ISSN:0730-7268    

DOI:10.1002/etc.5620130901

出版商:Wiley Periodicals, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractThe Kenaga nomogram is a simple device that was developed by the U.S. Environmental Protection Agency (EPA) in the early 1980s and is currently used to predict the maximum potential pesticide residue levels in the food chain of wildlife before pesticide registration. To evaluate the accuracy of this nomogram, predicted levels were compared to levels reported in the literature. Data (obtained from the UTAB database developed by the University of Oklahoma) demonstrated that day‐0 levels predicted by the nomogram were often exceeded. Data from the UTAB database exceeded the nomogram predictions by the following percentages listed by crop: short range grass, 0; leafy crops, 3; long grass, 4; pods/seeds, 8; fruits, 19; and forage (legumes), 22. Minor modification of the nomogram is recommended. Recommended modifications would result in an elevation of the predicted residue levels for fruits and forage (legume) crop

ISSN:0730-7268    

DOI:10.1002/etc.5620130902

出版商:Wiley Periodicals, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractVarious preparative techniques were used to extract nonpolar organic compounds from the muscle tissue of Lake Ontario rainbow trout (Oncorhynchus mykiss). In this extract, PCBs and organochlorine compounds were detected in nanogramper‐milliliter quantities, and polychlorinated dibenzo‐p‐dioxins and dibenzofurans were detected in picogram‐per‐milliliter quantities. The extract and various subfractions of the extract were tested for embryotoxicity in a bioassay with embryos of Japanese medaka (Oryzias latipes). The whole extract was embryotoxic to medaka, as were an extract fraction containing PCBs (fraction A) and extract fractions containing nonpolar organochlorine compounds (fractions B and C). When subfractions prepared from fraction A were tested for embryotoxicity, a subfraction containing non‐ortho‐substituted PCB congeners was embryo‐toxic, whereas subfractions containing mono‐ortho‐ and di‐ortho‐substituted PCB congeners were relatively nontoxic. Pathological lesions characteristic of exposure to planar halogenated aromatic hydrocarbons were observed only in embryos exposed to the non‐ortho‐PCB subfraction. The non‐ortho‐PCB subfraction of fraction A was more toxic than the original fraction A, which indicates that nontoxic PCBs reduce the toxicity of the non‐ortho‐PCBs through some unknown mechanism. This study indicates that organochlorine compounds and non‐ortho‐substituted PCBs have the potential to be embryotoxic to early life stages of Great Lakes fish, but nontoxic contaminants can modify this toxic response. These data are relevant to the interpretation of correlations between embryo mortalities and concentrations of persistent organi

ISSN:0730-7268    

DOI:10.1002/etc.5620130903

出版商:Wiley Periodicals, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractPCB congener 81 (3,4,4′,5‐tetrachlorobiphenyl) has been detected in fish tissues from various sites in North America. The embryotoxicity of this compound to medaka (Oryzias latipes) and the induction of hepatic aryl hydrocarbon hydroxylase (AHH) in rainbow trout (Oncorhynchus mykiss) were determined to assess the toxic potency of this compound relative to 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD) and two other non‐ortho‐substituted PCB compounds, congener 77 (3,3′,4,4′‐tetrachlorobiphenyl) and congener 126 (3,3′,4,4′,5‐pentachlorobiphenyl). The TCDD toxic equivalency factors (TEFs) estimated for congener 81 from two end points in the medaka embryotoxicity assay were 0.0014 (from mortality data) and 0.006 (from swim bladder inflation data). The TEF estimated for congener 81 from data on AHH induction in rainbow trout was 0.004. All TEFs were greater than those estimated for congener 77 but were less than the TEFs estimated for congener 126. On the basis of these toxicity data, it is suggested that this congener may contribute significantly to the toxic burden of planar halogenated arom

ISSN:0730-7268    

DOI:10.1002/etc.5620130904

出版商:Wiley Periodicals, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractThe bioaccumulation and elimination of organotin compounds in Pagrus major during dietary uptake and/or direct uptake from water were studied. When tributyltin (TBT) and triphenyltin (TPT) compounds were accumulated in fish from seawater and from feed simultaneously, about one‐quarter of the bioaccumulation was due to the dietary uptake. The biomagnification factors (BMFs) were 0.26 to 0.38 for TBT and 0.57 for TPT. BMF was not significantly altered by the concentration nor the species of chemicals in the feed. The assimilation efficiency of ingested TBT and TPT was 9.5 to 12.7 and 19.6%, respectively, and percentage retention was 24.2% for TBT and 60.1% for TPT. The BMF, percentage retention, and assimilation efficiency of TBT were all lower than those of TPT, suggesting that TPT compounds are more easily accumulated by dietary uptake than TBT compounds. Compared to PCBs and methylmercury chloride, the assimilation efficiency and the percentage retention of organotin compounds were low. These lower values imply that the risk of bioaccumulating the ingested organotin compounds might be smaller than for PCBs and methylmercury chlorid

