Steve Bursian
Michigan State University, Animal Science, Faculty Member
Previous studies demonstrated that dietary exposure to 24 ppb 3,3',4,4',5-pentachlorobiphenyl (PCB 126) or 2.4 ppb 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induced maxillary and mandibular proliferation of periodontal squamous... more
Previous studies demonstrated that dietary exposure to 24 ppb 3,3',4,4',5-pentachlorobiphenyl (PCB 126) or 2.4 ppb 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induced maxillary and mandibular proliferation of periodontal squamous epithelium, osteolysis of alveolar bone, and loose and displaced teeth in juvenile mink (Mustela vison). This study determined if such effects could be induced in laboratory rats. Feeding weanling male Long Evans rats 20 or 100 ppb PCB 126 or 1 or 10 ppb TCDD for up to 101 days caused a dose-dependent decrease in body weight gains but did not produce the jaw lesion observed in PCB 126- or TCDD-treated mink.
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Previous research has shown that ingestion of 3,3',4,4',5-pentachlorobiphenyl (PCB 126) by juvenile mink (kits) caused a lesion in the mandible and maxilla that consisted of proliferation of sQuamous epithelium in the periodontal... more
Previous research has shown that ingestion of 3,3',4,4',5-pentachlorobiphenyl (PCB 126) by juvenile mink (kits) caused a lesion in the mandible and maxilla that consisted of proliferation of sQuamous epithelium in the periodontal ligament, osteolysis of adjacent alveolar bone, and loose and displaced teeth. Similar, but less severe changes, developed in adult mink fed 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The present study was conducted to compare similarities and differences of the lesion within the jaws of mink fed these 2 polyhalogenated hydrocarbons. Diets containing 24 ppb PCB 126 or 2.4 ppb TCDD were fed to 6-w-old kits for 36 d. Similar diets were fed to 12-w-old kits for 35 d. Some of these mink were then fed untreated feed for an additional 50 d. All mink treated with PCB 126 or TCDD had reductions in body weight gains which were more severe in the 6-w-old kits than the 12-week-old kits. By 28 days of exposure, many of the 6- and 12-week-old mink treated with ...
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Thirty-six male mink were fed diets that contained 0, 1, 2 or 4% supplemental salt (sodium chloride) and were given drinking water ad libitum for 7 d. Three mink on each diet were then placed on ad libitum, 50% ad libitum or 25% ad... more
Thirty-six male mink were fed diets that contained 0, 1, 2 or 4% supplemental salt (sodium chloride) and were given drinking water ad libitum for 7 d. Three mink on each diet were then placed on ad libitum, 50% ad libitum or 25% ad libitum drinking water for the next 14 d. Ad libitum water consumption was directly proportional to the salt content of the diets. Feed consumption was inversely related to the level of dietary salt, although water restriction had a greater effect in reducing feed consumption than did the supplemental salt. The clinical signs of salt toxicity-water restriction observed were increased thirst, mild dehydration, decreased feed consumption, decreased body weight, rough coat, crusty nose and eyes, irritability in the early stage, and lethargy in the later stages. In general, serum and urinary sodium and chloride ion concentrations increased with increasing dietary salt concentrations. Expressed as a percent of brain weight, liver, spleen, kidney and heart weig...
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Research Interests: Biology, Multidisciplinary, Phosphorus, Kidney, Liver, and 15 moreMycotoxins, Female, Animals, Alkaline phosphatase, Blood Urea Nitrogen, Fumonisin, Alanine Aminotransferase, Body Weight, Food Contamination, Mink, Clinical Signs, Aspartate Aminotransferase, Fumonisins, Chronic Toxicity, and Feed Consumption
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Feed that is typically used on commercial mink ranches is an ideal environment for bacterial growth because of the raw animal by-products used as ingredients. Recently, formaldehyde was approved for use as an antimicrobial agent in... more
Feed that is typically used on commercial mink ranches is an ideal environment for bacterial growth because of the raw animal by-products used as ingredients. Recently, formaldehyde was approved for use as an antimicrobial agent in poultry feed. Experiments in our laboratory were carried out to investigate the effects of incorporating different concentrations of formalin into the feed of mink on the growth of gram-negative and gram-positive bacteria. Feed containing 0, 550 or 1100 ppm formalin was kept refrigerated for up to 7 d and the number of colony forming units of gram-negative and gram-positive bacteria derived from the feed was determined each day. Colony forming units in the formalin-treated feed were significantly fewer than colony forming units in untreated feed. In the second trial, feed containing the same concentrations of formalin was maintained at 30 C for 24 h and cultured bacterial colonies were counted at 0, 12 or 24 h of feed incubation. Both concentrations of fo...
