Manganese potential toxicity

Caroli S, Forte G, Iamiceu AL, Galoppi B 1999) Determination of essential and potentially toxic trace elements in honey by inductively coupled plasma-based techniques. Talanta 50 327-336. Chiswell B, Johnson D (1994) Manganese. In Seiler HG, Sigel A, Sigel H, eds. Handbook on metals in clinical and analytical chemistry. Dekker, New York. 

For infants the UL could not be set because. There is concern about the potential toxicity for infants whose immature hepatic develop-the biliary excretion of excess manganese, only dietary source of manganese in the age months should be from normal diet or from... 

The therapeutical use of CujZujSuperoxide dismutase as scavenger for the potentially toxic superoxide anion is limited on very special events The half-time of circulation in the organism is very short and it is unable to pass cellular membranes. As a consequence it was attempted to search for lipophilic substances, able to catalyze the dismutation of superoxide, but resistant to biological chelators. One approach was the use of different metalloporphyrins. Some iron and manganese prophyrins catalyze the disnxutation of superoxide with about 3 % efficiency of native CUjZnj-SOD 268) Apart from copper porphyrins, which are inactive as superoxide dismutases, no copper complexes have been described which are at the same time scavengers of superoxide and stable to proteins or EDTA. 

The inherent potential toxicity of each element for plant and animal life has also to be taken into account. In general, an excess of an element which is already biologically essential, such as copper, manganese or zinc, is less likely to produce toxic effects than an excess of certain non-essential elements, such as mercury, cadmium, lead, beryllium and thallium. Also, elements which are already major components of the earth s crust, like silicon, aluminium and iron, are not normally involved in toxicity conditions, and their further dispersion throughout the biosphere presents few problems, since no dramatic change in the background level in the soil is produced. 

The method was later tested with three different substances known to be potentially toxic as air pollutants [43]. In preliminary experiments it was found that non-viable macrophages did not have any heat production. This was assumed to be the case in all experiments. It was considered that exposure to toxic substances always causes a change of cell metabolism. Manganese dioxide... 

One-electron reduction or oxidation of organic compounds provides a useful method for the generation of anion radicals or cation radicals, respectively. These methods are used as key processes in radical reactions. Redox properties of transition metals can be utilized for the efficient one-electron reduction or oxidation (Scheme 1). In particular, the redox function of early transition metals including titanium, vanadium, and manganese has been of synthetic potential from this point of view [1-8]. The synthetic limitation exists in the use of a stoichiometric or excess amount of metallic reductants or oxidants to complete the reaction. Generally, the construction of a catalytic redox cycle for one-electron reduction is difficult to achieve. A catalytic system should be constructed to avoid the use of such amounts of expensive and/or toxic metallic reagents. 

Species may differ by oxidation state for example, manganese(II) and (IV) iron(II) and (III) and chromium(III) and (VI). Oxidation state is influenced by the redox potential. Mobility is affected because oxidation state influences precipitation-dissolution reactions and also toxicity in the case of heavy metals. 

A wide range of research publications has identified various soil properties and their potential influence on substance behavior. Soil properties such as organic matter, iron, manganese, and aluminum (hydro)oxide concentrations, cation exchange capacity, and pH can all affect the bioavailability, form, and toxicity of substances. 

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