Canadian researchers studying children in Quebec seem to have found a link between higher levels of manganese in groundwater and lower IQ (intelligence quotient) in children.
Since 1931, manganese, a metal, number 25 on the periodic table, has been considered an essential trace element. But it is one of three toxic essential trace elements, meaning that while essential in lower amounts, it can become toxic in higher concentrations.
A lack of manganese can result in the following health effects, among others:
- Glucose intolerance
- Blood clotting
- Skin problems
- Birth defects
- Neurological symptoms
However, prolonged exposure to too much manganese can affect the nervous system and result in symptoms that can include:
- sleepiness
- paralysis
- recurring leg cramps
- spastic gait
Recently, Canadian researchers have noticed an apparent link between excessive manganese consumption and lower IQ scores. Manganese levels can be high for people whose primary source of drinking water is ground water. Manganese, present in soils can leach into ground water. Though not conclusively proving cause and effect, it might be enough of a warning to have people consider filtration systems of their water supplies.
Manganese levels in drinking water are not regulated in Canada or the U.S.
Manganese in Ground Water linked to lower IQ scores in children
