Dietary alewife and bloater chub effect on lake trout egg thiamine; Report on early mortality syndrome workshop
No abstract available at this time
Conference Paper↗
Geology topics
D. E. Tillitt
Publications and source records attributed to D. E. Tillitt.
Progress and over-view of current GLFT EMS project: Report on Early Mortality Syndrome Workshop
No abstract available at this time
Conference Paper↗
Cytochrome P4501A induction, benzo[a]pyrene metabolism, and nucleotide adduct formation in fish hepatoma cells: Effect of preexposure to 3,3',4,4',5-pentachlorobiphenyl
In PLHC-1 hepatoma cells, benzo[a]pyrene (B[a]P) caused a maximum induction of cytochrome P4501A (CYP1A) activity, measured as ethoxyresorufin O-deethylation (EROD), after 4 to 8 h of exposure, depending on the B[a]P concentration. The decline of EROD activity at longer exposure times was probably caused by the rapid metabolism of B[a]P in this system (57% metabolism within 4 h incubation). In subsequent experiments, PLHC-1 cells were preinduced with PCB 126 for 24 h and then received a dose of 10, 100, or 1,000 nM 3H-B[a]P. A 1-nM concentration of PCB 126 caused an 80-fold induction of CYP1A activity, resulting in an increase in B[a]P metabolism of less than 10%, except at the highest concentration of B[a]P (1,000 nM), where a 50% increase was observed. In another experiment, an 80-fold induction of CYP1A activity caused a 20% increase in the metabolism of B[a]P (100 nM), and RNA adduct formation was increased approximately twofold. These results indicate that, at exposure concentrations up to 100 nM B[a]P, CYP1A activity is not rate limiting for B[a]P metabolism. Furthermore, CYP1A seems to also he specifically involved in B[a]P activation in PLHC-1 cells. However, CYP1A induction causes only a relatively small increase in activation, probably because of the action of other enzymes involved in B[a]P activation and deactivation.
Environmental Toxicology and Chemistry↗
Review of a natural thiamine deficiency causing reproductive failure in feral salmonid species of the Great Lakes
No abstract available at this time
FASEB Journal↗
Factors associated with temporal variation in EMS: Research task report on early mortality syndrome workshop
No abstract available at this time
Conference Paper↗
Effects of 3,3′,4,4′,5-pentachlorobiphenyl and 2,3,7,8-tetrachlorodibenzo-p-dioxin injected into the yolks of double-crested cormorant (Phalacrocorax auritus) eggs prior to incubation
Double-crested cormorant ( Phalacrocorax auritus ) eggs were injected with either 3,3′,4,4′,5-pentachlorobiphenyl (polychlorinated biphenyl [PCB] 126; 70-698 μg/kg egg) or 2,3,7,8-tetrachlorodibenzo- p -dioxin (TCDD; 1.3-11.7 μg/kg egg) prior to incubation. These compounds were injected into the yolks of cormorant eggs collected from incomplete clutches at isolated colonies on Lake Winnipegosis, Manitoba, Canada. Eggs were incubated for approximately 26 to 28 d. After hatching the brain, bursa, heart, liver, and spleen were dissected and weighed. Torsos were preserved in formalin for examination of the gonads. Median lethal doses (LD50s) calculated from mortality data at hatching were 177 and 4.0 μg/kg egg for PCB 126 and TCDD, respectively. No significant differences were found in the incidence of developmental abnormalities in any of the treatment groups. Bursa weights were significantly less in the greatest (11.7 μg/kg egg) TCDD group compared to the vehicle control group. Spleen weights were significantly less in the 349 μg PCB 126/kg egg and the 5.4 and 11.7 μg TCDD/kg egg groups when compared to the vehicle control group. No histological alterations of the gonads were found. Hepatic ethoxyresorufin- O -deethylase activity in all PCB 126 and TCDD dose groups was significantly greater compared to the control activity. The toxic equivalency factor for PCB 126 was 0.02.
