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At least 289 records · Page 16Linked to original sources
USGS1984

Evaluation of the potential hazard to barn owls of talon (brodifacoum bait) used to control rats and house mice

During 1980, a radiotelemetry study on barn owls ( Tyto alba ) was conducted to evaluate the secondary hazards of the anticoagulant rodenticide TALON® (containing 0.005% brodifacoum) when it was used for controlling rats ( Rattus spp.) and house mice ( Mus musculus ) on farms. Thirty‐five active nests were located in about 1,100 km 2 (430 mi 2 ) in southwestern New Jersey. Starting on June 9, 1980, radio transmitters with tail clips were attached to 26 adult nesting barn owls and 8 fledged young of the year. In one 20‐km 2 (about 8 mi 2 ) area, which was the most intensively searched, 12 active barn owl nests were located. Of all 35 active nests, 66% were in trees, 11% in barns, 8.5% in silos, 8.5% in chimneys and 6% in miscellaneous locations. Analysis of regurgitated pellets showed that meadow voles ( Microtus pennsylvanicus ) were the most common prey at all sites. Although Norway rats ( Rattus norvegicus ) and house mice occurred in some pellet collections, they made up only a small part of the diet (3.9% rats and 2% mice) of barn owls in the study area. Baiting at farms with TALON was begun on July 24, and ended on September 29, 1980. TALON was not observed to cause or implicated in barn owl mortality during the study. However, trace residues (< 0.05 ppm, the limit of determination) of brodifacoum were found in one electrocuted barn owl. Young barn owls were fledged from at least eight sites where poisoned rodents were available on the farms for at least part of the nesting and feeding period (including pre‐ and postfledging). Furthermore, radiotelemetry confirmed that at least 9, and possibly 12, of the radio‐equipped owls were present on sites posttreatment, when census evaluations showed commensal rodents were present and consuming TALON bait.

New Jersey↗
USGS1984

Organochlorine residues in eggs of black-crowned night herons from Colorado and Wyoming

Eggs of black-crowned night-herons Nycticorax nycticorax (L.) were collected for analysis from seven nesting sites in Colorado and Wyoming in 1979. One egg was taken per nest from as many as 20 nests per site during early incubation. The nests were marked and revisited after hatching, but before fledging, to record the number of live young. DDE was detected in all of the collected eggs (total 147) at a mean concentration of 3.1 ppm, fresh basis (residue means are geometric). Mean DDE at the seven sites varied from 1.8 to 7.6 ppm. Polychlorinated biphenyls (PCBs) were detected in 81 eggs (mean 1.0 ppm); the highest mean at any site was 2.2 ppm. Twelve other organochlorines were each detected in 1 to 30 eggs, usually at a concentration of > 1.0 ppm. Mean total organochlorines in the eggs from the seven sites ranged from 2.0 to 10.1 ppm and the median number of compounds per egg ranged from one to five. Eggshell thickness was negatively correlated (p > 0.001, r = – 0.585) with DDE levels in the 147 eggs. Average shell thickness (0.258 ± 0.030 mm) was 8.8% lower than the average thickness (0.283 ± 0.016mm) of 40 pre-DDT eggs from this region. The nesting sites with the highest DDE and total organochlorine residues in the eggs had the thinnest shells, produced the fewest young and had more nonviable eggs and dead young. At four of the seven sites, the average number of live young per nest was > 2.0, the minimum long-term mean required for population maintenance. The source of the contaminants found in the heron eggs in this study was not determined.

Environmental Toxicology and Chemistry↗
USGS1984

Field and laboratory evaluation of the influence of copper-diquat on apple snails in southern Florida

The recent decline of apple snail ( Pomacea paludosa ) populations in canals surrounding Loxahatchee National Wildlife Refuge in southern Florida coincided with the use of copper-diquat for the control of the aquatic weed hydrilla ( Hydrilla verticillata ). Field and laboratory studies were designed to assess the effects of copper-diquat on apple snails, which are the primary food of the endangered snail kite Rostrhamus sociabilis (formerly known as the Everglade kite). Acute toxicities (96-h LC 50 values) of Cutrine-Plus and Komeen (chelated formulations of copper) to immature apple snails were 22 and 24 μg/L, respectively. Diquat was toxic at a concentration of 1,800 μg/L and did not increase the toxicity of copper when the chemicals were used in combination. Evaluation of field samples indicated that copper concentrations were higher in detritus than in water, plants and mud, and that there was a gradient of copper concentration from the canal to the interior, the highest residues being in samples from the canal. Copper associated with detritus (up to 150 μg/g) had no effect on growth or survival of apple snails in field cage and tank studies. Also, field applications of copper-diquat to hydrilla had no effect on survival of caged adult and immature snails. Copper from field applications was rapidly taken out of solution by plants and organic material in the water and subsequently incorporated into the bottom detritus. Although the effects of repeated applications of copper-diquat and high body burdens of copper (accumulated during exposure to herbicidal treatment) on survival and reproduction of apple snails are not known, the information available indicates that treatment of hydrilla with copper-diquat was probably not responsible for the decline in the apple snail population. Application at recommended rates should pose no threat to these snails in the organically rich waters of southern Florida.

