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E. F. Hill

Publications and source records attributed to E. F. Hill.

At least 37 records · Page 2Linked to original sources
USGS1988

Brain cholinesterase activity of apparently normal wild birds

Organophosphorus and carbamate pesticides are potent anticholinesterase substances that have killed large numbers of wild birds of various species. Cause of death is diagnosed by demonstration of depressed brain cholinesterase (ChE) activity in combination with chemical detection of anticholinesterase residue in the affected specimen. ChE depression is determined by comparison of the affected specimen to normal ChE activity for a sample of control specimens of the same species, but timely procurement of controls is not always possible. Therefore, a reference file of normal whole brain ChE activity is provided for 48 species of wild birds from North America representing 11 orders and 23 families for use as emergency substitutes in diagnosis of anticholinesterase poisoning. The ChE values, based on 83 sets of wild control specimens from across the United States, are reproducible provided the described procedures are duplicated. Overall, whole brain ChE activity varied nearly three-fold among the 48 species represented, but it was usually similar for closely related species. However, some species were statistically separable in most families and some species of the same genus differed as much as 50%.

Journal of Wildlife Diseases↗
USGS1987

Seasonal variation in diagnostic enzymes and biochemical constituents of captive northern bobwhites and passerines

1. A variety of biochemical measurements were taken periodically in captive northern bobwhite ( Colinus virginianus L.), European starlings ( Sturnus vulgaris L.), red-winged blackbirds ( Agelaius phoeniceus L.) and common grackles ( Quiscalus quiscula L.) to determine whether baseline values remain sufficiently stable throughout the year for general clinical use in the absence of concurrent control specimens. 2. Variables included whole blood hemotacrit and hemoglobin, plasma lactate dehydrogenase, α-hydroxybutyrate dehydrogenase, aspartate aminotransferase, alinine aminotransferase, creatine kinase, butyrylcholinesterase, alkaline phosphatase, glucose, albumin, total protein, creatinine, urea nitrogen, uric acid, cholesterol, and triglycerides, and brain acetylcholinesterase. Butyrl- and acetylcholinesterase were included because of their specific uses in toxicology. 3. Significant seasonal differences were detected for each of the variables except brain acetylcholinesterase in at least one of the species. Significant species differences were detected during at least one season for all of the variables measured. 4. All species were maintained outdoors, but only northern bobwhites came into reproductive condition and showed sex-differences in the clinical variables during their normal breeding season. 5. It was concluded that reference values for the 18 clinical variables measured could be calculated from our data for adult specimens of the species studied, and that results for one species cannot be extrapolated with certainty to any other species. 6. Estimated normal bounds for each of the 18 variables measured by commonly used clinical procedures are presented for reproductively quiescent northern bobwhites, European starlings, red-winged blackbirds, and common grackles.

Comparative Biochemistry and Physiology, Part B: C↗
USGS1987

Oral and intramuscular toxicity of inorganic and organic mercury chloride to growing quail

The lethal toxicity of inorganic (HgCl 2 ) and organic (CH 3 HgCl) mercury chloride was compared for Coturnix (Japanese quail, Coturnix japonica) of different ages from hatch through adulthood by single‐dose acute oral and intramuscular injections and by a 5‐d dietary trial. Sublethal mercury toxicity was studied by evaluation of plasma and brain cholinesterase activity. CH 3 HgCl was more toxic than HgCl 2 in all tests at each age tested. LD50s consistently increased over the first 4 wk for both acute methods and both mercurials and then stabilized. The striking difference between single‐dose acute and 5‐d dietary tests was that CH 3 HgCl averaged about twice as toxic as HgCl 2 by both acute methods, compared to 100 times as toxic by the dietary method. For example, at 2 wk of age, the oral LD50s for CH 3 HgCl and HgCl 2 were 18 and 42 mg/kg and the dietary LC50s were 47 and 5086 ppm. When birds were fed HgCl 2 and developed clinical signs of intoxication, they could recover once treatment was withdrawn; however, on CH 3 HgCl, clinical signs often commenced after treatment was withdrawn, and then actually intensified for several days and culminated in death.