Environmental Toxicology and Chemistry↗
Loading capacity and chromatographic behavior of a porous graphitic carbon column for polychlorinated biphenyls
A porous graphitic carbon column (Hypercarb) was used for the fractionation of polychlorinated biphenyls (PCBs) into classes of 2-4 ortho chlorines, 1 ortho chlorine and 0 ortho chlorine congeners. A method was developed that combined the fractionation of PCBs, polychlorinated dibenzo- p -dioxins and dibenzofurans in a variety of biotic environmental samples. Many of these samples have high concentrations of PCBs which cause fractionation problems as adsorption sites on the graphitic surface are occupied. The loading capacity of the column for PCBs was determined by injecting up to 1 mg of total PCBs and monitoring changes in chromatographic behavior of tetra-/di- ortho , mono- ortho and non- ortho substituted PCBs. Effective loading capacities were 1 mg for tetra-/di- ortho PCBs, but only 3–5 μg for non- ortho PCBs and about 2 μg for mono- ortho PCBs. Loading capacity of the PGC column for environmental fish and avian egg samples was determined to depend on the mono- ortho and non- ortho PCB levels found in these samples.
Journal of Chromatography A↗
Organochlorine contaminants in double-crested cormorants from Green Bay, Wisconsin: II. Effects of an extract derived from cormorant eggs on the chicken embryo
White Leghorn chicken ( Gallus domesticus ) eggs were injected prior to incubation with one of four concentrations (0.001, 0.01, 0.1, and 1.0 egg-equivalent) of an extract derived from 1,000 double-crested cormorant ( Phalacrocorax auritus ) eggs collected at Spider Island adjacent to Green Bay in Lake Michigan. One egg-equivalent corresponded to the concentration of contaminants present in an average cormorant egg. This was approximately 322 pg toxic equivalents (TEQs)/g, ww egg with polychlorinatedbiphenyl congener 126 (3,3′,4,4′,5-pentachlorobiphenyl) accounting for over 70% of the TEQs. Injection of 1.0 egg-equivalent resulted in 77% mortality at hatch. The incidence of developmental abnormalities (structural defects or edema) was not affected by injection of the extract. Body weight gain of chicks was reduced in the 1.0 egg-equivalent dose group in the first, second, and third week's post-hatch. Relative brain weights were greater and relative bursa weights were less in the 1.0 egg-equivalent dose group than in the vehicle control at three weeks of age. There were no significant differences in the relative weights of the heart, liver, spleen, testes, or comb among treated and control birds.
Wisconsin↗
Reproductive success, developmental anomalies and environmental contaminants in double-crested cormorants (Phalacrocorax auritus)
To test an association between environmental contaminants and the prevalence of congenital anomalies in colonial waterbirds, we collected representative eggs for chemical analysis from double-crested cormorant nests at colonies in Lake Michigan, Wisconsin, USA, and Lake Winnipegosis, Manitoba, Canada, and periodically revisited the nests to determine the hatching success, survivorship of hatchlings, and number of deformed hatchlings in the remainder of each clutch. Total concentrations of polychlorinated biphenyls (PCBs) in eggs were determined by capillary gas chromatography. The combined activity of planar chlorinated hydrocarbons (PCHs) in the eggs was measured in an in vitro bioassay based on the induction of ethoxyresorufin- O -deethylase (EROD) activity in rat hepatoma cells. The combined EROD induction activity was expressed as 2,3,7,8–tetrachlorodibenzo- p -dioxin equivalents (TCDD-EQ). Total concentrations of PCBs and TCDD-EQ were seven to eight times greater in eggs from Lake Michigan (7.8 μg/g and 138 pg/g, respectively) than in those from Lake Winnipegosis (1.0 μg/g and 19 pg/g, respectively). The proportion of eggs hatching at the Lake Michigan colony (59%) was less ( p < 0.05) than at Lake Winnipegosis (70%), and the prevalence of hatchlings with deformed bills was greater ( p < 0.001) at Lake Michigan (0.79 vs. 0.06%). However, within the Lake Michigan colony, concentrations of PCBs and TCDD-EQ were not correlated with either hatching success or the occurrence of deformities in nestlings.