Environmental Toxicology and Chemistry↗
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↗
USGS1985

Toxicity of abate® 4E (temephos) in mallard ducklings and the influence of cold

Diets mixed to contain 0, 0.1, 1.0, 10 and 100 ppm temephos (determined chemically to contain less than 0.5, less than 0.5, 0.89, 6.0 and 59 ppm temephos, respectively) in an Abate® 4E formulation, were fed to mallard (Anas platyrhynchos) ducklings for 7 d. During this period, half of the ducklings in each dietary treatment group were housed in a heated brooder (39 to 41 °C) and half were housed in an unheated brooder (10 to 18°C). Mortality in all dietary groups in the unheated brooder was higher than in the heated brooder. High temephos-related mortality occurred in the 100 ppm group in the unheated brooder but not in any other diet-temperature groups. Ingestion of the 100 ppm temephos diet inhibited plasma Cholinesterase (ChE) activity and elevated plasma corticosterone concentration and creatine phosphokinase activity, but other selected plasma chemistries were not affected in a dose-related manner. Brain ChE activity was depressed only in the 100 ppm dietary groups; maximum inhibition of brain ChE activity was 48%. These findings suggest that diets containing up to 10 ppm temephos do not directly affect duckling survival during the first week of life and that the toxicity of 100 ppm temephos is markedly enhanced by cold.

Environmental Toxicology and Chemistry↗
USGS1985

Geochemical investigations of polychlorinated dibenzo-p-dioxins in the subsurface environment at an abandoned wood-treatment facility

The discharge of effluents containing creosote and pentachlorophenol into two unlined surface impoundments at a wood-treatment facility in Pensacola, Florida, resulted in contamination of the underlying sand and gravel aquifer. These wastes contained significant amounts of chlorinated dioxins, such as isomers of hexa- and heptachlorodibenzo-p-dioxins and octachlorodibenzo-p-dioxin, probably derived from commercial pentachlorophenol. Geochemical investigations of pond sludge, groundwater and porous media from the unsaturated and saturated zones indicated that these geologic materials were contaminated by chlorinated dioxins. The fate and movement of these compounds in the subsurface environment were studied using the technique of GC-MS-MS. Chlorinated dioxins migrated both vertically and horizontally in the subsurface and were present at considerable distances from the source of contamination. Concentrations of chlorinated dioxins in groundwater were several orders of magnitude lower than in porous media from the unsaturated and saturated zones. Ratios of the various isomers remained relatively constant in highly contaminated areas. However, in less contaminated areas, isomer ratios changed dramatically; at certain locations, one hexachlorodibenzo-p-dioxin isomer predominated. The environmental significance of these compounds is discussed.

Environmental Toxicology and Chemistry↗
USGS1986

Toxicity of methyl parathion to bats: Mortality and coordination loss

The 24-h oral LD50 of methyl parathion (phosphorothioic acid O, O -dimethyl O-(4-nitrophenyl) ester) to little brown bats ( Myotis lucifugus ) (372 mg/kg) was 8.5 times the LD50 for mice ( Mus musculus ) (44 mg/kg). However, orally dosed mice either died or appeared behaviorally normal after 2 to 3 h, whereas many dosed bats, although alive at 24 h, could not right themselves when placed on their backs. The oral dose estimated to cause this loss of coordination in 50% of a sample of big brown bats ( Eptesicus fuscus ) was one-third or less the LD50 of this species. Cholinesterase activity depression in brains of little brown bats was similar whether dosage was oral or dermal. With death as the criterion, bats proved relatively insensitive to methyl parathion in 24-h tests, but considerations of the chemical's potential to cause coordination loss, leading to capture and death by predators, coupled with bats' naturally low reproductive rates, suggest possible injury to exposed bat populations.