Journal of Toxicology and Environmental Health↗
USGS1987

Case histories of bald eagles and other raptors killed by organophosphorus insecticides topically applied to livestock

Since 1982 when secondary poisoning of a red-tailed hawk ( Buteo jamaicensis ) was documented following the recommended use of famphur applied topically to cattle, the Patuxent Wildlife Research Center has tested dead birds of prey for poisoning by famphur and other pouron organophosphorus (OP) insecticides. Brain cholinesterase (ChE) activity was first determined, then if ChE was depressed ≥50%, stomach and/or crop contents were evaluated for anti-ChE compounds. This report presents the circumstances surrounding the OP-caused deaths of eight bald eagles ( Haliaeetus leucocephalus ), two red-tailed hawks, and one great horned owl ( Bubo virginianus ) between March 1984 and March 1985. OP poisoning of raptors by pour-on insecticides in the United States is widespread, but its magnitude is unknown.

Journal of Wildlife Diseases↗
USGS1986

Analysis of cyanide in whole blood of dosed cathartids

A gas-liquid chromatographic method was modified to quantify both unmetabolized (“free”) and metabolized (“bound”, i.e., thiocyanates) cyanides. The methods for both are efficient and sensitive to 0.05 ppm. Repeated freezing and thawing of whole blood from treated cathartids caused an initial increase in free cyanide concentrations, followed by a gradual decline to a plateau. Bound cyanide concentrations declined after repeated freezing and thawing.

Environmental Toxicology and Chemistry↗
USGS1986

Differences in mortality among bobwhite fed methylmercury chloride dissolved in various carriers

Twelve-day-old bobwhite chicks were fed a diet containing 0, 5.4 or 20 ppm methylmercury chloride. The methylmercury chloride was added to the diet either in a dry, pulverized form or dissolved in acetone, propylene glycol or corn oil. Mortality was measured for 6 weeks, and samples of liver were saved for mercury analysis. Mortality was significantly lower in birds fed 20 ppm methylmercury chloride when acetone was the solvent. The reduced mortality could not be explained by effects of acetone on dietary level of mercury or on uptake of mercury into the body.

Environmental Toxicology and Chemistry↗
USGS1986

Acute oral toxicity of sodium cyanide in birds

Sensitivities of six avian species, black vulture ( Coragyps atratus ), American kestrel ( Falco sparverius ), Japanese quail ( Coturnix japonica ), domestic chicken ( Gallus domesticus ), eastern screech-owl ( Otus asio ), and European starling ( Sturnus vulgaris ), to acute poisoning by sodium cyanide (NaCN) were compared by single dose LD50's. Three species, domestic chickens, black vultures, and turkey vultures ( Cathartes aura ), were dosed with NaCN to determine cyanide residues in those that died and also in survivors, in addition to postmortem fate. Three flesh-eating species (black vulture, American kestrel, and eastern screech-owl; LD50's 4.0–8.6 mg/kg) were more sensitive to NaCN than three species (Japanese quail, domestic chicken, and European starling; LD50's 9.4–21 mg/kg) that fed predominantly on plant material. Elevated concentrations of cyanide were found in the blood of birds that died of cyanide poisoning; however, concentrations in birds that died overlapped those in survivors. Blood was superior to liver as the tissue of choice for detecting cyanide exposure. No gross pathological changes related to dosing were observed at necropsy.

Journal of Wildlife Diseases↗
USGS1986

Lethal Dietary Toxicities of Environmental Contaminants and Pesticides to Coturnix

Five-day subacute dietary toxicity tests of 193 potential environmental contaminants, pesticides, organic solvents, and various adjuvants are presented for young coturnix (Japanese quail, Coturnix japonica Temminck and Schlegel). The report provides the most comprehensive data base available for avian subacute dietary toxicity tests and is primarily intended for use in ranking toxicities by a standard method that has a reasonable degree of environmental relevance. Findings are presented in two parts: Part I is a critique of selected drugs that includes discussion of subacute toxicity in relation to chemical class and structure, pesticide formulation, and age of animals; Part II is a summary of toxicologic findings for each test substance and provides a statistically basis for comparing toxicities. Data presented include the median lethal concentration (LC50), slope of the probit regression curve (dose-response curve), response chronology, and food consumption. We observed that: 1) fewer than 15% of the compounds were classed 'very' or 'highly' toxic (i.e, LC50 < 200 ppm) and all of these were either chlorinated hydrocarbons, organophosphates, or organometallics; 2) subacute toxicity may vary widely among structurally similar chemicals and between different formulations of the same chemical; therefore, conclusions about lethal hazard must be made cautiously until the actual formulation of inset has been tested: 3) inclusion of a general standard in each battery of tests is useful for detection of atypical trials and monitoring population changes but should not be used indiscriminantly for adjusting LC50's for intertest differences unless the chemicals of concern and the standard elicit their toxicities through the same action; 4) although other species have been tested effectively under the subacute protocol, coturnix were ideal for the stated purpose of this research because they are inexpensive, well-adapted to the laboratory environment, and yield good intertest reproducibility of response.

