摘要:

AbstractRelationships between structure and biodegradability were evaluated for 28 pyridine derivatives in nutrient solutions inoculated with soil and incubated at 24°C. Compounds studied included pyridine; mono‐ and disubstituted pyridinecarboxylic acids; and hydroxy‐, chloro‐, amino‐and methylpyridines. Disappearance of the pyridine added was measured by UV spectrophotometry, and the ammonium released by cleavage of the pyridine ring was measured by colorimetry. Volatilization was estimated by analysis of the pyridines collected on the polyurethane foam stoppers used to plug the incubation vessels; sorption by soil was estimated from the initial decrease in solution concentration upon addition of soil. Pyridinecarboxylic acids, monohydroxypyridines and the unsubstituted pyridine ring did not volatilize and were degraded within 7 to 24 d. Methylpyridines were intermediate in degradability, disappearing in from less than 7 to more than 30 d. None of the aminopyridines was completely degraded in 30 d. Of the chloropyridines tested, only 4‐chloropyridine was completely degraded in 24 d. The susceptibility of 4‐chloropyridine to degradation may be attributed to the ease with which a chlorine group is removed from position 4 on the pyridine ring. No degradation was detected in 30 d for any of the other chloropyridines. Chloro‐and methylpyridines volatiliz

ISSN:0730-7268    

DOI:10.1002/etc.5620050601

出版商:Wiley Periodicals, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe genotoxicity of nitrogen heterocycles isolated from a sediment taken from the Black River near Loraine, Ohio, in an area that received effluents from the coking ovens of a steel plant was studied. These compounds were isolated by gel permeation chromatography and silicic acid adsorption chromatography from the moderately polar fraction of an organic extract of this sediment. Two complex mixtures of secondary and tertiary nitrogen heterocycles containing three to five aromatic rings were characterized using capillary column gas chromatography with selective detection. Both mixtures induced significant unscheduled DNA synthesis in primary rat hepatocytes and accounted for essentially all of the genotoxicity of the fraction from which they were isolated.

ISSN:0730-7268    

DOI:10.1002/etc.5620050602

出版商:Wiley Periodicals, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractThree rapid marine toxicity tests were evaluated to determine their potential usefulness in a toxicity testing program: early embryo growth test and sperm cell toxicity test, both using the sea urchinArbacia punctulata, and Microtox. Toxicity values (EC50s) were derived for eight organic chemicals and five metals using each system. Results were compared with LC50 values for the same chemicals from standard aquatic tests withPimephales romelasandDaphnia magnaand for the metals withMenidia menidiaandMysidopsis bahia.The EC50 values for the sea urchin early embryo growth test for organics and the LC50 values for fish and crustaceans for organics and metals with which the rapid tests were compared were from the literature.For organic chemicals, EC50s from rapid tests closely approximated LC50s and toxicity rankings, except that the sperm cell test was particularly sensitive to 2,4‐pentanedione and 2‐methyl‐2,4‐pentanediol. EC50s for metals were generally comparable with each other and with other tests using embryo and sperm of other sea urchins and oysters but not with LC50s forMysidopsisandMenidia.These results indicate the potential value of rapid tests to screen and rank substances for toxicity. Additional information on the usefulness of these tests will be gained through continuing comparisons using a broad spectrum of single substances and complex mixtures with varying modes of

ISSN:0730-7268    

DOI:10.1002/etc.5620050603

出版商:Wiley Periodicals, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractDaphnia magnawere exposed to cadmium, copper and cyanazine to determine the relative sensitivities of several age groups: less than 4 h, less than 24 h, 1 d, 2 d, 3 d, 4 d, 5 d and 6 d old. Mean cadmium 48‐h EC50 values for each age group ranged from 23 to 164 μg/L. Mean copper EC50 values ranged from 6 to 18 μg/L. Cyanazine EC50 values ranged from 53 to 106 mg/L. The 1‐d‐old and 5‐d‐oldDaphniamean EC50s were 48 and 49 μg/L for cadmium, 10 and 10 μg/L for copper and 84 and 86 μg/L for cyanazine, respectively. These similar sensitivities indicate that older animals can be used in tests equally as well as younger animals, thus simplifying the recovery of daphnids in acute sediment

ISSN:0730-7268    

DOI:10.1002/etc.5620050604

出版商:Wiley Periodicals, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe toxicity of pentachlorophenol (PCP) was determined in the laboratory for 11 aquatic species. Tests were conducted seasonally in ambient Mississippi River water and under controlled conditions in Lake Superior water. Fifty‐one acute toxicity tests were conducted, with LC50 values ranging from 85 μg/L for the white suckerCatastomus commersoniduring the summer to greater than 7,770 μg/L for the isopodAsellus racovitzaiduring the winter. The effect of PCP on growth and/or reproduction was determined for seven species. The most sensitive chronically exposed organisms were the cladoceranCeriodaphnia reticulataand the snailPhysa gyrina.Both were adversely affected at the lowest concentrations tested, i.e., 4.1 and 26 μg/L, respectively. The duckweedLemna minorwas the least sensitive, with no apparent effects after exposure for 21 d to concentrations as high as 1,440 μg/L.The greatest variation in toxicity was due to species sensitivity. Within a given season there was as much as a 40‐fold difference in LC50 values between species. For any one species, the maximum variation in LC50 between seasons was approximately 14‐fold. There were also substantial differences in acute‐chronic relationships, with acute/chronic ratios ranging from greater than 37 forC. reticulatato 1 forSimocephalus vetulus.It is suggested that the composition of the aquatic community should be the most important consideration in estimating the potential environmental eff

