Showing papers on "Zinc toxicity published in 1986"
TL;DR: The results suggest that zinc should be included on the growing list of endogenous central neurotoxins which may be involved in the pathogenesis of CNS cell loss in a variety of disease states.
184 citations
TL;DR: Although both zinc and VAM influenced the uptake and translocation of various minerals, differences in mineral concentrations could not explain why a higher biomass is produced by grasses infected with mycorrhiza in zinc-polluted soil.
Abstract: Vesicular-arbuscular mycorrhizae (VAM) are known to enhance the uptake of heavy metals in the host and could therefore increase the effects of heavy metal pollution on plant populations. The effect of mycorrhizal infection on two grasses occurring in coastal dunes downwind of a blast furnace complex and which are becoming increasingly polluted, was examined. In a 2 × 2 factorial experiment, the effects of VAM and zinc on the growth and mineral nutrition of Festuca rubra and Calamagrostis epigejos was established. It appeared that VAM infection alleviated the negative effect of zinc on growth in both species. Although both zinc and VAM influenced the uptake and translocation of various minerals, differences in mineral concentrations could not explain why a higher biomass is produced by grasses infected with mycorrhiza in zinc-polluted soil.
135 citations
TL;DR: It is still uncertain whether zinc can cause malignant transformation but zinc is needed for cellular proliferation of existing tumours and tumour growth is retarded by zinc deficiency, and zinc deficiency may be harmful to the developing organism.
Abstract: Zinc is a common element in the human environment and constitutes an important trace element intervening in many biological processes. Toxicity of zinc is low; zinc deficiency represents, however, a hazard for human health. Zinc is not mutagenic and has little, if any, clastogenic properties. Zinc can induce tumours but only following local application, and does not represent a carcinogenic risk to man. It is still uncertain whether zinc can cause malignant transformation but zinc is needed for cellular proliferation of existing tumours and tumour growth is retarded by zinc deficiency. Zinc is not teratogenic; it can, in fact, avert teratogenicity of other agents. Conversely, zinc deficiency may be harmful to the developing organism.
71 citations
39 citations
TL;DR: The anorexia, pancreatic and gizzard lesions which resulted from incorporating 20,000 and 25,000 mg zinc as zinc oxide perkg diet were not prevented by concurrent daily injections of 0.3 mg selenium or the addition of 500 and 2500 mg lead per kg diet, suggesting that zinc may act directly on the pancreas rather than by interfering with the protective function of the seenium.
Abstract: Summary Some dietary, enzymic and morphological relationships of selenium, lead and copper to the toxicity of zinc in adult female fowls have been investigated. The anorexia, pancreatic and gizzard lesions which resulted from incorporating 20,000 and 25,000 mg zinc as zinc oxide per kg diet were not prevented by concurrent daily injections of 0.3 mg selenium or the addition of 500 and 2500 mg lead per kg diet. Anorexia and gizzard lesions were also produced by feeding copper sulphate at levels of 2000 and 4000 mg per kg of diet but the pancreas was unaffected. This suggests that zinc may act directly on the pancreas rather than by interfering with the protective function of the selenium. Glutathione peroxidase activity significantly decreased in the blood when zinc‐containing diets were fed and selenium injection prevented this. Activity in the liver was also reduced but in the pancreas it was increased by both zinc and zinc plus selenium. Electron microscopy showed that there was an infiltration of heter...
26 citations
TL;DR: The author describes the use of a cell culture assay using growing cells as a screen for aquatic toxicity using Cadmium, copper and zinc toxicity were measured.
Abstract: A new bioassay using cultured mammalian cells was reported. In this report, the author describes the use of a cell culture assay using growing cells as a screen for aquatic toxicity. Cadmium, copper and zinc toxicity were measured.
14 citations
TL;DR: In this article, suspended solids were shown to be important in reducing zinc toxicity to water column organisms, and the slopes of dose-response curves proved to be useful for assessing the potential of an organism to respond to changes in aqueous phase zinc concentrations, and may be a useful biological parameter when considering site-specific water quality criteria for chemicals.
Abstract: Current procedures for setting site-specific water quality criteria consider abiotic and biotic factors. Suspended solids were shown to be important in reducing zinc toxicity to water column organisms. At zinc concentrations of approx. = 1 mg/L in solutions with < 100 mg/L of all suspended solids tested, zinc toxicity to D. magna was reduced. Sorption of zinc to suspended solids and/or changes in water chemistry due to the addition of suspended solids appear to have been the factors causing reductions in zinc toxicity to D. magna. Only suspended solids levels of 483-734 mg/L of a type that increased total alkalinity, total hardness, and total dissolved carbon clearly reduced the toxicity of approx. = 20 mg/L zinc to P. promelas. The toxic form of zinc to these organisms appears to reside in the aqueous phase. Characteristics of suspended solids did not influence the partition coefficient of zinc in sorption experiments of less than or equal to 96 h. The slopes of dose-response curves proved to be useful for assessing the potential of an organism to respond to changes in aqueous phase zinc concentrations, and may be a useful biological parameter when considering site-specific water quality criteria for chemicals.
8 citations
8 citations
TL;DR: In this article, the physic-chemical processes affecting copper, zinc, and tin toxicity to algae were studied and the relative importance of these interactions (both magnitude and time dependence) were discussed.
Abstract: Publisher Summary This chapter focuses on the physic-chemical processes affecting copper, zinc, and tin toxicity to algae. Both Cu and Zn are essential algal micronutrients, cofactors in numerous biochemical processes. The availability of a nutrient or toxic substance can be significantly affected by precipitation. Methods for modeling the effects of adsorption–desorption reactions have been previously reviewed. Useful predictions of algal response require an understanding of the relative importance of these interactions (both magnitude and time dependence). Photoreduction and dissolution of Mn oxides by dissolved humic substances has been proposed as an important factor regulating dissolved Mn distribution in seawater. Photodegradation of iron (Fe) chelates also enhances Fe uptake by algae. Anderson et al. observed that Fe uptake by Thalassiosira weissflogii in a chemically defined medium dominated by FeEDTA complexation doubled in the presence of light.
6 citations
TL;DR: Cadmium was much more toxic than the three other metal ions in both types of cells and its toxic effect was reversed by simultaneous addition of zinc at nontoxic concentrations.
Abstract: The toxicity of chloride salts of physiological (zinc, manganese, nickel) and non-physiological (cadmium) bivalent metal ions was studied in normal or carcinogen-transformed mouse embryo fibroblast cells. The dose response curves for toxicity to both types of cells exhibited similar shapes. The transformed cells, however, were about twice as sensitive to zinc toxicity as normal cells. When normal and transformed cells were grown together and incubated for several hours with an appropriate concentration of zinc, the malignant cells were selectively killed. Cadmium was much more toxic than the three other metal ions in both types of cells. Its toxic effect was reversed by simultaneous addition of zinc at nontoxic concentrations.
5 citations