D. A. Best
United States Fish and Wildlife Service
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Archives of Environmental Contamination and Toxicology | 1994
John P. Giesy; David A. Verbrugge; R. A. Othout; William W. Bowerman; Miguel A. Mora; Paul D. Jones; John L. Newsted; Christine Vandervoort; S. N. Heaton; Richard J. Aulerich; S. J. Bursian; James P. Ludwig; G. A. Dawson; Timothy J. Kubiak; D. A. Best; Donald E. Tillitt
Populations of mink (Mustela vison) have declined in many areas of the world. Such declines have been linked to exposures to synthetic, halogenated hydrocarbons. In the Great Lakes region, mink are fewer in areas along the shore of the Great Lakes and their tributaries where mink have access to fish from the Great Lakes. Recently, there has been discussion of the relative merits of passage of fishes around hydroelectric dams on rivers in Michigan. A hazard assessment was conducted to determine the potential for adverse effects on mink, which could consume such fishes from above or below dams on the rivers. Concentrations of organochlorine insecticides, polychlorinated biphenyls (PCBs), 2,3,7,8-tetrachloridibenzo-p-dioxin equivalents (TCDD-EQ), and total mercury were measured in composite samples of fishes from above or below hydroelectric dams on the Manistee and Muskegon Rivers, which flow into Lake Michigan, and the Au Sable River, which flows into Lake Huron. Concentrations of organochlorine insecticides, PCBs, and TCDD-EQ were all greater in fishes from below the dams than those from above. Concentrations of neither organochlorine insecticides nor mercury in fishes are currently a risk to mink above or below the dams. All of the species of fishes collected from downstream of the dams contained concentrations of PCBs and TCDD-EQ, which represent a hazard to mink. The hazard index for PCBs was less than one for the average of all species from the upstream reaches of the Manistee and Au Sable Rivers, but not the Muskegon. The hazard index (concentration in fish/NOAEC) was greater than 1 for all of the species collected from below the dams, in all three rivers. The greatest hazard index was observed for carp (Cyprinus carpio) downstream on the Muskegon River. Because the concentrations of PCBs used in the hazard assessment were corrected for relative toxic potencies, the hazard ratios based on PCBs should be similar to those based on TCDD-EQ. This was found to be true. Thus, either total PCBs or TCDD-EQ could be used as the critical toxicant in the hazard assessment. However, if uncorrected concentrations of PCBs, expressed as Aroclors®, were used in the hazard assessment, the toxicity of the weathered mixture would have been underestimated by approximately five-fold, and, in that instance, TCDD-EQ would be the critical contaminant for the hazard assessment. The average maximum allowable percentage of fish from above the dams, which would result in no observable adverse effects of TCDD-EQ, was 70%. Based on the average TCDD-EQ concentrations in the fishes, an average of 8.6% of the diet could be made up of fishes from below dams on the rivers. The most restrictive daily allowable intakes were for carp on the Muskegon and steelhead trout (Onchorhyncus mykiss) on the Manistee Rivers. Only 2.7% of the diet could be made up of these two species from influenced portion of the Au Sable River, they would be exposed to 390 μg PCBs and 8.55 ng of TCDD-EQ per day, respectively (Giesy et al. 1994b). Thus, it would take 15.1 or 77 days for mink to receive their total annual dose of PCBs or TCDD-EQ, respectively. At least for chinook salmon, the critical contaminant for the purposes of hazard assessment would be total concentrations of PCBs. Consuming chinook salmon for as little as 2 weeks would deliver the annual allowable dose of PCBs to mink.
Chemosphere | 2000
William W. Bowerman; D. A. Best; Teryl G. Grubb; James G. Sikarskie; John P. Giesy
Environmental endocrine disruption in wildlife has primarily focused on estrogenic/androgenic end points and their antagonists. We describe here the work that has occurred within the Great Lakes of North America that has used the bald eagle (Haliaeetus leucocephalus) as a sentinel species of the effects of environmental toxicants, including endocrine disruption. Our data suggests that population level effects of hormone disrupting chemicals, not necessarily estrogen/androgen mimics and their antagonists, have been associated with reproductive and teratogenic effects observed in the bald eagle population within the Great Lakes Basin. Additional laboratory and field studies are necessary to further clarify the role of environmental endocrine disruptors on reproduction in avian populations. The use of sea eagles (Haliaeetus spp.) as biosentinels of pollution in other regions of the world is also discussed.