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The efficacy of dietary tamoxifen (TAM) to alleviate the hyperestrogenic effects of the mycotoxin zearalenone (ZEN) was assessed by pathologic examination of the reproductive organs of female mink (Mustela vison). Mink were fed 20 mg/kg... more
The efficacy of dietary tamoxifen (TAM) to alleviate the hyperestrogenic effects of the mycotoxin zearalenone (ZEN) was assessed by pathologic examination of the reproductive organs of female mink (Mustela vison). Mink were fed 20 mg/kg ZEN, 10 mg/kg TAM, or 20 mg/kg ZEN + 10 mg/kg TAM from about 2 mo prior to breeding until the kits reached 3 w of age. All female mink fed ZEN mated, but only 25% whelped. No mink fed TAM or TAM + ZEN mated. Postmortem examination revealed moderate to severely distended uteri filled with caseated necrotic substances in the TAM, ZEN and ZEN + TAM fed mink. Histologic examination revealed mild to severe endometrial hyperplasia to uterine atrophy, endometritis, metritis and pyometra. Ovarian follicles were atrophied and degenerated. TAM was not effective in alleviating the hyperestrogenic effects of ZEN but was a potent estrogen agonist in mink.
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Tamoxifen (TAM), which binds to estrogen receptors and can act as an estrogen antagonist, was incorporated into the diets of swine and mink to determine if it would ameliorate the effects of the estrogenic mycotoxin zearalenone (ZEN).... more
Tamoxifen (TAM), which binds to estrogen receptors and can act as an estrogen antagonist, was incorporated into the diets of swine and mink to determine if it would ameliorate the effects of the estrogenic mycotoxin zearalenone (ZEN). Sows and female mink were fed diets containing 2 ppm (swine) or 20 ppm (mink) ZEN and/or 10 ppm TAM from day 30 of gestation through weaning (swine) or from 2 months prior to breeding through weaning (mink). The diets containing ZEN and/or TAM did not adversely affect reproduction in the sows. Although some hyperestrogenic effects on testes, uterine and ovarian weights were observed in the F1 piglets at 21 days of age, subsequent breeding performance was not affected. All the female mink exposed to ZEN mated, but only 25% whelped. No mink fed TAM (singly or in combination with ZEN) mated. Necropsy of these unmated females fed TAM revealed consistent severe pyometra. Histological examination of the reproductive tracts of the ZEN, TAM and ZEN + TAM-treated mink showed similar alterations, including ovarian follicular atrophy and degeneration, and mild to severe uterine atrophy, pyometra and endometritis. The results of these studies indicate that TAM was not effective in ameliorating the hyperestrogenic effects of ZEN in swine and mink, but rather it acted as an estrogen agonist.
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Diets supplemented with 0.01 or 0.05 ppm (mg/kg) of 3,4,5,3',4',5'-hexachlorobiphenyl (345-HCB) were fed to mink to investigate the toxicological manifestations of this toxic... more
Diets supplemented with 0.01 or 0.05 ppm (mg/kg) of 3,4,5,3',4',5'-hexachlorobiphenyl (345-HCB) were fed to mink to investigate the toxicological manifestations of this toxic polychlorinated biphenyl congener in a sensitive species. Dietary exposure of mink to 0.05 ppm 3,4,5,3',4',5'-hexachlorobiphenyl for 135 days resulted in 50% mortality while no deaths occurred on 0.01 ppm 345-HCB. Clinical signs of toxicity included anorexia, bloody
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The Oil Pollution Act of 1990 establishes liability for injuries to natural resources because of the release or threat of release of oil. Assessment of injury to natural resources resulting from an oil spill and development and... more
The Oil Pollution Act of 1990 establishes liability for injuries to natural resources because of the release or threat of release of oil. Assessment of injury to natural resources resulting from an oil spill and development and implementation of a plan for the restoration, rehabilitation, replacement or acquisition of natural resources to compensate for those injuries is accomplished through the Natural Resource Damage Assessment (NRDA) process. The NRDA process began within a week of the Deepwater Horizon oil spill, which occurred on April 20, 2010. During the spill, more than 8500 dead and impaired birds representing at least 93 avian species were collected. In addition, there were more than 3500 birds observed to be visibly oiled. While information in the literature at the time helped to identify some of the effects of oil on birds, it was not sufficient to fully characterize the nature and extent of the injuries to the thousands of live oiled birds, or to quantify those injuries...