ISSN:0730-7268    

DOI:10.1002/etc.5620050605

出版商:Wiley Periodicals, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe toxicities of pure (greater than 99%) pentachlorophenol (PCP) and of a mixture of the major impurities in commercial PCP, composed mostly of octa‐ and nonachlorophenoxyphenols (POPs), were evaluated in 90‐d partial life‐cycle toxicity tests with fathead minnows (Pimephales promelasRafinesque). The exposure concentrations were 8 to 130 μg/L for the pure PCP and 6 to 93 ng/L for the mixture of POPs. A spontaneous conversion of a 2‐hydroxy isomer of nonachlorophenoxyphenol in the POPs mixture to octachlorodibenzodioxin was observed in the stock solution and exposure water during the POPs study. Pure PCP did not affect survival, growth or bone development at any concentration tested. The mixture of POPs did not affect survival but did reduce growth in fish exposed to 93 ng/L for 30 d and stimulated growth in fish exposed to 6 to 47 ng/L for 60 d or to 23 to 47 ng/L for 90 d. Bone development was significantly altered by exposure to POPs concentrations of 12 ng/L or higher; collagen concentration was elevated, and both hydroxyproline concentration (a key cross‐linking amino acid in collagen) and bone density were reduced. Degeneration of the fins was noted at 30 d of exposure to 93 ng/L POPs, but fin development appeared nearly normal at 90 d. The sublethal effects of POPs at low concentrations, when compared with those of pure PCP, indicate that POPs may be a major contributor in the toxicity of commercial P

ISSN:0730-7268    

DOI:10.1002/etc.5620050606

出版商:Wiley Periodicals, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractHexageniaare an important component of fish and waterfowl diets, provide an ecological link in the conversion of detritus to usable nutrients and are useful test organisms for monitoring trends in aquatic contaminants. Consequently,Hexagenia bilineatawere used in toxicity tests to determine their sensitivity to leachate from spent shale oil and to evaluate the influence of including artificial glass burrows in exposure chambers. Gill beat frequency and mortality were significantly higher (p= 0.01) in nymphs that were not afforded an opportunity to burrow than in those exposed to the toxicant but that had access to artificial burrows. Molting frequency was depressed inHexagenialacking burrows, and it was further decreased as the amount of toxicant increased. Thus, thigmotactic stress accentuated by the presence of shale oil leachate was relieved by including artificial burrows in the exposure chambers. The resulting toxicity data are more ecologically meaningful because the burrowing life history characteristic of theHexageniawas addressed and incorporated into the test protocol.

ISSN:0730-7268    

DOI:10.1002/etc.5620050607

出版商:Wiley Periodicals, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractThis article presents an improved DNA‐based embryo toxicity test in which growth is measured as the increase in DNA during a 5‐h postfertilization period. The test, using direct fluoro‐metric determination of DNA rather than thymidine incorporation, is fast, sensitive, easy to conduct and correlates well with other 48‐ and 96‐h acute aquatic tests. The need for radioisotopes has been eliminated and data variability is substantially reduced. It is recommended that this test be incorporated into a battery of rapid tests used to estimate aquatic

ISSN:0730-7268    

DOI:10.1002/etc.5620050608

出版商:Wiley Periodicals, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractAn in vivo rainbow trout (Salmo gairdneri) preparation was used to evaluate the gill uptake and toxicokinetics of [3H]fenvalerate ([R,S]‐α‐cyano‐3‐phenoxybenzyl [R,S]‐2‐[4‐chloro‐phenyl]‐3‐methylbutyrate), a synthetic pyrethroid insecticide. Fish were exposed to technical‐grade fenvalerate (0.28 or 23 ng/L) or an emulsifiable‐concentrate formulation (16 ng/L) for 36 to 48 h. No significant effects of emulsifiers or fenvalerate concentration on uptake were observed. The overall mean gill uptake efficiency was determined to be 28.6 + 4.4%. Following 8‐ to 48‐h depuration periods, carcass and bile contained 80 to 90% and 10 to 20% of the gill‐absorbed doses, respectively. Urine, feces and blood each contained less than 2% of the dose. Significant excretion and blood transport of fenvalerate equivalents were completed within 8 to 12 h after termination of exposure. Specific tissues from trout exposed to 0.28 ng/L fenvalerate were analyzed for fenvalerate equivalents. After a 48‐h depuration period, bile contained the highest concentration of fenvalerate equivalents (7,000 pg/g), followed by fat (200 pg/g). Remaining tissues contained 15 to 45 pg/g. Analysis of biliary metabolites indicated that the glucuronide of 4′‐HO‐fenvalerate was the only significant degradation product. Results from the present study suggest that efficient gill uptake does not explain the extreme sensitivity of fish to fenvalerate. Rather, a low rate of biotransformation and excretion may play a significant role in the susceptibility of rainbow trout to

ISSN:0730-7268    

DOI:10.1002/etc.5620050609

出版商:Wiley Periodicals, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractMethoxychlor was applied to 125‐m3limnocorrals at nominal concentrations of 3 and 300 μg L−1in 1981 and of 5 and 50 μg L−1in 1982. The half‐life of methoxychlor in water rangedfrom6 to 13 d; however, methoxychlor was strongly adsorbed to and slowly released from the polyethylene liners and the sediments on the bottom of the enclosures. Forced mixing of methoxychlor in the water resulted in greater adsorption to the sediments than did surface application. Methoxychlor had little effect on water chemistry parameters, although nitrite and dissolved inorganic carbon concentrations were higher in the treated than in the control corrals in each year of

ISSN:0730-7268    

DOI:10.1002/etc.5620050610

出版商:Wiley Periodicals, Inc.    

年代:1986

数据来源: WILEY