Manganese is also used in portland cement mixtures. Manganese is an important element for human health, essential for development, metabolism, and the antioxidant system. Nevertheless, excessive exposure or intake may lead to a condition known as manganism, a neurodegenerative disorder that causes dopaminergic neuronal death and symptoms similar to Parkinson's disease. The classes of enzymes that have manganese cofactors is large and includes oxidoreductases, transferases, hydrolases, lyases, isomerases, ligases, lectins, and integrins. The reverse transcriptases of many retroviruses (though not lentiviruses such as HIV) contain manganese. The best-known manganese-containing polypeptides may be arginase, the diphtheria toxin, and Mn-containing superoxide dismutase (Mn-SOD).
Manganese(II) carbonate to give water-soluble salts. Manganese carbonate decomposes with release of carbon dioxide, i.e. calcining, at 200 °C to give MnO: This method is sometimes employed in the production of manganese dioxide, which is used in dry-cell batteries and for ferrites. Manganese carbonate is widely used as an additive to plant fertilizers to cure manganese deficient crops. It is also used in health foods, in ceramics as a glaze colorant and flux, and in concrete stains. It is used in medicine as a hematinic. Manganese poisoning, also known as manganism, may be caused by long-term exposure to manganese dust or fumes.