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Scoping studies were designed whereby double-crested cormorants (Phalacocorax auritus) were dosed with artificially weathered Deepwater Horizon (DWH) oil either daily through oil injected feeder fish, or by application of oil directly to... more
Scoping studies were designed whereby double-crested cormorants (Phalacocorax auritus) were dosed with artificially weathered Deepwater Horizon (DWH) oil either daily through oil injected feeder fish, or by application of oil directly to feathers every three days. Preening results in oil ingestion, and may be an effective means of orally dosing birds with toxicant to improve our understanding of the full range of physiological effects of oral oil ingestion on birds. Blood samples collected every 5-6 days were analyzed for a number of clinical endpoints including white blood cell (WBC) estimates and differential cell counts. Plasma biochemical evaluations were performed for changes associated with oil toxicity. Oral dosing and application of oil to feathers resulted in clinical signs and statistically significant changes in a number of biochemical endpoints consistent with petroleum exposure. In orally dosed birds there were statistically significant decreases in aspartate amino tran...
Research Interests: Chemistry, Petroleum, Food, Wildlife Ecology And Management, Medicine, and 15 morePhosphorus, Environmental Sciences, Birds, Animals, Weather, Eating, CHEMICAL SCIENCES, Feathers, Toxicity Tests, Petroleum Pollution, Academic, Leukocytes, Blood Proteins, Medical and Health Sciences, and leukocyte Count
Injury assessment of birds following the Deepwater Horizon (DWH) oil spill in 2010 was part of the Natural Resource Damage Assessment. One reported effect was hemolytic anemia with the presence of Heinz bodies (HB) in birds, however, the... more
Injury assessment of birds following the Deepwater Horizon (DWH) oil spill in 2010 was part of the Natural Resource Damage Assessment. One reported effect was hemolytic anemia with the presence of Heinz bodies (HB) in birds, however, the role of route and magnitude of exposure to oil is unknown. The purpose of the present study was to determine if double-crested cormorants (Phalacocorax auritis; DCCO) exposed orally and dermally to artificially weathered crude oil would develop hemolytic anemia including HB and reticulocytosis. In the oral experiment, sub-adult, mixed-sex DCCOs were fed control (n = 8) or oil-injected fish with a daily target dose of 5 (n = 9) or 10 (n = 9) ml oil/kg for 21 days. Then, subadult control (n = 12) and treated (n = 13) cormorant groups of similar sex-ratio were dermally treated with approximately 13ml of water or weathered MC252 crude oil, respectively, every 3 days for 6 dosages approximating 20% surface coverage. Collected whole blood samples were ana...
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Oral and external dosing methods replicating field exposure were developed using the double crested cormorant (DCCO) to test the toxicity of artificially weathered Deepwater Horizon Mississippi Canyon 252 oil. The majority of previous oil... more
Oral and external dosing methods replicating field exposure were developed using the double crested cormorant (DCCO) to test the toxicity of artificially weathered Deepwater Horizon Mississippi Canyon 252 oil. The majority of previous oil dosing studies conducted on wild-caught birds used gavage methods to dose birds with oil and determine toxicity. However, rapid gut transit time of gavaged oil likely reduces oil absorption. In the present studies, dosing relied on injection of oil into live feeder fish for oral dosing of these piscivorous birds, or applying oil to body contour feathers resulting in transdermal oil exposure and oral exposure through preening. Both oral and external oil dosing studies identified oil-related toxicity endpoints associated with oxidative stress such as hemolytic anemia, liver and kidney damage, and immuno-modulation or compromise. External oil application allowed for controlled study of thermoregulatory stress as well. Infrared thermal images indicated...
Research Interests: Environmental Toxicology, Petroleum, Biology, Ecology, Environmental Monitoring, and 13 moreAnimal Physiology, Medicine, Environmental Sciences, BP/Deepwater Horizon Oil Spill, Birds, Animals, Body temperature regulation, Eating, CHEMICAL SCIENCES, Feathers, Body Weight, Environmental Pollutants, and Medical and Health Sciences
Research Interests: Biology, Polymers, Medicine, Enzymes, Kidney, and 15 moreLiver, Steel, Femur, Female, Animals, Male, Lead, Iron, Ducks, Hematocrit, Gonads, Caprolactam, Tissue distribution, Drug residues, and Bird diseases
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Research Interests: Reproduction, Archives, Biology, Medicine, Multidisciplinary, and 7 morePregnancy, Female, Animals, Carboxylic Acids, Mink, Teratogens, and Fumonisins
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Mink are known to be very sensitive to the toxic effects of planar halogenated hydrocarbons (PHHs). Previously the authors reported the reproductive effects in mink fed a diet containing 10, 20, or 40% fish taken from Saginaw Bay, Lake... more
Mink are known to be very sensitive to the toxic effects of planar halogenated hydrocarbons (PHHs). Previously the authors reported the reproductive effects in mink fed a diet containing 10, 20, or 40% fish taken from Saginaw Bay, Lake Huron. In this presentation the authors report the complete chemical analyses of the diets and the adult mink livers, along with a comparison of an additive model of toxicity with the results of the H411E bioassay on these samples. The H411E bioassay consistently estimated greater dioxin toxic-equivalents (TEQS) as compared to an additive model of toxicity and chemical analyses. TEQs derived from chemical analyses accounted for approximately 60% of the TEQs observed with the H411E bioassay. The difference is likely due to the presence of compounds which were not quantitated as opposed to synergistic interactions of the mixtures. Significant reproductive effects were observed in the lowest treatment group (10% fish, or 19.4 pg TEQs/g). The implications...
