摘要:

AbstractEarly‐life‐stage (ELS) toxicity tests were conducted to determine the effect of selected water temperatures on the toxicity of 4‐nitrophenol and 2,4‐dinitrophenol to rainbow trout (Oncorhynchus mykiss). NOECs were determined for growth and mortality at selected time intervals and water temperatures of 7, 12, and 17°C. As tests progressed, NOECs leveled to constant time‐independent values that were similar for tests at each temperature. In 4‐nitrophenol tests, the time‐independent NOEC values at 7, 12, and 17°C, respectively, were 1.16, 1.20, and 1.16 mg/L for growth and 3.40, 3.38, and 2.20 mg/L for mortality. For 2,4‐dinitrophenol, time‐independent NOEC values at 7, 12, and 17°C, respectively, were 1.07, 0.50, and 0.80 mg/L for growth and 1.30, 1.89, and 1.60 mg/L for mortality. Temperature did, however, affect the rate at which time‐independent NOECs were reached. More time was required to reach time‐independent NOECs as temperature decreased. For example, the time‐independent NOEC in 4‐nitrophenol tests at 17°C was reached in 14 d, whereas it required 42 d at 7°C. The effect of temperature on toxicity must be considered in hazard assessment protocols to assess risk accurately and protect aquatic organisms adequately. Chronic toxicity tests are necessary to assess risk because acute toxicity tests cannot provide the information necessary to predict the long‐term effects of factors such as tem

ISSN:0730-7268    

DOI:10.1002/etc.5620130111

出版商:Wiley Periodicals, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractToxicity tests (28‐d early‐life‐stage) were conducted to determine the effects of nine combinations of salinity (15, 20, 25 ppt) and temperature (22, 27, 32°C) on the toxicity of 2,4‐dinitrophenol (2,4‐DNP) and 4‐nitrophenol (4‐NP) to sheepshead minnows (Cyprinodon variegatus). The highest tested concentration having no observed effect (NOEC) on mortality and growth was derived weekly. The NOECs at test termination indicated that the survival and growth of fish exposed to 2,4‐dinitrophenol were not significantly affected by salinity, temperature, or the salinity temperature interaction. However, 28‐d NOECs of fish surviving from 4‐nitrophenol exposures were significantly affected by temperature, but the highest value exceeded the lowest by only a factor of two. The overall data suggest that variations of salinity and temperature do not change the NOEC; only the exposure time required to attain the

ISSN:0730-7268    

DOI:10.1002/etc.5620130112

出版商:Wiley Periodicals, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractThe toxicokinetic behavior of some chlorobenzenes in earthworms (Eisenia andrei) kept in soil was studied. To determine elimination kinetics, worms were exposed to chlorobenzenes for 7 d, followed by a depuration period of 15 or 35 d. Elimination of chlorobenzenes by earthworms kept in soil was best fitted using a bi‐exponential elimination curve. The half‐life belonging to the slow phase was in good agreement with measured elimination half‐lives for the same compounds by earthworms kept in water. Accumulation of chlorobenzenes in earthworms was studied by exposure over 50 d. Equilibrium was rapidly achieved within 7 d. BAFs based on the concentration in soil and on the concentration in the interstitial water were calculated. BAFs of 1,2,3,4‐tetrachlorobenzene and pentachlorobenzene in earthworms kept in soil and BCFs in earthworms kept in water were comparable, demonstrating that uptake proceeds mainly via the interstitial water. For hexachlorobenzene, the BAF was much larger than the BCF, which suggests that intestinal uptake for this compound is an important complementar

ISSN:0730-7268    

DOI:10.1002/etc.5620130113

出版商:Wiley Periodicals, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractToxicity of technical carbaryl, Sevin®‐4‐Oil, and technical malathion to federally endangered Colorado squawfish (Ptychocheilus lucius) and bonytail (Gila elegans) was estimated by 4‐d renewal‐acute and 32‐d early life‐stage (ELS) tests. Median lethal concentrations were estimated by probit analysis. Effect concentrations for ELS tests were estimated by ANOVA and an alternative procedure using a linear‐plateau regression model. Linear‐plateau regression estimated a threshold concentration above which toxic effects began to occur. Median lethal concentrations and 95% confidence limits (in parentheses) for carbaryl, Sevin‐4‐Oil, and malathion were 1.31 (1.23, 1.40), 3.18 (2.87, 3.52), and 9.14 mg/L (8.36, 10.0) for Colorado squawfish and 2.02 (1.78, 2.25), 3.31 (3.06, 3.55), and 15.3 mg/L (14.4, 16.4) for bonytail. NOECs for Colorado squawfish were 445 μg/L carbaryl and 1,680 μg/L malathion. The NOECs for bonytail were 650 μg/L carbaryl and 990 μg/L malathion. Threshold concentrations for Colorado squawfish in ELS tests were 364 μg/L carbaryl and 455 μg/L malathion. Threshold concentrations for bonytail were 217 μg/L carbaryl and 521 μg/L malathion. Estimates of effect concentrations from linear‐plateau regression were consistently lower than those estimated by hypothesis testing. Linear‐plateau regression models accounted for a significant amount of total variation and adequately described the observed