Fish and Wildlife Technical Report↗
USGS1985

Effects of wildlife of ethyl and methyl parathion applied to California USA rice fields

Selected rice fields on the Sacramento National Wildlife Refuge Complex were aerially sprayed one time during May or June 1982 with either ethyl (0.11 kg Al/ha) or methyl (0.84 kg AI/ha) parathion for control of tadpole shrimp, Triops longicaudatus. No sick or dead vertebrate wildlife were found or adjacent to the treated rice fields after spraying. Specimens of the following birds and mammals were assayed for brain cholinesterase (ChE) activity to determine exposure to either form of parathion; house mouse, Mus musculus; black-tailed jackrabbit, Lepus californicus; mallard, Anas platyrhynchos; ring-necked pheasant, Phasianus colchicus; American coot, Fulica americana; and red-winged blackbird, Agelaius phoeniceus. Both mice and pheasants from methyl parathion-treated fields had overall mean ChE activities that were significantly (P < 0.05) inhibited compared with controls, and 7, 40, 54 and 57% of individual blackbirds, pheasant, mice, and coots, respectively, had inhibited brain ChE activities (i.e., less than -2 SD of control mean). Although no overall species effect was detected for ethyl parathoid treatment, pheasants (43%), coots (33%), and mice (37%) had significantly inhibited brain ChE activities. Neither of the parathion treatment appeared acutely hazardous to wildlife in or adjacent to rice fields, but sufficient information on potential hazards was obtained to warrant caution in use of these chemicals, especially methyl parathion, in rice fields.

California Fish and Game↗
USGS1984

Avian models for toxicity testing

The use of birds as test models in experimental and environmental toxicology as related to health effects is reviewed, and an overview of descriptive tests routinely used in wildlife toxicology is provided. Toxicologic research on birds may be applicable to human health both directly by their use as models for mechanistic and descriptive studies and indirectly as monitors of environmental quality. Topics include the use of birds as models for study of teratogenesis and embryotoxicity, neurotoxicity, behavior, trends of environmental pollution, and for use in predictive wildlife toxicology. Uses of domestic and wild-captured birds are discussed.

Journal of the American College of Toxicology↗
USGS1984

Subchronic mercury exposure in coturnix and a method of hazard evaluation

The sublethal toxicity of inorganic (HgCl 2 ) and organic (CH 3 HgCl) mercury chloride was studied in coturnix ( Coturnix japonica ) by feeding them mercuric compounds (CH 3 HgCl at concentrations of 0.125,0.5,2 and 8 ppm; HgCl 2 at 0.5, 2, 8 and 32 ppm) in ad libitum diets from hatching to adulthood. Differences of response to the mercurials were compared on the basis of selected indicator enzymes and plasma chemistries. Comparisons of response to equivalent concentrations of the two mercurials and dose-response relationships were made at 1,3,5,7 and 9 weeks. Changes of activity were detected for brain acetylcholinesterase (AChE) and the plasma enzymes aspartate aminotransferase (ASAT), butyrylcholinesterase (BChE), lactate dehydrogenase (LDH) and ornithine carbamoyl transferase (OCT). Changes of ASAT, LDH and OCT were then quantified by probit analysis and the mercurials were compared through their median effective concentrations (EC 50 ). This quantal procedure was based on the establishment of normal control values for each enzyme and then classifying mercury-treated outliers (more than ± 2 SD) as respondents. The EC 50 values at 9 weeks for ASAT, LDH and OCT, respectively, were 9, 3 and 63 ppm for HgCl 2 , and 5, 1 and 4 ppm for CH 3 HgCl. These results provided the basis for two hazard indices that were calculated by dividing the EC 50 into the oral LD 50 and the 5-d dietary LC 50 . Mercury also had contradictory effects on gonadal maturation in both sexes.