Manitoba, Wisconsin↗
Organochlorine contaminants in double-crested cormorants from Green Bay, WI: I. Large-scale extraction and isolation from eggs using semi-permeable membrane dialysis
A 41.3-kg sample of double-crested cormorant ( Phalacrocorax auritus ) egg contents was extracted, yielding over 2 L of egg lipid. The double-crested cormorant (DCC) egg extract, after clean-up and concentration, was intended for use in egg injection studies to determine the embryotoxicity of the organic contaminants found within the eggs. Large-scale dialysis was used as a preliminary treatment to separate the extracted contaminants from the co-extracted sample lipids. The lipid was dialyzed in 80×5 cm semi-permeable membrane devices (SPMDs) in 50-ml aliquants. After the removal of 87 g of cholesterol by freeze-fractionation, the remaining lipid carryover (56 g) was removed by 100 routine gel permeation chromatography (GPC) operations. A 41,293-g sample was thus extracted and purified to the extent that it could easily be placed at a volume of 5 ml, the volume calculated to be necessary for the egg injection study. Analyses were performed comparing contaminant concentrations in the final purified extract to those present in the original egg material, in the extract after dialysis and cholesterol removal, and in the excluded materials. Recoveries of organochlorine pesticides through dialysis and cholesterol ranged from 96% to 135%. Total polychlorinated biphenyls in the final extract were 96% of those measured in the original egg material. Analysis of excluded lipid and cholesterol indicated that 92% of the polychlorinated dibenzo-dioxins and-furans were separated into the final extract.
Archives of Environmental Contamination and Toxico↗
Effects of 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) injected into the yolks of chicken (Gallus domesticus) eggs prior to incubation
The yolks of White Leghorn chicken ( Gallus domesticus ) eggs were injected prior to incubation with either 3,3′,4,4′,5- pentachlorobiphenyl (PCB 126) at doses ranging from 0.1 to 12.8 μg/kg egg or 2,3,7,8-tetrachlorodibenzo- p -dioxin (TCDD) at doses ranging from 0.04 to 0.64 μg/kg egg. Chicks were subjected to necropsy within 24 h of hatching. The brain, bursa, heart, liver, and spleen were removed and weighed. Assessment of the rate of hatching indicated an LD 50 ±S.E. of 2.3±0.19 μg/kg egg (7.1±0.58 nmol/kg egg) for PCB 126 and 0.15±0.012 μg/kg egg (0.47±0.037 nmol/kg egg) for TCDD. No significant differences in the incidence of developmental abnormalities (structural defects and edema) were observed in TCDD-exposed embryos, while PCB 126 caused significantly more developmental abnormalities at 3.2, 6.4, and 12.8 μg/kg egg than the vehicle control. PCB 126 caused lower hatchling weights and greater relative brain, heart, and liver weights when compared to the vehicle control group at a dose of 3.2 μg/kg egg which is greater than the LD 50 . TCDD at 0.08 μg/kg egg caused relative bursa weights to be less than those of the vehicle control. A toxic equivalency factor (TEF) of 0.07 was determined for PCB 126 in relation to TCDD based on overt lethality.
Archives of Environmental Contamination and Toxico↗
Rainbow trout embryotoxicity of a complex contaminant mixture extracted from Lake Michigan lake trout
Persistent Hydrophobic contaminants such as poly chlorinated dibenzo- p -dioxins, dibenzofurans and biphenyl congeners are present in aquatic systems, and are known to produce adverse effects in fish. Reproductive failure in fish populations has been observed in aquatic systems contaminated with persistent hydrophobic compounds. In order to mimic maternal transfer of environmental contaminants to newly fertilized fish eggs, a complex environmental extract was tested for embryotoxicity in a nanoinjection bioassay with embryos of rainbow trout. The extract was obtained from whole adult lake trout collected from Lake Michigan in 1988. The tissue extraction involved blending and dehydration with sodium sulfate, column extraction, dialysis separation, reactive cleanup and, finally, high-performance gel permeation chromatography. Egg gram-equivalent doses (g tissue/g egg normalized for egg % lipid) of the final extract (0.02, 0.10, 0.20, 1.0, 2.0, 4.0, 10.0, 20.0 eggEQ) were injected into newly fertilized rainbow trout eggs using triolein as the vehicle. The extract of the lake trout was embryotoxic to rainbow trout, with an LD 50 of 35 eggEQ, based on total cumulative mortality. Gross physical abnormalities characteristic of dioxin exposure, such as hemorrhaging, yolk-sac edema and craniofacial deformities, were observed and showed significant dose-related increases. Sublethal effects in the rainbow trout, such as delayed time to hatch, mild hemorrhaging and moderate yolk-sac edema, resulted from estimated total PCB exposure as low as 8.8 ng/g, and this may have significant implications on Great Lakes lake trout fry and juvenile mortality.