ISSN:0730-7268    

DOI:10.1002/etc.5620130905

出版商:Wiley Periodicals, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractJuvenile fathead minnows (Pimephales promelas) were exposed to thiocyanate (SCN−) concentrations of 0, 1.1, 7.3, 16.6, or 32.6 mg/L for 124 d while monitoring growth, physiological, reproductive, and histological parameters. The NOEC for decreased egg production, increased time to first spawn, and development of overt goiter was 1.1 mg/L, whereas the LOEC for these parameters was 7.3 mg/L. Histological changes in thyroidal tissue were the most sensitive parameter observed, with an LOEC of 1.1 mg/L. Fish exposed to 16.6 or 32.6 mg SCN−/L neither completed development of secondary sexual characteristics nor spawned. The LOEC for decreased growth and hematocrit was 32.6 mg/L. SCN−accumulated in the plasma of fish exposed to 16.6 and 32.6 mg/L, with BCFs of 2.7 and 13.8, respectively. Development and mortality of embryos and larvae to 3 d post‐hatch were also monitored in eggs spawned by adults exposed to 0 or 1.1 mg SCN−1/L and subsequently incubated and hatched at 0, 1.1, 7.3, 16.6, or 32.6 mg/L. Eggs spawned by adults exposed to 1.1 mg SCN−1/L exhibited increased percentage of eyeup and hatch, while decreasing time to hatch and mortality. There were no effects of SCN−concentration during incubation on egg viability. After the 124‐d exposure, adults were transferred to SCN−‐free water for 30 d. Insufficient numbers of adults were available from groups exposed to 32.6 mg/L to be included in the recovery study. Eggs were spawned by all groups during the recovery period, regardless of the SCN−preexposure level, although time to first spawn increased with pree

ISSN:0730-7268    

DOI:10.1002/etc.5620130906

出版商:Wiley Periodicals, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractThe implementation of freshwater mussel watch programs has been hindered by a lack of information on biological factors affecting the levels of contaminants accumulated by these organisms. This study investigated the influence of species and sex on metal residues in Elliptio complanata and Lampsilis radiata radiata (Family Unionidae) from the St. Lawrence River. Mussels were collected from sites representing a wide range of types and degrees of metal pollution. Composite samples of five specimens (males and females combined) per species per site and five specimens per sex per species per site were analyzed for residues of 12 metals in the soft tissues to determine the effects of species and sex, respectively, on variability in the data. Interspecific differences in bioaccumulation were observed for most metals; however, concentrations were frequently correlated between species and the differences could therefore be quantified. Elliptio complanata demonstrated a broader response range to the same exposures than Lampsilis radiata radiata for most metals, suggesting that it may be more sensitive to changes in pollution status. Differences in metal uptake between the sexes were less pronounced than differences between species, and male specimens displayed less variability than females. Consideration of these factors in mussel biomonitoring programs should greatly improve sensitivity and precision.

ISSN:0730-7268    

DOI:10.1002/etc.5620130907

出版商:Wiley Periodicals, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractA series of experiments were conducted to estimate assimilation efficiencies of two hydrophobic organic contaminants and the influence of particle sizes on the selective sediment ingester, Diporeia spp. Florissant soil was divided into particle‐size fractions consisting of 0 to 63 μm, 0 to 20 μm, and 20 to 63 μm and dosed with radiolabeled 2,2′,4,4′,5,5′‐hexachlorobiphenyl (HCBP) and/or benzo[a]pyrene (BaP) to which animals were exposed for individual assays. At the end of timed exposure intervals, individual Diporeia and any fecal pellets they produced were removed from the sediment and analyzed for contaminant content. Assimilation efficiency was estimated via a selectivity index based on organic carbon. Assimilation efficiency of BaP (5.6–32.7%) was comparable to previous studies. However, HCBP did not correlate with organic carbon over a range of particle sizes. Accumulation of both contaminants was greatest when animals were exposed to the 20‐ to 63‐μm size fraction, suggesting that Diporeia selectively fed within this particle‐size range. Accumulation of HCBP was consistently greater than BaP in all dual‐labeled assays, suggesting a greater bioavailability of the PCB to Diporeia. Sediment analysis indicated that BaP and HCBP were associated with different particle‐size fractions possessing different amounts of organic carbon, with BaP having the greater tende

