Showing papers on "Zinc toxicity published in 1980"

Survival and growth of Tanytarsus dissimilis (Chironomidae) exposed to copper, cadmium, zinc, and lead

Abstract: Tanytarsus dissimilis (Johannsen) was exposed to four heavy metals. Static exposure began during embryogenesis and continued through hatching and larval development to the 2nd or 3rd instar. The LD50 concentrations for cadmium, copper, and zinc were 3.8, 16.3, and 36.8 microgram/l, respectively. The LC50 for lead was 258 microgram/l. Growth was not reduced at exposure concentrations less than the LC50. The LC50 concentrations obtained in this insect exposure are as much as 1,600 times lower than other insect exposures reported in the literature. This is probably due to a combination of exposure of this insect during important life cycle events and species-specificity.

Acute toxicity of zinc and copper singly and in combination to the bluegill (Lepomis macrochirus)

Abstract: Zinc and copper are common components of aquatic effluents from various industrial and mining sources. The acute toxicity of various compounds of Cu and Zn has been determined for many species of fish using continuous flow as well as static toxicity tests under different chemical, temperature, and temporal regimes. Similarly, the toxicity of mixtures of these two, as well as of more complex mixtures of heavy metals, has been studied by many researchers. While many of these studies report the toxicity of Cu and/or Zn to the bluegill (Lepomis macrochirus), to our knowledge the literature does not mention the acute toxicity of mixtures of these two metals to this species. The present study was undertaken to investigate the acute toxicity of divalent Zn-Cu mixtures to the bluegill.

Mortality, accumulation, and distribution of zinc in the gill system of the dogfish following zinc treatment.

Abstract: Besides being an essential element, Zn has been shown to be toxic to aquatic organisms Acute lethalities of Zn salts to teleosts have been reported, but few data regarding Zn toxicity to elasmobranchs can be found To evaluate the effect of Zn on elasmobranchs and to compare the data with those on teleosts this paper studies Zn toxicity and the accumulation of the metal in the gills of the dogfish Scyliorhinus canicula exposed to 180 and 80 ppM of zinc

Prevention of ovine lupinosis by the oral administration of zinc sulphate and the effect of such therapy on liver and pancreas zinc and liver copper.

Abstract: Three experiments were carried out using Merino wethers to investigate if oral administration of zinc sulphate would provide protection against the liver damage that occurs in lupinosis. At the same time, the effect of this zinc therapy on liver and pancreas zinc, and liver copper concentrations, was studied. The zinc therapy caused increases in liver and pancreas zinc concentrations, and a drop in the liver copper concentration. Administration of the toxins of Phomopsis leptostromiformis with the zinc increased the magnitude of these changes. Administration of 0.5 g zinc or greater per day, as zinc sulphate, reduced the liver damage caused by the toxins of P. leptostromiformis. The degree of liver protection provided by the zinc therapy varied both between animals within treatments and between treatments in different experiments. Zinc toxicity was encountered.

Toxic effects of cobalt and zinc to Chlorella pyrenoidosa (26) in soft and hard water.

Abstract: Different concentrations (0.83, 3.33, 10 ppm) of cobalt (cobalt sulphate) and zinc (zinc chloride) were added to bristol media prepared using soft water (addition of 20 mg/l calcium carbonate) and hard water (addition of 400 mg/l calcium carbonate). A known amount of Chlorella pyrenoidosa (26) was inoculated into various media, and the number of Chlorella cells was counted every other day for a period of 8 days. Cobalt and zinc were more toxic in media prepared using soft water than hard water as revealed by the growth rate of C. pyrenoidosa. These results agree with studies elsewhere on other aquatic organisms.