Environmental Toxicology and Chemistry↗
USGS1986

Adaptation of Selenastrum capricornutum (Chlorophyceae) to copper

Selenastrum capricornutum Printz, growing in a chemically defined medium, was used as a model for studying adaptation of algae to a toxic metal (copper) ion. Cells exhibited lag‐phase adaptation to 0.8 μM total Cu (10 −12 M free ion concentration) after 20 generations of Cu exposure. Selenastrum adapted to the same concentration when Cu was gradually introduced over an 8‐h period using a specially designed apparatus that provided a transient increase in exposure concentration. Cu adaptation was not attributable to media conditioning by algal exudates. Duration of lag phase was a more sensitive index of copper toxicity to Selenastrum that was growth rate or stationary‐phase cell density under the experimental conditions used. Chemical speciation of the Cu dosing solution influenced the duration of lag phase even when media formulations were identical after dosing. Selenastrum initially exposed to Cu in a CuCl 2 injection solution exhibited a lag phase of 3.9 d, but this was reduced to 1.5 d when a CuEDTA solution was used to achieve the same total Cu and EDTA concentrations. Physical and chemical processes that accelerated the rate of increase in cupric ion concentration generally increased the duration of lag phase.

Environmental Toxicology and Chemistry↗
USGS1986

Cholinesterase inhibition in meadow voles (Microtus Pennsylvanicus) following field applications of orthene®

Brain acetylcholinesterase activity in field-caught meadow voles ( Microtus pennsylvanicus ) was depressed after a field-spray of Orthene® (acephate: acetylphosphoramidothioic acid O,S -dimethyl ester) by as much as 32% in 1982 and 38% in 1983. Short-term recovery was demonstrated and occurred in a time-dependent fashion in 1982. Plasma Cholinesterase levels were more variable but also were depressed. Residues were detected in vegetation samples and in the gastrointestinal tracts of exposed voles. Residues in vegetation were diluted or absent 7 to 8 d following the treatment.

Environmental Toxicology and Chemistry↗
USGS1986

Discrimination learning in adult bobwhite quail fed paraquat

Adult male bobwhite quail ( Colinus virginianus ) were fed a diet containing 0, 25 or 100 ppm paraquat dichloride. After 60 d on treated diets, discrimination learning was evaluated with acquisition and reversal tests. The three groups performed similarly on these tests. Dose-related histopathological lesions were not found in liver, kidney or lung tissues.

Environmental Toxicology and Chemistry↗
USGS1986

Organochlorine contaminants in passeriformes and other avian prey of the peregrine falcon in the western United States

About 1,150 individuals of 38 species of Passeriformes and other small birds were collected in 1980 at 36 locations in eight western U.S. states for organochlorine (OC) chemical analysis. The bird carcasses (less beak, tarsi, gastrointestinal tract, and feathers) were combined by species and location (4 to 15 specimens per sample) into 124 composited samples for analysis. Also analyzed were 77 single specimens of four species, to assess variation in residue concentrations in individual birds. The chemicals detected (greater than 0.05 ppm) were the following (in order of frequency): DDE, polychlorinated biphenyls (PCBs), hexachlorocyclohexane (HCH), heptachlor epoxide, oxychlordane, dieldrin and toxaphene. DDE accounted for 72% of total OC concentrations (ppm DDE/ppm total OCs) overall and PCBs accounted for 3%. DDE mean (geometric) residues were highest in tree swallows ( Tachycineta bicolor Vieillot), 12.0 ppm; killdeer ( Charadrius vociferus L.), 5.9 ppm; and Brewer's blackbirds ( Euphagus cyanocephalus Wagler), 2.7 ppm. Eight migratory species showed mean DDE residues 13 times higher than those in four resident species (1.3 vs. 0.1 ppm, p < 0.05), but PCB residues were similar (0.03 vs. 0.02 ppm). Insectivorous species showed higher DDE, PCB and total OC residues than did either omnivores or granivores ( p < 0.05). Males of some species showed higher residues of DDE, PCBs and total OCs than did females ( p < 0.05). DDE residues, but not PCBs, in killdeer, Brewer's blackbirds and violet-green swallows ( Tachycineta thalassina Swainson) were significantly related (0.01 < p < 0.08) to latitude and longitude of origin. Concentrations of DDE in the carcass fat of some individual tree swallows and killdeer would be in the lethal range if 15 to 20% of the stored DDE were rapidly mobilized to the brain. Samples of 13 species contained DDE concentrations (greater than 3 ppm) considered sufficient to inhibit the normal reproduction of avian predators feeding on them. The evidence suggests that potentially harmful OC concentrations are present in certain western migrants and pose an even greater hazard to avian predators such as the peregrine falcon ( Falco peregrinus Tunstall).

