorbed on the sediment and the reduction of the bioconcentration factor. The same relationship was found from results of studies reported in the literature.This study also showed that small amounts of sediment can be present in the intestines of the fish when the fish are exposed in a sediment suspension. Depending on the affinity of the chemical for the sediment, the concentrations of the test compounds measured in the whole fish can be significantly influenced.

ISSN:0730-7268    

DOI:10.1002/etc.5620090604

出版商:Wiley Periodicals, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractNitrate‐reducing and methanogenic microbial consortia capable of using 2‐furaldehyde (furfural) as a sole source of carbon and energy were isolated from a mixture of soil and municipal sewage and from municipal anaerobic digestor sludge, respectively. Under nitrate‐reducing conditions, more than 97% of the furfural was biodegraded in 0.25, 1.5, 4 and 32 d at initial substrate concentrations of 0.5, 5, 50 and 500 ppm, respectively. In all cases microbial populations were able to reduce furfural levels to less than the detection limit of 20 ppb as measured by HPLC. At 500 ppm, there was a 12‐d lag period before detectable activity was noted, while there was no lag period at the lower concentrations tested. When the disappearance of both furfural (50 ppm) and nitrate was measured, the molar ratio of nitrate to furfural consumed was approximately 4.2:1, Which is in good agreement with the theoretical ratio of 4.0:1. The biodegradation of furfural was generally more rapid under methanogenic than under nitrate‐reducing conditions. The methanogenic consortium was able to metabolize 97% of the furfural in 2, 4, 48 and 144 h at initial concentrations of 0.5, 5, 50 and 500 ppm, respectively. No lag period was noted at any concentrations tested. As under nitrate‐reducing conditions, populations were able to reduce furfural levels to less than 20 ppb. Complete metabolism of furfural in cultures that received an initial concentration of 50 ppm resulted in the production of 0.056 mM methane or 43% of the theoretical yield that would result from complete conversion of the material to carbon dioxide and methane. This is the first report of the biodegradation of furfural under nitrate‐reduci

ISSN:0730-7268    

DOI:10.1002/etc.5620090605

出版商:Wiley Periodicals, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractHenry's law constants (HLCs) were determined for 12 pesticides, 9 polynuclear aromatic hydrocarbons (PAHs) and 2 polychlorinated biphenyl (PCB) congeners using a wetted‐wall column (WWC) technique. The WWC equilibrates an organic solute between a thin film of water and a concurrent flow of air in a vertical column. Air and water collected from the WWC were either solvent extracted or trapped on solid phase sorbents and were analyzed by gas chromatographic methods. HLCs were calculated from analyte concentrations in air and water collected from the WWC. Results of the HLCs determined by the WWC are compared with calculated values and determinations made by other investigators using purge bottle and static equilibration technique

ISSN:0730-7268    

DOI:10.1002/etc.5620090606

出版商:Wiley Periodicals, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractThe cytotoxicity of three heavy metals that are representative environmental contaminants was investigated in primary cultures of rat hepatocytes. The cells were exposed to Cd, Ag or Hg and to mixtures comprised of Cd and either Ag or Hg at various concentrations. Incorporation of [3H]arginine ([3H]Arg) into proteins was used to monitor cytotoxic effects. In parallel, the uptake of metals by the cells was also determined. Concentration‐response profiles for each individual agent show that among the metals studied Cd is the most cytotoxic. This effect is not due to preferential uptake because the amounts of Ag and Hg accumulated by the cells (at low exposure concentrations) were similar to those of Cd. When Ag was used in combination with Cd, amino acid incorporation data showed no evidence of modulated toxicity. In contrast, when Hg was added with Cd, the results suggested the possibility of interaction: The reduction in incorporated [3H]Arg was more pronounced than that expected on the basis of individual responses. Measurement of metal uptake by the cells revealed that intracellular levels of Ag were comparable whether Cd was present or not. Similarly, the amount of Cd accumulated by the hepatocytes was not significantly affected by the presence of Ag or Hg. In conclusion, the present data describe the cytotoxicity of nonessential heavy metals in hepatocytes and their concomitant accumulation by the cells. It is therefore possible to examine one phenomenon in relation to the other. The results are further discussed in the light of the bioinorganic properties of the metals investigate

ISSN:0730-7268    

DOI:10.1002/etc.5620090607

出版商:Wiley Periodicals, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractThe acute toxicity of a synthetic hexachloroethane (HC) smoke combustion products mixture to nine freshwater aquatic organisms was determined. Synthetic HC smoke combustion products are a complex mixture containing Zn, Cd, As, Pb, Al, CCl4, C2Cl4, C2Cl6, C6Cl6and HCl. Juvenile fish exposed to this mixture for 96 h included the fathead minnow, bluegill, channel catfish and rainbow trout. Invertebrates tested for 48 h included the neonate water flea, early young amphipod, midge larva and the mayfly larva. The effect of the mixture on the growth of the green algaSelenastrum capricornutumwas also studied.The dissolved components of the synthetic HC smoke combustion products mixture were found to be quite toxic to a number of freshwater species, especially the algae, rainbow trout and water flea. A test solution containing only 5.6% of a stock mixture of these components caused both an algistatic and algicidal effect on the alga. The rainbow trout and the water flea had 96‐ and 48‐h LC50s of 2.2 and 9.3% of the stock solution, respectiv

ISSN:0730-7268    

DOI:10.1002/etc.5620090608

出版商:Wiley Periodicals, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractSynthetic hexachloroethane (HC) smoke combustion products are a complex mixture containing Zn, Cd, As, Pb, Al, CCl4, C2Cl4, C2Cl6, C6Cl6and HCl. The dissolved components of the synthetic HC smoke combustion products mixture are quite toxic to a number of freshwater species, especially a green alga, rainbow trout and water flea. Acute 48‐h static bioassays were conducted with neonateDaphnia magnato assess the toxicity of various individual components and mixtures of components of the synthetic HC smoke combustion products mixture. These tests showed that the metals, zinc in particular, were the major toxic component of the mixture. When the chlorinated organics were tested as a group, they caused only minimal toxicity to the daphnid

ISSN:0730-7268    

DOI:10.1002/etc.5620090609

出版商:Wiley Periodicals, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractDuckweed (Lemna minor), a small vascular plant, grows rapidly, is sensitive to a wide variety of toxicants and is easy to culture. A method is described that measures duckweed frond growth and chlorophyll levels as indicators of growth inhibition. The method requires a small testing volume (15 ml) of reconstituted test medium that is prepared by using commercial grade soil to promote frond and chlorophyll production.A variety of single toxicants, industrial effluents and wastewater treatment plant effluents were tested. For most chemicals, the duckweed was as sensitive as other frequently used test species. The comparative toxicities toCeriodaphnia dubiaand fathead minnows (Pimephales promelas) with various effluents indicates that, for some industrial effluents, duckweed was the most sensitive indicator used.

ISSN:0730-7268    

DOI:10.1002/etc.5620090610

出版商:Wiley Periodicals, Inc.    

年代:1990

数据来源: WILEY