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
Ingestion	Diet	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
Inhalation	Ambient 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 sources	Relatively lower but implication for childhood exposure