Archives of Environmental Contamination and Toxicology | 1994
John P. Giesy; David A. Verbrugge; R. A. Othout; William W. Bowerman; Miguel A. Mora; Paul D. Jones; John L. Newsted; Christine Vandervoort; S. N. Heaton; Richard J. Aulerich; S. J. Bursian; James P. Ludwig; Matthew E. Ludwig; G. A. Dawson; Timothy J. Kubiak; D. A. Best; Donald E. Tillitt
Fishes of the Great Lakes contain hazardous chemicals such as synthetic halogenated hydrocarbons and metals. These fish can move from the lakes into the Great Lakes tributaries of Michigan. In doing so, they transport concentrationsof contaminants which may represent a risk to wildlife. Concentrations of mercury (Hg), total polychlorinated biphenyls (PCBs), 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TCDD-EQ), total DDT complex, aldrin, endrin, dieldrin, heptachlor, heptachlor epoxide, lindane, hexachlorobenzene, cis-chlordane, oxychlordane, endosulfan-I, methoxychlor, trans-chlordane, and trans-nonachlor were determined in composite samples of fishes from above and below Michigan hydroelectric dams, which separate the fishes which have access to the Great Lakes from fishes that do not. Mean concentrations of total PCBs, TCDD-EQ, DDT, and most of the other pesticides were greater in composite samples of six species of fishes from below than above the dams on the Au Sable, Manistee, and Muskegon Rivers. Concentrations of mercury, were the same or greater above the dams than below. However, this difference was statistically significant only on the Au Sable. Mercury concentrations ranged from less than 0.05 mg/kg to 0.73 mg Hg/kg, ww. Total concentrations of PCBs ranged from 0.02 to 1.7 mg/kg, ww. Concentrations of 2,3,7,8-tetrachlordibenzo-p-dioxin equivalents varied among fishes and locations. The concentrations of TCDD-EQ ranged from 2.4 to 71 μg/kg, ww, with concentrations in carp being the greatest. Concentrations of TCDD-EQ were greater than the concentrations which would be expected to occur, due solely to the presence of polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF), and technical mixtures of PCBs.
Chemosphere | 1993
Paul D. Jones; Gerald T. Ankley; D. A. Best; Robert Crawford; N. DeGalan; John P. Giesy; Timothy J. Kubiak; James P. Ludwig; John L. Newsted; Donald E. Tillitt; David A. Verbrugge
Abstract In recent years contamination of the Great Lakes ecosystem with planar chlorinated hydrocarbons (PCHs) has attracted considerable concern due to their known reproductive and teratogenic effects. The H4IIE bioassay has been standardized as a means of measuring the biological potency of a PCH mixture as 2,3,7,8-tetrachloro-p-dibenzodioxin equivalents (TCDD-EQ). Using this bioassay we have investigated the biomagnification of TCDD-EQ in a semi-closed ecosystem. The biomagnification of TCDD-EQ is demonstrated and results indicate that the food chain is the major pathway for TCDD-EQ through this ecosystem. The H4IIE assay system is demonstrated to be a viable integrative measure of the total concentration of TCDD-EQ in different trophic levels.
Toxicological & Environmental Chemistry | 2003
Kurunthachalam Senthilkumar; William W. Bowerman; Kelly F. Millenbah; D. A. Best; Takumi Takasuga; Shigeki Masunaga
Population collapse of common tern (Sterna hirundo) from Lime Island in the St. Marys River, Michigan, USA were related to the 2,3,7,8-chlorine substituted dioxins, furans, dioxin-like PCBs, and other possible factors using unhatch egg target contaminant analysis. The most toxic congeners, 2,3,7,8-TCDD/DF was found in all samples at noticeable concentrations. Magnitude of sum 2,3,7,8-PCDD/DFs were within the range of 39–93 pg/g wet wt. Dioxin-like PCBs were within the range of 360–1230 ng/g wet wt. Great Toxic Equivalent Quantity (TEQ) contributions by 2,3,7,8-TCDF, 2,3,4,7,8-PeCDF, 2,3,7,8-TCDD, 1,2,3,7,8-PeCDD, and dioxin-like PCBs such as CB-77, CB-126 and CB-105 are considered greatly due to their influence of poor embryo development and consequent damage of embryos of common terns in egg injection studies. However, other organochlorines, heavy metals, and/or synergistic effects also taken in to account. On the whole, TEQs in the tern eggs were greater than the Lowest-Observable-Adverse Effect Level (LOAEL) for bald eagle (Haliaeetus leucocephalus) embryos observed in British Columbia, Canada. Concentrations of dioxin-like PCBs, dioxins, furans in the St. Marys River food chain are at levels for concern for nesting colonial waterbirds. Eventually, the possible movements of analyzed chemicals downstream from a man-made flood event are discussed.
Archive | 1996
Diane S. Henshel; Jw Martin; D. A. Best; Km Cheng; John E. Elliott; Diana S. Rosenstein; James G. Sikarskie
Recent evidence indicates that avian embryonic exposure to polychlorinated dibenzodioxins (PCDDs) and related compounds is associated with the development of a gross brain asymmetry which can be quantified. Three methods can be used to quantify the asymmetry, including external measurements of the intact brain, measurements of brain cross-sections and measurements of computer tomography (CT)-generated images of brain sections. All three methods produce reliable results. The whole brain measurements do not require specialized equipment, and are the most flexible. However, the possibility for unintentional bias is greatest for this technique. The CT scan technology is non-invasive, but requires access to specialized equipment and may be expensive. The cross-sectional measurements, which are similar to the CT scan measurements, require careful processing prior to measurement.
Ecotoxicology and Environmental Safety | 1994
Paul D. Jones; John P. Giesy; John L. Newsted; David A. Verbrugge; James P. Ludwig; Matthew E. Ludwig; Heidi J. Auman; Robert Crawford; Donald E. Tillitt; Timothy J. Kubiak; D. A. Best
Chemosphere | 2010
Katherine F. Leith; William W. Bowerman; Michael R. Wierda; D. A. Best; Teryl G. Grubb; James G. Sikarske
Environmental Toxicology and Chemistry | 2002
D. Vaughn Weseloh; Kimberly D. Hughes; Peter J. Ewins; D. A. Best; Timothy J. Kubiak; Mark C. Shieldcastle
Organohalogen compounds | 2002
Kurunthachalam Senthil Kumar; William W. Bowerman; Takumi Takasuga; D. A. Best; Shigeki Masunaga