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

Reproduction and health of mallards fed endrin

Concentrations of 0, 1 and 3 ppm endrin in dry duck mash were fed to mallards ( Anas platyrhynchos ) starting in December, and health and reproduction were measured the following spring and summer. One male fed 3 ppm endrin died with 2.0 ppm endrin (wet weight), a diagnostically lethal level, in its brain. Birds fed 1 ppm endrin reproduced as well as, if not better than, controls. Birds fed 1 ppm endrin had significantly greater hatching success of fertile eggs than did those fed 0 or 3 ppm, and their clutches hatched significantly earlier than did those of birds fed 3 ppm. Mallards fed 3 ppm endrin appeared to reproduce more poorly than controls, but this finding must be regarded with caution because the results of statistical tests often were not significant. Endrin accumulated in eggs to a mean of 1.1 and 2.9 ppm (wet weight) when fed to hens at 1 and 3 ppm. The concentration of endrin in the carcasses of adults was similar to that in eggs, but the concentration in the fat of adults was about 4 to 7 times higher than in eggs.

Environmental Toxicology and Chemistry↗
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↗
USGS1987

Fate and movement of azaarenes and their anaerobic biotransformation products in an aquifer contaminated by wood-treatment chemicals

Infiltration of wastes containing creosote and pentachlorophenol from surface impoundments at an abandoned wood-treatment facility near Pensacola, Florida, resulted in contamination of the underlying sand and gravel aquifer. Pond sludges and sediments near the source were contaminated with 2- to 5-ring azaarenes having log Kow values of from 2.0 to 5.6. However, the ground water contained only azaarenes and their oxygenated and methylated derivatives having log Kow values of less than 3.5. These compounds also were present in coal tar-contaminated ground water at a site near St. Louis Park, Minnesota. Laboratory anaerobic degradation studies and on-site observations indicated that oxygenated azaarenes probably were biotransformation products of reactions mediated by indigenous microbial populations. Microbial N-methylation, C-methylation and O-methylation reactions are reported here for the first time. In the presence of nutrients and carbon sources such as acetate and propionate, all azaarenes studied were either partially or completely degraded. Evidence for the microbial degradation of azaarenes in ground water from anaerobic zones is presented. Oxygenated azaarenes were relatively more water-soluble, mobile and persistent in hydrogeologic environments.

Minnesota, Florida↗
USGS1987

Industrial halide wastes cause acute mortality of snow geese in Oklahoma

An examination of 97 dead migratory waterfowl collected at an industrial facility showed that the birds had had severe gastric and intestinal hemorrhaging. Water samples taken at on-site waste lagoons contained 6,750 mg/L fluoride, 4,500 mg/L bromine and 1,500 mg/L boron. Brain and liver tissues contained high levels of fluoride, as compared with tissues of birds collected at a control site. From the necropsy results, the high concentration of fluoride in the water samples and the elevated tissue residues, we conclude that the birds died from acute fluoride poisoning.

Oklahoma↗
USGS1987

Products of hexachlorocyclopentadiene (C-56) in aqueous solution

The photodegradation and degradation products of hexachlorocyclopentadiene (C-56) in aqueous solutions were studied in the laboratory. In each case, the half-life of C-56 was less than 4 min when exposed to sunlight. At least eight degradation products were positively or tentatively identified: 2,3,4,4,5-Pentachloro-2-cyclopentenone, hexachloro-2-cyclopentenone and hexachloro-3-cyclopentenone were the primary photodegradation products, and pentachloro- cis -2,4-pentadienoic acid, Z- and E-pentachlorobutadiene and tetrachlorobutyne were the secondary degradation products. Dissociation of the primary photolysis products may proceed through corresponding pentadienoic acids to form smaller molecular weight compounds such as pentachlorobutadiene isomers and tetrachlorobutyne. In addition, dimerization of 2,3,4,4,5-pentachloro-2-cyclopentenone to form higher molecular weight compounds such as hexachloroindenone may present a minor route of degradation. The results also indicate that C-56 is highly photoreactive and suggest a possible pathway for the compound's transformation in the environment when exposed to sunlight.

Environmental Toxicology and Chemistry↗