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Abstract Enrichment studies for wild carnivores (e.g., in zoos) are often short-term, use enrichments of unknown motivational significance, and focus on glucocorticoids and stereotypic behaviour (SB), ignoring other stress-relevant... more
Abstract Enrichment studies for wild carnivores (e.g., in zoos) are often short-term, use enrichments of unknown motivational significance, and focus on glucocorticoids and stereotypic behaviour (SB), ignoring other stress-relevant variables. Our study assessed the broad behavioural and physiological effects of enriching American mink—a model carnivore—with preferred stimuli long-term, and investigated the welfare implications of individual differences in SB. We raised 64 male-female pairs with or without enrichment. At 7 months, pairs were split and mink individually housed (adults being solitary), first by being temporarily moved to identical non-enriched cages (permitting observation blind to rearing condition). Two weeks later, one mink per original pair (half female, half male) was returned to his/her rearing cage for re-observation, sample collection for faecal cortisol metabolite (FCM) analysis, and additional research for 1.5 years before being humanely killed. Stress-sensitive variables were then measured post-mortem . Enriched-raised mink in their rearing conditions excreted less FCM ( F 1,29 =8.33, p =0.003), and performed less SB than non-enriched mink. Two SB sub-types occurred: (1) ‘loco' stereotypies: locomotor, whole body and head stereotypies (e.g., pacing, nodding), previously shown to correlate with recurrent perseveration; and (2) repetitive scrabbling with the forepaws. Enriched housing reduced both (at 7 months: loco stereotypies: F 1,60 =25.3, p F 1,60 =24.0, p F 1,58 =31.33, p Post-mortem , enriched-reared mink showed less skeletal fluctuating asymmetry ( F 1,42 =2.87, p =0.048) and had heavier lymphoid organs (thymus: F 1,41 =3.43, p =0.035; spleen: F 1,45 =13.11, p =0.010). However, within treatment groups, neither these measures nor FCM covaried with SB. In conclusion, long-term housing with preferred enrichments not only reduced SB and FCM, but also induced anatomical changes consistent with better cell-mediated immunity and reduced developmental stress. In addition, these results should refine the use of SB and its sub-types in welfare assessment, since scrabbling seemed to reflect the prevailing presence/absence and utilisation of enrichment, while motor, whole body and head SBs appeared to reflect more stable, long-term effects of differential rearing; and furthermore, within each housing type, individual differences in SB appeared to reflect response styles rather than differential welfare.
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A series of toxicity tests were conducted to assess the effects of low to moderate exposure to artificially weathered Deepwater Horizon Mississippi Canyon 252 crude oil on representative avian species as part of the Natural Resource... more
A series of toxicity tests were conducted to assess the effects of low to moderate exposure to artificially weathered Deepwater Horizon Mississippi Canyon 252 crude oil on representative avian species as part of the Natural Resource Damage Assessment. The present report summarizes effects of oral exposure (n=26) of double-crested cormorants (DCCO; Phalacrocorax auritus) to 5 or 10ml oil kg(-1) day(-1) for up to 21 days or dermal application (n=25) of 13ml oil to breast and back feathers every three days totaling 6 applications in 21 days on organ weights and histopathology. Absolute and relative kidney and liver weights were increased in birds exposed to oil. Additionally, gross and/or histopathologic lesions occurred in the kidney, heart, pancreas and thyroid. Clinically significant renal lesions in the orally dosed birds included squamous metaplasia and increased epithelial hypertrophy of the collecting ducts and renal tubules and mineralization in comparison to controls. Gross ca...
