Table 1: The table shows the major sources and routes of manganese exposure along with their relative potential for exposure to population.

Route of exposure Source of exposure Basis for exposure Relative potential for exposure

IngestionDiet Manganese in breast milk, infant formula, and leafy vegetables, fruit, and fruit juices Relatively lower for general population but higher prenatal and infant exposure
Ground water
Drinking water
Surface water
As a natural constituent of water but elevated level may present at some water source because of pollution sources or bedrock formation Lower
Soil Manganese may present in soil but not a major contributor to exposure Lower

InhalationAmbient air Higher air concentration nearby industries (mining operations, metal processing plants, etc.) (MMT as additive in gasoline) is cause of concern for residential population Higher
Indoor air Significantly lower but associated with Mn in outdoor dust and the distance from industrial point sourcesRelatively lower but implication for childhood exposure