ISSN:0730-7268    

DOI:10.1002/etc.5620130114

出版商:Wiley Periodicals, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractThe effects of equitoxic mixtures of CuCl2, ZnCl2, and CdCl2on the filtration rate of the freshwater musselDreissena polymorphawere determined. The amounts of added metals were expressed in toxic units, and a range of toxic units was tested. Cu + Zn was less than concentration additive, Zn + Cd was concentration additive, and Cu + Cd was more than concentration additive in their effects on the filtration rate ofDreissena polymorpha. An equitoxic mixture of all three metals was concentration additive. The effect of a mixture could not be predicted from the effects of the single metals. The concentrations at which Cu and Cd contributed to the toxicity of a mixture of Cu + Zn + Cd were at or below the NOECs for these metals, determined in single‐metal toxicity tests. At low but elevated Cu and Zn concentrations in water, no accumulation of these metals in the mussels took place; Cd, on the contrary, was accumulated at all Cd concentrations in the wate

ISSN:0730-7268    

DOI:10.1002/etc.5620130115

出版商:Wiley Periodicals, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractRecent laboratory studies with hybrid red‐legged partridges have shown that the interaction of certain combinations of agricultural pesticides can lead to an enhancement of toxicity. In view of this finding, captive feral pigeons (Columba livia) and European starlings (Sturnus vulgaris), in addition to hybrid red‐legged partridges (Alectoris rufacross), were used in a laboratory study to extend investigations of the enhancement of toxicity of the organophosphorus (OP) insecticide malathion in birds predosed with the ergosterol‐biosynthesis‐inhibiting (EBI) fungicide, prochloraz. Following pretreatment with either 90 or 180 mg/kg prochloraz, both pigeons and partridges showed significantly greater inhibition of serum butyrylcholinesterase (BuChE) activity (1.4‐ to 2.1‐fold increase for pigeons and 1.3‐ to 3.8‐fold increase for partridges) when dosed with malathion than control birds; this difference was evident at some or all of the blood‐sampling time points. On the other hand, starlings given either 180 or 300 mg/kg prochloraz showed no difference from controls in serum BuChE inhibition after dosing with malathion. The enhanced inhibition of serum BuChE in the pigeon and the partridge after malathion dosing was attributed to the increased activation of malathion to malaoxon following induction of the hepatic monooxygenase system by prochloraz. Serum BuChE inhibition may be useful in studying the interactive effects of OPs and EBI fungic

ISSN:0730-7268    

DOI:10.1002/etc.5620130116

出版商:Wiley Periodicals, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractLevels of PCB methyl sulfones (MeSO2‐CBs) and DDE methyl sulfones (MeSO2‐DDEs) have been determined in tissues from polar bear (Ursus martimus), beluga whale (Delphinapterus leucas), and false killer whale (Pseudorca crassidens) from the Canadian environment, and grey seal (Halichoerus grypus), otter (Lutra lutra), and wild mink (Mustela vison) from the Swedish environment. Up to 30 MeSO2‐CB congeners and three MeSO2‐DDE isomers were shown to be present in the analyzed tissues. The concentration of total MeSO2‐CBs ranged from 0.1 to 21 μg/g extracted lipids. 3‐MeSO2‐2,5,2′,4′,5′‐penta‐CB is the dominating MeSO2‐CB congener in all the analyzed samples, but the corresponding 4‐MeSO2‐CB also is present in high concentrations. A smaller number of MeSO2‐CBs, always dominated by the meta‐substituted MeSO2‐CBs, were present in livers of grey seal, otter, and mink than in adipose tissue or muscle. In all studied mammals the concentrations of MeSO2‐CBs were higher in liver than in blubber or muscle. Seven PCB congeners were identified as precursors of the PCB methyl sulfones: 2,4,2′,5′‐tetra‐CB (CB‐49), 2,5,3′,4′‐tetra‐CB (CB‐70), 2,4,5,2′,5′‐penta‐CB (CB‐101), 2,3,4,5,2′,5′‐penta‐CB (CB‐87), 2,3,6,2′,4′,5′‐hexa‐CB (CB‐149), 2,3,4,2′,3′,6′‐hexa‐CB (CB‐132), and 2,3,4,2′,5′‐hexa‐CB (CB‐141). All species except beluga whale contained 3‐MeSO2‐4,4′‐DDE, but at a much lower concentration in mink and otter than in the other mammals. Polar bear and grey seal liver also contained 2‐MeSO2‐4,4′‐DDE. The concentrations of 2‐ and 3‐MeSO2‐DDE ranged from 0.01 to 1.3 μg/g extracted lipids. A hitherto unknown MeSO2‐DDE isomer was determined in false killer whale blubber by GC‐MS, along with 2‐ and 3‐MeSO2‐4,4′‐DDE and several unknown MeSO2‐penta‐

