Manganese to life and health. Generally, exposure to ambient Mn air concentrations in excess of 5 μg Mn/m3 can lead to Mn-induced symptoms. Increased ferroportin protein expression in human embryonic kidney (HEK293) cells is associated with decreased intracellular Mn concentration and attenuated cytotoxicity, characterized by the reversal of Mn-reduced glutamate uptake and diminished lactate dehydrogenase leakage. Waterborne manganese has a greater bioavailability than dietary manganese. According to results from a 2010 study, higher levels of exposure to manganese in drinking water are associated with increased intellectual impairment and reduced intelligence quotients in school-age children. It is hypothesized that long-term exposure due
Symbol "symbol", which he used to stand for something that is unknown and that cannot be made clear or precise. An example of a symbol in this sense is Christ as a symbol of the archetype called "self". For example, written languages are composed of a variety of different symbols that create words, p. . Through these written words humans communicate with each other. Kenneth Burke described "Homo sapiens" as a "symbol-using, symbol making, and symbol misusing animal" to suggest that a person creates symbols as well as misuses them. One example he uses to indicate what he means by the