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Manganese in Drinking Water

Manganese is an essential nutrient found naturally in the environment. It can be present in: 

  • Air
  • Food
  • Water
  • Soil and rocks 

Manganese gets into drinking water sources when water dissolves minerals that contain manganese. It can also enter drinking water sources through human activity, such as: 

  • Mining activities  
  • Industrial discharges (e.g., in the steel industry)  
  • Manufacture of various products (e.g. fireworks, dry-cell batteries, fertilizers, fungicides, cosmetics, and paints)  
  • Leaching from landfills 

Note: Manganese will not enter the body through the skin or by breathing in vapours while showering or bathing. Bathing and showering in water that contains levels of manganese above the guideline value is considered safe. 

Health Effects

Although humans need to consume small amounts of manganese to be healthy, too much manganese in drinking water can lead to adverse health effects.

Drinking water that contains high levels of manganese can be a health risk to infants.

Formula-fed infants may be at risk for neurological effects if the water used to prepare their formula contains excess manganese. This is because:

  • Their brains are developing rapidly
  • They drink more water based on body weight
  • They absorb more manganese and are less able to remove it from their bodies.

For adults and older children, short-term exposure to manganese in drinking water slightly above the guideline is unlikely to cause negative health effects.

Health Canada’s Guideline

Although the Province of Ontario does not have a health-based drinking water quality standard for manganese, it does have an aesthetic objective of 0.05 mg/L (50 µg/l) for manganese. The aesthetic objective is meant to prevent staining of fixture units (e.g. sinks, toilets, etc.) as well as taste issues.

Health Canada’s maximum acceptable concentration (MAC) for total manganese in drinking water is 0.12 mg/L (120 µg/L), this is a health-based value intended to protect infants, the most sensitive population. This value is also protective for children and adults.

Reducing Manganese Exposure in Drinking Water

There are two categories of treatment units that can reduce manganese in water in your home:

  • units installed directly at the tap: used to reduce specific contaminants at one tap only (point of use units). Reverse osmosis is the most effective and reliable way to reduce manganese levels in drinking water that will be used for drinking and food preparation.
  • units installed where the water supply enters the home: used to reduce specific contaminants in water in the entire household (point of entry units). Water softeners and manganese “greensand filters” can be used to reduce the potential for discoloured water and staining of laundry. Greensand filters require careful maintenance to ensure that they are effectively removing manganese.

Make sure that any treatment unit you use is:

Options can be explored with professionals specialized in water treatment to choose the right treatment system that best fits your needs.

References

Health Canada. Water Talk – Manganese in drinking water, 2023.