Marine Environmental Research↗
Contaminants in fishes from great lakes-influenced sections and above dams of three Michigan Rivers: III. Implications for health of bald eagles
Recently, there have been discussions of the relative merits of passage of fishes around hydroelectric dams on three rivers (Au Sable, Manistee, and Muskegon) in Michigan. A hazard assessment was conducted to determine the potential for adverse effects on bald eagles that could consume such fishes from above and below dams on the three primary rivers. The hazard assessments were verified by comparing the reproductive productivities of eagles nesting in areas where they ate primarily fish from either above or below dams on the three primary rivers, as well as on two additional rivers in Michigan, the Menominee and Thunder Bay. Concentrations of organochlorine insecticides (OCI), polychlorinated biphenyls (total PCBs), 2,3,7,8-tetrachlorodibenzo- p -dioxin equivalents (TCDD-EQ), and total mercury (Hg) were measured in composite samples of fishes from above and below hydroelectric dams on the Manistee and Muskegon Rivers, which flow into Lake Michigan, and the Au Sable River, which flows into Lake Huron. Mean concentrations of OCI, total PCBs, and TCDD-EQ were all greater in fishes from below the dams than in those from above. The hazard assessment indicated that current concentrations of Hg and OCI other than DDT (DDT + DDE + DDD) in fish from neither above nor below dams would present a significant hazard to bald eagles ( Haliaeetus leucocephalus ). Both total PCBs and TCDD-EQ in fishes from below the dams currently present a significant hazard to bald eagles, since their mean hazard quotients (HQ) were all greater than one.
Michigan↗
Dietary exposure of mink to carp from Saginaw Bay, Michigan. 1. Effects on reproduction and survival, and the potential risks to wild mink populations
Carp ( Cyprinus carpio ) collected from Saginaw Bay, Michigan, containing 8.4 mg total polychlorinated biphenyls (PCBs)/kg and 194 ng of 2,3,7,8-tetrachloro-dibenzo- p -dioxin equivalents (TEQs)/kg, were substituted for marine fish at levels of 0, 10, 20, or 40% in the diets of adult ranch mink ( Mustela vison ). The diets, containing 0.015, 0.72, 1.53, and 2.56 mg PCBs/kg diet, or 1.03, 19.41, 40.02, and 80.76 ng TEQs/kg diet, respectively, were fed to mink prior to and throughout the reproductive period to evaluate the effects of a naturally-contaminated prey species on their survival and reproductive performance. The total quantities of PCBs ingested by the mink fed 0, 10, 20, or 40% carp over the 85-day treatment period were 0.34, 13.2, 25.3, and 32.3 mg PCBs/mink, respectively. The corresponding quantities of TEQs ingested by the mink over the same treatment period were 23, 356, 661, and 1,019 ng TEQs/mink, respectively. Consumption of feed by mink was inversely proportional to the PCB and TEQ content of the diet. The diets containing Saginaw Bay carp caused impaired reproduction and/or reduced survival of the kits. Compared to controls, body weights of kits at birth were significantly reduced in the 20 and 40% carp groups, and kit body weights and survival in the 10 and 20% carp groups were significantly reduced at three and six weeks of age. The females fed 40% carp whelped the fewest number of kits, all of which were stillborn or died within 24 hours. Lowest observable adverse effect levels (LOAEL) of 0.134 mg PCBs/kg body weight/day or 3.6 ng TEQs/kg body weight/day for adult female mink were determined. The potential effects of exposure of wild mink to contaminated Great Lakes fish were assessed by calculating “maximum allowable daily intakes” and “hazard indices” based on total concentrations of PCB residues in several species of Great Lakes fish and mink toxicity data derived from the study.
