Toxicity excessive manganese

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... 

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. 

Inorganic solid wastes, particularly those containing toxic metals and toxic metal compounds, used Raney nickel, manganese dioxide, etc. should be placed in glass bottles or lined fiber drums, sealed, properly labeled, and arrangements made for disposal in a secure landfill. Used mercury is particularly pernicious and small amounts should first be amalgamated with zinc or combined with excess sulfur to solidify the material. 

The soils of humid regions are commonly low in calcium thus, ground limestone usually is applied tu add the clement, reduce the toxicity uf aluminum and manganese, and correct soil acidity. The soils of dry areas are frequently rich in calcium. There is little evidence to indicate a strung relationship between human nutrition and calcium excesses or deficiencies in the soil. Even wiih farm livestock, most calcium deficiencies are not related to levels of av ailable calcium in the sail. The reason for this anomaly is evident when one examines some of the controls over the movement of calcium in Ihe food chain. 

Manganese occurs in the liver of the animal body. Even though the amount ol manganese present in mammalian tissues is very small, its concentration seems to be accurately controlled by elaborate mechanisms These mechanisms function primarily by promoting the excretion of excesses of the element from the body rather than by regulating the amounts ol manganese the body absorbs. The mechanisms are located in the liver and on the mucosa of the gut. In cases of manganese toxicity, it is assumed that these mechanisms become saturated. 

Manganese has been found to be an essential nutrient for the human as well as for many other living organisms however, in excessive amounts, it is also a toxic material (1-6). Deficiency symptoms for manganese in several species have been created and manganese metabolic roles have, at least in part, been defined (5,7-15). So called "normal" manganese concentrations in blood have been established (1,10,16). Kinetics of manganese uptake and metabolism by... 

---