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Double-crested cormorants (Phalacrocorax auritus, DCCO) were orally exposed to Deepwater Horizon Mississippi Canyon 252 (DWH) oil to investigate oil-induced toxicological impacts. Livers were collected for multiple analyses including... more
Double-crested cormorants (Phalacrocorax auritus, DCCO) were orally exposed to Deepwater Horizon Mississippi Canyon 252 (DWH) oil to investigate oil-induced toxicological impacts. Livers were collected for multiple analyses including cytochrome P4501A (CYP1A) enzymatic activity and protein expression. CYP1A enzymatic activity was measured by alkoxyresorufin O-dealkylase (AROD) assays. Activities specific to the O-dealkylation of four resorufin ethers are reported: benzyloxyresorufin O-debenzylase (BROD), ethoxyresorufin O-deethylase (EROD), methoxyresorufin O-demethylase (MROD), and pentoxyresorufin O-depentylase (PROD). CYP1A protein expression was measured by western blot analysis with a CYP1A1 mouse monoclonal antibody. In study 1, hepatic BROD, EROD, and PROD activities were significantly induced in DCCO orally exposed to 20ml/kg body weight (bw) oil as a single dose or daily for 5 days. Western blot analysis revealed hepatic CYP1A protein induction in both treatment groups. In ...
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Research Interests: Environmental Risk Assesment, Molecular Toxicology, Homology Modeling, Cercopithecus aethiops, Sequence alignment, and 15 moreLiver, Birds, Animals, Aryl Hydrocarbon Receptor, Amino Acid Profile, Lethal Dose, Amino Acid Sequence, Protein Binding, Ligands, Predictive value of tests, Dioxins, Molecular Sequence Data, binding sites, Reporter gene, and Pharmacology and pharmaceutical sciences
A multidisciplinary approach was employed to assess the possible biological effects of chronic exposure of rats to 100-MHz continuous wave (CW) radiofrequency (RF) radiation. A group of 20 time-bred rats were exposed in a transverse... more
A multidisciplinary approach was employed to assess the possible biological effects of chronic exposure of rats to 100-MHz continuous wave (CW) radiofrequency (RF) radiation. A group of 20 time-bred rats were exposed in a transverse electromagnetic mode (TEM) ...
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There are large differences in sensitivity to the toxic and biochemical effects of dioxins and dioxin-like compounds (DLCs) among vertebrates. Previously, we demonstrated that the difference in sensitivity between domestic chicken (Gallus... more
There are large differences in sensitivity to the toxic and biochemical effects of dioxins and dioxin-like compounds (DLCs) among vertebrates. Previously, we demonstrated that the difference in sensitivity between domestic chicken (Gallus gallus domesticus) and common tern (Sterna hirundo) to aryl hydrocarbon receptor 1 (AHR1)-dependent changes in gene expression following exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is based upon the identities of the amino acids at two sites within the ligand binding domain of AHR1 (chicken--highly sensitive; Ile324_Ser380 vs common tern--250-fold less sensitive than chicken; Val325_Ala381). Here, we tested the hypotheses that (i) the sensitivity of other avian species to TCDD, 2,3,4,7,8-pentachlorodibenzofuran (PeCDF), and 2,3,7,8-tetrachlorodibenzofuran (TCDF) is also determined by the amino acids at sites that are equivalent to sites 324 and 380 in chicken, and (ii) Ile324_Ala380 and Val324_Ser380 genotypes confer intermediate sensitivity to DLCs in birds. We compared ligand-induced transactivation function of full-length AHR1s from chicken, common tern, ring-necked pheasant (Phasianus colchicus; Ile324_Ala380) and Japanese quail (Coturnix japonica; Val324_Ala380), and three Japanese quail AHR1 mutants. The results support our hypothesis that avian species can be grouped into three general classes of sensitivity to DLCs. Both AHR1 genotype and in vitro transactivation assays predict in vivo sensitivity. Contrary to the assumption that TCDD is the most potent DLC, PeCDF was more potent than TCDD at activating Japanese quail (13- to 26-fold) and common tern (23- to 30-fold) AHR1. Our results support and expand previous in vitro and in vivo work that demonstrated ligand-dependent species differences in AHR1 affinity. The findings and methods will be of use for DLC risk assessments.