Environmental Toxicology and Chemistry↗
USGS1984

Acute toxicity of diazinon is similar for eight stocks of bobwhite

Nine-week-old bobwhite ( Colinus virginianus ) from eight different game farms were tested for their sensitivity to an acute oral exposure of technical-grade diazinon (phosphorothioic acid O,O -diethyl- O -[6-methyl-2-(l-methylethyl) -4-pyrimidinyl]ester). Extraneous variables associated with interlaboratory differences in husbandry were eliminated by incubating eggs and rearing chicks to test age for all stocks simultaneously in the same facilities at the Patuxent Wildlife Research Center. Under this single set of conditions, the responses of the eight stocks of bobwhite to diazinon were statistically inseparable, with LD 50 values varying from 13 mg/kg (95% confidence interval, 8–21 mg/kg) to 17 mg/kg (95% confidence interval, 11–25 mg/kg). The pooled LD 50 for the eight stocks was 14.7 mg/kg (95% confidence interval, 13.1–16.5 mg/kg).

Environmental Toxicology and Chemistry↗
USGS1984

Toxicity of anticholinesterase insecticides to birds: Technical grade versus granular formulations

The acute toxicities of 13 granular anticholinesterase insecticides were compared with their technical grade active ingredients by administering single oral doses of chemical to adult Northern bobwhites (Colinus virginianus) and evaluating resultant LD50 values and dose-response curves. Similar tests with ringed turtledoves (Streptopelia risoria) were conducted with five of the granular formulations to check for interspecific differences. The test chemicals were Amaze 15G (isofenphos), Counter 15G (terbufos), Dasanit 15G (fensulfothion), Diazinon 14G (diazinon), Di-Syston 15G (disulfoton), Dyfonate 20G (fonofos), Furadan 10G (carbofuran), Lorsban 15G (chlorpyrifos), Nemacur 15G (fenamiphos), Parathion 10G (parathion), Tattoo 10G (bendiocarb), Temik 15G (aldicarb), and Thimet 15G (phorate). Information is also presented on dose-response relations and their use in hazard assessment, granule size and hazard, response patterns, and toxic signs. The general conclusions were: (1) The organophosphates (fenamiphos and fensulfothion) and the carbamate (aldicarb) were the most toxic of the insecticides tested. (2) The granular formulation and its technical grade active ingredient were of equivalent toxicity, or the granular was significantly less toxic. (3) The dose-response curve enhances hazard assessment. (4) Ingestion of a single granule of Temik 15G was shown to be life threatening to bobwhite-sized birds, and ingestion of fewer than five granules could be lethal to sparrow-sized birds for Dasanit 15G, Diazinon 14G, Dyfonate 20G, Furadan 15G, and Nemacur 15G. (5) It is therefore suggested that the hazard associated with granular insecticides may be more dependent on which species (cf. size and feeding behavior) inhabit a treated area than on the actual application rate.

Ecotoxicology and Environmental Safety↗
USGS1983

Parathion alters incubation behavior of laughing gulls

One member of each pair of incubating laughing gulls at 9 nests was trapped, orally dosed with either 6 mg/kg parathion in corn oil or corn oil alone, and marked about the neck with red dye. Each nest was marked with a numbered stake and the treatment was recorded. A pilot study with captive laughing gulls had determined the proper dosage of parathion that would significantly inhibit their brain AChE activity (about 50% of normal) without overt signs of poisoning. After dosing, birds were released and the nests were observed for 21/2 days from a blind on the nesting island. The activities of the birds at each marked nest were recorded at 10-minute intervals. Results indicated that on the day of treatment there was no difference (P>0.05, Chi-square test) in the proportion of time spent on the nest between treated and control birds. However, birds dosed with 6 mg/kg parathion spent significantly less time incubating on days 2 and 3 than did birds receiving only corn oil. By noon on the third day, sharing of nest duties between pair members in the treated group had approached normal, indicating recovery from parathion intoxication. These findings suggest that sublethal exposure of nesting birds to an organophosphate (OP) insecticide, such as parathion, may result in decreased nest attentiveness, thereby making the clutch more susceptible to predation or egg failure. Behavioral changes caused by sublethal OP exposure could be especially detrimental in avian species where only one pair member incubates or where both members are exposed in species sharing nest duties.