ISSN:0730-7268    

DOI:10.1002/etc.5620130117

出版商:Wiley Periodicals, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractThe presence and concentrations of non‐ortho‐, mono‐ortho‐, and di‐ortho‐substituted PCB congeners in the polecat (n= 7), a member of the mustelid family, were investigated. PCBs were extracted with a Soxhlet apparatus. After cleanup the non‐ortho‐substituted PCB congeners were separated from the other PCBs by HPLC. Determinations were accomplished with GC‐ECD or GC‐MSD. Patterns of PCBs were examined in different organs and tissues: liver, kidney, muscle, anal gland secretion, mesenteric fat, and subcutaneous fat. Using a multivariate statistical method for data analysis (SIMCA), a significant difference of PCB patterns between anal gland secretion and the other organs and tissues was revealed. Lesser concentrations of congeners with seven and eight chlorine atoms in anal gland secretion were mainly responsible for this phenomenon. A more or less organ‐ and tissue‐specific PCB pattern was observed in all animals. PCB patterns were not dependent on prey choice, which ranged from terrestrial (small rodents) to aquatic (amphibians). This finding implies that PCB patterns in the polecat seem to be controlled by metabolic processes rather than diet factors. The total concentration of PCBs (sum of 29 congeners) in polecats varies widely, two orders of magnitude, from 1 to 370 μg/g lipid. In some animals, PCBs exceeded the experimentally determined reproduction effect concentrations of mink and ferrets. Using the toxic equivalent approach, it was observed that planar PCB 126 accounts for 63 to 98% of the toxic equivalents. The results showed that juvenile animals contain greater PCB levels than adult males and females, which might be related to an increased elimination of PCBs in adult animals due to anal gland secretion. High concentrations of PCBs were observed in such secretion. A preliminary model for concentrations of PCBs in polecats including

ISSN:0730-7268    

DOI:10.1002/etc.5620130118

出版商:Wiley Periodicals, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractFly ash was collected from five large‐scale or pilot tests in which burning of bleached kraft pulp mill sludge was studied. The content of dioxin‐like compounds in this fly ash was estimated both chemically and biologically. Fly ash was analyzed chemically for 17 PCDD and PCDF congeners by high‐resolution GC‐MS, and the data were transformed to Nordic TCDD equivalents. The biological analyses were based on the induction of several enzymes (aryl hydrocarbon hydroxylase [AHH], 7‐ethoxyresorufinO‐deethylase [EROD], aldehyde dehydrogenase‐3 [ALDG3]) by the fly ash extracts in a mouse hepatoma cell line, Hepa‐1. The inducing potencies were expressed as biological TCDD equivalents. There was a good correlation between the Nordic and the biological TCDD equivalents. Differences in the amounts of dioxin‐like compounds among the combustions were attributed mainly to the boiler types and not to fuel characteristics or comb

ISSN:0730-7268    

DOI:10.1002/etc.5620130119

出版商:Wiley Periodicals, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractHumans generally are exposed simultaneously to a number of toxins, including complex mixtures of unknown and variable origin. Although procedures for assessing the potential toxic risks associated with exposure to individual chemicals are relatively well established, methods for assessing the risks of complex mixtures are still in the developmental stages. One source of considerable uncertainty in these estimates is the potential for interaction among chemicals in complex mixtures. The objective of this work was to gain a better understanding of the effects posed by toxicant interactions and to test a new approach for analyzing the dose‐response effects of binary toxic mixtures. This new method of analysis enables a more rapid and quantitative assessment of the interactive effects of pairs of toxic chemicals. A number of experimental studies showing multicompo‐nent toxicity were tested using the proposed approach. Both positive and negative interactions of the toxicants were documented for these studies, with significantly acceptable predictive capabilities observed for the mo

ISSN:0730-7268    

DOI:10.1002/etc.5620130120

出版商:Wiley Periodicals, Inc.    

年代:1994

数据来源: WILEY