Research Interests: Environmental Science, Molecular Biology, Risk Management, Risk assessment, Environmental Risk Assesment, and 15 moreGene expression, Multidisciplinary, Environmental science and technology, Molecular Toxicology, Cercopithecus aethiops, Birds, Animals, Japanese Quail, Aryl Hydrocarbon Receptor, Chickens, Amino Acid Profile, Risk Assessment, Lethal Dose, Full Length Movies, and Dioxins
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... Acknowledgements We would like to thank all field/laboratory personnel that helped with this project, especially the following: Arianne Neigh, Karl Strause, Mike Fales, Stephanie Plautz,Cassie Steiler, Melissa Palmer, ... Hlth. Persp.... more
... Acknowledgements We would like to thank all field/laboratory personnel that helped with this project, especially the following: Arianne Neigh, Karl Strause, Mike Fales, Stephanie Plautz,Cassie Steiler, Melissa Palmer, ... Hlth. Persp. 106:775-792. 5. Bishop et al. 1998. J. Toxicol. ...
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Double-crested cormorants (Phalacrocorax auritus, DCCO) were orally exposed to Deepwater Horizon Mississippi Canyon 252 (DWH) oil to investigate oil-induced toxicological impacts. Livers were collected for multiple analyses including... more
Double-crested cormorants (Phalacrocorax auritus, DCCO) were orally exposed to Deepwater Horizon Mississippi Canyon 252 (DWH) oil to investigate oil-induced toxicological impacts. Livers were collected for multiple analyses including cytochrome P4501A (CYP1A) enzymatic activity and protein expression. CYP1A enzymatic activity was measured by alkoxyresorufin O-dealkylase (AROD) assays. Activities specific to the O-dealkylation of four resorufin ethers are reported: benzyloxyresorufin O-debenzylase (BROD), ethoxyresorufin O-deethylase (EROD), methoxyresorufin O-demethylase (MROD), and pentoxyresorufin O-depentylase (PROD). CYP1A protein expression was measured by western blot analysis with a CYP1A1 mouse monoclonal antibody. In study 1, hepatic BROD, EROD, and PROD activities were significantly induced in DCCO orally exposed to 20ml/kg body weight (bw) oil as a single dose or daily for 5 days. Western blot analysis revealed hepatic CYP1A protein induction in both treatment groups. In ...
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Scoping studies were designed whereby double-crested cormorants (Phalacocorax auritus) were dosed with artificially weathered Deepwater Horizon (DWH) oil either daily through oil injected feeder fish, or by application of oil directly to... more
Scoping studies were designed whereby double-crested cormorants (Phalacocorax auritus) were dosed with artificially weathered Deepwater Horizon (DWH) oil either daily through oil injected feeder fish, or by application of oil directly to feathers every three days. Preening results in oil ingestion, and may be an effective means of orally dosing birds with toxicant to improve our understanding of the full range of physiological effects of oral oil ingestion on birds. Blood samples collected every 5–6 days were analyzed for a number of clinical endpoints including white blood cell (WBC) estimates and differential cell counts. Plasma biochemical evaluations were performed for changes associated with oil toxicity. Oral dosing and application of oil to feathers resulted in clinical signs and statistically significant changes in a number of biochemical endpoints consistent with petroleum exposure. In orally dosed birds there were statistically significant decreases in aspartate amino transferase (AST) and gamma glutamyl transferase (GGT) activities, calcium, chloride, cholesterol, glucose, and total protein concentrations, and increases in plasma urea, uric acid, and phosphorus concentrations. Plasma electrophoresis endpoints (pre-albumin, albumin, alpha-2 globulin, beta globulin, and gamma globulin concentrations and al-bumin: globulin ratios) were decreased in orally dosed birds. Birds with external oil had increases in urea, creatinine, uric acid, creatine kinase (CK), glutamate dehydrogenase (GLDH), phosphorus, calcium, chloride, potassium, albumin, alpha-1 globulin and alpha-2 globulin. Decreases were observed in AST, beta globulin and glucose. WBC also differed between treatments; however, this was in part driven by monocytosis present in the externally oiled birds prior to oil treatment.
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During the Deepwater Horizon Natural Resource Damage Assessment, gross morphologic cardiac abnormalities, including softer, more distensible musculature, were noted upon gross necropsy in hearts from laughing gulls and double-crested... more
During the Deepwater Horizon Natural Resource Damage Assessment, gross morphologic cardiac abnormalities, including softer, more distensible musculature, were noted upon gross necropsy in hearts from laughing gulls and double-crested cormorants exposed to weathered MC252 crude oil. A species specific, echocardiographic technique was developed for antemortem evaluation of function that was used to evaluate and better characterize cardiac dysfunction. Control (n=12) and treated (n=13) cormorant groups of similar sex-ratio and ages were dermally treated with approximately 13 ml of water or weathered MC252 crude oil, respectively, every 3 days for 6 dosages. This resulted in a low to moderate external exposure. Upon visualization and clinical assessment of the hearts of all test subjects, comprehensive diagnostic cardiographic measurements were taken twice, prior to oil application and after a 21 day dermal oil exposure. Oil-treated birds showed a decrease in cardiac systolic function, as characterized by an increased left ventricular internal dimension-systole and left ventricular stroke volume as well as concurrent decreased left ventricular ejection fraction and left ventricular fractional shortening when compared to both control birds' and the treated birds' time zero values. These changes are indicative of a possible dilative cardiomyopathy induced by oil exposure, although further eluci-dation of possible collagen damage is recommended. Arrhythmias including tachycardia in two treated birds and bradycardia in all treated birds were documented, indicating further clinically significant abnormalities induced by MC252 oil that warrant further investigation. A statistically significant increase in free calcium concentration, important to muscular and neurologic function in treated birds was also noted. This study documents that weathered MC252 oil caused clinically significant cardiac dysfunction that could result in mortality and decrease recruitment.