Texas↗
USGS1982

Anticholinesterase poisoning of birds: Field monitoring and diagnosis of acute poisoning

Organophosphorus and carbamate pesticides are cholinesterase (ChE) inhibiting chemicals that have been responsible for avian die-offs. Identification of chemicals implicated in these die-offs is difficult and sometimes conclusions are solely circumstantial. However, when marked depression (inhibition) of brain ChE activity accompanies organophosphorus or carbamate residues in body tissues or ingesta, cause-effect diagnosis is enhanced. To achieve this end, normal brain ChE activity is estimated for controls of the affected species and then die-off specimens are individually evaluated for evidence of ChE inhibition. This approach to evaluation of antiChE poisoning may also be used to monitor exposure of vertebrates to field application of organophosphorus or carbamate pesticides. Problems associated with this kind of evaluation, and the main topic of this report, include variability of brain ChE activity among species, postmortem influences of ambient conditions (storage or field) on ChE activity, and differential patterns of ChE activity when inhibited by organophosphorus or carbamate compounds. Other topics discussed are the ChE assay procedure, example case reports and interpretation, and research needed for improving the diagnostic utility of ChE activity in a field situation.

Environmental Toxicology and Chemistry↗
USGS1982

Subacute toxicity testing with young birds: Response in relation to age and intertest variability of LC50 estimates

The variability in toxic response of Japanese quail (Coturnix coturnix japonica) to a standardized 5-day subacute feeding trial was studied while age was increased at weekly intervals from 1 to 21 days and at different times with 14-day-old birds. The objectives were to identify the strengths and limitations of this subacute toxicity protocol and to provide possible explanations for differences in response among the various classes of pesticides. The variables included the median lethal concentration (LC50), the dose-response slope, food consumption, mortality patterns, and procedures of preparing toxic diets. Carbamate, organophosphate, chlorinated hydrocarbon, and organic mercury compounds were represented. A total of 60 subacute tests were involved in this evaluation. The general conclusions of the study are as follows: (1) The basic protocol yields good within-laboratory reproducibility of results. (2) The LC50s increase as birds grow older, and the change was reasonably predictable between 7 and 21 days of age. (3) Monitoring of time-related response patterns, such as food consumption, onset and remission of overt toxicity, and mortality, is critical to the evaluation of potential hazard. (4) Different orders of toxicity may occur at different ages for an array of compounds, but differences do not appear to be large enough to seriously alter the interpretation. (5) For optimal comparisons, all testing should be conducted on birds of a single age.

Book chapter↗
USGS1982

Subacute dietary toxicities of dicrotophos and dieldrin in time-replicated trials with young ring-necked pheasants and mallards

The dietary toxicities of (E)-phosphoric acid 3-(dimethylamino)-1-methyl-3-oxo-1-propenyl dimethyl ester (dicrotophos) and 3,4,5,6,9,9-hexachloro-1a,2,2a,3,6,6a,7,7a-octahydro-2,7:3,6-dimethanonaphth[2,3-b]oxirene (dieldrin) to 10-day-old ring-necked pheasants (Phasianus colchicus) and 5-day-old mallards (Anas platyrhynchos) were compared in five time-replicated trials. Toxicities were calculated as median lethal concentrations (LC50s) based on 5 days of ad libitum feeding on geometrically spaced concentrations of toxicant. The LC50s were more uniform for dieldrin than for dicrotophos with both species and more uniform for pheasants than for mallards with both compounds. The LC50s of dieldrin and dicrotophos averaged 59 [standard deviation (SD) = 4.4] and 45 ppm (SD = 5.0) for pheasants, and 156 (SD = 24.9) and 102 ppm (SD = 24.9) for mallards. Changes in LC50s between successive trials, although possibly haphazard, were nearly always in the same direction for both compounds with both species. Feeding rates at various concentrations of equivalent potency gave meaningful insight into the sensitivity and vulnerability of both species to these insecticides. Comparisons of 5 and 10-day-old mallards demonstrated the importance of age differences to interpretation of short-term subacute toxicity data. For example, at 5 days dicrotophos was 1.5 times more toxic than dieldrin, but at 10 days dieldrin was 2.6 times more toxic. These differences are explained.

Book chapter↗