Archives of Environmental Contamination and Toxico↗
Relation among cytochrome P450, AH-active PCB congeners and dioxin equivalents in pipping black-crowned night-heron embryos
Pipping black-crowned night-heron (Nycticorax nycticorax) embryos were collected from a relatively uncontaminated site (next to Chincoteague National Wildlife Refuge, VA) and three polluted sites (Cat Island, Green Bay, Lake Michigan, WI; Bair Island, San Francisco Bay, CA; West Marin Island, San Francisco Bay, CA). Hepatic cytochrome P-450-associated monooxygenases and cytochrome P-450 proteins, induced up to 85-fold relative to the reference site, were associated with concentrations of total polychlorinated biphenyls (PCBs) and 11 PCB congeners that are presumed to express toxicity through the arylhydrocarbon (Ah) receptor. Multiple regression revealed that up to 86% of the variation of cytochrome P450 measurements was accounted for by variation in the concentration of these PCB congeners. Toxic equivalents (TEQs) of sample extracts, predicted mathematically (summed product of PCB congener concentrations and toxic equivalency factors), and dioxin equivalents (TCDD-EQs), derived by bioassay (ethoxyresorufin-O-dealkylase activity of treated H4IIE rat hepatoma cells), were greatest in Cat Island samples. Cytochrome P450-associated monooxygenases and cytochrome P450 proteins were related to TEQs and TCDD-EQs; adjusted r-2 often exceeded 0.5 for the relation among mathematically predicted TEQs and cytochrome P450 measurements. These data extend previous observations in heron embryos of an association between P450 and total PCB burdens to include Ah-active PCB congeners, and presumably other compounds, which interact similarly with the Ah receptor. Benzyloxyresorufin O-dealkylase, ethoxyresorufin O-dealkylase, and cytochrome P450 1A appear to be the most reliable measures of exposure to Ah-active PCB congeners in black-crowned night-heron embryos. These findings provide further evidence that cytochrome P450-associated parameters have considerable value as a biomarker for assessing environmental contamination of wetlands.
Environmental Toxicology and Chemistry↗
Accumulation of 2,3,7,8-Tetrachlorodibenzo-p-dioxin equivalents by double-crested cormorant ( Phalacrocorax auritus , Pelicaniformes) chicks in the North American Great Lakes
Concentrations of polychlorinated biphenyls (PCBs), and 2,3,7,8-tetrachlordibenzo- p -dioxin equivalents (TCDD-EQ) were determined in eggs and chicks of double-crested cormorants (DCC) which were collected in 1989 from eight locations in the Laurentian Great Lakes. The mean biomagnification factor (BMF) from forage fish to eggs was found to be 31.3. Absolute and relative concentrations as well as rates of accumulation of total concentrations of PCBs and TCDD-EQ were measurable in all of the samples. The concentrations of both PCBs and TCDD-EQs decreased immediately upon hatching of chicks, due to growth dilution. Initial decreases in absolute masses of TCDD-EQ in chicks were also observed, which indicates that there can be significant elimination of these compounds during early development. The initial rates of accumulation by chicks were dependent only on the mass of fish consumed. After the chicks began thermoregulating, the rates of accumulation, expressed as a concentration, normalized to body weight, became greater. Rates of accumulation of both PCBs and TCDD-EQ were correlated with their respective concentrations in forage fish consumed by the chicks. The relative potency, expressed as the ratio of the concentration of TCDD-EQ to that of total PCBs was calculated to determine if there was significant trophic-level enrichment of the TCDD-EQs, relative to total concentrations of PCBs. A significant enrichment was observed at the more and less contaminated locations, but the degree of enrichment was greater at the less contaminated locations (26 vs 72 μg/g).
Ecotoxicology and Environmental Safety↗