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Injury assessment of birds following the Deepwater Horizon (DWH) oil spill in 2010 was part of the Natural Resource Damage Assessment. One reported effect was hemolytic anemia with the presence of Heinz bodies (HB) in birds, however, the... more
Injury assessment of birds following the Deepwater Horizon (DWH) oil spill in 2010 was part of the Natural Resource Damage Assessment. One reported effect was hemolytic anemia with the presence of Heinz bodies (HB) in birds, however, the role of route and magnitude of exposure to oil is unknown. The purpose of the present study was to determine if double-crested cormorants (Phalacocorax auritis; DCCO) exposed orally and dermally to artificially weathered crude oil would develop hemolytic anemia including HB and reticulocytosis. In the oral experiment, sub-adult, mixed-sex DCCOs were fed control (n = 8) or oil–injected fish with a daily target dose of 5 (n = 9) or 10 (n = 9) ml oil/kg for 21 days. Then, subadult control (n = 12) and treated (n = 13) cormorant groups of similar sex-ratio were dermally treated with approximately 13 ml of water or weathered MC252 crude oil, respectively, every 3 days for 6 dosages approximating 20% surface coverage. Collected whole blood samples were analyzed by light (new methylene blue) and transmission electron microscopy. Both oral and dermal treatment with weathered DWH MC252 crude oil induced regenerative, but inadequately compensated, anemia due to hemolysis and hematochezia as indicated by decreased packed cell volume, relative increase in re-ticulocytes with lack of difference in corrected reticulocyte count, and morphologic evidence of oxidant damage at the ultrastructural level. Hemoglobin precipitation, HB formation, degenerate organelles, and systemic oxi-dant damage were documented. Heinz bodies were typically < 2 µm in length and smaller than in mammals. These oblong cytoplasmic inclusions were difficult to see upon routine blood smear evaluation and lacked the classic button appearance found in mammalian red blood cells. They could be found as light, homogeneous blue inclusions upon new methylene blue staining. Ultrastructurally, HB appeared as homogeneous, electron-dense structures within the cytosol and lacked membranous structure. Oxidant damage in avian red blood cells results in degenerate organelles and precipitated hemoglobin or HB with different morphology than that found in mammalian red blood cells. Ultrastructural evaluation is needed to definitively identify HB and damaged or-ganelles to confirm oxidant damage. The best field technique based on the data in this study is assessment of PCV with storage of blood in glutaraldehyde for possible TEM analysis.
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A B S T R A C T The Oil Pollution Act of 1990 establishes liability for injuries to natural resources because of the release or threat of release of oil. Assessment of injury to natural resources resulting from an oil spill and... more
A B S T R A C T The Oil Pollution Act of 1990 establishes liability for injuries to natural resources because of the release or threat of release of oil. Assessment of injury to natural resources resulting from an oil spill and development and implementation of a plan for the restoration, rehabilitation, replacement or acquisition of natural resources to compensate for those injuries is accomplished through the Natural Resource Damage Assessment (NRDA) process. The NRDA process began within a week of the Deepwater Horizon oil spill, which occurred on April 20, 2010. During the spill, more than 8500 dead and impaired birds representing at least 93 avian species were collected. In addition, there were more than 3500 birds observed to be visibly oiled. While information in the literature at the time helped to identify some of the effects of oil on birds, it was not sufficient to fully characterize the nature and extent of the injuries to the thousands of live oiled birds, or to quantify those injuries in terms of effects on bird viability. As a result, the US Fish and Wildlife Service proposed various assessment activities to inform NRDA injury determination and quantification analyses associated with the Deepwater Horizon oil spill, including avian toxicity studies. The goal of these studies was to evaluate the effects of oral exposure to 1–20 ml of artificially weathered Mississippi Canyon 252 oil kg bw-1 day-1 from one to 28 days or one to five applications of oil to 20% of the bird's surface area. It was thought that these exposure levels would not result in immediate or short-term mortality but might result in physiological effects that ultimately could affect avian survival, reproduction and health. These studies included oral dosing studies, an external dosing study, metabolic and flight performance studies and field-based flight studies. Results of these studies indicated changes in hematologic endpoints including formation of Heinz bodies and changes in cell counts. There were also effects on multiple organ systems, cardiac function and oxidative status. External oiling affected flight patterns and time spent during flight tasks indicating that migration may be affected by short-term repeated exposure to oil. Feather damage also resulted in increased heat loss and energetic demands. The papers in this special issue indicate that the combined effects of oil toxicity and feather effects in avian species, even in the case of relatively light oiling, can significantly affect the overall health of birds.
