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7 recordsLinked to original sources
USGS1980

Intestinal absorption of 5 chromium compounds in young black ducks (Anas rubripes)

An in vivo intestinal perfusion technique was used to measure the absorption rates of five Cr compounds in black ducks. Cr was absorbed from saline solutions of KCr(SO 4 ) 2 and CrO 3 at a rate about 1.5 to 2.0 times greater than from solutions of Cr, Cr(NO 3 ) 3 , and Cr(C 5 H 7 O 2 ) 3 . These results suggest the ionic form of Cr in solution may be an important factor in determining absorption of Cr compounds from the small intestine.

Toxicology Letters↗
USGS1981

Avoidance behavior of young black ducks treated with chromium

Pairs of adult black ducks (Anas rubripes) were fed a diet containing 0, 20, or 200 ppm chromium in the form of chromium potassium sulfate. Ducklings from these pairs were fed the same diets as adults and were tested for their avoidance responses to a fright stimulus. Neither level of chromium had a significant effect on avoidance behavior.

Toxicology Letters↗
USGS1981

Acute toxicities of toxaphene and endrin to larvae of seven species of amphibians

Seven species of amphibian larvae were exposed to toxaphene and endrin in a continuous-flow dosing system to determine differences in sensitivity to the two compounds, EC50 and LC50 estimates varied from those for Rana sphenocephala by no more than one order of magnitude when calculated on the basis of intended concentrations. Removal of pesticides from water by the test animals was significant and it makes interpretation of results difficult. Continuous-flow toxicity tests conflict with the adaptations of amphibian larvae for static water; use of such tests for amphibians requires further evaluation.

Toxicology Letters↗
USGS1981

Effects of industrial effluents, heavy metals, and organic solvents on mallard embryo development

Mallard eggs were externally exposed at 3 and 8 days of incubation to 7 different industrial effluents and to 7 different heavy metal, organic solvent, and petroleum solutions to screen for potential embryo-toxic effects. This route of exposure was chosen in order to simulate the transfer of pollutant from the plumage of aquatic birds to their eggs. Five of the effluents including mineral pigment, scouring effluent, sludge, and tannery effluent resulted in small but significant reductions in embryonic growth. Treatment with methyl mercury chloride solution of 50 ppm (Hg) impaired embryonic growth but much higher concentrations were required to affect survival and cause teratogenic effects. Oil used to suppress road dust was the most toxic of the pollutants tested and only 0.5 microliter/egg caused 60% mortality by 18 days of development. These findings, in combination with other studies suggest that petroleum pollutants, or effluents in combination with petroleum, may pose a hazard to birds' eggs when exposure is by this route.

Toxicology Letters↗
USGS1985

Organophosphorus insecticide induced decrease in plasma luteinizing hormone concentration in white-footed mice

Oral intubation of 50 and 100 mg/kg acephate inhibited brain acetylcholinesterase (AChE) activity by 45% and 56%, and reduced basal luteinizing hormone (LH) concentration by 29% and 25% after 4 h in white-footed mice ( Peromyscus leucopus noveboracensis ). Dietary exposure to 25, 100, and 400 ppm acephate for 5 days substantially inhibited brain AChE activity, but did not affect plasma LH concentration. These preliminary findings suggest that acute exposure to organophosphorus insecticides may affect LH secretion and possibly reproductive function.

Toxicology Letters↗
USGS1985

Effects of fluoride on screech owl reproduction: Teratological evaluation, growth, and blood chemistry in hatchlings

The effects on reproduction in screech owls ( Otus asio ) of chronic dietary sodium fluoride administration at 0, 40, and 200 ppm were examined. Fluoride at 40 ppm resulted in a significantly smaller egg volume, while 200 ppm also resulted in lower egg weights and lengths. Day-one hatchlings in the 200 ppm group weighed almost 10% less than controls and had shorter crown-rump lengths. No gross abnormalities were apparent. Skeletal clearing and staining revealed significantly shorter tibiotarsus lengths in the 40 ppm and 200 ppm groups and a shorter radius-ulna length in the 200 ppm group. By 7 days of age, body weights and lengths did not differ from controls, but the tibiotarsus in the 200 ppm group remained shorter. No significant differences were detected in hematocrit, hemoglobin, plasma calcium or alkaline phosphatase. Plasma phosphorus levels were higher in the 40 ppm group than in controls. These results, in combination with the findings of Pattee et al. [25], revealed significant impairment of overall reproduction, suggesting that sodium fluoride could cause slight to moderate reproduction disorders in owls in fluoride-polluted areas.

Toxicology Letters↗
USGS2023

Establishing an in vitro model to assess the toxicity of 6PPD-quinone and other tire wear transformation products

The tire wear transformation product 6PPD-quinone (6PPDQ) has been implicated as the causative factor for broad scale mortality events for coho salmon in the Pacific Northwest. Highly variable sensitivity to 6PPDQ in closely related salmonids complicates efforts to evaluate the broader toxicological impacts to aquatic ecosystems. Our goals were to (1) validate the large range of in vivo species sensitivities reported for coho, Chinook, and sockeye salmon and (2) develop an in vitro platform for assessing 6PPDQ toxicity. In vivo studies confirmed the acute sensitivity of juvenile coho (12 h LC 50 = 80.4 ng/L) and demonstrated that sockeye salmon were not vulnerable to mortality. Chinook salmon were sensitive to 6PPDQ mortality at initial concentrations >25 μg/L, ∼10-fold greater than reported environmental measurements. In vitro , the coho salmon cell line CSE-119 was acutely sensitive to 6PPDQ (metabolic EC 50 = 7.9 μg/L, cytotoxicity EC 50 = 6.1 μg/L). Analogous Chinook (CHSE-214) and sockeye salmon (SSE-5) cell lines were nonresponsive in both assays, and rainbow trout RTG-2 cells began showing metabolic effects at 68 μg/L (EC 5 ). Recreation of species-specific 6PPDQ sensitivity in vitro implicates conserved modes of action in CSE-119 that could be utilized for mechanistic studies of 6PPDQ toxicity and screening of other PPD transformation products.

Environmental Science and Technology Letters↗