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
Methylcyclopentadienyl manganese tricarbonyl ferrocene, which has also been used as an additive to gasoline. Although of no practical value, the related compound cyclopentadienyl manganese tricarbonyl (CH)Mn(CO) is also well studied. Up to two of the CO ligands in MMT can be replaced with thiocarbonyl groups, as illustrated by the compounds (CHCH)Mn(CS)CO and (CHCH)Mn(CS)(CO). The human and environmental health impacts that may result from the use of MMT will be a function of exposure to either: (1) MMT in its original, unchanged, chemical form and/or (2) manganese combustion products emitted from vehicles operating on gasoline containing MMT as an octane improver. The general public