A eview of the literature revealed that bioaccumulation of silver in soil is rather low, even if the soil is amended with silver-containing sewage sludge. Plants grown on tailings of silver mines were found to have silver primarily in the root systems. In marine and freshwater systems, the highest reported bioconcentration factors (BCFs) were observed in algae (>105), probably because of adsorption of the dissolved silver (<0.45 μm fraction) to the cell surface. In herbivorous organisms (e.g., zooplankton and bivalves), the BCF was lower by about two orders of magnitude. Low amounts of silver were assimilated from food with no substantial biomagnification. In carnivores (e.g., fish), the BCF was also lower by one order of magnitude with no indication of biomagnification. Toxicity of silver occurs mainly in the aqueous phase and depends on the concentration of active, free Ag+ ions. Accordingly, many processes and water characteristics reduce silver toxicity by stopping the formation of free Ag+, binding Ag+, or preventing binding of Ag+ to the reactive surfaces of organisms. The solubility of a silver compound, and the presence of complexing agents (e.g., thiosulfate or chloride), dissolved organic carbon, and competing ions are important. In soil, sewage sludge, and sediments, in which silver sulfide predominates, the toxicity of silver, even at high total concentrations, is very low. The highly soluble silver thiosulfate complex has low toxicity, which can be attributed to the silver complexed by thiosulfate. Silver nitrate is one of the most toxic silver compounds. The toxic potential of silver chloride complexes in seawater is and will be an important issue for investigation. Aquatic chronic tests, long-term tests, and tests including sensitive life stages show lower toxicity thresholds (˜1 μg Ag+/L). The organisms viewed as most sensitive to silver are small aquatic invertebrates, particularly embryonic and larval stages.

https://setac.onlinelibrary.wiley.com/doi/epdf/10.1002/etc.5620180112

Bioaccumulation and toxicity of silver compounds: A review

Toxic effects of cadmium: A review

This report is the result of a review by a
Panel on Hazardous Trace Substances, as
part of a report to an ad hoc Committee on
Environmental Health Research whose chairman
was Dr. David Rall, Director of the
National Institute of Environmental Health
Sciences, NIH.

Environmental impact of cadmium: a review by the Panel on Hazardous Trace Substances.

On sait, depuis les travaux de Guittonneau et Chevalier (1935), qu'un type de fromage peut etre caracterise, entre autres choses, par le rapport existant entre sa teneur en calcium et sa teneur en phosphore. La composition minerale des fromages exerce dans son ensemble une influence essentielle sur les qualites organoleptiques de ces produits, notamment sur leur texture (Veisseyre, 1966). De faibles variations de la teneur en mineraux des coagulum obtenus apres action de la presure sur le lait peuvent entrainer des modifications considerables des qualites organoleptiques des fromages (Davies et White, 1960). Or la teneur en mineraux des fromages resulte de la repartition de ces memes mineraux, provenant du lait, entre le lactoserum et le coagulum au cours de l'egouttage, repartition dependant etroitement de l'etat physico-chimique dans lequel se trouvent ces elements pendant la synerese.

/pdf/etude-de-la-teneur-en-elements-mineraux-des-produits-obtenus-4f5rury6yj.pdf

G.K. Murthy

Papers

Determination of Major Cations in Milk by Atomic Absorption Spectrophotometry

Cadmium and Silver Content of Market Milk

Rubidium and Lead Content of Market Milk

Rubidium-87 concentration in market milk.

Effect of Ion Exchange Resins on Composition of Milk and Its Fractions