ISSN:0730-7268    

DOI:10.1002/etc.5620130908

出版商:Wiley Periodicals, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractThe oligochaete Lumbriculus variegatus has been proposed for whole‐sediment bioassays to assess sediment contamination. Our work examines Lumbriculus variegatus exposure to pyrene‐dosed Lake Michigan sediment at 0.4 ng g−1and 64, 132, 206, and 269 μg g−1. Both bioaccumulation and survival were followed to enhance Lumbriculus variegatus development as a bioassay organism. Lumbriculus variegatus accumulated sediment‐associated pyrene rapidly and achieved apparent steady state within 48 to 168 h. The pyrene uptake clearances (ks, g sed g−1animal h−1) ranged from 0.039 to 0.132 and decreased with increasing pyrene concentration. At high pyrene concentrations, the worms avoided the sediment, which reduced accumulation and likely minimized the mortality response. In addition, the effect of organism loading on bioaccumulation was determined at different animal densities, 1:10, 1:50, and 1:100 g dry weight Lumbriculus variegatus:g sediment organic carbon, and a sediment pyrene concentration of 0.4 ng g−1. Surprisingly, the bioaccumulation declined as organism density decreased. Pyrene elimination was rapid in clean sediment (ke= 0.026 ± 0.002 h−1) but was much slower in water (ke= 0.0043 ± 0.0007 h−1). Bioavailability apparently declined for exposures in sediment stored 1.5 months, based on the estimate of kefrom nonlinear regression compared to direct measures of elimination. The apparent decline was attributed to both a decline in lipid content during the experiment and changes in pyrene bioavailability. Finally, for bioaccumulation studies, gut purging at a set time (e.g., 24 h) may result in an underestimate of contaminant concentration in organisms. An elimination study with extrapolation to the initial body burden can ensure that biases due to incomplete elimination of gut contents and body burden losses during the purging

ISSN:0730-7268    

DOI:10.1002/etc.5620130909

出版商:Wiley Periodicals, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractA suite of biochemical, physiological, and pathological measures was used to assess possible effects of exposure to bleached‐kraft mill effluent (BKME) on wild longnose sucker (Catostomus catostomus) and mountain whitefish (Prosopium williamsoni) in the Wapiti/Smoky river system, as compared to similar populations in a reference river system without BKME inputs. Individual fish body burden data (i.e., metals, polychlorinated dioxins and furans, fatty and resin acids, chlorophenolics) were examined for correlations between chemical exposure and biological response. General incidence of gross pathology and histopathology showed no relationship with exposure to BKME, and no neoplastic or preneoplastic lesions were observed in either exposed or reference fish. The few significant differences observed in longnose sucker blood parameters were not correlated with exposure to BKME and appeared to reflect, at least in part, habitat gradients. Liver somatic indexes were higher for female BKME‐exposed longnose sucker, but were not significantly different in male sucker nor in mountain whitefish. Some differences in circulating sex steroid levels were observed in longnose sucker exposed to BKME (but not in mountain whitefish, the species with higher contaminant body burdens). Steroid profile differences may have been related to natural differences in duration of spawning periods in the two fish populations. Other measures of reproductive capacity (relative gonad size, fecundity, young‐of‐the‐year) showed no reductions in exposed fish. The detoxification enzyme cytochrome P4501A was induced in both species, with greater induction in whitefish than in longnose sucker. Whitefish P4501A induction correlated well with some BKME exposure measures, but not with liver or gonad weights, pathology, reproductive capacity, or population‐level parameters. Increased liver size and apparent differences in sex steroid profiles in longnose sucker did not translate to other health effects or population‐level effects. Thus, exposure to this biologically treated BKME produced one consistent biochemical marker of exposure (P4501A) in the two fish species that was not associated with any discernible adverse effects on individua

ISSN:0730-7268    

DOI:10.1002/etc.5620130910

出版商:Wiley Periodicals, Inc.    

年代:1994

数据来源: WILEY