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Research Interests: Population Dynamics, Biological Sciences, Environmental Sciences, Female, Animals, and 16 moreMale, Statistical Significance, Michigan, Ecological Risk Assessment, Field Study, Polychlorinated Biphenyl, CHEMICAL SCIENCES, Ecosystem, Body Mass, Time Factors, World Health Organization, Mink, Environmental Pollutants, Integrated, Aromatic Hydrocarbon, and Reference Value
Concentrations of polybrominated diphenyl ethers (PBDEs) in humans and wildlife suggest significant bioaccumulation potential in mammals, but no quantitative biomagnification data from controlled experiments are currently available. As... more
Concentrations of polybrominated diphenyl ethers (PBDEs) in humans and wildlife suggest significant bioaccumulation potential in mammals, but no quantitative biomagnification data from controlled experiments are currently available. As part of a larger study examining the effects of PBDEs on mink (Mustela vison) reproduction and development, we examined congener-specific tissue distribution, maternal transfer, biotransformation, and biomagnification of the technical penta-BDE mixture, DE-71, in farmed mink. Adult female mink were fed one of four concentrations of DE-71 (0-2.5 microg/g) in the diet from breeding through gestation and until weaning at 6 weeks postparturition. Parent PBDEs were measured in tissues and excreta of adult mink, kits, and juveniles, whereas hydroxylated PBDEs (OH-PBDEs) were measured in juveniles only. Similar lipid-normalized concentrations of PBDEs were detected in most tissues of adult mink with the exception of brain, in which concentrations were significantly lower. Kits, however, had a higher proportion of PBDEs in brain compared with adults, presumably because of incomplete development of the blood-brain barrier. Maternal transfer favored lower-brominated PBDE congeners, and the bulk of the body burden in kits at weaning resulted from lactational rather than transplacental transfer. Lipid-normalized, whole-body biomagnification factors ranged from 0.5 to 5.2 for the major congeners and were highest for BDEs 47 and 153. Metabolism clearly limited the biomagnification of some PBDEs, and OH-PBDEs were detectable in plasma, liver, and feces. On a mass basis, OH-PBDEs accounted for 28 to 32% of the excreted fraction, indicating metabolism was an important elimination pathway. Further studies are required to understand the mechanisms of PBDE biotransformation.
Research Interests:
Oral and external dosing methods replicating field exposure were developed using the double crested cormorant (DCCO) to test the toxicity of artificially weathered Deepwater Horizon Mississippi Canyon 252 oil. The majority of previous oil... more
Oral and external dosing methods replicating field exposure were developed using the double crested cormorant (DCCO) to test the toxicity of artificially weathered Deepwater Horizon Mississippi Canyon 252 oil. The majority of previous oil dosing studies conducted on wild-caught birds used gavage methods to dose birds with oil and determine toxicity. However, rapid gut transit time of gavaged oil likely reduces oil absorption. In the present studies, dosing relied on injection of oil into live feeder fish for oral dosing of these piscivorous birds, or applying oil to body contour feathers resulting in transdermal oil exposure and oral exposure through preening. Both oral and external oil dosing studies identified oil-related toxicity endpoints associated with oxidative stress such as hemolytic anemia, liver and kidney damage, and immuno-modulation or compromise. External oil application allowed for controlled study of thermoregulatory stress as well. Infrared thermal images indicated significantly greater surface temperatures and heat loss in treated birds following external oil applications; however, measurements collected by coelomically implanted temperature transmitters showed that internal body temperatures were stable over the course of the study period. Birds exposed to oil externally consumed more fish than control birds, indicating metabolic compensation for thermal stress. Conversely, birds orally dosed with oil experienced hypothermia and consumed less fish compared to control birds.